DOC ID© Chevron 2007

Chemical EOR Implementation for the Captain Field, UK

30th IEA EOR Symposium and WorkshopSeptember 2009Anette Poulsen, Chevron Upstream Europe, Aberdeen, Scotland

September 2009

Outline

1. Background

2. Project Definition

3. Strategy

4. Pilot Objectives and Deliverables

3

Location:Block 13/22a, UK North Sea.

First Oil 1997: 12 years production history

Current gross oil production: 40,000 bbls/ day.

Equity:

85%

15%

Captain Field Location

Captain Development Discovered 1977

Early development challenges

Multiple platforms and over 300 vertical wells!

Early 1990ies technology advances

Horizontal drilling and ESP development

Successful EWT – 1993

1997 installed WPP & FPSO, first oil

2000 expansion project: BLP and subsea Area B template installed

2006 Captain Area C - further 2 subsea well development 4km east of Area B template

Polymer injection facilities installed as part of original development

Captain Infrastructure

OWC -3028

OWC -3251

OWC -2921OWC -2982

GOC -2799 GOC -2723

UCSUCSUCS

LCS LCS LCS

Wick

S-UCS

-3500’

-2500’

-3000’

Ross CentralRoss Central

Lower Captain Sandstone Lower Captain Sandstone

OWC -2992

Area AArea A

Captain Ridge

0 2km

Ross

Devonian

Upper Captain SandstoneUpper Captain Sandstone

West RossWest Ross

Southern

Terrace

Southern

TerraceGas CapGas Cap

Ross SandstoneRoss Sandstone

LCS EastLCS East

Area A WPPArea A WPP Area B TemplateArea B Template

Ross EastRoss East

Far EastFar East

BurnsBurns

Area C ManifoldArea C Manifold

Eastern ExtensionEastern Extension

Captain Reservoir X-Section

Upper Captain Sandstone : Sheet-like deepwater sandstone,

Lower Captain Sandstone : Channelised deepwater sandstone,

Ross/Burns Sandstone : Fluvial/ shallow marine sandstone.

Captain Waterflood Performance

Volumetric sweep

Injection water slumps down, under-running oil column

Water cones up to producers from OWC or under-running water

Significant hydrocarbon volumes by-passed

Microscopic sweep

Poor SCAL data (unconsolidated rock)

Large uncertainty in ROS and Sorw

Outline

1. Background

2. Project Definition

3. Strategy

4. Pilot Objectives and Deliverables

Captain Long Term Development Project

Long Term Development Sub-Projects – Chemical EOR

Positives

Exceptionally high permeability

Low temperature, moderate salinity

Medium to high oil acidity

Challenges

Heavy/viscous oil

High hardness (Ca, Mg ions in formation water)

Offshore (impact on facilities, brown field modifications)

Key Issues

Incremental sweep

Chemical compatibility and chemical performance

Offshore space/weight/POB constraints

Existing equipment suitability/conditions

Project Definition

Opportunity Statement:

To develop an integrated Chemical EOR Field and Reservoir strategy and timely implementation plans to increase ultimate recovery in order to develop P4–

P6 resources into the proved developed reserves category.

Success Vision:

Economically implement chemical EOR in Captain to achieve at least 50% recovery factor in all reservoirs

where chemical EOR will be applied

Impact on Life of Field

Polymer Flood EOR Potential for Upper Captain Sand

0

20

40

60

80

2000 2005 2010 2015 2020 2025

Oil

Pro

du

ctio

n (

Mbo

pd)

EOR likely to extend Captain

field life

UCS MAIN

UCSPOLYMER FLD

ADDITIONALDEVELOPMENT& EXPANSION

Polymer Flood EOR Potential for Upper Captain Sand

0

20

40

60

80

2000 2005 2010 2015 2020 2025

Oil

Pro

du

ctio

n (

Mbo

pd)

EOR likely to extend Captain

field life

UCS MAIN

UCSPOLYMER FLD

ADDITIONALDEVELOPMENT& EXPANSION

Outline

1. Background

2. Project Definition

3. Strategy

4. Pilot Objectives and Deliverables

EOR Strategy

Evaluate suitable chemicals (polymer and ASP) for Captain

Implement pilot polymer flood project using existing equipment on the Captain facilities

Follow by ASP flood if viable

Develop reliable forecasting tools and evaluate full field implementation

Implement EOR scheme on Captain

Outline

1. Background

2. Project Definition

3. Strategy

4. Pilot Objectives and Deliverables

Pilot Objectives

Demonstrate polymer flood technical feasibility in Captain field

Early identification of potential showstoppers

Provide data to evaluate economic viability for further expansion

Reduce range on key uncertainties

Meet above objectives within desired timeframe

Key Uncertainties

Ability to ship, mix, filter and inject polymer offshore, in the North Sea

Well injectivity

Increase in sweep efficiency, oil cut and oil production rate

Chemical usage

Impact on production efficiency

Operability of facility

Pilot Strategy Table

2x2x

1 No pilots, only injectivity tests2 No pilots, no injectivity tests, start full field engineering now3 Single pilot with multiple injectivity tests4 Resolution of all key reservoir uncertainties5 Resolution of all key reservoir uncertainties in an aggressive time frame6 Resolution of top two key reservoir uncertainties

UCS

5

6

1

2

3

4

2

0Fastest but high risk

Addressing Key Uncertainties

Injectivity Tests

1 SUCS

Shortest lead time to full field expansion decision (only one key reservoir uncertainty addressed)

Just do full field expansion now

Maximum Information - Minimum Lead Time

Maximum Information - Minimum Risk

ReservoirPilot Timing

n/a

Ross

LCS

none

Pilots

1

0

4

Simultaneous Pilots

Overlapping series of Pilots

contained oil

none

aquifer

variation in deposition, rock

and fluid properties

Key Reservoir Features

gas cap3 or more

2

Sequential series of Pilots

3

Project Milestones

Water injectionbaseline 4Q09

The Last Slide