Decom Segmentation Final

Decommissioning break down structure

November 2008

Design Alpha as P.O. Box 24, 5358 Fjell, Norway

T: +47 91716184 [email protected]

Contents 1. Introduction 2. Decommissioning market potential

2.1 Cost pie of a “typical offshore decommissioning project

3. Operators initial preparation

4. TIER ONE Break down 4.1 Platform Hot to Cold 4.2 Engineering 4.3 Offshore Activities 4.4 Removal and Marine Operation 4.5 Onshore Demolition

5. TIER TWO Break down 5.1 TIER TWO Platform hot to cold – breakdown

5.1.1 Platform closing down 5.1.2 Wells P&A work 5.1.3 Pipeline and subsea decommissioning 5.1.4 Hook down –method independent activities

5.2 TIER TWO Engineering – breakdown 5.2.1 FEED / Design Competition 5.2.2 Project Management / Project Control 5.2.3 Detail Engineering and Planning

5.3 TIER TWO Offshore Activities – breakdown 5.3.1 Safety access 5.3.2 Offshore construction 5.3.3 Riser/conductor cutting and lifting 5.3.4 NDT inspection 5.3.5 Weighing

5.4 TIER TWO Removal and Marine Operation – breakdown 5.4.1 Offshore marine operations 5.4.2 Inshore marine operations – load in

5.5 TIER TWO Onshore Demolition – breakdown 5.5.1 Onshore engineering 5.5.2 Onshore pre-demolition activities 5.5.3 Demolition work 5.5.4 Waste management

6. Appendix

6.1 TIER TWO – break down matrix


1 Introduction

This report was commissioned by Scottish Enterprise to break down the decommissioning market into smaller segments, to identify the qualifications and competence required for each segment. To review how the Scottish Supply Chain (being Tier 1 – Tier 2 or Tier 3) might identify its scope of work within the large and prosperous decommissioning market.

In the UK, there are approximately 470 offshore oil and gas installations. These are mainly located in the Northern, Central and Southern North Sea, as well as in the waters west of Shetland and in the Irish Sea. According to BERR the estimated decommissioning dates are seen in the table below:

Decommissioning is the process of physical removal and disposal of structures at the end of their working life. The process starts with a plan formulated by the operator, approved by the government and then implemented. The overall timescale for this is several years, as the program has to take into account many diverse factors. Several companies and organisations are involved in the total decommissioning chain over these several years.

In this study, we shall deal with the decommissioning activities that will be initiated by the operator after the decommissioning plans have been approved by the government. We shall divide the different activities into individual segments, and discuss what sort of technology, competence, tools and equipment that is required to execute each individual segment – on its own - or whether it has to be integrated into a larger work scope.


2 Decommissioning market potential

As with timing estimates, projections of the overall cost of decommissioning for the UKCS also vary widely; from around £10bn to £20bn. Oil & Gas UK’s own activity survey places the cost at just under £12 billion in real terms. The variables responsible for this range of estimates include:

• the inclusion/exclusion of wells and pipelines • the level of removal i.e. success in achieving derogations for installations

(and final status for pipelines) • cost estimation methods

2.1 Cost pie of a “typical” decommissioning project


3 Operators initial preparation prior to removal

The operator needs to develop numerous documents and produce background documentation before any approval will be given from the authorities for commencing the physical decommissioning work.

• Local and international regulations • Impact on the marine environment and other users of that environment • Re-use and re-cycling opportunities • Cost, safety and practical availability of technology

As a part of the cessation program – the operator needs to develop numerous documents and produce background documentation before any approval will be given from the authorities for commencing the physical decommissioning work.

• Descriptions of items to be decommissioned • Inventory of materials • Removal and disposal options • Wells documentation • Drill cuttings documentation • Environmental Impact Assessment • Party and stakeholders consultations • Cost and schedule • And many more…

Issues which also need to be considered by the operator include:

• Well killing, plugging, abandonment • Ageing and corroding to structures • Clean-up, preparation and removal of topside • Dealing with contaminants – LSA scale – special waste – • hazardous materials • Steel jacket removal options • Transport and infield flow lines • Marine vessel interactions • Adjacent field still producing • Clearance of all debris on the sea floor • And more…


4 TIER ONE – break down

The timescale of the physical removal program of a decommissioning project might vary from 1 year to 4-6 years or more – depending on complexity of the field, and the numbers of structures to be removed. An efficient decommissioning program is dependant on the specific characteristics of a particular facility, but some generalisations can be made.

