PIPELINE DESIGN PREMISE REPORT - LOTOS

PIPELINE DESIGN PREMISE REPORT

Z12/112996-ENG-RPT-00001 Rev 02 02.08.2016 Page 1 of 19


Z12/112996-ENG-RPT-00001. Rev 02 Client: LOTOS PETROBALTIC S.A. Project Number: Z12/112996 Project Name: B8 GAS PIPELINE INSTALLATION ENGINEERING

Date Revision Description of Revision Prepared Checked Approved

02.08.2016 02 Issued for Construction M. Bowie G. Cowie A. Cowie

Sheet 1 of 2

DOCUMENT COMMENT SHEET

CLIENT: Lotos Petrobaltic PROJECT : B8 Gas Pipeline Installation

Engineering Date : 13.06.2016

Comments : The response to : Installation Engineering Report Document

Document Type : Report

Document No.: Z12/112996-ENG-PT-00001 Revision : 00 Date : 10.06.2016

Document Title : Pipeline Design Premise Report

Received by : A. Wojcikowski Date : 13.06.2016 Transmittal No. CSL-OPS-P422-DTN-002

Item Reference Comment Comment By

Contractor’s Response

1. Section 1.1 General

Amend first sentence wording from Petro-Baltic to PetroBaltic

M. Maciejewski

(21.06.2016)

Noted and amended accordingly

2. Section 2.3 Coating Specification

The coating shall be removed local to the Zap-Lok™ joint and protective sleeve applied (TBC). Investor confirmed that protective sleeve shall be used.

A. Wojcikowski (20.06.2016)

Noted and remove TBC reference

3. Section 3.1 Process Conditions

Change flowrate in table from 4122m³/hr to range 2000-9000 kg/hr

A. Wojcikowski

(20.06.2016)

Noted and will amend accordingly

4. Section 4.1 General Description

In second sentence replace the word “separation” for “compression”

A. Wojcikowski

(20.06.2016)


5. Section 4.2 Pipeline Route

The third sentence reads “The alignment charts for the route are as follows (HOLD).” Why is on hold status? Does LPB need to provide these charts or are they in preparation by Contractor

A. Wojcikowski

(20.06.2016)

The contractor is not contracted to produce these charts and therefore shall require these from LPB. Sentence will be amended to reflect LPB responsibility for aligment charts and that the charts will need survey data along the route and detail of the survey parameters.


The fourth sentence reads “The minimum lay radius along the route is (TBC).” In our opinion minimum radius along the route should be prepared by Contractor as part of documentation

A. Wojcikowski

(20.06.2016)

The minimum lay radius can be estimated as part of the installation analysis. The radius was TBC due to there being radii on the pipeline route, which are not known.

7. Section 4.4 Pipeline Connections

The second sentence reads “ The flange connection shall be a 4” ANSI 1500#RTJ (TBC).” On the platform side flange connection is as follows; 5-1/8” x 10K API 6A and onshore side is as written in particular document

A. Wojcikowski

(20.06.2016)

Noted and shall amend sentence to suggested wording. Reference to be made to correct document for onshore connection detail.

Sheet 2 of 2

Item Reference Comment Comment By

Contractor’s Response

8. Section 5.0 Metocean Data

Replace the fourth sentence with the following When HDD will reach end point of borehole, it will be 1.3 – 1.4km from shore, vertical depth of hole below the beach is approximately 20 metres below ground level.

A. Wojcikowski

(20.06.2016)


9. Section 5.1 Seawater Properties

LPB provided Environmental Conditions Data Sheet to allow hold points in table to be completed

M. Maciejewski

(21.06.2016)

Noted and will amend table accordingly

10. Section 5.4 Current Profile

The third sentence reads “There are no details on the current in near shore sections.” LPB is in process of acquiring required data from Maritime Authority

A. Wojcikowski

(20.06.2016)

Noted and will amend sentence to indicate once data available LPB will issue.

11. Section 6.0 Geotechnical Data

LPB have provide “Geotechnical” and Geotechnical attachments” document (in Polish) as further references for this section.

