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A REPORTON
DESIGN amp ANALSYS OF BEND STIFFENER CONNECTOR amp HOLD BACK CLAMP
BYRAJA ROHIT SINGH 11STUHHME0079
ATDEEPSEA TECHNOLOGIES ( I ) PVT LTD
AN INTERNSHIP PROGRAM-III STATION OF
MECHANICAL ENGINEERING
Faculty of Science amp Technology
IFHE University
JANUARY 02ND - JUNE 15TH 2015
A REPORT
ONDESIGN amp ANALSYS OF BEND STIFFENER
CONNECTOR amp HOLD BACK CLAMP
BYRAJA ROHIT SINGH 11STUHHME0079
Prepared in partial fulfillment of the
Internship Program-III Course
ATDEEPSEA TECHNOLOGIES ( I ) PVT LTD
AN INTERNSHIP PROGRAM ndashIII STATION
Faculty of Science amp TechnologyIFHE University Hyderabad
JANUARY 02ND - JUNE 15TH 2015
Deepsea Technologies (India) Pvt Ltd ndash DT(I)PL - will provide state of the art Computer Aided Design (CAD) Computer Aided Engineering (CAE) and Business Process Outsourcing services to worldwide customers in the Subsea amp Deepwater Oil amp Gas Field Development Industry
Technical support and training will be obtained from Deepsea Technologies Inc (DTI) a subsea engineering and manufacturing company based n Houston Texas USA
DTI will also be one of the primary customers of DT(I)PL
AcknowledgementsI would like to express my special thanks of gratitude to my
faculty Prof Murali as well as our Director Dr Srinivasa
reddy Founder of Deepsea technologies Mr Konda
Sanjay Reddy amp Engineering Manager of Deepsea
Technologies Mr Srinivas changalpet who gave me the
golden opportunity to do this wonderful project which also
helped me in doing a lot of Research and i came to know about
so many new things I am really thankful to them
Secondly i would also like to thank my parents and colleagues
Mr Suhas Gadgoli Mrs Uma Puranik Mr Ramesh
Katragadda Mr Dayaram karri Mr Naveen kumar Mr
Srinivas vishwanath and Mr Vincent Paul who helped me a
lot in finishing this project within the limited time
I am making this project not only for marks but to also
increase my knowledge
THANKS AGAIN TO ALL WHO HELPED ME
FACULTY OF SCIENCE amp TECHNOLOGYIFHE HyderabadStationdeepseaa technologiesDuration2nd Jan To 15th June2015Name and designation of the expert Sushas gadgoliIP faculty Prof Murali Project area BSC FUNCTIONALITY DESIGN CRITERIA STRUCTURAL ARRANGEMENT STRENGTH ANALYSIS STATIC ANALYSIS FATIGUE ANALYSIS
Abstract This report documents the analysis performed to verify the structural integrity of the Bend Stiffener Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations Overview of the company and Project
equipment required for a HBC amp BSC Introduction about subsea and functioning of the RIG in oil amp gas industry The report consists of explanation on usage of enterprise product data management in a MNC amp how data can be kept secured Bend stiffeners connector introductions This has a new innovation in the study of hold back clamps for more efficiency and reducing the time constrains for repairing of the umbilical inside HBC Operations and working of a Remotely Operated vehicles from the deck Stud Calculations of preload and torque using Math CAD
Signature of student Signature of IP Faculty Date Date
6
TABLE OF CONTENT
1 INTRODUCTION8
11 scope and Bsc functionality8
12 SUMMARY9
13 REFERENCE DRAWINGS amp DOCUMENTS9
2 PLETs amp PLEMs 11
3 Hydrate Remediation Equipment 12
4 Flowline Insulation Equipment 12
5 Riser Bend Stiffener Connectors 13
6 Bend Stiffener Connector (BSC) 13
Major benefits of using DTI Bend Stiffener Connectors14
2aSUBSEA UMBILICAL EQUIPMENT15
UMBILICAL CLAMP15
2b IWOCS EQUIPMENT16
2c INSTALLATION EQUIPMENT 16
3 ROV TOOLS AND EQUIPMENTamp18
Oil and gas19
Underwater mining19
Remotely operated vehicles20
4 a DIVERLESSBEND STIFFENER CONNECTOR24
b WORKING OF AN ROV28
5 ENTERPRISE PRODUCT DATA MANAGEMENT37
6 COMPONENTS IN A BEND STIFFENER CONNECTOR44
7 MATHCAD47
7a STUD CALCULATIONS48
8 DESIGN CRITERIA47
81 Codes and Standards47
82 Material Selection47
83 Design Loads48
84 Allowable CRITERIA48
9 STRUCTURAL ARRANGEMENT51
10 STRENGTH ANALYSIS53
101 Static Analysis55
1011 SolidModel55
1012 FE Model55
1013 Boundary Conditions and Loads59
7
1014 Results61
102 Fatigue Analysis70
103 DISCUSSION AND Conclusion73
LIST OF TABLES
8
MAIN REPORT
9
Error Reference source not foundLIST OF FIGURES
Main Report
Fig 1 Typical General Arrangement Sketch of BSC51
Fig 2 BSC - Solid Model55
Fig 3 BSC Shaft - Finite Element Model56
Fig 4 BSC Funnel - Finite Element Model57
Fig 5 Shaft Adapter Spool - Finite Element Model57
Fig 6 Assembly - Contact Definition Locations58
Fig 7 BSC Assembly - FE Model59
Fig 8 BSC Assembly Model - Loads and Boundary Conditions60
Fig 9 Shaft - Locations Considered for Stress Linearization62
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)62
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)63
Fig 12 BSC Funnel - Stress Linearization Locations63
Fig 13 Adapter Spool - Stress Linearization Locations64
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)66
(Window shown as Zoomed position)66
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)67
(Window shown as Zoomed position)67
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)68
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)68
LIST OF ABBREVIATIONS
DNV - Det Norske Veritas
10
API - American Petroleum Institute
AISC - American Institute of Steel Construction
BSC - Bend Stiffener Connector
SEQV - von Mises Stress
S1 - First Principal stress (Max Tensile)
S3 - Third Principal stress (Min Compressive)
BS - Bend Stiffener
DOF - Degree of Freedom
SF - Shear Force
BM - Bending Moment
11
Business Drivers
Most new and large oil and gas field developments are subsea deepwater fields
Subsea deepwater fields are generally in water depths between 1000 ft and 10000 ft below sea surface
Industry has gone from a nice area to a mainstream industry within the past 10-15 years
No CAD CAE BPO companies specializing in subsea deepwater technology currently exist in India
Know how (domain knowledge) is very important in this industry and learning curve is very steep
Also industry is very conservative and reluctant to use outside providers for these services Will only generally deal with individuals and companies with established track record
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
ONDESIGN amp ANALSYS OF BEND STIFFENER
CONNECTOR amp HOLD BACK CLAMP
BYRAJA ROHIT SINGH 11STUHHME0079
Prepared in partial fulfillment of the
Internship Program-III Course
ATDEEPSEA TECHNOLOGIES ( I ) PVT LTD
AN INTERNSHIP PROGRAM ndashIII STATION
Faculty of Science amp TechnologyIFHE University Hyderabad
JANUARY 02ND - JUNE 15TH 2015
Deepsea Technologies (India) Pvt Ltd ndash DT(I)PL - will provide state of the art Computer Aided Design (CAD) Computer Aided Engineering (CAE) and Business Process Outsourcing services to worldwide customers in the Subsea amp Deepwater Oil amp Gas Field Development Industry
Technical support and training will be obtained from Deepsea Technologies Inc (DTI) a subsea engineering and manufacturing company based n Houston Texas USA
DTI will also be one of the primary customers of DT(I)PL
AcknowledgementsI would like to express my special thanks of gratitude to my
faculty Prof Murali as well as our Director Dr Srinivasa
reddy Founder of Deepsea technologies Mr Konda
Sanjay Reddy amp Engineering Manager of Deepsea
Technologies Mr Srinivas changalpet who gave me the
golden opportunity to do this wonderful project which also
helped me in doing a lot of Research and i came to know about
so many new things I am really thankful to them
Secondly i would also like to thank my parents and colleagues
Mr Suhas Gadgoli Mrs Uma Puranik Mr Ramesh
Katragadda Mr Dayaram karri Mr Naveen kumar Mr
Srinivas vishwanath and Mr Vincent Paul who helped me a
lot in finishing this project within the limited time
I am making this project not only for marks but to also
increase my knowledge
THANKS AGAIN TO ALL WHO HELPED ME
FACULTY OF SCIENCE amp TECHNOLOGYIFHE HyderabadStationdeepseaa technologiesDuration2nd Jan To 15th June2015Name and designation of the expert Sushas gadgoliIP faculty Prof Murali Project area BSC FUNCTIONALITY DESIGN CRITERIA STRUCTURAL ARRANGEMENT STRENGTH ANALYSIS STATIC ANALYSIS FATIGUE ANALYSIS
Abstract This report documents the analysis performed to verify the structural integrity of the Bend Stiffener Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations Overview of the company and Project
equipment required for a HBC amp BSC Introduction about subsea and functioning of the RIG in oil amp gas industry The report consists of explanation on usage of enterprise product data management in a MNC amp how data can be kept secured Bend stiffeners connector introductions This has a new innovation in the study of hold back clamps for more efficiency and reducing the time constrains for repairing of the umbilical inside HBC Operations and working of a Remotely Operated vehicles from the deck Stud Calculations of preload and torque using Math CAD
Signature of student Signature of IP Faculty Date Date
6
TABLE OF CONTENT
1 INTRODUCTION8
11 scope and Bsc functionality8
12 SUMMARY9
13 REFERENCE DRAWINGS amp DOCUMENTS9
2 PLETs amp PLEMs 11
3 Hydrate Remediation Equipment 12
4 Flowline Insulation Equipment 12
5 Riser Bend Stiffener Connectors 13
6 Bend Stiffener Connector (BSC) 13
Major benefits of using DTI Bend Stiffener Connectors14
2aSUBSEA UMBILICAL EQUIPMENT15
UMBILICAL CLAMP15
2b IWOCS EQUIPMENT16
2c INSTALLATION EQUIPMENT 16
3 ROV TOOLS AND EQUIPMENTamp18
Oil and gas19
Underwater mining19
Remotely operated vehicles20
4 a DIVERLESSBEND STIFFENER CONNECTOR24
b WORKING OF AN ROV28
5 ENTERPRISE PRODUCT DATA MANAGEMENT37
6 COMPONENTS IN A BEND STIFFENER CONNECTOR44
7 MATHCAD47
7a STUD CALCULATIONS48
8 DESIGN CRITERIA47
81 Codes and Standards47
82 Material Selection47
83 Design Loads48
84 Allowable CRITERIA48
9 STRUCTURAL ARRANGEMENT51
10 STRENGTH ANALYSIS53
101 Static Analysis55
1011 SolidModel55
1012 FE Model55
1013 Boundary Conditions and Loads59
7
1014 Results61
102 Fatigue Analysis70
103 DISCUSSION AND Conclusion73
LIST OF TABLES
8
MAIN REPORT
9
Error Reference source not foundLIST OF FIGURES
Main Report
Fig 1 Typical General Arrangement Sketch of BSC51
Fig 2 BSC - Solid Model55
Fig 3 BSC Shaft - Finite Element Model56
Fig 4 BSC Funnel - Finite Element Model57
Fig 5 Shaft Adapter Spool - Finite Element Model57
Fig 6 Assembly - Contact Definition Locations58
Fig 7 BSC Assembly - FE Model59
Fig 8 BSC Assembly Model - Loads and Boundary Conditions60
Fig 9 Shaft - Locations Considered for Stress Linearization62
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)62
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)63
Fig 12 BSC Funnel - Stress Linearization Locations63
Fig 13 Adapter Spool - Stress Linearization Locations64
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)66
(Window shown as Zoomed position)66
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)67
(Window shown as Zoomed position)67
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)68
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)68
LIST OF ABBREVIATIONS
DNV - Det Norske Veritas
10
API - American Petroleum Institute
AISC - American Institute of Steel Construction
BSC - Bend Stiffener Connector
SEQV - von Mises Stress
S1 - First Principal stress (Max Tensile)
S3 - Third Principal stress (Min Compressive)