The various phases below encompass the majority of the various activities – that might involve a TIER ONE Contractor. Production cessation is the starting point of the indicated chain of activities.

The operator might consider various contractual regimes – like a Lump Sum EPRD contract (Engineering – Preparation – Removal – Demolition) or divide the activity chain into separated contracts – to be awarded to suitable and capable contractors.

This study will divide the main phases into a lower level of activities/segments – and discuss the requirement of technology, competence – man power – tools and equipment that is required to execute each and individual segment.


4.1 Platform hot to cold

After the final decision of field cessation, the platform production and operation will be closed down – fully or partially. Hence, depending on the cessation plan, the platform will continue into a status of minimum operation, having only necessary safety and support systems in force. Or the platform will be made safe for an unmanned platform status.

The operating company is normally in charge of such operation, due to the fact that several platform and field operations might be run in parallel. An extensive engineering activity is performed - under supervision of the operating company - to define any interfacing with other producing fields, and to detail the platform “hot to cold” activities.

• Wells to be closed and plugged (P&A) • Pipelines to be decommissioned • Platform production systems to be closed down • Utility and Safety Systems to be closed or scaled down to support the

remaining platform activities • Maintenance activities to be planned and organized according to the

cessation program • Mapping of waste and preserving/cleaning/purging of platform equipment • Contractual preparation for Removal and Demolition of the structures

4.2 Engineering

The engineering phase might be initiated by awarding a decommissioning FEED (Front End Engineering Design) or a Design Competition to the TIER ONE contractors.

The Operator is selecting the competitive FEED contractors through a PQ (Pre Qualification) exercise. In the PQ documents, the Operator has normally prescribed its preferred contracting strategy. During the FEED / Design Competition phase - the various Contractors will develop their preferred Removal Method.

Based on the result from the FEED / Design Competition, the Operator will define its final contracting strategy, and thereafter award the contract (or contracts) accordingly. The contracts might vary from an integrated EPRD contract (Engineering – Preparation – Removal – Demolition) to a main Contractor, or divide the total scope among – to several contractors. This is the starting point of the major engineering activity within the decommissioning chain – starting 12-18 months prior to offshore construction. Required resources: 60-100 graduate multi-discipline engineering workforce. Including 70% with structural competence.


4.3 Offshore activities

The offshore construction phase is in its nature similar to executing a seasonal Shut Down operation. You will have the same requirement for skilled workforce and supervision – all pre-requisites to be in place – i.e. work packages – documentation -pre-fabrications – onshore support – tools and equipment – scaffolding – crane support – marine spread and further. The operating workforce is numbered and composed according to the selected removal method – to safety and emergency restrictions – to availability of bed spaces – to offshore duration - and to the efficiency factors.

Depending on the selected topside or jacket removal method, there will be important interfaces with the individual removal operator.

Estimates schedule for offshore construction duration:

• 2–6 months for topside Heavy lifting preparation. Thereafter the heavy lift operator – using their own lifting crew – takes over the lifting operation. The modules/structures will be lifted onto the deck area onboard the heavy lift vessel – for transportation directly to shore. Or the structure might be placed on flat top barges, to be towed to shore.

• 6–8 months for Piece small preparation, including offshore cutting and demolition by hydraulic shears into chargeable sizes - for onshore shipment in containers. (Offshore demolition capacity 600–800 tons per week.)

• 4–6 months for platform refloat operation. Thereafter the physical refloat will be operated from a dedicated Master control vessel and towed to shore.

• The jacket removal operation will be executed from dedicated marine vessels, with only minor assistance from the topside construction crew.

Required offshore resources: 100–300 multi-skilled operators on each rotation.


4.4 Removal and marine operations

As of today, the removal methods have been:

• Use of Heavy lift vessels – for removal of topside modules, jackets, loading buoys, flares, bridges and various sub sea installations.

• Use of Construction vessels for removal of 2-6 inch field pipelines, umbilicals, and various sub sea installations.