M. Maciejewski

(21.06.2016)

Noted and will update section reference to the document.

12. Section 7.2 Pipeline Pinning

The second sentence in third paragraph reads “In addition the mattresses will also have to be checked to ensure they do not sink into softer soils potentially damaging the pipeline.” LPB previously informed Contractor that concrete mattresses are not planned for installation in softer rocks areas.

A. Wojcikowski

(20.06.2016)

Noted and paragraph shall be amended to reflect accordingly

13. Section 7.3 Ploughing

Section reads “Ploughing of the pipeline will need to consider the stability of the plough in the very soft soils and the potential rapid backfill of material. Areas of hard soil need to be determine to allow the plough to transition out of the trench without creating excessive free spans.” LPB has planned that in those specially dedicated areas concrete mattresses are designed to be used. LPB are not planning any ploughing or trenching

A. Wojcikowski

(20.06.2016)

Noted and paragraph shall be amended to reflect accordingly.

Section 7.4 Trenching shall also be amended to reflect same detail


LPB has issued examples of Pipeline Route Alignment Charts for B8 pipeline fro Contractor to review and reference within this section.

M. Maciejewski

(29.07.2016)

Updated section with reference to example Pipeline Alignment Charts to ensure appropriate data incorporated.



REVISION RECORD SHEET

Date Revision Status Reason for Change(s)

02.08.2016 02 IFC Issued for Construction

01.07.2016 01 IFA Issued for Approval

10.06.2016 00 IFK Issued for Review

TABLE OF CONTENTS

1.0 INTRODUCTION ........................................................................................................................... 3 1.1 General .................................................................................................................................................. 3 1.2 Objective ................................................................................................................................................ 3 1.3 Key Coordinates ..................................................................................................................................... 3 1.4 Abbreviations & Nomenclatures ........................................................................................................... 4 1.5 References ............................................................................................................................................. 4

2.0 PIPELINE AND ZAP-LOK™ CHARACTERISTICS. .............................................................................. 5 2.1 Pipeline Specification............................................................................................................................. 5 2.2 Zap-Lok™ Connection Specification ....................................................................................................... 5 2.3 Coating Specification ............................................................................................................................. 6 2.4 Cathodic Protection ............................................................................................................................... 6

3.0 PROCESS DATA ............................................................................................................................ 7 3.1 Process Conditions. ............................................................................................................................... 7

4.0 PIPELINE SYSTEM & ROUTING ..................................................................................................... 8 4.1 General Description ............................................................................................................................... 8 4.2 Pipeline Route ....................................................................................................................................... 8 4.3 Platform Layout / Target Box................................................................................................................. 8 4.4 Pipeline Connections. ............................................................................................................................ 8 4.5 Pipeline Crossings .................................................................................................................................. 8

5.0 METOCEAN DATA ........................................................................................................................ 9 5.1 Seawater Properties .............................................................................................................................. 9 5.2 Water Depths ........................................................................................................................................ 9 5.3 Tidal Range and Surge ........................................................................................................................... 9 5.4 Current Profiles ...................................................................................................................................... 9 5.5 Wave Data ........................................................................................................................................... 13 5.6 Wind Data ............................................................................................................................................ 14 5.7 Marine Growth .................................................................................................................................... 14

6.0 GEOTECHNICAL DATA ................................................................................................................ 15 7.0 PROTECTION AND STABILISATION PHILOSOPHY ....................................................................... 16

7.1 Pipeline Sinkage ................................................................................................................................... 16 7.2 Pipeline Pinning ................................................................................................................................... 16

APPENDIX A – PROPOSED PIPELINE ROUTE .......................................................................................... 17



1.0 INTRODUCTION

1.1 General

Lotos Petrobaltic are planning an offshore gas pipeline which will connect a production platform located on the B8 field to a combined heat and power plant (CHP) situated onshore in Wladyslawowo. Prior to being transported in the pipeline the natural gas will be separated from the crude on the production platform. The platform is located in the Poland exclusive economic zone (EEZ) in the Baltic Sea. The B8 field spans an area of 387.1sqare km which was defined in the Concession No. 1/2006 on 5th September 2006 and amended by the Minister for the Environment No. DGiKGe-4770-69/4579/09/MO on 26 October 2009.

