The Construction and Maintenance Plan for a Grand Banks Multi-Purpose Pipeline

D.W. (Don) Wilson, Director, North Atlantic Pipeline Partners, L.P.

NOIA 2000 ConferenceJune, 2000

Grand Banks Multi-Purpose Pipeline Route

January 2000

Grand Banksof

Newfoundland

Newfoundland

Come by Chance

St. John’s

Argentia

50o

44o

50o

48o

56o54o 52o 50o 48o 46o

48o

46o

56o54o 52o 50o 48o 46o

46o

44o

Jeanne D’ArcGBS

620 km30 Inch

Export Pipeline

Grand Banks Pipeline Profile and Wall Thickness

15

17

19

21

23

25

27

29

31

33

35

0 50 100 150 200 250 300 350 400 450 500 550 600

Buckle Arrestors Required

Riser & NearPlatform Pipe

Shore Crossing

OffshorePipeline

OnshorePipeline

22.5 mm

21.5 mm

34.3 mm34.3 mm

23.8 mm 23.8 mm

-350

-300

-250

-200

-150

-100

-50

0

50

100

150

200

Distance Km

Wal

l Thi

ckne

ss (m

m)

Elevation (m

LA

T ref.)

Sea Level

Come By Chance

Seabed

North Atlantic Pipeline

Partners, L.P.Grand Banks Pipeline

External Anticorrosion

Coating

Internal Epoxy Flow Coating API 5L X70 Grade

Steel Reinforced Concrete

Weight Coating

Cross Section

Design Parameters

Pressure & MAOP 3150 psig

Length 620 Km

Water Depth 256 m av. / 305 m max.

Pipeline Outside Diameter 30 inch

Steel Grade API 5L X70 Grade

Wall Thickness 0.846 - 0.938 inch

Concrete Coating Thickness 40 mm - 100 mm

External Cathodic Protection Aluminum Anodes

External Anticorrosion Coating Asphalt Enamel

Internal Epoxy Flow Coating Roughness = 0.01mm

- Moderate Depths

- Conventional S-Lay

- At least 4 or 5 conventional lay barges available with requisite capability

North Atlantic Pipeline Partners, L.P.Pipeline Installation

SEMISUBMERSIBLE PIPELAY VESSELDP PIPELAY VESSEL

North Atlantic Pipeline Partners, L.P.Pipeline Installation

North Atlantic Pipeline Partners, L.P.

Pipeline Assembly Onboard Pipelay Vessel

North Atlantic Pipeline Partners, L.P.

Pipeline Installation Stinger

Shaw & Shawpipecoatingfacility at Sheet Harbour, Nova Scotia

North Atlantic Pipeline Partners, L.P.

North Atlantic Pipeline Partners, L.P.

EXTERNAL INSPECTION:Via Remotely Operated Vehicle (ROV)

INTERNAL INSPECTION:Via Intelligent pigging

North Atlantic Pipeline Partners, L.P.

Pipeline Cleaning:

Cleaning pig train including the use of bi-directional pigs and solvent swab

Pipeline Repair Protocol

1 Leak detection and compressor shut down

2 Damage location

3 Excavate pipe

4 Remove concrete

5 Cold-cut pipe ends

6 Insert pipeline plugs

7 Deploy hyperbaric chamber

8 Perform hyperbaric repair welding

9 Repair coating

10 Recommission pipeline

North Atlantic Pipeline Partners, L.P.

Major North Sea Pipelines

GermanyNetherlandsZeebruge

Esbjerg

Map Not to Scale

Norway

Denmark

Bacton

St Fergus

Kollsnes

Edmund

United Kingdom

Brighouse Bay

Theddlethorpe

Teesside

Kaergärd

Karsto

Troll

Stafjord

Magnus

Brent

Ekofisk

Draupner

Sleipner

Cod

Everest

Brittania

Miller

Beryl

Heimdal

Frigg

MurdochGorm

Dunkirk

Existing Gas PipelineProposed Gas PipelineExisting Oil Pipeline 20”

30”36” (2)

40”

40”

28”

42”

36”

40”

30”

26”

36”

32” (2)

30”

36”

40”42”

40”

26”

40”36”

30”

24”

Eire

36” Tyra

Sullom Voe

Flotta

North Atlantic Pipeline Partners, L.P.

Comparison of Grand Banks Pipeline to North Sea Pipelines

GermanyNetherlandsZeebruge

Esbjerg

Map Not to Scale

Norway

Denmark

Bacton

St Fergus

Kollsnes

Edmund

United Kingdom

Brighouse Bay

Theddlethorpe

Teesside

Kaergärd

Karsto

Troll

Stafjord

Magnus

Brent

Ekofisk

Draupner

Sleipner

Cod

Everest

Brittania

Miller

Beryl

Heimdal

Frigg

MurdochGorm

Dunkirk

Existing Gas PipelineProposed Gas PipelineExisting Oil Pipeline 20”

30”36” (2)

40”

40”

28”

42”

36”

40”

30”

26”

36”

32” (2)

30”

36”

40”42”

40”

26”

40”36”

30”

24”

Eire

36” Tyra

Sullom Voe

Flotta

Grand Banks

Come by Chance

North Atlantic Pipeline Partners, L.P.

