Oil Field Development Schemes

Development of Oil & Gas Fields Development Schemes ( 90% – Floating platforms : < 10% – Surface and/or subsea wells

•

Comprehensive studies are necessary to select the most appropriate and cost effective field architecture (ref. to Field development process)

•

Main field architecture options : – Wells – Drilling mode – Platforms – Storage and export facilities

© 2005 ENSPM Formation Industrie - IFP Training

Field Architecture Options (1) •

Wells – Surface wells • Single wells (mainly in shallow water) • Multi-wells cluster – Subsea wells • Satellite wells • Multi-wells cluster – Combination surface + subsea wells – Well profile • Vertical, deviated • Horizontal • Extended reach • Multi-drains Selection depends on : – Platform type : fixed or floating – Reservoir geometry (extended, compact, multi-layers, ….) – Artificial lift and well intervention requirements – Costs

Subsea satellite well

Deviated well

Extended reach well

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Field Architecture Options (2) Drilling mode (fixed platforms)

Tender Drilling Rig

Jack-up Drilling Rig

Compact Drilling Rig Drilling deck

Max water depth ~ 110 m

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Field Architecture Options (3) Platforms – Fixed • Steel – Structure piled in the seabed – Or, self elevated platform (rare) • Concrete – Floating • Semi-submersible (associated with subsea wells only) • Tension Leg Platform – TLP (associated with surface or subsea wells)

Fixed Steel Platform

Fixed Concrete Platform

Floating platforms

Selection depends mainly on : – Water depth – Type of wells (surface, subsea) – Environmental conditions (waves, wind, current) – Topsides equipment (weight, size) – Construction strategy & constraints (yard availability, …) – Costs

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Field Architecture Options (4) • Oil storage and loading – Onshore storage and loading

– Offshore storage and loading

• Tanker loading at jetty (case 1) • Tanker loading from floating buoy (case 2)

• Floating storage + Tanker loading at buoy (case 3) • Floating storage + tandem loading (case 4) Case 3

storage

tanker

tanker Loadin g buoy

Case 1

Floating storage Production Plant

tanker

Case 2

storage

tanker Floating buoy

Case 4 Production Plant

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Oil Storage And Loading (Examples)

Oil Storage

Tanker

Tankers loading at jetty (case 1) Floating storage (cases 3 & 4)

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Conventional Development Scheme With Fixed Platforms Frigg field (UK/Norway) Wells DP2 DP2

Gas treatment & compression

TCP2

TCP2 TP1

DP1

Gas treatment

TP1

QP

Living quarters

QP

CDP1

Norway

Wells UK

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Conventional Development Scheme With Fixed Platforms Ekofisk field (Norway)

Oil storage

Drilling

Living quarters

Flare

Mobile drilling rig (jack up)

Oil processing

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Conventional Development Scheme With Fixed Platforms Elgin/Franklin field (UK)

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Subsea Development Scheme With Floating Platform Buchan field (UK) Production semisubmersible DRILL MASTER

Shuttle tanker

Exploration well

Loading buoy

Risers

2 Satellite wells 4 wells template

• Operator : BP • Location : North Sea UK • Water depth : 119 m • First Prod : 1981 • Reserves : 200 MMBOE Development scheme • 7 subsea wells (2 Satellites + 4 template + 1 explo recovered) • Floating production platform • Loading buoy © 2005 ENSPM Formation Industrie - IFP Training

Mixed Development Scheme With Fixed Platforms Gullfaks field satellites (Norway) (Gullfaks South, Rimfaks, Gullveig)

Gullfaks A

• • • • •

Operator : Statoil Location : North Sea Norway Water depth : 315 – 345 m Discovery : 1979 Sanction : 1996

Development scheme : • Subsea wells tiedback to existing subsea platform Gullfaks A • 8 subsea templates, 31 slots • Prod capacity : 125 000 b/d

© 2005 ENSPM Formation Industrie - IFP Training

Subsea Development Scheme With Floating Platforms Troll West field (Norway)

Troll C

• Operator : Norsk Hydro • Location : North Sea Norway • Discovery : 1979 • Water depth : 315 – 345 m