• Use of Construction vessels for pre-removal operations, like ROV inspection, saturated diving operations, sub sea cutting and dredging and other sub sea activities.

• Use of Construction vessels to support lift off operation of a gravity based steel platform structure, by use of buoyancy volume from platform sub sea storage tanks.

• Use of Construction vessels to support jacket lift off operation by use of BTA (Buoyancy Tank Assembly).

• Use of Caterpillar type hydraulic shears, for cutting and demolition of top side installations. The hydraulic shears will cut the topside structure into chargeable sizes for container shipment.

The above mentioned removal methods require its individual detail engineering and planning of marine spread. I.e. selection of various sized tugs, survey vessels, tanker vessel, logistic vessels, trawlers and flat top barges c/w grillage and sea fastening.

The offshore marine operation engineering – will detail the individual vessel operation and define interfacing procedures and bridging documents, where the ultimate responsibility - for each and individual marine activity - is clearly identified and acknowledged by the various parties and vessels.

The inshore marine activities depend on the harbour area and the quay side facilities. During the engineering phase, the offshore removal method including the onshore offloading will be defined having the access to the demolition yard in mind.

The cost of marine operations, amount to approximately 50% of the total decommissioning project cost.


4.5 Onshore demolition The onshore demolition site will have access to sea, offloading facilities and ample area for handling and demolition of structures, including warehouse and office facilities. The harbour area must be surrounded by sheltered waters, for various inshore marine activities. The quayside must be constructed to support skidding or trailing operations - from flat top barges.

The ideal site would have a deep water quay – having possibility to receive Heavy Lift Vessels for direct offloading to the quayside – area to facilitate any future decommissioning removal method – like topside transported by a Single Lift Vessel or sub sea foundation for grounding of jackets being removed by buoyancy tanks.

The open land area must have facilities for environmental protection from liquid spillage, area for scrap handling, waste segregation and storage, lifting/crane support and safe driveways for transport and logistic operations.

The area must be securely fenced in and protected from unwanted traffic and personnel movement. The Demolition site Operator – must comply with any licenses from local and governmental authorities, to execute onshore demolition work at the dedicated area, licenses for any sort of waste treatment, storage, handling and transporting, including scrap handling.


5 TIER TWO – break down

5.1 TIER TWO Platform hot to cold break down

5.1.1 Platform closing down

Activities might include:

• Closing down of production systems • Closing down utility systems and safety systems only for maintaining and

securing the planned and final operations and duties • Preservation – cleaning – purging of instruments, equipment, tools, skids,

vessels and piping systems • Waste mapping • Preparation for commencement of removal activities or preparing the top side

for a Normally Unmanned phase The close down and cleaning operation do not require any special decommissioning expertise or technology. An experienced offshore maintenance contractor having in house engineering, supervision, foremen and operators, is qualified to execute the offshore task.

Having in depth knowledge about the platform systems and the “as built” documentation. The oil and gas production systems will be closed down in sequence – system by system – or area by area.

Any vessels, tanks, pumps and pipe works shall be vented and pressure released before internal flushing and cleaning. Electrical equipment and batteries to be neutralized and released for any electrical energy. All areas to be inspected and mapped for hazardous materials and special waste.

Equipment like generators, turbines, cranes, pumps, motors, special skids and usable equipment to be preserved for possible future reuse.

Due to some special cleaning operations and removal of hazardous waste, there might be some assistance from high pressure cleaning equipment and operators - including authorized operators for handling of special waste – like Asbestos.


Deliverables

• Equipment for system cleaning including. removal of special waste, fluids and solids

• Scaffolding • Safety/emergency system planning • System decommissioning engineering • Waste management – mapping and removal • High pressure equipment and operation crew • Operators – riggers – fitters - mechanics – electricians - foremen –

supervisors – field engineers – safety officers • Rope access personnel (Abseilors)

5.1.2 Wells P&A work

The facility operator is required to obtain governmental consent to abandon any well. This entails the submission of a well abandonment program for governmental approval. The program will detail the procedures and equipment to be used in the shut-in, isolation and abandonment.

The process of P&A may include a time lag between cessation of production and completion of removal operations. In such cases the process plant may be decommissioned (made cold) but the installation maintained intact pending its subsequent removal.

