Chemical EOR Implementation for the Captain Field UK

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 © Chevron 2007 DOC ID

Outline 1. Background 2. Project Definition 3. Strategy 4. Pilot Objectives and Deliverables

Captain Field Location: Block 13/22 a, UK North Sea. First Oil 1997: 12 years production history Current gross oil production: 40, 000 bbls/ day. Equity: 85% 15% 3

Captain Development n Discovered 1977 n Early development challenges l Multiple platforms and over 300 vertical wells! n Early 1990 ies technology advances l Horizontal drilling and ESP development n Successful EWT – 1993 n 1997 installed WPP & FPSO, first oil n 2000 expansion project: BLP and subsea Area B template installed n 2006 Captain Area C - further 2 subsea well development 4 km east of Area B template n Polymer injection facilities installed as part of original development

Captain Infrastructure

Captain Reservoir X-Section Area A WPP Area B Template Area C Manifold Upper Captain Sandstone Area A Gas Cap Eastern Extension Southern Far East Terrace -2500’ S-UCS OWC -2982 -3000’ UCS LCS OWC -2992 LCS East Lower Captain Sandstone Burns OWC -2921 Ross OWC -3028 Wick OWC -3251 -3500’ Captain Ridge GOC -2723 GOC -2799 West Ross Devonian Ross Central Ross East 0 Ross Sandstone Upper Captain Sandstone : Sheet-like deepwater sandstone, Lower Captain Sandstone : Channelised deepwater sandstone, Ross/Burns Sandstone : Fluvial/ shallow marine sandstone. 2 km

Captain Waterflood Performance n Volumetric sweep l Injection water slumps down, under-running oil column l Water cones up to producers from OWC or under-running water l Significant hydrocarbon volumes by-passed n Microscopic sweep l Poor SCAL data (unconsolidated rock) l 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 n Positives l Exceptionally high permeability l Low temperature, moderate salinity l Medium to high oil acidity n Challenges l Heavy/viscous oil l High hardness (Ca, Mg ions in formation water) l Offshore (impact on facilities, brown field modifications) n Key Issues l Incremental sweep l Chemical compatibility and chemical performance l Offshore space/weight/POB constraints l 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 P 4– P 6 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 n Evaluate suitable chemicals (polymer and ASP) for Captain n Implement pilot polymer flood project using existing equipment on the Captain facilities l Follow by ASP flood if viable n Develop reliable forecasting tools and evaluate full field implementation n Implement EOR scheme on Captain

Outline 1. Background 2. Project Definition 3. Strategy 4. Pilot Objectives and Deliverables

Pilot Objectives n Demonstrate polymer flood technical feasibility in Captain field l Early identification of potential showstoppers n Provide data to evaluate economic viability for further expansion n Reduce range on key uncertainties n Meet above objectives within desired timeframe

Key Uncertainties n Ability to ship, mix, filter and inject polymer offshore, in the North Sea n Well injectivity n Increase in sweep efficiency, oil cut and oil production rate n Chemical usage n Impact on production efficiency n Operability of facility

Pilot Strategy Table

Project Milestones Expansion decision 3 Q 11 Polymer pilot results 2 Q 11 Injectivity test 2 Q 10 Water injection baseline 4 Q 09 ASP pilot 4 Q 11 Commence field wide polymer (& ASP) flood 2015

The Last Slide