BS - Bend Stiffener
DOF - Degree of Freedom
SF - Shear Force
BM - Bending Moment
11
Business Drivers
Most new and large oil and gas field developments are subsea deepwater fields
Subsea deepwater fields are generally in water depths between 1000 ft and 10000 ft below sea surface
Industry has gone from a nice area to a mainstream industry within the past 10-15 years
No CAD CAE BPO companies specializing in subsea deepwater technology currently exist in India
Know how (domain knowledge) is very important in this industry and learning curve is very steep
Also industry is very conservative and reluctant to use outside providers for these services Will only generally deal with individuals and companies with established track record
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
Deepsea Technologies (India) Pvt Ltd ndash DT(I)PL - will provide state of the art Computer Aided Design (CAD) Computer Aided Engineering (CAE) and Business Process Outsourcing services to worldwide customers in the Subsea amp Deepwater Oil amp Gas Field Development Industry
Technical support and training will be obtained from Deepsea Technologies Inc (DTI) a subsea engineering and manufacturing company based n Houston Texas USA
DTI will also be one of the primary customers of DT(I)PL
AcknowledgementsI would like to express my special thanks of gratitude to my
faculty Prof Murali as well as our Director Dr Srinivasa
reddy Founder of Deepsea technologies Mr Konda
Sanjay Reddy amp Engineering Manager of Deepsea
Technologies Mr Srinivas changalpet who gave me the
golden opportunity to do this wonderful project which also
helped me in doing a lot of Research and i came to know about
so many new things I am really thankful to them
Secondly i would also like to thank my parents and colleagues
Mr Suhas Gadgoli Mrs Uma Puranik Mr Ramesh
Katragadda Mr Dayaram karri Mr Naveen kumar Mr
Srinivas vishwanath and Mr Vincent Paul who helped me a
lot in finishing this project within the limited time
I am making this project not only for marks but to also
increase my knowledge
THANKS AGAIN TO ALL WHO HELPED ME
FACULTY OF SCIENCE amp TECHNOLOGYIFHE HyderabadStationdeepseaa technologiesDuration2nd Jan To 15th June2015Name and designation of the expert Sushas gadgoliIP faculty Prof Murali Project area BSC FUNCTIONALITY DESIGN CRITERIA STRUCTURAL ARRANGEMENT STRENGTH ANALYSIS STATIC ANALYSIS FATIGUE ANALYSIS
Abstract This report documents the analysis performed to verify the structural integrity of the Bend Stiffener Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations Overview of the company and Project
equipment required for a HBC amp BSC Introduction about subsea and functioning of the RIG in oil amp gas industry The report consists of explanation on usage of enterprise product data management in a MNC amp how data can be kept secured Bend stiffeners connector introductions This has a new innovation in the study of hold back clamps for more efficiency and reducing the time constrains for repairing of the umbilical inside HBC Operations and working of a Remotely Operated vehicles from the deck Stud Calculations of preload and torque using Math CAD
Signature of student Signature of IP Faculty Date Date
6
TABLE OF CONTENT
1 INTRODUCTION8
11 scope and Bsc functionality8
12 SUMMARY9
13 REFERENCE DRAWINGS amp DOCUMENTS9
2 PLETs amp PLEMs 11
3 Hydrate Remediation Equipment 12
4 Flowline Insulation Equipment 12
5 Riser Bend Stiffener Connectors 13
6 Bend Stiffener Connector (BSC) 13
Major benefits of using DTI Bend Stiffener Connectors14
2aSUBSEA UMBILICAL EQUIPMENT15
UMBILICAL CLAMP15
2b IWOCS EQUIPMENT16
2c INSTALLATION EQUIPMENT 16
3 ROV TOOLS AND EQUIPMENTamp18
Oil and gas19
Underwater mining19
Remotely operated vehicles20
4 a DIVERLESSBEND STIFFENER CONNECTOR24
b WORKING OF AN ROV28
5 ENTERPRISE PRODUCT DATA MANAGEMENT37
6 COMPONENTS IN A BEND STIFFENER CONNECTOR44
7 MATHCAD47
7a STUD CALCULATIONS48
8 DESIGN CRITERIA47
81 Codes and Standards47
82 Material Selection47
83 Design Loads48
84 Allowable CRITERIA48
9 STRUCTURAL ARRANGEMENT51
10 STRENGTH ANALYSIS53
101 Static Analysis55
1011 SolidModel55
1012 FE Model55
1013 Boundary Conditions and Loads59
7
1014 Results61
102 Fatigue Analysis70
103 DISCUSSION AND Conclusion73
LIST OF TABLES
8
MAIN REPORT
9
Error Reference source not foundLIST OF FIGURES
Main Report
Fig 1 Typical General Arrangement Sketch of BSC51
Fig 2 BSC - Solid Model55
Fig 3 BSC Shaft - Finite Element Model56
Fig 4 BSC Funnel - Finite Element Model57
Fig 5 Shaft Adapter Spool - Finite Element Model57
Fig 6 Assembly - Contact Definition Locations58
Fig 7 BSC Assembly - FE Model59
Fig 8 BSC Assembly Model - Loads and Boundary Conditions60
Fig 9 Shaft - Locations Considered for Stress Linearization62
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)62
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)63
Fig 12 BSC Funnel - Stress Linearization Locations63
Fig 13 Adapter Spool - Stress Linearization Locations64
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)66
(Window shown as Zoomed position)66
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)67
(Window shown as Zoomed position)67
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)68
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)68
LIST OF ABBREVIATIONS
DNV - Det Norske Veritas
10
API - American Petroleum Institute
AISC - American Institute of Steel Construction
BSC - Bend Stiffener Connector
SEQV - von Mises Stress
S1 - First Principal stress (Max Tensile)
S3 - Third Principal stress (Min Compressive)
BS - Bend Stiffener
DOF - Degree of Freedom
SF - Shear Force
BM - Bending Moment
11
Business Drivers
Most new and large oil and gas field developments are subsea deepwater fields
Subsea deepwater fields are generally in water depths between 1000 ft and 10000 ft below sea surface
Industry has gone from a nice area to a mainstream industry within the past 10-15 years
No CAD CAE BPO companies specializing in subsea deepwater technology currently exist in India
Know how (domain knowledge) is very important in this industry and learning curve is very steep
Also industry is very conservative and reluctant to use outside providers for these services Will only generally deal with individuals and companies with established track record
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
AcknowledgementsI would like to express my special thanks of gratitude to my
faculty Prof Murali as well as our Director Dr Srinivasa
reddy Founder of Deepsea technologies Mr Konda
Sanjay Reddy amp Engineering Manager of Deepsea
Technologies Mr Srinivas changalpet who gave me the
golden opportunity to do this wonderful project which also
helped me in doing a lot of Research and i came to know about
so many new things I am really thankful to them
Secondly i would also like to thank my parents and colleagues
Mr Suhas Gadgoli Mrs Uma Puranik Mr Ramesh
Katragadda Mr Dayaram karri Mr Naveen kumar Mr
Srinivas vishwanath and Mr Vincent Paul who helped me a
lot in finishing this project within the limited time
I am making this project not only for marks but to also
increase my knowledge
THANKS AGAIN TO ALL WHO HELPED ME
FACULTY OF SCIENCE amp TECHNOLOGYIFHE HyderabadStationdeepseaa technologiesDuration2nd Jan To 15th June2015Name and designation of the expert Sushas gadgoliIP faculty Prof Murali Project area BSC FUNCTIONALITY DESIGN CRITERIA STRUCTURAL ARRANGEMENT STRENGTH ANALYSIS STATIC ANALYSIS FATIGUE ANALYSIS
Abstract This report documents the analysis performed to verify the structural integrity of the Bend Stiffener Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations Overview of the company and Project
equipment required for a HBC amp BSC Introduction about subsea and functioning of the RIG in oil amp gas industry The report consists of explanation on usage of enterprise product data management in a MNC amp how data can be kept secured Bend stiffeners connector introductions This has a new innovation in the study of hold back clamps for more efficiency and reducing the time constrains for repairing of the umbilical inside HBC Operations and working of a Remotely Operated vehicles from the deck Stud Calculations of preload and torque using Math CAD
Signature of student Signature of IP Faculty Date Date
6
TABLE OF CONTENT
1 INTRODUCTION8
11 scope and Bsc functionality8
12 SUMMARY9
13 REFERENCE DRAWINGS amp DOCUMENTS9
2 PLETs amp PLEMs 11
3 Hydrate Remediation Equipment 12
4 Flowline Insulation Equipment 12
5 Riser Bend Stiffener Connectors 13
6 Bend Stiffener Connector (BSC) 13
Major benefits of using DTI Bend Stiffener Connectors14
2aSUBSEA UMBILICAL EQUIPMENT15
UMBILICAL CLAMP15
2b IWOCS EQUIPMENT16
2c INSTALLATION EQUIPMENT 16
3 ROV TOOLS AND EQUIPMENTamp18
Oil and gas19
Underwater mining19
Remotely operated vehicles20
4 a DIVERLESSBEND STIFFENER CONNECTOR24
b WORKING OF AN ROV28
5 ENTERPRISE PRODUCT DATA MANAGEMENT37
6 COMPONENTS IN A BEND STIFFENER CONNECTOR44
7 MATHCAD47
7a STUD CALCULATIONS48
8 DESIGN CRITERIA47
81 Codes and Standards47
82 Material Selection47
83 Design Loads48
84 Allowable CRITERIA48
9 STRUCTURAL ARRANGEMENT51
10 STRENGTH ANALYSIS53
101 Static Analysis55
1011 SolidModel55
1012 FE Model55
1013 Boundary Conditions and Loads59
7
1014 Results61
102 Fatigue Analysis70
103 DISCUSSION AND Conclusion73
LIST OF TABLES
8
MAIN REPORT
9
Error Reference source not foundLIST OF FIGURES
Main Report
Fig 1 Typical General Arrangement Sketch of BSC51
Fig 2 BSC - Solid Model55
Fig 3 BSC Shaft - Finite Element Model56
Fig 4 BSC Funnel - Finite Element Model57
Fig 5 Shaft Adapter Spool - Finite Element Model57
Fig 6 Assembly - Contact Definition Locations58
Fig 7 BSC Assembly - FE Model59
Fig 8 BSC Assembly Model - Loads and Boundary Conditions60
Fig 9 Shaft - Locations Considered for Stress Linearization62
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)62
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)63
Fig 12 BSC Funnel - Stress Linearization Locations63
Fig 13 Adapter Spool - Stress Linearization Locations64
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)66
(Window shown as Zoomed position)66
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)67
(Window shown as Zoomed position)67
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)68
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)68
LIST OF ABBREVIATIONS
DNV - Det Norske Veritas
10
API - American Petroleum Institute
AISC - American Institute of Steel Construction
BSC - Bend Stiffener Connector
SEQV - von Mises Stress
S1 - First Principal stress (Max Tensile)
S3 - Third Principal stress (Min Compressive)
BS - Bend Stiffener
DOF - Degree of Freedom
SF - Shear Force
BM - Bending Moment
11
Business Drivers
Most new and large oil and gas field developments are subsea deepwater fields
Subsea deepwater fields are generally in water depths between 1000 ft and 10000 ft below sea surface
Industry has gone from a nice area to a mainstream industry within the past 10-15 years
No CAD CAE BPO companies specializing in subsea deepwater technology currently exist in India
Know how (domain knowledge) is very important in this industry and learning curve is very steep
Also industry is very conservative and reluctant to use outside providers for these services Will only generally deal with individuals and companies with established track record