Well plugging and abandonment work is normally executed by specialized service companies, having task specific tools /equipment and in-house operators. The sub sea well intervention is supported by fixed platforms or floating vessels. The selected Contractor has to deal with wellheads and casing in various structural conditions. Due to the P&A specialized operations and risk involved, the numbers of P&A contractors are few and also highly specialized. (This study will not cover any P&A work).


5.1.3 Pipeline and sub sea decommissioning

In the UK continental shelf there are 11.000(+) km of sub sea pipelines. Ranging from <6 inch to 40> inch. Some pipelines are buried – some are covered by mattresses etc. – some pipelines are lying uncovered on the seafloor. Standard procedures for decommissioning of any pipeline include cleaning and purging of all internals for hydrocarbons. This removes all the volatile liquids that might be hazardous to the marine environment.

This is a market for specialized contractors. i.e. contractors having in depth knowledge of pipeline cleaning - removal/disposal of wax and contamination – like mercury and LSA scale – using various pigging and flushing techniques.

Contractors will have access to tools and equipment for dredging and cutting of guideposts, piles and anchoring arrangements – including spooling of umbilicals / pilelines and lifting of the various sub sea installations to the surface for further onshore demolition.

Sub sea decommissioning calls for contractors having access to sub sea support vessels, ROV operations – including divers – and special knowledge of pipeline cleaning - both large transport pipelines – including removal and spooling of infield pipelines and umbilicals.

Deliverables

• Construction vessels and marine crew – lifting/cranage • Sub sea cutting tools – engineering and operators • Dredging equipment – engineering and operators • Pipeline pigging and cleaning tools incl. fluids for cleaning and preservation • Marine operation engineering • ROV operations – equipment and crew • Engineering for pipeline decommissioning • Disposal of contaminated waste – corrosion products – and fluids – waste

route • Structural and metallurgical engineering • Geotechnical experience


5.1.4 Hook down – method independent activities

At the tail end of Platform Close Down activities, the Operator might initiate a Method Independent Hook Down activity. The task includes engineering, planning and removal of closed down equipment, pipelines, cables and cable supports between modules and structures, without interfering with any possible steel supports or structural integrity for later heavy lifting. Such activity could be an extension of the close down activities using the same operating crew. Or the SOW could be given to the selected removal contractor as a pre start-up activity.

Deliverables

• Multi discipline engineering work force • Operators – riggers – fitters - mechanics – electricians - foremen –

supervisors – field engineers


5.2 TIER TWO Engineering break down

5.2.1 FEED / design competition

During a decommissioning FEED / Design Competition phase -the Removal Method will be developed. The Operating company selects the FEED contractor through a PQ (Pre Qualification) exercise. In the invitation documents to the PQ, the Operator has normally prescribed its preferred contracting strategy.

The selected FEED-contractor will seek to develop the most competitive, efficient, safe - and cost effective removal method by selecting the best tools for the job.

A FEED-contractor having ownership in Heavy Lift Vessels, will ultimately select a method where its HLV is the cornerstone.

A FEED-contractor having ownership in Single Lift Vessel, will ultimately select a method where the single lifter is the tool.

A FEED-contractor having ownership in any other removal tool, will select a method that strongly support such tools.

A FEED-contractor without any link or ownership to any removal tool, will develop its method - based upon its own experience, knowledge and competence – and they will introduce the most cost effective and method without being biased to any vessel or specialized tool.

As a part of the FEED study, the contractors will be given access to the structure for inspection, and to company provided documents and structural models. The structural models will be further developed by the contractors to safeguard the structural integrity throughout the selected methods.


Deliverables

• Experienced Project management • Multi discipline engineering task force • Removal tool – like heavy lift vessel – single lift vessel – other removal tools • Access to required marine spread • Access to sub sea competence • Access to onshore facilities • Established relationship with assisting specialized sub-contractors • FEED documentation and Execution Statement


5.2.2 Project Management / Project Control

The overall project team – and its organization form - is very much similar to an offshore installation project. Having its project management, staff and support functions, including the direct operating functions – clearly identified as line management and subsequent reporting lines.

The project organization reflects the contractual regime, defined by the operator. The contract regime might be an all inclusive EPRD (Engineering – Preparation – Removal – Demolition) contract where the Main Contractor is responsible for project execution and coordinating of the selected sub-contractors. Hence, the main Contractor accepts any interfacing risk between phases and subcontractors. As such the Main Contractor owns the schedule and the selected Method(s).