1.2 Objective

The objective of this document is to collate together all the relevant data which may be used for the design of the offshore section of the pipeline system.

1.3 Key Coordinates

The coordinate for the production platform are 55°E 24.0’ N, 18° 43.3’E (WGS 84’). The waypoint for the pipeline are as follows

Point Easting Northing

A 55° 24' 0.41" 18° 43' 20.1"

B 55° 23' 55.97" 18° 44' 10.78"

C 55° 23' 47.97" 18° 44' 52.86"

D 55° 23' 35.43" 18° 45' 28.24"

E 55° 23' 18.24" 18° 47' 47.4"

F 55° 22' 47.98" 18° 46' 3.40"

G 55° 21' 44.34" 18° 45' 59.17"

G' 54° 58' 55.17" 18° 33' 41.12"

H 54° 48' 27.60" 18° 28' 7.69"

I 54° 48' 12.37" 18° 27' 56.84"

J 54° 47' 59.34" 18° 27' 43.74"

K 54° 47' 41.14" 18° 27' 22.38"

L 54° 47' 32.19" 18° 27' 9.53"

M 54° 47' 26.4" 18° 26' 52.74"

N 54° 47' 24.18" 18° 26' 27.90"

GPOG 54° 47' 27.68" 18° 25' 36.90"



1.4 Abbreviations & Nomenclatures

1.4.1 Abbreviations

Abbreviation Description

3LPP 3 Layer Pipeline Protection

API American Petroleum Institute

HDD Horizontal directional Drilled

HDPE High Density Polyurethane

Hmax Maximum Wave Height

Hs Significant Wave Height

km Kilo-metre

kN Kilo-Newton

KP Kilometre Point

MPa Mega-Pascal (1,000,000Pa)

OD Outside Diameter

SMHI Swedish Meteorological and Hydrological Institute

T Wave Period

TBC To Be Confirmed

1.5 References

1.5.1 Industry Guidelines

Description

1. API 5L, “Specification for Line Pipe”

2. ASME B16.5, “Pipe Flange and Flanged Fittings”

3. DNV-RP-F105 “Free spanning Pipelines”, February 2006.

4. DNV-RP-F102 “Pipeline Field Joint coating and Field repair of Linepipe Coating”, May 2011.

5. DNV-RP-F101 “Corroded Pipelines”, January 2015.

6. DNV-RP-F107 “risk Assessment of Pipeline Protection”, October 2010.

7. DNV-RP-F109 “On-Bottom Stability Design of Submarine Pipelines”, October 2010.

8. DNV-RP-F111 “Interference between Trawl Gear and Pipelines”, September 2014.

9. DNV-OS-F101 “Submarine Pipeline Systems”, October 2013.

1.5.2 Project Documents and Drawings

Description

10. “Preliminary Geotechnical Analysis”, Geostab Ltd, July 2014.

11. “Calculation of Pipeline”, DP00315-OWR, Rev 0, 27.05.2015, Urbanowicz.

12. “Wind and Wave Statistics in the Southern Baltic Sea”, 2008/559/204, Version 1.1 SMHI

13. “Pipeline Route Alignment Charts examples.compressed” Issued by LPB 29th July 2016



2.0 PIPELINE AND ZAP-LOK™ CHARACTERISTICS.

2.1 Pipeline Specification

The pipeline has the following specification.