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
FACULTY OF SCIENCE amp TECHNOLOGYIFHE HyderabadStationdeepseaa technologiesDuration2nd Jan To 15th June2015Name and designation of the expert Sushas gadgoliIP faculty Prof Murali Project area BSC FUNCTIONALITY DESIGN CRITERIA STRUCTURAL ARRANGEMENT STRENGTH ANALYSIS STATIC ANALYSIS FATIGUE ANALYSIS
Abstract This report documents the analysis performed to verify the structural integrity of the Bend Stiffener Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations Overview of the company and Project
equipment required for a HBC amp BSC Introduction about subsea and functioning of the RIG in oil amp gas industry The report consists of explanation on usage of enterprise product data management in a MNC amp how data can be kept secured Bend stiffeners connector introductions This has a new innovation in the study of hold back clamps for more efficiency and reducing the time constrains for repairing of the umbilical inside HBC Operations and working of a Remotely Operated vehicles from the deck Stud Calculations of preload and torque using Math CAD
Signature of student Signature of IP Faculty Date Date
6
TABLE OF CONTENT
1 INTRODUCTION8
11 scope and Bsc functionality8
12 SUMMARY9
13 REFERENCE DRAWINGS amp DOCUMENTS9
2 PLETs amp PLEMs 11
3 Hydrate Remediation Equipment 12
4 Flowline Insulation Equipment 12
5 Riser Bend Stiffener Connectors 13
6 Bend Stiffener Connector (BSC) 13
Major benefits of using DTI Bend Stiffener Connectors14
2aSUBSEA UMBILICAL EQUIPMENT15
UMBILICAL CLAMP15
2b IWOCS EQUIPMENT16
2c INSTALLATION EQUIPMENT 16
3 ROV TOOLS AND EQUIPMENTamp18
Oil and gas19
Underwater mining19
Remotely operated vehicles20
4 a DIVERLESSBEND STIFFENER CONNECTOR24
b WORKING OF AN ROV28
5 ENTERPRISE PRODUCT DATA MANAGEMENT37
6 COMPONENTS IN A BEND STIFFENER CONNECTOR44
7 MATHCAD47
7a STUD CALCULATIONS48
8 DESIGN CRITERIA47
81 Codes and Standards47
82 Material Selection47
83 Design Loads48
84 Allowable CRITERIA48
9 STRUCTURAL ARRANGEMENT51
10 STRENGTH ANALYSIS53
101 Static Analysis55
1011 SolidModel55
1012 FE Model55
1013 Boundary Conditions and Loads59
7
1014 Results61
102 Fatigue Analysis70
103 DISCUSSION AND Conclusion73
LIST OF TABLES
8
MAIN REPORT
9
Error Reference source not foundLIST OF FIGURES
Main Report
Fig 1 Typical General Arrangement Sketch of BSC51
Fig 2 BSC - Solid Model55
Fig 3 BSC Shaft - Finite Element Model56
Fig 4 BSC Funnel - Finite Element Model57
Fig 5 Shaft Adapter Spool - Finite Element Model57
Fig 6 Assembly - Contact Definition Locations58
Fig 7 BSC Assembly - FE Model59
Fig 8 BSC Assembly Model - Loads and Boundary Conditions60
Fig 9 Shaft - Locations Considered for Stress Linearization62
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)62
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)63
Fig 12 BSC Funnel - Stress Linearization Locations63
Fig 13 Adapter Spool - Stress Linearization Locations64
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)66
(Window shown as Zoomed position)66
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)67
(Window shown as Zoomed position)67
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)68
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)68
LIST OF ABBREVIATIONS
DNV - Det Norske Veritas
10
API - American Petroleum Institute
AISC - American Institute of Steel Construction
BSC - Bend Stiffener Connector
SEQV - von Mises Stress
S1 - First Principal stress (Max Tensile)
S3 - Third Principal stress (Min Compressive)
BS - Bend Stiffener
DOF - Degree of Freedom
SF - Shear Force
BM - Bending Moment
11
Business Drivers
Most new and large oil and gas field developments are subsea deepwater fields
Subsea deepwater fields are generally in water depths between 1000 ft and 10000 ft below sea surface
Industry has gone from a nice area to a mainstream industry within the past 10-15 years
No CAD CAE BPO companies specializing in subsea deepwater technology currently exist in India
Know how (domain knowledge) is very important in this industry and learning curve is very steep
Also industry is very conservative and reluctant to use outside providers for these services Will only generally deal with individuals and companies with established track record
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
6
TABLE OF CONTENT
1 INTRODUCTION8
11 scope and Bsc functionality8
12 SUMMARY9
13 REFERENCE DRAWINGS amp DOCUMENTS9
2 PLETs amp PLEMs 11
3 Hydrate Remediation Equipment 12
4 Flowline Insulation Equipment 12
5 Riser Bend Stiffener Connectors 13
6 Bend Stiffener Connector (BSC) 13
Major benefits of using DTI Bend Stiffener Connectors14
2aSUBSEA UMBILICAL EQUIPMENT15
UMBILICAL CLAMP15
2b IWOCS EQUIPMENT16
2c INSTALLATION EQUIPMENT 16
3 ROV TOOLS AND EQUIPMENTamp18
Oil and gas19
Underwater mining19
Remotely operated vehicles20
4 a DIVERLESSBEND STIFFENER CONNECTOR24
b WORKING OF AN ROV28
5 ENTERPRISE PRODUCT DATA MANAGEMENT37
6 COMPONENTS IN A BEND STIFFENER CONNECTOR44
7 MATHCAD47
7a STUD CALCULATIONS48
8 DESIGN CRITERIA47
81 Codes and Standards47
82 Material Selection47
83 Design Loads48
84 Allowable CRITERIA48
9 STRUCTURAL ARRANGEMENT51
10 STRENGTH ANALYSIS53
101 Static Analysis55
1011 SolidModel55
1012 FE Model55
1013 Boundary Conditions and Loads59
7
1014 Results61
102 Fatigue Analysis70
103 DISCUSSION AND Conclusion73
LIST OF TABLES
8
MAIN REPORT
9
Error Reference source not foundLIST OF FIGURES
Main Report
Fig 1 Typical General Arrangement Sketch of BSC51
Fig 2 BSC - Solid Model55
Fig 3 BSC Shaft - Finite Element Model56
Fig 4 BSC Funnel - Finite Element Model57
Fig 5 Shaft Adapter Spool - Finite Element Model57
Fig 6 Assembly - Contact Definition Locations58
Fig 7 BSC Assembly - FE Model59
Fig 8 BSC Assembly Model - Loads and Boundary Conditions60
Fig 9 Shaft - Locations Considered for Stress Linearization62
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)62
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)63
Fig 12 BSC Funnel - Stress Linearization Locations63
Fig 13 Adapter Spool - Stress Linearization Locations64
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)66
(Window shown as Zoomed position)66
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)67
(Window shown as Zoomed position)67
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)68
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)68
LIST OF ABBREVIATIONS
DNV - Det Norske Veritas
10
API - American Petroleum Institute
AISC - American Institute of Steel Construction
BSC - Bend Stiffener Connector
SEQV - von Mises Stress
S1 - First Principal stress (Max Tensile)
S3 - Third Principal stress (Min Compressive)
BS - Bend Stiffener
DOF - Degree of Freedom
SF - Shear Force
BM - Bending Moment
11
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Most new and large oil and gas field developments are subsea deepwater fields
Subsea deepwater fields are generally in water depths between 1000 ft and 10000 ft below sea surface
Industry has gone from a nice area to a mainstream industry within the past 10-15 years
No CAD CAE BPO companies specializing in subsea deepwater technology currently exist in India
Know how (domain knowledge) is very important in this industry and learning curve is very steep
Also industry is very conservative and reluctant to use outside providers for these services Will only generally deal with individuals and companies with established track record
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
7
1014 Results61
102 Fatigue Analysis70
103 DISCUSSION AND Conclusion73
LIST OF TABLES
8
MAIN REPORT
9
Error Reference source not foundLIST OF FIGURES
Main Report
Fig 1 Typical General Arrangement Sketch of BSC51
Fig 2 BSC - Solid Model55
Fig 3 BSC Shaft - Finite Element Model56
Fig 4 BSC Funnel - Finite Element Model57
Fig 5 Shaft Adapter Spool - Finite Element Model57
Fig 6 Assembly - Contact Definition Locations58
Fig 7 BSC Assembly - FE Model59
Fig 8 BSC Assembly Model - Loads and Boundary Conditions60
Fig 9 Shaft - Locations Considered for Stress Linearization62
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)62
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)63
Fig 12 BSC Funnel - Stress Linearization Locations63
Fig 13 Adapter Spool - Stress Linearization Locations64
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)66
(Window shown as Zoomed position)66
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)67
(Window shown as Zoomed position)67
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)68
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)68
LIST OF ABBREVIATIONS
DNV - Det Norske Veritas
10
API - American Petroleum Institute
AISC - American Institute of Steel Construction
BSC - Bend Stiffener Connector
SEQV - von Mises Stress
S1 - First Principal stress (Max Tensile)
S3 - Third Principal stress (Min Compressive)
BS - Bend Stiffener
DOF - Degree of Freedom
SF - Shear Force
BM - Bending Moment
11
Business Drivers
Most new and large oil and gas field developments are subsea deepwater fields
Subsea deepwater fields are generally in water depths between 1000 ft and 10000 ft below sea surface
Industry has gone from a nice area to a mainstream industry within the past 10-15 years
No CAD CAE BPO companies specializing in subsea deepwater technology currently exist in India
Know how (domain knowledge) is very important in this industry and learning curve is very steep
Also industry is very conservative and reluctant to use outside providers for these services Will only generally deal with individuals and companies with established track record
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
8
MAIN REPORT
9
Error Reference source not foundLIST OF FIGURES
Main Report
Fig 1 Typical General Arrangement Sketch of BSC51
Fig 2 BSC - Solid Model55
Fig 3 BSC Shaft - Finite Element Model56
Fig 4 BSC Funnel - Finite Element Model57
Fig 5 Shaft Adapter Spool - Finite Element Model57
Fig 6 Assembly - Contact Definition Locations58
Fig 7 BSC Assembly - FE Model59
Fig 8 BSC Assembly Model - Loads and Boundary Conditions60
Fig 9 Shaft - Locations Considered for Stress Linearization62
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)62
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)63
Fig 12 BSC Funnel - Stress Linearization Locations63
Fig 13 Adapter Spool - Stress Linearization Locations64
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)66
(Window shown as Zoomed position)66
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)67
(Window shown as Zoomed position)67
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)68
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)68
LIST OF ABBREVIATIONS
DNV - Det Norske Veritas
10
API - American Petroleum Institute
AISC - American Institute of Steel Construction
BSC - Bend Stiffener Connector
SEQV - von Mises Stress
S1 - First Principal stress (Max Tensile)
S3 - Third Principal stress (Min Compressive)
BS - Bend Stiffener
DOF - Degree of Freedom
SF - Shear Force
BM - Bending Moment
11
Business Drivers
Most new and large oil and gas field developments are subsea deepwater fields
Subsea deepwater fields are generally in water depths between 1000 ft and 10000 ft below sea surface
Industry has gone from a nice area to a mainstream industry within the past 10-15 years