The project management for an EPRD contract requires extensive project management experience. Not only from execution of large offshore projects, but also extensive experience from decommissioning projects. Understanding the “cause and effect” within the decommissioning value chain. Taking the right decisions at the early stages, will heavily effect the final result – both technically and commercially.

The overall premises for efficiency, safety and cost, are very much defined in the FEED/Design Competition and in the Detail Engineering. A TIER 1 contractor will include key people from the selected sub-contractors (TIER 2 and 3) into the overall project team.

Segmented contracts call for their own experienced project management team.

Special attention should be made to Safety and Environmental issues, Change Management – Risk Management – Sub-contract management and Interfacing Management.

Deliverables

• Experienced project management crew • Project control systems • HSE management • Sub-contracting management • Establish support and logistic functions


5.2.3 Detail Engineering and planning

This is the major engineering activity within the decommissioning chain - starting 12–18 months prior to offshore construction. Information and documentation from the operator is the key to success. A survey of all available documentation relating to the offshore facility, design, modifications and maintenance records is the starting point. All such company provided documents and models will be studied in detail. All methodologies, project procedures and guidelines will be developed – all safety and preparatory work will be defined - pre-fabrication and construction drawings will be developed – work packages and detail planning will be developed and defined. All interfacing documents will be defined. Any sub-contracting assistance will be defined and awarded.

This engineering defines the removal method – the marine activities – efficiency of the offshore crew – and will ultimately govern the technical – safety – commercial and reputation success of the decommissioning program.

Each individual engineer will have to develop its own decommissioning experience path. Therefore, experiences from earlier decommissioning projects are most important to the individual engineer. An engineering workforce of 50–100 persons is required during detail engineering of a decommissioning project that consists of 1–5 platforms.

Deliverables

• Multi discipline engineering task force - 70% structural engineers • Marine engineering • Waste control and Demolition engineering • Individual engineering by the Sub-contractors


5.3 TIER TWO Offshore activities break down

5.3.1 Safety access

Before any offshore mobilization, the work place must be made safe. A crew of structural engineers, safety officers and abseilers (rope access personnel) is sent to the workplace to inspect all walkways, stairways, lay down areas and any safety – and emergency exits. Anything that requires strengthening, will be rectified or replaced. Safe areas will be defined, and areas for possible dropping objects will be clearly marked.

Deliverables

• Structural engineers – safety officers – rope access personnel – welders and mechanics

• Scaffolding • Steel strengthening support deliveries

5.3.2 Offshore construction

During the offshore construction phase – the operating workforce is numbered and composed according to – the selected method – safety and emergency restrictions – availability of bed spaces – facility access and man power efficiency. The offshore construction phase is very much identical to planning for a seasonal Shut Down operation.

Detailed plan – defined tasks – all prerequisites in place – streamlined and skilled operating crew ready for operation – defined duration.

The offshore crew will be introduced to various induction courses prior to offshore mobilization. Special attention is made to the safety and mental aspects entering a “dead” platform. No noise from operation – focus on structural wear and tear – focus on dropping objects – restricted areas – removal of pipe supports is different from installation – the platform physically disappears between each working period – and other topics.


The composition of an offshore decommissioning work force is somewhat similar to an offshore maintenance/construction type work crew, having offshore skilled operators including supervision, onshore support and required logistic support.

During construction, the platform facilities must remain operational with respect to essential services, like -

• Electrical power • Support systems for various tools and equipment • Fire and Safety equipment • Life support Systems • Living Quarters (Flotel)

If none of these support systems are available, temporary support systems must be supplied as an integrated part of the construction mobilisation.

The onshore support is primarily project management – personnel for crew change including logistics operations – like helicopters/supply vessels/pre-fabrication/supply of tools and equipments.