Characteristic Value

Material API X65C

Steel density 7850kg/m3

Nominal outside diameter 114.3mm

Wall thickness 6.35mm

Nominal inner diameter 101.6mm

Design pressure 144.6bar

Maximum working pressure (MAOP) 342.0bar

Yield Strength 448MPa

Ultimate Tensile Strength 531MPa

Coating thickness 5.7mm

Coating average density 960kg/m3

Weight in air 19.0kg/m

Weight in seawater (empty) 6.25kg/m

Weight in seawater (operational) 9.44kg/m

Weight in seawater (filled with seawater) 14.56kg/m

SG in seawater (empty) 1.49

SG in seawater (operational) 1.74

SG in seawater (filled with seawater) 2.14

Bend radius limit (elastic limit) Approximately 27m

2.2 Zap-Lok™ Connection Specification

The Zap-Lok™ joint is a widely used mechanical interference connection for pipeline use. The joint has pressure, mechanical and fatigue strength suitable for the same service as welded joints, but the cost of making and inspecting Zap-Lok™ joints is lower and installation rates are faster. The Zap-Lok™ process works on the basis of pre-forming a bell (female), or expanded area, which is formed on one end of a pipe joint, and a pin (male) which is formed on the opposite end, Figure 1. This part of the process can occur at various locations i.e. a Zap-Lok™ facility, pipe mill, or coating plant. These end preparations are automatically controlled to specifications required for the Zap-Lok™ joint. In the field, Zap-Lok™ field equipment is used to push together the bell end of one pipe joint and pin end of another to form a metal-to-metal seal face. A specialised company specific Epoxy, known as Zapoxy, is applied to each end to lubricate the joint during the pressing process as well as providing a smooth bore and secondary seal.

Once the Zapoxy cures, the result is a metal-to-metal interference fit, with the connection made up of the pipe itself, as can be envisaged by observation of the diagram below.



Figure 1 - Zap-Lok™ Joint The Zap-Lok™ process produces strong, permanent joints which can be used in the same pressure service as welded lines. This allows the pipeline system design to be based on a joint strength of 100%. Extensive independent evaluations under varied laboratory test conditions and in-service performance records have proven the Zap-Lok™ joint to be strong, reliable and leak proof. There have been no reported in-service failures over its entire 40-year history. The Zap-Lok™ method can be used to join relatively thin wall pipe, down to Schedule 20, which cannot be easily welded. Additionally, the Zap-Lok™ joint can carry corrosive fluid without the vulnerability of threaded couplings, or damaged internal coating resulting from the high temperatures produced for a welded joint. The ends of the coiled tubing on one side shall be opened outwards to form a ‘bell’ end with the inside diameter of the bell slightly less than the nominal outside diameter of the pipeline. The other ‘pin’ end will be forced into the bell to form a swaged connection. The insertion depth of the pin will be 150mm. Subject to the optimal installation philosophy the connection between each end of the coiled tubing may be via a ‘pup-piece’ which will act as the temporary abandonment head. The pup-piece, if used, will be the pin end for the connection to the coil tubing and thus negate the requirement for coating removal from the pin end.

2.3 Coating Specification

The pipeline coating is a three-layer (3LPP) system, consisting of;

Fusion bonded epoxy primer applied to a prepared steel surface

Adhesive copolymer tie layer

Extruded polyolefin top-coat (high density polyethylene) The coating shall be removed local to the Zap-Lok™ joint and protective sleeve applied.

2.4 Cathodic Protection

No anodes shall be attached to the pipeline, due to the high risk of anodes being damaging during installation and thus unacceptable risk of localised corrosion to the pipeline. Corrosion protection shall be provided from the platform end of the pipeline.



3.0 PROCESS DATA

3.1 Process Conditions.

The pipeline will be used to transport natural gas under the following conditions. Data is taken from the Pipeline Calculations report [2].