No CAD CAE BPO companies specializing in subsea deepwater technology currently exist in India
Know how (domain knowledge) is very important in this industry and learning curve is very steep
Also industry is very conservative and reluctant to use outside providers for these services Will only generally deal with individuals and companies with established track record
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
9
Error Reference source not foundLIST OF FIGURES
Main Report
Fig 1 Typical General Arrangement Sketch of BSC51
Fig 2 BSC - Solid Model55
Fig 3 BSC Shaft - Finite Element Model56
Fig 4 BSC Funnel - Finite Element Model57
Fig 5 Shaft Adapter Spool - Finite Element Model57
Fig 6 Assembly - Contact Definition Locations58
Fig 7 BSC Assembly - FE Model59
Fig 8 BSC Assembly Model - Loads and Boundary Conditions60
Fig 9 Shaft - Locations Considered for Stress Linearization62
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)62
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)63
Fig 12 BSC Funnel - Stress Linearization Locations63
Fig 13 Adapter Spool - Stress Linearization Locations64
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)66
(Window shown as Zoomed position)66
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)67
(Window shown as Zoomed position)67
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)68
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)68
LIST OF ABBREVIATIONS
DNV - Det Norske Veritas
10
API - American Petroleum Institute
AISC - American Institute of Steel Construction
BSC - Bend Stiffener Connector
SEQV - von Mises Stress
S1 - First Principal stress (Max Tensile)
S3 - Third Principal stress (Min Compressive)
BS - Bend Stiffener
DOF - Degree of Freedom
SF - Shear Force
BM - Bending Moment
11
Business Drivers
Most new and large oil and gas field developments are subsea deepwater fields
Subsea deepwater fields are generally in water depths between 1000 ft and 10000 ft below sea surface
Industry has gone from a nice area to a mainstream industry within the past 10-15 years
No CAD CAE BPO companies specializing in subsea deepwater technology currently exist in India
Know how (domain knowledge) is very important in this industry and learning curve is very steep
Also industry is very conservative and reluctant to use outside providers for these services Will only generally deal with individuals and companies with established track record
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
10
API - American Petroleum Institute
AISC - American Institute of Steel Construction
BSC - Bend Stiffener Connector
SEQV - von Mises Stress
S1 - First Principal stress (Max Tensile)
S3 - Third Principal stress (Min Compressive)
BS - Bend Stiffener
DOF - Degree of Freedom
SF - Shear Force
BM - Bending Moment
11
Business Drivers
Most new and large oil and gas field developments are subsea deepwater fields
Subsea deepwater fields are generally in water depths between 1000 ft and 10000 ft below sea surface
Industry has gone from a nice area to a mainstream industry within the past 10-15 years
No CAD CAE BPO companies specializing in subsea deepwater technology currently exist in India
Know how (domain knowledge) is very important in this industry and learning curve is very steep
Also industry is very conservative and reluctant to use outside providers for these services Will only generally deal with individuals and companies with established track record
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
11
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Subsea deepwater fields are generally in water depths between 1000 ft and 10000 ft below sea surface
Industry has gone from a nice area to a mainstream industry within the past 10-15 years
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Know how (domain knowledge) is very important in this industry and learning curve is very steep
Also industry is very conservative and reluctant to use outside providers for these services Will only generally deal with individuals and companies with established track record
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
12
SECTION 10
INTRODUCTION
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
13
1 INTRODUCTION
This report documents the analysis performed to verify the structural integrity of the Bend Stiffener
Connector (BSC) for Umbilical to be supplied to Aker Solutions for use in the Noble Gunflint
Project The BSCs are used to structurally connect the umbilical bend stiffener to its corresponding
I-tube The BSCs have a tube-in-tube design to react the bending moment and the shear force
imparted at the umbilical bend stiffener flange onto the I-tube This revision of report contains
reverification of the BSC after the BSC Funnel height was increased to allow higher clearance on
Funnel for ROV operations
The report comprises of the following sections briefly summarized below
Section 2 Design codes materials utilized and the design loads
Section 3 General arrangement of the BSC
Section 4 Strength analysis procedures and results
11 SCOPE AND BSC FUNCTIONALITY
The purpose of this report is to verify the structural integrity of the BSC when subjected to loads
provided by Aker Solutions as listed in Ref [2] The BSC assembly consists of a Shaft assembly
Funnel assembly and Shaft Adapter Spool The Shaft Adapter Spool is bolted to the top of the bend
stiffener The Funnel is connected to the bottom of the I-tube through a mating flange arrangement
BSC Funnel (BSC Female assembly) is assembled to the I tube flange first Then the umbilical is
pulled into the I-tube during this phase the BSC Shaft (BSC male assembly) enters the Funnel A
spring loaded latch arrangement then locks the Shaft to the Funnel The umbilical is pulled to the
top of the I-tube and clamped The bending moment and the shear force imparted by the umbilical
through the bend stiffener are reacted by top and bottom bearing surfaces within the Shaft and
Funnel assemblies The stresses due to these loads on the Shaft and Funnel are analyzed for static
load conditions as detailed in Section 4 of this report
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
14
12 SUMMARY
The analysis of the BSC shows that the induced stresses for the Operating case Extreme case and
Fatigue case are well within the allowable stressesdamage ratio for the materials used in their
construction
13 REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Revision Description
Customer Documents
1BSC Interface Details Required (first
submission)D BSC Interface Details
2 Max moment and Shear Tables 1 Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint 1 BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001 DGA 26in BSC With Inverted
Nut Tray - Aker Gunflint
- This revision of drawing is still being worked upon and all the changes which might affect structural
strength have already been included in this verification
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
15
ABOUT THE COMPANY AND BUSSINESS PLANDeepsea Technologies Inc (DTI) engineers and manufactures a wide range of products and equipment used in subsea oil amp gas field development projects We have been in business since 2001 and our quality system is ISO 90012008 Our customers include a number of oil amp gas majors and independents tree amp wellhead manufacturers drilling companies installation companies and other service contractors The companyrsquos products and equipment have been used in projects in the US Gulf of Mexico Brazil the North Sea West Africa India Southeast Asia and Australia
bullDeepsea Technologies Inc (DTI) was established in March 2001
bullCompany provides turnkey design engineering and manufacturing of equipment for subsea field development projects
bullCustomers include EampP Majors Independents Oilfield Equipment Suppliers and Service Companies
bullDTI operates under an ISO 9001-2008 Certified Quality System
bullCompanyrsquos products and services have been used in various projects in the USA (GOM) West Africa India Australia amp S E Asia
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
16
PROJECTS
PROJECT EQUIPMENT
SUBSEA FLOWLINE EQUIPMENTbull PLETS amp PLEMSbull FLOWLINE JUMPERSbull FLOWLINE INSULATION EQUIPMENTbull HYDRATE REMEDIATION PANELSbull RISER BEND STIFFENER CONNECTORSbull LONG TERM PRESSURE CAP PANELSSUBSEA UMBILICAL EQUIPMENTbull UMBILICAL TERMINATION ASSEMBLIESbull FLYING LEADSbull UMBILICAL CLAMPS bull UMBILICAL BEND STIFFENER CONNECTORSIWOCS EQUIPMENTbull IWOCS REELSbull DEPLOYMENT SHEAVESbull IWOCS HPUS
INSTALLATION EQUIPMENTbull INSTALLATION REELSbull POWERED DEPLOYMENT FRAMESFLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENTbull SUBSEA INSULATION SYSTEMSbull SUBSEA PIG LAUNCHERSbull HYDRATE REMEDIATION PANELSSUBSEA INTERVENTION EQUIPMENTbull INTERVENTION PANELS FOR HYDRATE REMEDIATIONbull LONG TERM PRESSURE CAP PANELSbull CLUMP WEIGHT LOCKSSPECIAL PURPOSE EQUIPMENT
PLETS (PIPELINE END TERMINATION) amp PLEMS (PIPELINE END MANIFOLDS)
DTI provides turnkey engineering and manufacturing of PLETs amp PLEMs which includes conceptual design structural analysis amp fabrication
Detailed structural Finite Element Analysis Mudmat Calculations and Cathodic Protection Calculations are performed for each structure
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
17
Design and Manufacturing of PLETs amp PLEMs is performed under a documented Quality Plan
DTI has successfully built various PLETs for EampP companies and installation contractors
2 HYDRATE REMEDIATION EQUIPMENT DTI DESIGNS AND MANUFACTURES HYDRATE REMEDIATION EQUIPMENT WHICH CAN BE MOUNTED ON JUMPERS AS WELL AS ON MANIFOLD
ApplicationHydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct DescriptionHRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
18
3 FLOWLINE INSULATION EQUIPMENT DTI IS ACTIVELY INVOLVED IN THE DEVELOPMENT OF ONE OF THE MOST ADVANCED AND SIMPLIFIED PRODUCTS TO TACKLE THE PROBLEMS OF INSULATION OF MANIFOLDS AND PIPELINES WITH DAMAGED INSULATIONS
4 RISER BEND STIFFENER CONNECTORS BEND STIFFENER CONNECTOR (BSC) WAS DEVELOPED TO FACILITATE ldquoDIVER LESSrdquo CONNECTION OF UMBILICAL AND FLOW LINE BEND STIFFENERS TO I-TUBE OR J-TUBE THE INNOVATIVE DESIGN (PATENT PENDING) ENABLES EASY INSTALLATION IN THREE SIMPLE STEPS WHICH REDUCES THE COMPLEXITY OF THE PROCESS AND ALSO REDUCES THE COST OF OPERATION
5 BEND STIFFENER CONNECTOR (BSC) (A) BSC CONSISTS OF A FUNNEL WELDMENT (I-TUBE INTERFACE) AND A SHAFT ASSEMBLY BEND STIFFENER INTERFACE) ALONG WITH A LOCKING MECHANISM THE TOP OF THE FUNNEL ASSEMBLY IS ATTACHED TO THE I-TUBE (WELDED OR FLANGED) AND THE SHAFT IS ATTACHED TO THE BEND STIFFENER WITH AN ADAPTER FLANGE THE SHAFT ASSEMBLY IS PULLED INTO THE FUNNEL ASSEMBLY AND IS AUTO-LATCHED TO THE FUNNEL ASSEMBLY WITH THE DOGS IN THE LATCHING MECHANISM (B) THE INITIAL POSITION OF THE SHAFT AND FUNNEL THE SHAFT BEING PULLED INTO THE FUNNEL (C) SHOWS THE FINAL POSITION AFTER THE CAM PLATE IS PUSHED BY THE ROV TO THE LOCK POSITION
6 MAJOR BENEFITS OF USING DTI BEND STIFFENER CONNECTORS
IMPROVED SAFETY ndash Eliminates need for diving operations for connecting bend stiffener to I-tube
LOWER SCHEDULING RISK ndash Eliminates the need to coordinate installation vessel activity with diving activity
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
19