Deliverables

• Construction tools and equipment • Pre-fabricated items • Follow-on engineering support and documentation • Operators – riggers – fitters – mechanics – welders – crane operators –

electricians – foremen – supervisors – field engineers – safety officers • Scaffolding – equipment and operators • Logistics operators


5.3.3 Riser/conductor cutting and lifting

Such contracts are often awarded to a specialized cutting company capable of cutting and lifting conductors and risers in one operation. The contractor will normally execute its own structural engineering for the cutting and lifting operations, and hence supply its own tools and equipment - accompanied by its own crew. Deliverables

• Engineering • Specialized crew for cutting and lifting operations • Tools and equipment

5.3.4 NDT inspection

A non destructive testing of the facility is required to identify

• Evidence of corrosion or mechanical damages • Status of lift attachment points • Identify any discrepancies between the as-found condition of the structure

and the as-built information • Estimate the degree of corrosion loss in the material thickness of critical

elements A crew of authorized non-destructive testing personnel is required, having radiographic equipment and isotopes for inspection of cracks in welding seams and other structural materials.

Test results are normally defined and documented by onshore laboratories.

Deliverables

• Field engineers and operators • Testing equipment • Onshore laboratory and metallurgical engineering


5.3.5 Weighing

A weight audit will be conducted to identify the actual platform weight. Starting from the as-built to include items added during its lifetime, and liquid stored and their distribution within the facility. Prior to any heavy lift off – detail weighing operation might be executed to identify COG (Centre of Gravity). There are various computerized weighing equipment on the market.

Deliverables

• Operators • Weighing equipment and controls

5.4 TIER TWO Removal and marine operations break down

5.4.1 Offshore marine operations

The offshore marine activities follow as a direct consequence of the defined methods for removal of topside and jackets. The construction crew onboard the platform will interface with:

• Heavy Lifting operators that will operate its own equipment including its own dedicated crew onboard the heavy lift vessel.

• Piece small operator using its hydraulic shears. The shearing machines will be given adequate area for manoeuvring. The machines will be lifted on board the facility, and set in operation in designated areas.

• Buoyancy float off marine operators that will require special equipment and marine spread.

• Single lift operators - (Future operations?).


The marine activities require detailed marine engineering planning – interfacing procedures and bridging documents, where the ultimate responsibility - for each and individual marine activity - is clearly identified and acknowledged by the various parties and vessels.

The offshore marine activities also include:

• Tow and transport of the steel structures – topside and jackets. • Lifting and transport of piece small items in containers. • Sea floor inspection of towing route. • Grillage / sea fastening on flat top barges – engineering and construction. • Sub sea cutting – dredging and ROV inspection. • Trawling by the fishing industry for accepting a clean sea floor.

The offshore marine spread might include:

• Heavy Lift Vessel • Flat top barges • Tugs • Safety/stand by vessels • Supply vessels • Operation Master vessel • Construction vessel • Tanker • Survey vessel • Trawler vessel • Flotel/accommodation vessel

Deliverables

• Availability of vessels, flotel and transport barges – c/w dedicated crew • Availability of Hydraulic shears and operators • Marine engineering • Marine project management • Structural engineering • Grillage and sea fastening pre-fabrication • Welders and fitters • Survey documentation • Operation documentation




5.4.2 Inshore marine operations – load in

The inshore marine operations are executed in sheltered waters, and governed by the selected offshore decommissioning method - the transportation method - and the onshore receiving facilities. The water depth along the quay side is very often the limiting factor for the off-loading method.

The structures will be lifted, skidded or trailed over the quayside, and placed on a safe onshore foundation. Any grillage and sea fastening on barges will be removed or modified for the next transportation. If a Float Off and Tow method is selected, the facility will be safely moored in a sheltered position for further processing. The facility will be cut and lifted while in floating position. Shear leg lifting vessels might be used to lift off the facility in liftable sizes and transported to quayside.

Deliverables

• Pre laid mooring equipment • Mooring engineering • Trailing / skidding engineering • Trailing / skidding equipment and tools • Cranage vessels and equipment • Flat top construction barges c/w power supply and utilities • Burning and cutting tools • Welders and fitters • Support vessels

5.5 TIER TWO Onshore demolition break down

5.5.1 Onshore engineering

Before any structure is placed onto the quayside – or delivered to the demolition site - comprehensive engineering activity will be executed.

• The quay foundation and the grounding area must have the adequate supporting power to accept the tonnage of the received structures.

• Depending on the off-loading method, i.e. off-loading by crane, skidding or trailing or handling of scrap in containers - the set down area has to be planned and engineered in detail.