Characteristic Value

Fluids Condensate natural gas

Fluid density (@ design pressure) 394kg/m3

Design pressure 144.6bar

Inlet pressure 135bar

Outlet pressure 130bar

Inlet temperature (platform) 41°C

Outlet temperature (CHP) 4°C or seawater ambient

Flowrate 2000 – 9000kg/hr



4.0 PIPELINE SYSTEM & ROUTING

4.1 General Description

The pipeline layout will vary along the route from the production platform, through offshore section and to the onshore section. The total pipeline length is 74.8km. The pipeline will begin with a dynamic flexible riser at the production platform connecting the gas compression system to the main rigid pipeline. Located on the seabed in the vicinity of the platform. The rigid pipeline (offshore to coastal zone) will be laid on the seabed and protected (reference protection and stabilisation philosophy section). The connection between the onshore and coastal offshore zone will be via a horizontal directionally drilled conduit (HDD) which will exit the seabed at a depth of circa 9m.

4.2 Pipeline Route

With reference to Appendix A, the pipeline route starts at the HDD exit in approximately 9m water depth and heads in an Easterly direction in the coastal region. The majority of the route is in a North-Easterly direction, until the platform zone where the pipeline deviates to the West. The alignment charts for the route shall be responsibility of Lotos Petrobaltic to provide to installation contractor. These charts should include survey data along the route and detail of the survey parameters. Reference alignment charts [13]. The minimum lay radius along the route is 500m for the offshore section. Lay radii for the nearshore section are to be avoided.

4.3 Platform Layout / Target Box

The arrangement at the platform and target box will be confirmed by Lotos Petrobaltic during further detailed installation engineering.

4.4 Pipeline Connections.

All offshore connections between the coil tubing sections shall be via the Zap-Lok™ connection. The connection between the rigid pipeline and the flexible riser shall be via a flange connection. The flange connection shall be a 5 1/8” API 6A 10000#.

4.5 Pipeline Crossings

There are no pipeline crossings



5.0 METOCEAN DATA The environmental data to be used for the detailed design and installation works are summarised in the following sections. The statistics are available for the following 2 locations; Point 1 55° 24.0’ N 18° 43.3’ E Point 2 55° 49.0’ N 18° 42.8’ E The locations relate to points approximately 70km and 115km North of Wladyslawowo in the deeper water locations. When the HDD reaches the end point of the borehole, it will be 1.3 – 1.4km from the shore. The depth of the borehole exit below the beach is approximately 20 metres below ground level.

5.1 Seawater Properties

The Baltic Sea is generally less saline that the open ocean; however significant gradients are present. For the purposes of design, the density of seawater shall be taken as 1025kg/m3. The range of water temperatures are as follows.

Characteristic Min Max

Sea surface temperature 1°C 18°C

Seabed ambient temperature 3°C 6°C

5.2 Water Depths

The water depth varies along the route from 9m at the HDD exit to a maximum of 90m. The water depth at the platform is approximately 85m.

5.3 Tidal Range and Surge

No information on tidal ranges or surge is available.

5.4 Current Profiles

The current profiles and direction are summarised below. Further details can be found in the SMHI report [3]. There are no details on the current in the near shore sections at the time of writing this report. Lotos Petrobaltic in process of acquiring required data from Polish Maritime Authority and will make available in due course.



Depth Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

4 17.50 13.43 12.36 11.57 12.21 15.25 18.50 16.97 18.92 15.82 16.59 16.38

8 10.73 9.18 8.99 8.01 9.96 13.30 15.70 13.79 15.95 12.62 12.65 9.60

12 9.29 8.81 8.50 7.14 9.39 12.26 13.70 13.18 15.50 12.05 12.02 8.15

18 8.81 8.86 8.43 6.75 8.73 10.52 12.75 12.62 15.07 11.83 11.84 7.65

24 8.59 8.92 8.45 6.49 8.10 6.77 11.18 9.98 12.29 11.70 11.75 7.44

30 8.48 8.99 8.39 6.04 7.63 9.13 9.23 9.55 10.97 10.10 11.64 7.31

40 8.48 9.24 7.92 5.08 5.59 7.89 9.05 9.89 8.95 9.16 11.23 7.43

50 8.46 8.80 9.14 6.33 7.08 6.97 10.09 10.64 9.10 11.19 7.78 6.66

60 10.02 10.93 8.61 6.63 8.02 7.44 9.22 9.76 9.85 11.32 17.54 9.31

75 12.43 13.82 10.54 6.93 7.96 7.02 9.48 10.77 12.43 10.51 16.96 11.30

90 7.31 7.39 6.43 4.66 4.22 4.76 4.28 5.46 5.76 5.19 6.37 6.05

Table 1 - Mean current velocity at Point 1 (cm/s)