LOWER COST ndash Reduces the cost of installation by eliminating the need to have diving support available during riser installation and minimizing installation vessel standby time during the connection process
TIME SAVING ndash The total time for making up the connection is less than 12 hour when compared to 10-12 hrs total time using divers or other connectorsThe BSC connectors are manufactured in three standard sizes with customizable end interfaces depending on the requirement The sizes and load specification is included in Table 1 However the design is easily scalable to meet any Load Functional requirements The current maximum static bending load capacity is upto 800000 FT-LB (for 30rdquo Connector)
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flowline jumpers are connected to these headers in the later stages of field developmentProduct Description The LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and pipingUsage History The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
2A SUBSEA UMBILICAL EQUIPMENTUMBILICAL CLAMPApplication Umbilical clamps are designed to facilitate the installation of the Bend Stiffener Connector to the I-tubeJ-tube and prevent slipping of the bend
stiffener during installation
SN Size (in) Min Calculated Static Bending Load (lb-ft)
1 18 155712
2 20 376585
3 24 656672
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
20
Product Description An umbilical clamp consists of a hinged split pipe which wraps around the umbilical behind the bend stiffener to prevent it from slipping during its installation with the I-tube J-tube It is designed to be ROV operable
2B IWOCS EQUIPMENTIWOCS REEL IWOCS REELS TO SUIT THE CUSTOMERrsquoS SPECIFIC REQUIREMENTSDEEPSEA TECHNOLOGIES DESIGNS amp MANUFACTURES IWOCS REELS TO SUIT CUSTOMERS SPECIFIC REQUIREMENTS DESIGN AND MANUFACTURING OF IWOCS REELS IS PERFORMED UNDER A DOCUMENTED QUALITY PLAN
2C INSTALLATION EQUIPMENT INSTALLATION REELS DTI provides turnkey engineering and manufacturing of Installation Reels to suit the customerrsquos specific requirements
FLOW ASSURANCE amp HYDRATE REMEDIATION EQUIPMENT
FLOWLINE ASSURANCE EQUIPMENTSDeepsea Technologies is actively involved in provided innovative and cost effective solutions for flowline assurance and has concentrated its efforts in two major fields which include
SUBSEA INSULATION SYSTEMS Deepsea Technologies is actively involved in the development of one of the most advanced and simplified products to tackle the problems of insulation of manifolds and pipelines with damaged insulation
SUBSEA PIG LAUNCHERS Deepsea Technologies has successfully designed and manufactured a subsea Pig-Launcher which is currently deployed in the gulf of Mexico
HYDRATE REMEDIATION PANELS
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
21
Application Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediationProduct Description HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
2D SUBSEA INTERVENTION EQUIPMENT
INTERVENTION PANELS Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Application
Hydrate remediation panels (HRPs) can be mounted on Jumpers as well as on manifold and are used for hydrate remediation
Product Description
HRPs are fitted with standard Hot-Stab equipment and Valves They are designed to API specifications and are ROV accessible
LONG TERM PRESSURE CAP PANELS
Application Long Term Pressure Cap Panels (LTPCs) are designed to be left in place on headers until flow line jumpers are connected to these headers in the later stages of field development
ProductDescriptionThe LTPCs consist of a 1rdquo bore receptacle connected to the header with a flanged connection through 2 valves The receptacle can be used for pumping fluid into the header It also has the facility for hot water hydrate remediation of the LTPC spool and piping
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
22
UsageHistory The subsea manifolds on the BP Atlantis project subsea system use Long Term Pressure Caps (LTPC) to isolate some of the headers
3 ROV TOOLS AND EQUIPMENTamp bull ROV HOT STAB HARDWARE
bull ROV VALVE OPERATORS
bull TORQUE TOOL BUCKETS
bull NUT RETRACTION TOOLS
MANIFACTURING SERVICESDTI provides turnkey manufacturing services to customers
THE RANGE OF CAPABILITIES INCLUDECasting amp forging
Machining
Fabrication
Assembly
DTI follows a stringent quality assurance and quality control process to ensure the products fully meet the customerrsquos specifications
4 WHAT IS SUBSEA
Subsea is a term to refer to equipment technology and methods employed in MARINE BIOLOGY UNDERSEA GEOLOGY OFFSHORE OIL AND GAS DEVELOPMENTS UNDERWATER MINING and OFFSHORE WIND POWER industries
Subsea technology in offshore oil and gas production is a highly specialized
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
23
field of application with particular demands on engineering and simulation Most of the new oil fields are located in deep water and are generally referred to as deepwater systems
OIL AND GAS
Oil and gas fields reside beneath many inland waters and offshore areas around the world and in the oil and gas industry the term subsea relates to the exploration drilling and development of oil and gas fields in underwater locations
Under water oil field facilities are generically referred to using a subsea prefix such as subsea well subsea field subsea project and subsea development
Subsea oil field developments are usually split into Shallow water and Deepwater categories to distinguish between the different facilities and approaches that are needed
The term shallow water or shelf is used for very shallow water depths where bottom-founded facilities like JACKUP DRILLING RIGS and FIXED OFFSHORE STRUCTURES can be used and where SATURATION DIVING is feasible
Deepwater is a term often used to refer to offshore projects located in water depths greater than around 600 feet[1] where FLOATING DRILLING VESSELS and FLOATING OIL PLATFORMS are used and REMOTELY OPERATED UNDERWATER VEHICLES are required as manned diving is not practical
Subsea completions can be traced back to 1943 with the Lake Erie completion at a 35-ft water depth The well had a land-type Christmas tree that required diver intervention for installation maintenance and flow line connections[2]
SHELL completed its first subsea well in the GULF OF MEXICO in 1961
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
24
UNDERWATER MINING
Recent technological advancements have given rise to the use of REMOTELY OPERATED VEHICLES (ROVs) to collect MINERAL samples from prospective MINE sites Using drills and other cutting tools the ROVs obtain samples to be analyzed for desired minerals Once a site has been located a mining ship or station is set up to mine the area
REMOTELY OPERATED VEHICLESREMOTELY OPERATED UNDERWATER VEHICLE
Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor ROVs are available in a wide variety of function capabilities and complexities from simple eyeball camera devices to multi-appendage machines that require multiple operators to operate or fly the equipment
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
25
An oil platform offshore platform or (colloquially) oil rig is a large structure with facilities to drill wells to extract and process OIL and NATURAL GAS or to temporarily store product until it can be brought to shore for refining and marketing In many cases the platform contains facilities to house the workforce as well
Depending on the circumstances the platform may be FIXED to the ocean floor may consist of an ARTIFICIAL ISLAND or may FLOAT Remote SUBSEA wells may also be connected to a platform by flow lines and by UMBILICALconnections These subsea solutions may consist of one or more subsea wells or of one or more manifold centres for multiple wells
Types of OIL RIGS
FIXED PLATFORMSCOMPLIANT TOWERSSEMI-SUBMERSIBLE PLATFORMJACK-UP DRILLING RIGS
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
26
DRILLSHIPSFLOATING PRODUCTION SYSTEMSTENSION-LEG PLATFORMGRAVITY-BASED STRUCTURESPAR PLATFORMSNORMALLY UNMANNED INSTALLATIONS (NUI)CONDUCTOR SUPPORT SYSTEMS
MAINTENANCE AND SUPPLY
A typical oil production platform is self-sufficient in energy and water needs housing electrical generation water declinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a FLOATING PLATFORM or tanker loading facility or both Elements in the oilgas production process include WELLHEAD PRODUCTION MANIFOLD PRODUCTION SEPARATOR GLYCOL process to dry gas compressors water OILGAS EXPORT METERING and MAIN OIL LINE pumps
Larger platforms assisted by smaller ESVs (emergency support vessels) like the BRITISH OILIER that are summoned when something has gone wrong eg when a SEARCH AND RESCUE operation is required During normal operations PSVS (platform supply vessels) keep the platforms provisioned and supplied and AHTS VESSELS can also supply them as well as tow them to location and serve as standby rescue and firefighting vessels
DRAWBACKS RISKS The nature of their operation mdash extraction of volatile substances sometimes under extreme pressure in a hostile environment mdash means risk accidents and tragedies occur regularly The US MINERALS MANAGEMENT SERVICE reported 69 offshore deaths 1349 injuries and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010 On July 6 1988 167 people died when OCCIDENTAL PETROLEUMs PIPER ALPHA offshore production platform on the Piper field in the UK sector of the NORTH SEA exploded after a gas leak The resulting investigation conducted by Lord Cullen and publicized in the first CULLEN REPORT was
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
27
highly critical of a number of areas including but not limited to management within the company the design of the structure and the Permit to Work System The report was commissioned in 1988 and was delivered November 1990 The accident greatly accelerated the practice of providing living accommodations on separate platforms away from those used for extraction ECOLOGICAL EFFECTS Aquatic organisms invariably attach themselves to the undersea portions of oil platforms turning them into artificial reefs In the Gulf of Mexico and offshore California the waters around oil platforms are popular destinations for sports and commercial fishermen because of the greater numbers of fish near the platforms The UNITED STATES and BRUNEI have active RIGS-TO-REEFS programs in which former oil platforms are left in the sea either in place or towed to new locations as permanent artificial reefs In the US GULF OF MEXICO as of September 2012 420 former oil platforms about 10 percent of decommissioned platforms have been converted to permanent reefs
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
28
4a Diverless Bend Stiffener Connectors
BEND STIFFENERS INTRODUCTION1 Bend Stiffener Connector
As operators look to increase the number of subsea field tie-backs to their offshore facilities the ability to add new flexible risers and umbilicalrsquos quickly and easily in space-restricted locations without
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
29
the need for divers is the cost-effective proposition offered by deepsea range of self-energising ROV-less and diverless Bend Stiffener Connectors (BSC)
I The BSC is enabling operators to perform faster and safer installations of flexible risers and umbilicalrsquos to crowded platformsThe Deepsea-tech BSC comprises of a connector and a bend stiffener