• The structure footing supports must be distributed and “made to measure” for safe and stable positioning. The structure supports might be sandbags, concrete supports - or steel grillage.

• Distribution of structures on the demolition area require mapping of safety routes, access for personnel and equipment, logistic consideration – with respect to handling of materials, cranage support, scrap segregation facilities, cutting area, shipment on road and by vessels.

Special attention has to be given to environmental protection. Equipment carrying potential liquid and fluid substances to be placed in its designated area – noisy and smelling operation to be executed in protected areas. Any structure related to oil processing to be located within the special drained area to have any possible oil spillage under full control.

Deliverables

• Civil engineering • Structural engineering • Demolition engineering • Site mapping


5.5.2 Onshore pre‐demolition activities

When received on site, all structures will be thoroughly inspected and made safe before any further demolition work. There shall be no potential harm to people from falling objects or unsafe walkways or stairways The structures will be mapped and stripped for any sort of hazardous waste, LSA scale and other non-hazardous industrial waste. Any waste will be identified, segregated and removed for further processing and handling.

When all hazardous waste and other non-hazardous waste are removed from the structure, a certificate “Ready for demolition” will be handed over to the Demolition contractor for further physical demolition work.

Deliverables

• An experienced demolition crew • Storage containers for segregated waste

5.5.3 Demolition work

The physical demolition work is to cut and reduce the structure into manageable sizes for shipment/transport for final destruction or reuse. The structure will be demolished by use of mechanical/hydraulic cutting equipment, gas burning, or cut by diamond wire or high pressure water.

The final scrapping material will be segregated and sorted by type and grade, before loaded onboard vessels or trucks for final reuse destination. Equipment identified for possible re-sale are removed, refurbished and re-documented.

An onshore demolition contractor might have the capacity to scrap 30.000–50.000 tons per year.

Deliverables

• Engineering • Demolition operators • Hydraulic shears • Cutting tools – diamond wire equipment – high pressure water jets – gas

cutting tools • Licensed to handle scrap materials


Demolition ‐ hydraulic shears in action

5.5.4 Waste management

The Waste Management contractor has to comply with all relevant rules and regulations from local and national authorities for waste handling, storage and transport – including complying with any Health and Safety Act for handling, storage and shipment of LSA scale.

The Waste management is to identify, collect, process and transport the waste until final destruction at the specialist destruction centre. The total waste management chain shall be closely monitored and documented. A final documentation “Environmental Account Report” will be forwarded to the operator, giving detailed information of any waste – handling – reuse or destruction.

Deliverables

• Licensed personnel to handle relevant special waste • Comply with all relevant local and national approvals and licenses for waste

handling, storage and transportation


6 Appendix

6.1 TIER TWO break down matrix

Activity Resources Tools /

Equipment Minimum Experience

Risks / Uncertainties

Closing down

• Multi

discipline engineering

• Offshore maintenance multi skilled crew

As for normal offshore maintenance operation

Offshore maintenance operations

• Hot work • Parallel offshore

activities • Exposure to

hazardous waste

Pipeline and sub sea decommis-sioning

• Specialist engineering

• Operating crew

• Construction

vessels • Pigging and

cleaning • Sub sea

cutting • Dredging • ROV • Waste and

liquid handling • Onshore

disposal facility

• Pipeline decommissioning

• Sub sea installation

• Sub sea cutting

• Pipeline condition • Hazardous waste

exposure • Access to pig

launcher/ receivers • Structural integrity of

sub sea installations • Lifting operations

Hook down – method independent activities

• Multi


• Operating crew

As for normal offshore maintenance operation

Offshore maintenance operations

• Safety mind set • Hazardous waste

exposure • Structural integrity • Innovative solutions





FEED / Design Competition

• Multi discipline engineering

• Project management

• Assistance from sub-contractors

Engineering house/facilities

• Decommissioning value chain

• Project management

• Decommissioning execution and method development

• Marine operations

• Sub sea cutting and removal

• Onshore demolition operations

• HSE & Q • Cost and planning • Efficiency • Interfacing • Structural integrity • Logistics • Documentation