4 105 107 83 137 128 80 117 73 139 113 120 116

8 114 129 84 150 166 71 159 50 158 136 135 134

12 119 135 80 154 172 67 105 37 165 146 144 144

18 123 140 72 154 171 47 14 23 174 153 150 151

24 126 145 57 153 167 26 161 22 169 156 157 157

30 131 150 47 153 178 13 169 26 158 90 166 162

40 138 161 37 132 150 17 6 29 144 46 27 158

50 105 170 37 104 36 18 6 28 149 32 63 93

60 85 161 36 86 31 23 17 29 154 33 66 105

75 108 170 59 85 43 33 29 38 168 46 83 151

90 158 162 174 90 74 47 33 74 178 50 163 174

Table 2 - Direction of mean current at Point 1 (East is 90°)


4 86.24 56.11 75.09 57.85 46.84 77.21 63.39 52.01 71.91 90.57 69.99 60.06

8 52.54 39.59 45.06 33.76 30.29 55.23 61.15 40.56 55.91 57.68 38.62 32.48

12 40.48 35.23 34.97 26 25.15 47.52 41.1 38.06 50.92 47.22 33.37 24.01

18 33.54 33.33 29.54 21.47 23.3 40.04 38.29 33.35 44.8 41.55 31.6 23.29

24 28.77 32.9 28.49 17.65 22.63 31.83 33.65 28.57 35.49 36.58 31.48 23.38

30 25.32 32.83 27.93 15.87 21.09 30.19 25.56 25.78 25.97 28.42 30.85 23.26

40 25.83 32.35 29.36 14.96 16.99 35.48 22.13 22.84 19.19 32.11 31.64 23.37

50 31.08 28.99 35.26 23 24.1 29.66 25.63 24.84 23.94 42.05 23.98 20.4

60 41.99 39.34 34.03 25.04 24.4 27.93 22.44 23.01 27.82 44.55 39.96 27.37

75 61.8 48.49 41.89 24.6 21.9 28.5 20.09 24.74 28.41 43.39 38.17 30.65

90 27.24 21.91 21.31 22.92 12.46 18.39 12.93 14.22 14.82 21.79 18.6 17.39

Table 3 - Maximum current velocity at Point 1 (cm/s)




4 101 51 75 82 111 104 93 147 156 98 173 134

8 104 77 83 114 130 118 115 29 172 112 38 146

12 105 89 87 123 139 124 119 35 178 119 48 127

18 105 96 89 130 25 129 124 45 4 124 76 162

24 105 154 73 135 7 94 131 95 132 129 81 165

30 104 161 60 1 31 7 22 37 31 135 86 168

40 14 39 19 7 157 156 174 39 8 116 10 36

50 15 26 11 1 59 163 38 169 15 156 6 48

60 20 171 0 18 25 26 51 24 10 170 36 25

75 18 179 6 9 18 21 178 25 18 179 3 35

90 151 163 138 162 169 156 178 176 162 152 156 152

Table 4 - Direction of maximum current at Point 1 (East is 90°)