II First Subsea BSCs offerbull ROV-less and diverless installationbull Quick and easy engagementbull Simple release procedure
Abull Bend Stiffener Connector (BSC) was developed to facilitate
ldquodiver lessrdquo connection of Umbilical and Flow line bend stiffeners to I-tube or J-tube The innovative design (patent pending) enables easy installation in three simple steps which reduces the complexity of the process and also reduces the cost of operation
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
30
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
31
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
32
4b WORKING OF A ROVGENERAL SYSTEM LAYOUT AND DESCRIPTION
The typical HYDRA MAGNUM ROV system when assembled in a workingenvironment consists of the following major components Please note that theconfiguration of some systems may vary slightly depending upon the application and thetype of vessel where the system will be installed1048766POWER GENERATOR1048766CONTROL VAN1048766SURFACE HANDLING SYSTEM1048766MAIN LIFT UMBILICAL1048766SUB SEA DEPLOYMENT CAGE1048766FLYING TETHER1048766VEHICLE (ROV)1048766MAITENEANCE AND COTROL VAN
General ROV Layout
POWER GENERATORThe system power requirements are 480 VAC 3-PHASE 60 Hz A motor generatorprovides this with a 200 KVA capacity This generator is solely dedicated to the ROVsystem and thereby provides a regulated noise free power source
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
33
OCEANEERING uses two different types of generators on their ROV systems Onetype is diesel powered and is a self-contained unit The other type is a motor alternator which is dependent on an external power source The type of generator usedon a system will depend upon the application and the type of vessel where the systemwill be installedPOWER GENERATOR DIMENSIONS
DIESEL UNIT MOTOR ALTERNATOR UNITLENGTH 16 ft - 5 in (5030m) 8 ft (2438m)WIDTH5 ft - 10 in (1778m) 8 ft (2438m)HEIGHT 8 ft - 2 in (2489m) 8 ft - 6 in (3581m)WEIGHT 12 350 lbs (5602kg) 8700 lbs (3947kg)
Motor Generator Van
CONTROL VANThe control van is the operational control center during HYDRATM MAGNUM sub-seaoperations The entire operator interface with the cage and the vehicle takes place inthe control vanThe control van is equipped with a climate control (cooling heating) system lightingwith intensity adjustments GFI rated 110 VAC and 220 VAC electrical outlets firealarms and fire extinguishers The control van is also equipped with a documentationcenter which provides the ROV crew members an area for paperwork and
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
34
documentation storageStorage space is provided for the following10487661048766ELECTRONIC EQUIPMENT10487661048766VIDEO TAPE LIBRARY MINIMUM OF 30 TAPES10487661048766FLOPPY DISK STORAGE10487661048766DOCUMENTATION AND MANUALS10487661048766CHART RECORDER SUPPLIES10487661048766OPTICAL TIME DOMAIN REFLECTOMETER (OTDR)10487661048766GENERAL TOOL KIT10487661048766GENERAL OFFICE SUPPLIES10487661048766SPARE PERSONAL COMPUTER SYSTEM10487661048766LOG BOOKS
Control Van with Work Van Below
The control van has two sections that are the most vital and necessary part for theoperation and control of the ROV system They are1 CONSOLE2 POWER DISTRIBUTION UNITCONTROL VAN DIMENSIONSLENGTH 14 ft (43m)WIDTH 8 ft (245m)HEIGHT 8 ft (245m)WEIGHT 10000 lbs (4536kg)Control Van Dimensions
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
35
CONSOLEThe HYDRATM MAGNUM console is the interface point of the operator with the cageand the vehicle The console consists of three sections They arediams1048766PILOT CONSOLEdiams1048766NAVIGATOR CONSOLEdiams1048766OBSERVERS CONSOLE
Console
PILOT CONSOLEThe cage and the vehicle functions are controlled from the pilot console The followingcomponents comprise the pilot console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe video signals other than what is being selected andobserved on the pilotrsquos video monitor10487661048766INTERFACE TRAYThis 19-inch rack mounted tray houses the digital and analog telemetry interfacecomponents It also provides the operator with analog meters for observing main inputpower voltage and frequency10487661048766POWER TRAYThe power tray is the point where all power is switched on off for the console cageand vehicle It also houses the surface ground fault monitoring system and three DCpower supplies necessary for the console10487661048766PILOT VIDEO MONITORThis 17-inch S-VGA multi-sync monitor provides the pilot with the video necessary to
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
36
operate the cage and the vehicle This video is overlaid with the control computergraphics display The pilot may select various overlays including a second video calledpicture-in-picture provided by the Control Telemetry And Graphics (CTAG) software10487661048766PILOT TRAYThe pilot tray is the main interface of the cage and the vehicle with the operator Ithouses all the operator manual controls such as joystick controllers switches pilotcomputer trackball and manipulator controller10487661048766PILOT COMPUTERThe pilot computer is the main control computer It is the active or master computer ofthe control telemetry system This 19-inch rack mounted Pentium based computercontains all to the necessary input output interfacing hardware for controlling the cageand the vehicle functionsAUXILIARY COMPUTERThe auxiliary computer is a passive or slave computer of the control telemetry systemThe physical specifications and hardware are identical to the pilot computer except thatthere is only one video board installed in the auxiliary computer versus two video boardsin the pilot computer The input output interface hardware for the auxiliary computer isnot connected however the software control functions of the auxiliary computer areused by the navigator to aid the operator during sub-sea operations In the event of apilot computer failure the auxiliary computer can be quickly configured as the pilotmaster computer
NAVIGATOR CONSOLEThe navigator performs his duties from the navigator console This console provides thenavigator with all the hardware necessary for sonar navigation video switching datalogging and video recording of various tasks The following components comprise thenavigator console10487661048766TWO 9-INCH COLOR VIDEO MONITORSThese monitors are used to observe any two of the video signals and are selectable bythe navigator The selected signals are first sent through the two S-VHS recorders toinsure proper video recording is taking place1048766104876613-INCH MULTIPLE INPUT VIDEO MONITORThis monitor is used mainly for monitoring sonar but can be switched to observe anyvideo signal available10487661048766VIDEO SWITCHERThe Dynair video switcher uses state-of-the-art video switching technology which is
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
37
microprocessor controlled to provide 10 inputs selectable to any of 10 outputs10487661048766TWO S-VHS VIDEO RECORDERSThese video recorders are used to provide a recording of a selected video Onerecorder is designated as the high lights recorder The other recorder is designated asthe constant run recorder The highlights recorder is used to record selected highlightsof the sub sea operation The constant run recorder normally records the video beingobserved by the operator with the alarm graphics overlaid However the video beingrecorded by the constant run recorder is at the discretion of the supervisor in charge ofthe ROV system10487661048766SONAR PROCESSORThe Simrad Mesotech MS 900 Sonar Processor is specifically located to provide thenavigator with easy access This unit provides the means to manipulate and control allof the sonar functions and displays10487661048766NAVIGATOR DESK TRAYThis is the deskwork station for the navigator Along with the data logging the navigatorhas a trackball and keyboard connected to the auxiliary computer allowing operationand control of software inputs10487661048766OBSERVER CONSOLEThe observer console provides a work - station for an observer or a second data loggerThere is shelving provided for any extra equipment that might be required for particularjob applications The pilot computer keyboard is also located at the observer console
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
38
5 ENTERPRISE Product Data Management SOLIDWORKS EPDM TAKES CARE OF DATA SolidWorks Enterprise Product Data Management (EPDM) centralizes the storage of all engineering data and related files to give you these benefits bull Secure indexed repository for fast information retrieval bull Version control for both minor changes and major revisions to prevent data loss bull Integrated workflows that automate your design and approval process for more efficient review and release of final designs With SolidWorks EPDM WE can dramatically reduce the time WE spend searching for parts assemblies and drawings Part of the SolidWorks suite of product development solutionsmdashcovering design simulation sustainable design technical communication and data managementmdashSolidWorks EPDM will help we drive design reuse and manage your overall 3D design experience Implemented in a fraction of the time required by other data management solutions SolidWorks EPDM can scale from small workgroups to hundreds of designers located in offices anywhere in the world 5a ADVANTAGES Rapidly find data and control access Focus your design organization on product innovation with tools to quickly and efficiently find share and reuse data bull Search for data in multiple ways using parameters such as document or file name contained data or custom properties like part number description and current workflow state (for example released or in process) bull Save searches for easy reuse individually or across the enterprise bull Prevent designers from accidentally overwriting files through integrated version control bull Easily produce customized bills of materials (BOMs) for individual departments bull Manage view and print documents from more than 250 file types including major CAD formats Microsoftreg Office images and animations bull Protect data from theft damage or misuse with secure login bull Always ensure manufacturing has the right version avoiding costly mistakes Implement and scale quickly Realize an immediate return on your investment by launching SolidWorks EPDM in just days then scale it as your organization grows in people partners and geography
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
39