Project Management

Experienced management team from large offshore projects

• Project control system

• HSE & Q management

• Sub-contracting management

• Onshore support and logistic functions

Decommissioning project management

• HSE & Q • Schedule - progress

efficiency • Cost control • Change management • Interfacing • Coordination • Reporting

Detail Engineering

• Multi


• Planning • HSE & Q • Cost –

contract • Logistic • Sub-

contracting assistance

• Marine engineering

• Onshore demolition

• Engineering house / facilities

• Decommissioning

projects • Project

management • Decommissioning

execution and method development

• Offshore construction


• Sub sea cutting and removal

• Onshore demolition operations

• Waste management

• HSE & Q • Cost and planning • Efficiency • Interfacing • Structural integrity • Logistics • Documentation • Vessel availability • Resources - manning





Safety access

• Structural

engineers • Safety

officers • Climbers • Construction

personnel

• Pre-fabrications • Scaffolding • Construction

tools

Offshore construction

• Access to structure • Documentation • Safety • Structural integrity


• Field engineers

• Offshore construction crew

• Supervision • Logistics • Onshore

support

• Construction

tools • Cranes • Accommodation • Utility systems

Power supply • Life support

systems • Safety systems • Pre-fabrications • Documentation • Safety induction

courses • Procedures


• Work planning • Access • Exposure to

hazardous waste / liquid / fumes

• Mind set and cultures • Interfacing • Change management • Resources • Parallel activities

Riser / Conductor cutting and lifting

• Engineering • Operating

crew

• Cutting equipment

• Lifting equipment

Similar operations

• Access • Lifting and handling • Structural integrity • Interfacing

NDT Operating crew

• Ultrasonic –

radiographic testing

• Isotopes • Laboratory

testing • Documentation

Similar operations

• Access • Safety • Reporting

Weighing Operating crew

• Weighing cells • Weighing

control • Documentation

Similar operations

• Access • Interfacing • Reporting





Removal method

• Detailed

method engineering

• Operating crew • Construction

crew • Pre-

fabrications • Removal

method management

• Heavy lifting

vessel • Lifting spread • Marine spread • Hydraulic

shears • Containers • Topside cranes • Power supply • Buoyancy Tank

Assembly • Documentation • Procedures • Accommodation

Similar operations

• Access • Interfacing • Schedule • Availability • Lifting operations • Weather conditions • Structural integrity • Lay down area • Efficiency

Offshore marine operations

• Marine

operation engineering

• Marine crew • Construction

crew • Marine project

management

• Marine spread • Flat top barges • Sea fastening • Grillage • Accommodation • Procedures

Marine operations

• Interfacing • Parallel activities • Vessel availability • Transportation • Tow • Weather condition • Sub bottom survey

Inshore marine operations – load in

• Marine

operations engineering

• Mooring engineering

• Structural engineering

• Construction crew

• Trailing operators

• Skidding operators

• Ballasting crew • Onshore cranes • Governmental

and local approvals

• Inshore lifting barges

• Marine spread • Construction

barges • Cutting tools • Trailing

transportation • Skidding /

pulling • Procedures


• Steel cutting • Sub sea

cutting • Mooring • Trailing

operations • Skidding

operations • Ballasting

operations

• Environmental control • Structural integrity • Weather condition • Access • Working in heights





Onshore engineering

• Civil

engineering • Structural

engineering • Demolition

engineering

• Demolition area • Quay facilities • Pollution control • Documentation

Similar activities

• Soil and ground conditions

• Structural stability

Onshore pre-demolition

• Demolition crew • Authorised

special waste handling personnel

• Construction

tools • Containers for

waste segregation

• Waste mapping documentation

• Cleaning documentation

• Special waste removal habitat

Similar activities

• In trapped and hidden hazardous materials

• Exposure to hazardous fumes – liquids – LSA scale

Demolition work

• Engineering • Hydraulic shear

operators • Construction

crew • Authorisations

• Hydraulic

shears • Steel cutting

facilities • Steel

segregation and handling

• Concrete handling

• Work packages • Protected area

• Hydraulic shear operation

• Scrap handling

• Access • Structural integrity • Uncontrolled energy

release • Noise

Waste management

• Fully licensed operator

• Authorised personnel

• Storage and

segregation facilities

• Transportation equipment

• Documentation

Handling and authorisation of special waste

Non compliances


Documents

Decom Segmentation Final