4 16.96 14.03 13.5 11.37 11.86 16.77 20.49 17.8 19.85 16.65 15.29 16.28

8 10.24 9.02 9.41 8.82 9.43 14.26 16.06 14.33 17.78 13.85 11.43 9.38

12 8.83 8.24 8.57 8.3 8.73 13.02 13.69 12.75 17.47 13.37 10.81 7.91

18 8.36 8.11 8.2 7.96 7.88 11.27 12.69 11 16.23 13.13 10.59 7.41

24 8.13 8.05 7.89 7.45 7.56 7.31 9.27 8.85 10.91 11.76 10.41 7.16

30 7.97 7.95 7.53 6.61 6.95 7.55 8.12 7.73 10.57 8.4 10.23 6.93

40 7.77 8 6.83 5.54 5.56 6.91 8.9 9.08 8.58 8.14 9.53 6.61

50 7.62 6.77 6.59 6.79 6.25 6.02 7.67 7.86 7.72 11.74 6.97 5.36

60 9.09 10.48 7.89 6.54 7.84 5.96 6.15 5.15 5.52 10.7 13.25 9.15

75 7.69 9.83 8.13 5.84 6.46 4.86 4.77 4.65 5.52 6.31 12.67 6.4

90 7.22 7.12 6.85 5.24 4.55 4.52 4.38 5.22 4.48 4.37 8.17 6.22

Table 5 - Mean current velocity at Point 2 (cm/s)


4 114 38 163 7 169 148 143 84 124 114 142 109

8 133 173 3 42 24 169 26 157 150 145 167 123

12 145 172 12 54 33 178 25 158 164 160 1 131

18 156 174 19 63 37 5 41 128 167 180 11 138

24 166 178 24 71 33 13 64 152 115 22 20 146

30 177 2 31 84 34 4 87 155 108 76 32 154

40 20 3 42 105 42 168 84 149 142 105 60 173

50 61 11 33 129 52 131 79 159 155 111 171 97

60 160 8 57 152 107 92 1 8 147 125 91 85

75 37 175 52 173 170 45 36 27 126 65 47 91

90 50 67 52 2 6 39 32 30 110 93 55 106

Table 6 - Direction of mean current at Point 2 (East is 90°)




4 80.9 54.78 76.9 60.94 45.45 73.27 75.39 69.86 80.15 104.38 76.35 59.9

8 49.32 39.25 48.79 38.07 29.43 51.88 73.6 55.56 68.12 71.16 43.13 33.27

12 38.12 36.42 39.86 32.19 23.59 46.58 37.88 49.91 62.82 60.71 35.1 25.72

18 33.62 35.02 35.79 29.01 22.44 43.59 35.14 34.94 56.13 54.63 33.14 24.93

24 32.32 33.06 34.51 24.95 21.35 38.59 30.52 21.27 25.78 48.19 32.46 24.82

30 30.3 30.25 32.75 23.37 19.98 27.94 23.86 25.12 24.69 36.71 32.19 24.38

40 26.35 28.04 31.42 22.41 16.73 19.33 21.38 21.1 20.29 32.47 34.61 25.18

50 34.09 25.57 25.82 20.61 19.1 18.08 18.93 18.46 20.19 34.97 28.91 17.06

60 32.82 36.27 31.49 23.01 22.65 15.48 13.28 16.28 17.35 31.18 36.43 26.36

75 41.08 33.61 32.23 27.3 17.53 15.36 14.13 16.23 20.47 23.76 35.7 22.1

90 35.67 30.14 29.01 20.92 14.47 16.07 15.4 15.97 18.36 23.58 25.84 20.38

Maximum current velocity at Point 2 (cm/s) Depth Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

4 110 53 88 78 100 77 89 167 138 102 83 93

8 117 76 104 85 71 93 97 148 17 116 94 124

12 120 122 113 95 94 177 107 146 22 123 61 89

18 41 124 159 97 21 54 113 135 89 128 67 49

24 45 126 167 39 27 155 120 153 141 134 118 56

30 51 104 175 41 31 36 19 17 7 177 121 63

40 65 178 63 93 165 151 176 69 36 115 2 114

50 46 24 168 117 43 140 43 97 180 2 32 7

60 23 25 5 162 20 135 173 5 5 7 29 2

75 15 178 176 163 21 157 31 5 5 36 44 167

90 27 155 26 5 166 164 166 28 14 26 31 20

Direction of maximum current at Point 2 (East is 90°)



5.5 Wave Data

The most extreme wave are towards the East and North-East and thus the SMHI data reflects this by reporting those directions only. The scatter diagrams for other directions for Points 1 and 2 are illustrated in Appendix A.