bull Scale up to hundreds of users bull Get up and running within five days with our Quick Start Program bull Quickly adapt SolidWorks EPDM to your design processes team structure and industry through custom configuration bull Create custom applications to meet specific business requirements through the SolidWorks EPDM comprehensive application programming interface (API) We Get productive fast bull Engage new users quickly with the intuitive Windows Explorer interface bull See ldquowhere usedrdquo and ldquocontainsrdquo information for any design with one click bull Customize menus to personalize use and increase productivity bull Use integrated Windows Explorer search and browse capabilities to reduce desktop clutter and find files faster bull Instantly communicate with colleagues through information pop-ups Streamline essential processes bull Model company workflows and processes bull Increase productivity quality and accountability by automating workflows and approval processes bull Instantly access audit trails to meet internal and external reporting requirements document quality control and standards compliance and drive process improvement bull Automatically create files in common formats such as PDF at the end of an approved process Collaborate without boundaries Product development organizations can span continents and time zones SolidWorks EPDM creates a single collaborative community regardless of distance and location bull Gives distributed users quick access to designs specifications and documentation through Vault replication bull Enable staff and partners to contribute through remote-access portals bull Control access to specific engineering data and project information through secure access
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
40
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
41
6 Components in a bend stiffener connector
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
42
SCOPE OF SUPPLYGENERAL ARRANGEMENT (GA) DRAWING - 20 BSC MAIN UMBILICALFINAL ASSEMBLY DRAWING - 20 BSC MAIN UMBILICAL FUNNEL ASSEMBLY - 20 BSCSHAFT AND ADAPTER ASSEMBLYSHAFT ASSEMBLY - 20 BSCREDUCER WELDMENTFUNNEL PIPE DETAILFUNNEL CONE DETAILFUNNEL AND BOTTOM CONE WELDMENTFUNNEL AND BOTTOM CONE MACHININGFUNNEL amp BASE PLATE WELDMENT WITH FLANGEBASE PLATE DETAILROV HANDLE PAD EYEFUNNEL PLATE FLANGELATCHING DOG ndash FUNNELSPRING RETAINERCAM PLATE GUIDECAM PLATE WITH ROV CAM PLATE DETAILCAM PLATE LOCKING PIN NAME PLATE - FUNNEL SN 1SHAFT AND ANODE TAB WELDMENTSHAFT MACHININGSHAFT WELDMENT SHAFT PIPE DETAILSHAFT FLANGEANODE TAB ndash SHAFTNAME PLATE ndash SHAFTSHAFT ADAPTER SPOOL ASSEMBLY SHAFT ADAPTER WELDMENT SHAFT ADAPTER MACHININGNAME PLATE (Shaft adapter)REDUCER ROLLED PLATEREDUCER CONEREDUCER CONE AND ROLLED PLATE WELDMENTWELDMAP DRAWINGREDUCER CONE AND ROLLED PLATE MACHININGFUNNEL REDUCER PRESS BREAKFUNNEL REDUCER WELDMENTFUNNEL REDUCER CONEFUNNEL REDUCER PIPE
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
43
7 MATH CAD CALCULATIONSWhat is Math CADMathcad Parametric Technology Corporations engineering calculation solution is used by engineers and scientists in various disciplines ndash most often those of mechanical chemical electrical and civil engineering Originally conceived and written by Allen Razdow (of MIT co-founder of Mathsoft) Mathcad is now owned by PTC and is generally accepted as the first computer application to automatically compute and check consistency of engineering units such as the International System of Units (SI) throughout the entire set of calculations Mathcad today includes some of the capabilities of a computer algebra system but remains oriented towards ease of use and simultaneous documentation of numerical engineering applicationsMathcad is oriented around a worksheet in which equations and expressions are created and manipulated in the same graphical format in which they are presented as opposed to authoring in plain text an approach later adopted by other systems such as Mathematica and MapleMathcad is part of a broader product development system developed by PTC and often utilized for the many analytical touch points within the systems engineering processes It integrates with PTCrsquos other solutions that aid product development including Creo ElementsPro Windchill and Creo ElementsView Its live feature-level integration with Creo ElementsPro enables Mathcad analytical models to be directly used in driving CAD geometry and its structural awareness within Windchill allows live calculations to be re-used and re-applied toward multiple design models
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
44
7a
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
45
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
46
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
47
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
48
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
49
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
50
The pretorque range is 1896-1997 ft-lbf and is calculated using Collar friction coefficient in the range of 009-013 and tensioning bolt in the range of 70 to
90 Yield
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
51
SECTION 20
DESIGN CRITERIA
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
52
7 DESIGN CRITERIA
71 CODES AND STANDARDS
As applicable the following design codes have been applied in the design and analysis presented
herein
DNV-RP-C2032010 Fatigue Design of Offshore Steel Structures
DNV-RP-B401 Cathodic Protection Design
AISC - Steel Construction Manual
API RP 2A - Recommended Practice for Planning Designing and Constructing Fixed
Offshore PlatformsmdashWorking Stress Design 2000
API RP 2RD - Design of Risers for Floating Production Systems (FPSs) and
Tension-Leg Platforms (TLPs) 1998
72 MATERIAL SELECTION
The material listed below will be used as a minimum requirement for overall fabrication Special
material will be considered as required and shall be noted on the AFC drawings
Table 1 Material Properties
SNo Part DescriptionKey
Dimension
Drawing
ReferenceMaterial
1 Shaft - PipePipe 24rdquo
OD
D14043-03-057
Rev0
API 5L X52
(Yield Strength Fy = 52000 psi)
2 Shaft - Flange 275 thickD14043-03-058
Rev 0
API 2H GR 50
(Yield Strength Fy = 50000 psi)
3 Funnel - PipePipe 26rdquo
OD
D14043-03-010
Rev 0
API 5L X52
(Yield Strength Fy = 52000 psi)
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
53
4 Funnel- Flange plate 3 thickD14043-03-015
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
5 Shaft Adapter Spool Flange 2 thickD14043-02-055
Rev A
API 2H GR 50
(Yield Strength Fy = 50000 psi)
6 Shaft Adapter Spool PipePipe 24rdquo
SCH 140
D14043-02-055
Rev A
API 5L X52
(Yield Strength Fy = 52000 psi)
73 DESIGN LOADS
When BSC is connected the Bend Stiffener transfers the load to the BSC The significant loads
acting on the BSC are bending moment and shear force The bending moment and shear force loads
were obtained from Ref [2] The loads analyzed are shown in Table 3 These loads include the
Normal and Abnormal conditions
74 ALLOWABLE CRITERIA
Fatigue loading condition
Total Damage Ratio lt01 (Safety factor considered - 10)
The fatigue spectrum was given for 1 year the numbers of cycles were multiplied by 20 to get the
cycles for 20 years
Following are the maximum allowable von Mises Stress criteria in terms of material Yield
Strengths These are referred from the API RP 2RD Section 52
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
54
Table 2 Allowable Stresses
Load Case Operating Extreme Survival
Stress Component
(p)e Membrane 067 of y 08 of y y
(p+b)e Membrane+Bending y 12 y 15 y
(p+b+q)e Membrane+Bending+Secondary 2y 2y 2y
y is the Material minimum Yield Strength
p is the Membrane Stress component
b is the Bending Stress Component
q is the Secondary Stress Component
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
55
SECTION 30
STRUCTURAL ARRANGEMENT
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
56
8 STRUCTURAL ARRANGEMENT
Fig 1 Typical General Arrangement Sketch of BSC
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
57
SECTION 40
DETAILED STRENGTH ANALYSIS
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
58
9 STRENGTH ANALYSIS
Static and fatigue analyses were performed based on the load data provided in Ref [2] for BSC
Finite Element Analysis was performed using ANSYS software to calculate the stresses on the BSC
Funnel Shaft and Adapter Spool assemblies
The operational load path identified for BSC is as follows
Appendix E
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
59
Above image shows the operational load path (externally appliedtransferred) Left side portion
indicates the components and right side portion indicates the scope of supply and the verification of
the corresponding component
The above typical cross section sketch shows the different parts in the load path identified earlier
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
60
91 STATIC ANALYSIS
911 SolidModel
Fig2 shows the solid model used for analysis The BSC assembly model was arranged to represent
the assembly condition where the Funnel guide dogs are engaged in Shaft groove and Shaft hangs
on the Funnel dogs
BSC Assembly Funnel Weldment Shaft Weldment Adapter Spool Weldment
Fig 2 BSC - Solid Model912 FE Model
The BSC 3D model (Shaft Funnel and Adapter Spool) was meshed using Solid 186 20 noded brick
element type in Ansys This element is a quadratic type and has been meshed with global size of
0375 and local sizing of 011 to 015 at critical zones Fig3 Fig4 and Fig5 show the FE
models of Shaft Funnel and Adapter Spool respectively including the local mesh
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
61
The contacts were defined between Adapter spool and Shaft at the flange interface Shaft and
Funnel at the bearing areas to transfer load from one component to other Bonded always contacts
were defined at all weld locations between any two parts Fig 6 shows the contacts defined
between different components in the assembly for analysis BSC Assembly model was used for
static and fatigue load cases
Fig 3 BSC Shaft - Finite Element Model
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
62
Fig 4 BSC Funnel - Finite Element Model
Fig 5 Shaft Adapter Spool - Finite Element Model
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
63
Fig 6 Assembly - Contact Definition Locations
Shaft flange stud washer areamaster node
(For load application)
Shaft Flange lower face Adapter spool
upper flange top face
Shaft reaction surface and Funnel ID at two
locations
Base plate face Funnel outer face
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
64
Fig 7 BSC Assembly - FE Model
913 Boundary Conditions and Loads
The top face of the Funnels flange was constrained in all translations to simulate the bolted joint
between this flange and the I-tube flange refer Fig8
The loads applied in the analysis are listed in Section 413 Table 3 A contact pair was defined
between Adapter Spool lower flange nut face area nodes and a node at intersection of Adapter
Spool axis and lower flanges bottom face This uses the force distributed constraint equations to
transfer loads from target node to contact nodes The shear force and bending moment loads were
applied on this target node
The loads and BCs are shown in Fig 8
The load application direction is chosen so that the assembly is subjected to worst loading scenario
based on the study conducted internally at DTI and our proven experience in projects over time
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
65
Table 3 BSC Loads based on BSC Specification [Ref1]
Load CaseShear Force
(kN)Bending Moment
(kNm)
Normal (Operating)
Condition774 2519
Abnormal (Extreme)
Condition79 255
The load case sequence followed in Ansys was i) Fatigue unit Shear Force case ii) Fatigue unit
Bending Moment case iii) Operating case (Normal Condition) and iv) Extreme Case (Abnormal
Condition)
Fig 8 BSC Assembly Model - Loads and Boundary Conditions
Shear force and bending moment applied at the