Troll B TROLL B Oil & gas provinces • First oil : 9/1995 • 21 subsea oil producers • 24 subsea gas producers • Oil production : 270 000 b/d • Semi-sub production unit

TROLL C Gas province • First gas : 1999 • Prod capacity : •Oil : 190 000 b/d •Gas : 9 Mm3/d • Semi-sub production unit

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Platform Functions • Offshore platforms are used for different functions : – – – –

Development drilling Fluids processing Water, gaz injection Utilities

– Living quarters – Flare – Storage

Integrated

• Functions can be : – Split (one platform = one function ) – Integrated (one platform = several functions ) Field examples Split

Integrated

Oil storage Drilling Living quarters

Flare

Mobile drilling rig (jack up)

Processing

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Fixed Platform Concepts • Two main concepts of fixed platform – Gravity based platforms • Platform stability is provided by one compartment, filled with sand, located at the base • Concept used for concrete platforms • Very limited number of applications : less than 30 out of 20 000 platforms worlwide

– Tubular steel frame platforms • Structure (Jacket) piled in the seabed • Deck(s) supported by the piles

• Specific concepts – Self installed platform • Recent design, few applications so far

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Fixed Steel Platform : Vocabulary

Lifted deck Cut piled after setting Boat landing Sea level

Deck Jacket walkway

Horizontal diagonal

Conductor area

Boat landing

Jacket leg

Barge bumper

Jacket

Horizontal brace

Launch runner

Bracing stub Vertical diagonal Jacket leg can

Anodes

Skirt pile sleeve

Seabed PILE

Pile anchored In seabed

SKIRT PILE

Jacket

LAUNCH TRUSS

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Types Of Riser Riser : vertical section of sealine between seabed and surface

Top View Side View

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Platform Loads Example Water depth Environ. conditions Wind Waves Current (surface) Tid eStorm gap

Weights

Total weight

Area

Upper deck Lower deck

Topsides load Drilling Rig

+ Marine Growth, Corrosion © 2005 ENSPM Formation Industrie - IFP Training

Installation And Transport Loads Transport

Launching

! ! Launch stresses may control design of some structural members

!

Lifting

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Piling Forces

Different types of pile

F wind

Water

Water

Water

F wave + current

Piles

Soil

Soil

Soil

Forces on piles at seabed level Classical pile

Soil reactions

Insert pile

Skirt pile

• The insert pile allows to increase the driving depth • The skirt pile allows to reduce the diameter of the jacket legs © 2005 ENSPM Formation Industrie - IFP Training

Pile Installation Drilling Hammering Drilling rig Drilling platform

Installation barge Main battered pile

Jacket leg Main battered pile

Barge barge Installation Subsea Subsea Hammer hammer

Soil

Drill pipe Cemented pile

Skirt Skirtpile pile

Drilled hole Drill bit

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Pile Driving Pile Driving Operation Piles

Hammers

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Pile Driving

Pile Driving Operation

Pile Drive Hammer © 2005 ENSPM Formation Industrie - IFP Training

Jacket Installation

Installation Of Jacket By Launching

Installation Of Self-floating Jacket

Vertical Lift

Horizontal Lift

Installation of jacket by lifting

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Jacket Installation Transport on barge

Lifting

Launching

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Heavy Lift Vessels Balder

Saïpem 7000

Thialf

Saïpem 7000

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Module Support Frame (MSF) MSF : Interface structure between jacket and topsides equipment

Jacket piles

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Drilling Platform Topsides

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Production Platform Topsides

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Topsides Drilling & Production Platform 29. 30. 31. 32. 33.