Return Period Hs (m) T (secs)

10 8.2 8.4

50 8.9 9.0

100 9.2 9.0

Wave statistics towards East (Point 1)


10 5.3 7.4

50 6.7 8.0

100 7.5 8.3

Wave statistics towards North-East (Point 1)

Return Period Hs (m) Hmax (m) T (secs)

10 8.2 13.9 8.9

50 8.7 14.8 9.0

100 8.8 14.9 9.0

Unidirectional wave statistics (Point 1)


10 8.2 8.8

50 9.2 9.2

100 9.5 9.3

Wave statistics towards East (Point 2)


10 5.3 7.4

50 6.8 8.0

100 7.5 8.3

Table 7 - Wave statistics towards North-East (Point 1)

Return Period Hs (m) Hmax (m) T (secs)

10 8.6 14.6 9.2

50 9.5 16.2 9.6

100 9.9 16.8 9.7

Table 8 - Unidirectional wave statistics (Point 1)



5.6 Wind Data

The most frequent winds are from the West for both Points locations. The strongest winds are from the West for Point 1 and from the South-West for Point 2.

Return period

N NE E SE S SW W NW Max

10 22.3 20.5 18.1 18 18 22.6 25.7 22.9 25.7

50 24.8 24.6 21.3 19.7 19.3 25 28.2 21.6 28.2

100 25.8 26.3 22.7 20.2 19.7 26 29.1 21.8 29.1

Table 9 - Wind speed for Point 1 (m/s)

Return period

N NE E SE S SW W NW Max

10 21.9 20.7 17.2 18.1 19.2 24.3 25.2 20.6 25.2

50 24.2 23.8 18.2 19.0 20.8 27.5 26.2 22.3 27.5

100 25.0 24.9 18.5 19.2 21.4 28.7 26.4 21.4 28.7

Table 10 - Wind speed for Point 2 (m/s)

5.7 Marine Growth

There are no details on marine growth in the vicinity. The majority of the pipeline will be fully or partly buried.



6.0 GEOTECHNICAL DATA The geotechnical conditions were assessed in the “Preliminary Geotechnical Analysis” performed by Geostab Ltd in July 2014 [1]. The document was prepared as a preliminary geotechnical analysis for the placement of a gas pipeline connecting field B8 with Wladyslawowo CHP plant. With reference to Appendix A, the route is broadly split into 2 regions, the nearshore and continental shelf region is predominately fine to medium sands with a density of 1.8 – 1.9g/cm3 (1800 – 1900 kg/m3). The flatter region beyond the territorial waters limit is mostly softer clay and silts of densities in the region of 1.38 – 1.6g/cm3. There are areas of organic clays at the bottom of the slope and in the platform region of densities in the region of 1.3 – 1.34g/cm3. A total of 20 Vibrocore samples were taken along the route all of which indicate loose or soft material. The clay regions have a shear strength, Su, in the upper silts mainly in the region of 1- 5kPa, with one Vibrocore sample indicating 6 – 18kPa.



7.0 PROTECTION AND STABILISATION PHILOSOPHY

7.1 Pipeline Sinkage

The specific density of the pipeline is 1.49 empty and 2.14 seawater flooded. Given the lower specific density when empty trenching of the pipeline may be difficult in the denser sand sections, due to the pipeline tending to ‘float’ in any fluidised seabed. The soft and organic clays have a lower specific gravity than the pipeline and hence natural sinkage may be expected which will increase under the operational weight.

7.2 Pipeline Pinning

The base case protection and stabilisation philosophy is to pin the pipeline in place using intermediately placed concrete ‘link-lock’ mattresses. The pipeline is not planned to be either ploughed or trenched in location. The stability of the mattress will have to be confirmed to ensure they have sufficient weight to resistance movement under the environmental forces. The mattresses will not be installed in areas of softer soils to avoid damaging the pipeline.



APPENDIX A – PROPOSED PIPELINE ROUTE

INTENTIONALLY BLANK