North Atlantic Pipeline Partners, L.P.

End of Presentation

PIPELINEPIPELINE FAILURE,

CRACK, BUCKLE ETC.

REPAIR OF A DAMAGED SECTION OF PIPELINEAT 250 m WATER DEPTH USING A HYPERBARIC

WELDING SYSTEM FROM A DP- DSV

DYNAMIC POSITIONED (DP)DIVE SUPPORT VESSEL (DSV)

REMOTE OPERATED VEHICLE (ROV)

DAMAGED SECTION OF PIPELINE

PIPELINE

THE ROV WOULDFIRSTLY INSPECT

THE SITE

Once the pipeline pressure has been controlled a DP-DSV would mobilise to site

PIPE HANDLING FRAMES“GOAL-POSTS”

DIVING BELL

THE DIVERS WOULD DIRECT THE SETTINGOF THE GOAL-POSTPIPE HANDLING FRAMES

WOULD SET PIPE FRAMES APPROX. 30 - 40 m APPART

SETTING OF THE PIPE HANDLING FRAMES

DAMAGEDSECTION

6 m6 m

6 m

DIVER

HYDAULICOPERATION

PIPELINE

SLING

HOIST

OVERHEAD GANTRY

PONTOONS

SIDE ELEVATION END ELEVATION

Typical “goal-post” pipe lifting frames

AIR LIFTING BAGS

DIVERCONTROLLING THE LIFTINGOF THE PIPELINE USING THE

HYDRAULIC POWERED LIFTING FRAMES

BELLDAMAGED SECTION

DP - DSV

DIVERS RAISE THE PIPELINE SECTION OFF SEABEDUSING COMBINATION OF LIFTING FRAME AND AIR LIFTING BAGS

DIVERS CUT OUT THE DAMAGED SECTION OF PIPE-LINEUSING A COLD CUTTING TECHNIQUE TYP. A DIAMOND WIRE PIPE CUTTER

DIVER WILL IDEALY REMOVE A SECTION OF CONCRETE COAT

TO FIT THE HABITAT

DIVER

Divers cut out the damaged section of pipe

REMOVING CUT OUT DAMAGED SECTION

TO PREPARE FOR THE HABITAT•THE CONCRETE IS REMOVED FROM AROUND THE CUT ENDS•THE CUT ENDS ARE ROUGH BEVELED•BLADDER PIGS INSERTED IN SIDE EACH CUT END

PREPARING THE PIPE FOR PLACEMENT OF HABITAT

DSV PLACES THE HABITAT

THE HABITAT

ROV

PIPE

10 m 6 m

6 m

Side Elevation End Elevation

SEABED

3 m

Typical principal dimensions of a Hyperbaric Welding Habitat

PIPE LINE

CONCRETECOAT SECTION

CONCRETEREMOVED

EXTERNAL SHELL OF THE HABITAT

SEABED

SKIRT OF HABITAT

1/2 m

HABITAT BOTTOMCLOSING GATE

ANULAR RUBBER SEAL

ANULAR STEEL SEALING PLATE

CUT ANDBEVELEDPIPE END

The sealing of the pipeline inside the habitat

BACK TO DSV

SEABED

HABITAT

PIPELINE

DIVERS ENTRANCE

Approx. 1 m

HABITAT UMBILICAL CONTAINING :

• DIVERS GAS, COMMS, HOT WATER, VIDEO• HABITAT , POWER GAS, COMMS, VIDEO• WELDING, GAS POWER LEADS, SURVEILANCE ETC.

HABITAT GAS PRESSUREWILL BE MAINTAINED AT APPROX. 0.2 BAR ABOVE

THE AMBIENT SEA PRESURE

Setting the habitat ready for work (pumping dry)

HABITAT UMBILICAL

BELL

DIVERS ENTER THE HABITAT

Once the habitat is set the divers set the seals, pump dry andthen commence the hyperbaric weld

SEABED

PIPELINE

The hyperbaric weld

NEW SECTION OF PIPELINE “PUP”

WELDED IN-LINE

TWO FULL CIRCUMFERENCIALGIRTH WELDS PERFORMED,

NDT, AND CORROSION COATING APPLIED

DYNAMIC POSITIONED (DP)DIVE SUPPORT VESSEL (DSV)

REPAIRED SECTION OF PIPELINE

PIPELINE

Once the pipeline has been repaired the DP-DSV would recover the hyperbaric spread

NON-CONCRETE COATED SECTION OF PIPE LINE

APPROX. 12 m

DYNAMIC POSITIONED (DP)DIVE SUPPORT VESSEL (DSV)

PIPELINE

Once the pipeline has been repaired the DP-DSV would place a protection frame or concrete mats

CONCRETE MATTRESSES OR PROTECTION FRAMEPLACED OVER THE REPAIRED SECTION OF PIPELINE