DOC ID © Chevron 2007 Chemical EOR Implementation for the Captain Field, UK 30 th IEA EOR Symposium and Workshop September 2009 Anette 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 – 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

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

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

Project Milestones Injectivity test 2Q10 Polymer pilot results 2Q11 Expansion decision 3Q11 ASP pilot 4Q11 Commence field wide polymer (& ASP) flood 2015 Water injection baseline 4Q09

The Last Slide