Nut faces of the bolt holes using MasterSlave nodes
contact pair in Ansys
All DOFs were fixed at the top face of the
Funnel Flange
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
66
914 Results
Individual stress components were obtained by linearizing the von Mises stress at critical locations
in all the components namely Shaft Funnel and Adapter Spool
For Shaft the critical sections were Shaft groove Shaft interface between pipe and flange For each
section the linearized stress component values are reported in the Table 4 and Table 5 Localized
von Mises Stress plots and linearized stress plots are appended for corresponding load cases in
Appendix A Stress linearization was done across the pipe or plate thickness as appropriate
Fig9 specifies the locations considered for linearizing the stress in Shaft Linearization was done
across the reduced Shaft thickness at two locations As seen in the Table 4 and Table 5 the
calculated stresses in the Shaft are lower than the allowable stress components
Shaft Groove
Shaft Flange
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
67
Fig 9 Shaft - Locations Considered for Stress Linearization
Fig 10 Shaft ndash Normal Condition - Overall von Mises Stress Distribution (psi)
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
68
Fig 11 Shaft ndash Abnormal Condition - Overall von Mises Stress Distribution (psi)
Fig10 and Fig11 show the overall Shaft stress distribution for BSC in static casesHere the bending
moment was applied about X axis as shown in Fig8 and shear force was applied in YZ plane
(visible in the Fig8) and parallel to the adapter flange face Over the total height of the Shaft the
Shaft groove section has the maximum stress at the location We can also observe some magnitude
of stress at different locations in the Shaft because of combination of bearing shear and bending
stressesResult stress plots for other cases are included in Appendix A
For Funnel assembly stress linearization was done in at critical locations namely Funnel Window
corner Funnel pipeflange interface and Funnel Flange Refer Fig 12
For Adapter Spool stress linearization was done in at flange and pipe interface Refer Fig 13
Fig 12 BSC Funnel - Stress Linearization Locations
Window Corner
Funnel pipe Flange interface
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
69
Fig 13 Adapter Spool - Stress Linearization Locations
Flange
Pipe
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
70
Table 4 Normal Condition (Operating Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 067 335 3248 3484 2537 335 3907 3484 8816 335 7742 3484 4816
M+B 1 50 5906 52 3238 50 4003 52 1411 50 1306 52 2452
Total 2 100 7175 104 3035 100 4132 104 1552 100 2273 104 2846
Table 5 Abnormal Condition (Extreme Case) - BSC Stress Summary(All values are for von Mises Stress and in ksi)
ASCFunnel
Flange
Funnel pipe
(window)
Shaft
Flange
Shaft Pipe (Max of
Groove and Weld)
Adapter
Spool Flange
Adapter
Spool Pipe
σY 50 52 50 52 50 52
All Calc All Calc All Calc All Calc All Calc All Calc
M 08 40 3298 416 2570 40 3958 416 8945 40 7835 416 4874
M+B 12 60 5997 624 3280 60 4056 624 1432 60 1321 624 2481
Total 2 100 7285 104 3075 100 4187 104 1575 100 2301 104 2880
Where
σY - Material Yield Strength at that locationAll - Allowable Stress
Calc - Calculated Stress
ASC - Allowable Stress Coefficient
M - Membrane Stress
M+B - Membrane + Bending Stress
- It may be noted that the stresses were extracted at all critical locations but 1 element away at
locations having discontinuities per guideline in API RP 2RD Section 5211
Appendix- A shows the stress images for each location in addition to linearized stress graphs
As seen in Table 4 and Table 5 the calculated stresses in Shaft Funnel and Adapter Spool are
lower than the allowable stress components
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
71
Fig14 and Fig15 shows the overall Funnel stress distribution for BSC in Normal and Abnormal
Conditions
Fig 14 Funnel - Overall von Mises Stress Distribution - Normal Condition (psi)(Window shown as Zoomed position)
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
72
Fig 15 Funnel - Overall von Mises Stress Distribution - Abnormal Condition (psi)(Window shown as Zoomed position)
Fig16 and Fig17 show the overall Adapter Spool stress distribution for BSC in Normal and
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
73
Abnormal Conditions
Fig 16 Adapter Spool - Overall von Mises Stress Distribution - Normal Condition (psi)
Fig 17 Adapter Spool - Overall von Mises Stress Distribution - Abnormal Condition (psi)Table 6 lists the reactions calculated in Ansys for each of the static cases on the Funnel flange
constrained face This gives out the load on I tube flange and it helps for cross checking the
match between applied loads and the reactions The table also lists the applied loads for
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
74
comparison Further calculation details are presented below
Table 6 Reaction Loads calculated from FEA
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
75
Load Case Normal Condition Abnormal Condition
Load Applied Reaction Applied Reaction
SF (kN) 774 7711 79 78698
BM (kN m) 429328 428619 436096 435274
Bending moment applied column has the effective bending moment ie directly applied plus
the bending moment generated by shear force
Reaction bending moment is not directly output for solid element type in AnsysThe forces
(parallel to BSC axis) were extracted along with the corresponding node locations with respect
to bending neutral axis This force and distance combination was used to find out reaction
bending moment for each node and then each of this calculated bending moment were added
together for all applicable nodes on the Funnel flange constrained location
92 FATIGUE ANALYSIS
Loads for fatigue analysis were obtained from Ref [4]The fatigue analysis was performed as
per DNV RP C 2032010 Code of Fatigue Design of Offshore Steel Structures The
corresponding curve and parameters are appended in Appendix C Input Shear Force ranges and
Bending Moment ranges were given at the BS inteface flange and the number of cycles per year
were given for the BSC
The initial fatigue spectrum resulted in higher than acceptable fatigue damages Then DTI
provided stress values in BSC at critical locations for unit load cases to Aker and Aker in turn
provided DTI with stress time series fatigue spectrum consisting of Stress range and
corresponding number of cycles per year Number of cycles were multiplied by 20 to get the
effective cycles for 20 years for corresponding stress delta
The fatigue analysis methodology for the BSC assembly is explained below FEA was
conducted on the assembly using unit loads (1kN-m for moment and 1kN for shear) to get the
maximum stress on each assembly Four separate load cases were analyses as listed below
Case 1 Shear = 1kN Moment = 0 kN-m (at worst orientation of BSC)
Case 2 Shear = 0kN Moment = 1 kN-m (at worst orientation of BSC)
Case 3 Shear = 1kN Moment = 0 kN-m (at 90deg to worst orientation of BSC)
Case 4 Shear = 0kN Moment = 1 kN-m (at 90deg to worst orientation of BSC)
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
76
The entire method of FEA for Fatigue is same as static cases including the boundary
conditions The only difference being the loads applied These four fatigue cases were solved as
load step 1 to 4 in Ansys solution At any given location absolute maximum stress was extracted
out of Case1 and Case 2 and the corresponding node reference was noted For all four cases the
component stresses and combined stresses were extracted at this node for the location in
consideration This was repeated for all critical locations in the assembly These extracted
stresses were used to determine the time series fatigue spectrum by Aker This data was used to
determine cycles to failure These cycles to failure were used to calculate damage ratio for each
time series point
Based on the geometry amp weld type various points on the Shaft and Funnel correspond to
various curves on the S-N Curve chart as per DNV RP C 2032010 Details of the stresses amp the
damage ratios calculation are included in Appendix B in Table 1 to Table 6 for different cases
Suitable S-N curves were chosen from the referred code for all locations (refer Table 7)Stresses
considered for each location fatigue calculation and corresponding calculated damage ratios are
presented in Table7 The equation 241 from section 24 of DNV RP C 2032010 was used for
predicted number of cycles (N) to failure for stress range Log(N) = Log(ā) - mLog(Δσ) where
Log(ā) is intercept of log N-axis by S-N curve m is the negative inverse slope of S-N curve
Δσ is the stress range
The calculated number of cycles was used for each sub case to determine damage for each sub
case (nN where n is the number of cycles corresponding to the considered shear force and
bending moment loads) The calculated damage for each sub case were added together to arrive
at total damage for one fatigue case for each considered point in the model
Damage ratio for all locations were calculated using combined loads (SF and BM) All critical
locations were considered in the assembly for fatigue calculations Fatigue case stresses are
listed in Appendix B and resulting damages are listed in Table 7 below Fatigue calculation
tables are appended in Annexure -1 of this report
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
77
Table 7 Fatigue case damage ratio using combined loads and time series approach
Sl No
SN Curve used
Calculated Damage Max DamageNominal 50 North 50 South
1 B1 000057 000090 000066 000090
2 F 00000023 00000040 00000028 00000040
3 B1 00000004 00000006 00000004 00000006
4 F 00000438 00000192 00000118 00000438
5 F 00016718 00023676 00014781 00023676
6 F 00000408 00000645 00000474 00000645
7 F3 00000017 00000028 00000020 00000028
8 F3 00015521 00025953 00015725 00025953
9 F 0000000058 0000000103 0000000063 0000000103
10 F 00002639 00004563 00002795 00004563
11 F3 00000033 00000058 00000035 00000058
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
78
93 DISCUSSION AND CONCLUSION
The BSC was analyzed in assembly configuration for in service conditions Contact elements in Ansys were used in FE modeling between Shaft and Funnel models to simulate realistic load transfer between two parts
In service conditions include Normal Abnormal Conditions and Fatigue loading cases Based on the FEA results for static and fatigue cases referring Table 4 and Table 5(for static cases) and Table 7 (for fatigue case) the calculated stresses are within allowable limits and hence safe for their intended usage for the considered loading scenarios
All the loads used in this design verification are the maximum possible loads in the intended application of the BSC over its lifetime as communicated by Aker
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
79
REFERENCE DRAWINGS amp DOCUMENTS
Ref Document No Description
Customer Documents
1 BSC Interface Details Required (first submission) BSC Interface Details
2 Max moment and Shear Tables Interface Loads for Gunflint
3 Engineering Specification BSC Noble Gunflint BSC Engineering Specification
4 Fatigue spectrum file Time Series Fatigue Spectrum
DTI Documents
5 D14043-00-001GA 26in BSC With Inverted Nut
Tray - Aker Gunflint