DRILLING DECK & MAIN RIG 1. Export pipeline 2. Mud mat 3. Skirt pile sleeve 4. Skirt pile 5. Anodes 6. Conductors 7. Export riser 8. Jacket leg 9. Barge bumper 10.Boat landing 11.Riser guard 12.Motor control center & switchgear control building 13.Escape capsule 14.Living quarters 15.Helicopter pad 16.Bulk storage 17.Mud pump package 18.Derrick 19.Flare boom 20.Lift gas compression

Production manifold Production separator Crude oil heater Test & cleanup separator Injection gas compressor

PRODUCTION DECK 21. Water injection pump 22. Generator 23. Deaerator 24. Waste heat recovery unit 25. Firewall 26. Diesel storage 27. Wellheads 28. Chemical injection skid

CELLAR DECK 34. Potable water storage 35. Emergency generator 36. Water injection charge pump 37. Media filter 38. Cooling water cooler Cooling water surge drum Cooling water pumps 39. Air compressor 40. Sea water pumps 41. Gas lift & water injection manifold 42. Fire water pump 43. Crude oil cooler 44. Crude oil pipeline pump 45. Electrostatic treater 46. Inlet dehydration filter separator Glycol contactor Outlet dehydration filter separator 47. Production water treating 48. Glycol regenerator 49. Slug catcher 50. Plated deck 51. Flare scrubber © 2005 ENSPM Formation Industrie - IFP Training

Concrete Platforms • Concrete platforms are gravity based • Their use has been limited essentially to the North Sea & North Atlantic (Canada) • They are used for very large fields in severe environment necessitating heavy topsides equipment • They also provide large oil storage capacity at the base First concrete platforms

FRIGG TCP2 BERYL «A» BRENT «B»

BRENT «D»

STATFJORD «A» STATFJORD «B» STATFJORD «C»

Water depth (m)

118 m

140

104

140

145

145

145

Year installed

1975

75

77

76

77

81

84

Drill & Prod

Drill & Prod

Gas treatment

Drill & Prod

Drill & Prod

Drill & Prod

Drill & Prod

40

38

-

48

42

42

42

Peak production (bopd)

150 000

160 000

-

160 000

300 000

180 000

200 000

Storage capacity (Mb)

0.9

1.0

-

1.2

1.3

1.9

2.0

Max deck weight (tons)

28 000

24 000

21 000

24 000

50 000

50 000

50 000

Function Nb well slots

© 2005 ENSPM Formation Industrie - IFP Training

Concrete Platform Concepts

Monopod

Multipod © 2005 ENSPM Formation Industrie - IFP Training

The Different Types Of Sealines • Flowlines – Transport the fluids from the wells, located on a surface wellhead platform or on the seabed, to the production platform – Generally small diameter (4 to 12’’) and short length ( up to ~10 km )

• Pipelines (or trunk lines) – Transport the fluid from the production platform to the export terminal (onshore of offshore) for loading oil tankers or to the gas utilization center (LNG plant, power plant,…) – Generally large diameter ( up to 36’’) and long length (several hundreds of km)

• Loading lines – Transport the fluid from the storage facility to a nearby loading facility (buoy or other) – Generally large diameter (20’’ to 40’’)

© 2005 ENSPM Formation Industrie - IFP Training

Sealine : General Description A sealine generally consits in : – A steel pipe – An anti-corrosion protection (coating) – An external concrete layer to provide mechanical protection and weight Pipe characteristics :

Steel pipe Concrete layer (1’’ to 5’’ thick) OD

WT

• Steel grade : X + … (ex. : X65) • External diameter – OD (ex. : 32’’) • Wall Thickness – WT ( 0.75’’) • Chemical composition • Resilience • Dimensional tolerances

Anti-corrosion coating © 2005 ENSPM Formation Industrie - IFP Training

Sealine Installation Method (Logigram) Pipe Welding Offshore Pipe preparation in standard lenght : • 12 m « joints » • 24 m « double joints » Transport to site : • Supply vessel • Barge Welding and laying : • Barge 1st generation • Barge 2nd generation • Barge 3rd generation Conventional “ S” lay Shallow water < 200 m

Onshore Pipe preparation in long sections (up to several km) Transport to site : • Surface tow (with buoyancy modules) • Bottom tow • Spooled (small diameter, short lenght)

A few connections to perform offshore

“J” lay water depth > 200 m

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S-lay And J-lay Methods

S-lay

J-lay © 2005 ENSPM Formation Industrie - IFP Training

Pipe Lay Barges

Brown & Root Semac 1

Allseas Lorelay

Saïpem Castoro Sei

Stena Apache

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