Classification: Internal Status: DraftClassification: Internal Status: Draft

Kevin Dodds

on behalf of Alan Mathieson, Rob Bissell BPPhil Ringrose StatoilHydroDon Vasco, Ernie Majer LBNLJoe Morris LLNLEric Davis, Glenn McColpin Pinnacle Technologies Clare Bond MVEPeter Armitage Univ of Liverpool

In Salah CO2 JIP: Status and Overview5th IEA Monitoring Meeting, Tokyo, Japan June 2-3 2009

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Outline

•Geological and Structural Context

•Plume development modelling - Permedia

•Key Risks Risk Evaluation URS Risqueet al

•INSAR Deformation and Inversion Pinnacle Tech, LBNL

•Geomechanical / Geochemical Modelling and Experimental Summary

–LLNL, Univ of Liverpool,

•Monitoring Update

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Krechba Key Risk Locations

KB5

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The In Salah CO2 storage site at Krechba

Cretaceoussequence(900m)

Carboniferousmudstones(950m)

Definition and modelling of reservoir storage and

migrationReservoir (20-25m thick)

Definition and modelling of potential

cap-rock pathways

Gas Chemistrymonitoring

Fluid displacement monitoring (4D seismic)

Rock strain monitoring(Tilt, microseismic)

Productionmonitoring(Tracers)

CO2 injection(3 wells)

Gas production(5 wells)

Gas from other fields

Amine C02 removalSatellite

monitoring(InSAR)

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Conceptual Structural Geological Model for Krechba

Structural style schematic

Carboniferous reservoir (C10)• Broad folds influenced by

underlying strike-slip faults

Devonian sequence:• Deep seated faults reactivating

earlier extensional faults in dominantly strike-slip mode with some reverse faulting

Conceptual model for Krechba reservoir:• West limb of reservoir east-west faults probably

associated with fracturing

• East limb has some subtle faults and a steeper dip segment related to underlying fault activity

• Fracture density controlled by folding and faults

• Open fracture direction controlled by stress field

• Fracture density also controlled by lithology

N

Deep-seated faults propagating upwards

Minor faultsExpected

fracture zones

C10.1C10.2C20.1C20.2

Schematic of strata-bound fractures

Clare Bond MVE

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Technical questions for Research• How does subsurface CO2 injection affect rock properties (a) at the reservoir

level (b) in the overburden (c) surface deformation?

• How much is CO2 injection controlled by faults or fractures (or both)?

• Have we induced fractures in the reservoir (a) mechanically (b) thermally?

• What flow parameters control dispersion and channelling of the CO2 plume: (a) rock property heterogeneity (b) fracture distribution (c) rock mechanical response (d) fluid properties & PVT?

• How can the current monitoring dataset/package be best used to calibrate our models and ultimately long-term storage verification?

• What additional data should/could we be measuring?

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Faulting

• Subtle faults best detected on low-angle illumination of time surface (pre-reprocessed dataset)

• Reservoir model faults digitized using Gocad

Subtle seismic features that are not

seismic artefacts

Modelled Faults:• No dip information• Based on seismic

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Fault 12

KB-502

Analysis shows that:• Fault 12 could be open under the

current-day stress field.• Main fracture set is also closely

aligned with current-day field• Other fault and fracture sets more

likely closed/cemented/old

Faults and Fractures

σ1

σ1

Fault 12All digitised fault data

East

South

West

North

σ1

σ1

KB502 fractures

σ1

σ1

Main

fractures

Second

Fracture

set

Clare Bond MVE

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Permedia Study- mPath Andrew Cavanagh CO2 Toolkit

• Invasion percolation approach (capillary limit)• Preliminary result from high resolution mesh (400M cells)• Next stage will compare black-oil simulation with IP approach

Topographic control Fault control Fault & fracture control

1010

Well observations:• CO2 from injector KB-502

detected at appraisal well KB-5 after 2 years injection(Distance 1.3km)

Satellite Data:• Deformation ellipse detected

around injector• Larger area than the

breakthrough zone

Reservoir history match (Eclipse):• 4D permeability corridor

(suspected fault?)• Fracture flow also important

The KB-502 Story(First Break, 27, January 2009)

Injection wellKB-502

GWC

Observation well KB-5

Zone of surfacedeformation

Conductivefractureorientation

History-matched CO2 plume

Possible CO2 plume extension

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Risk assessment aims• General aims to assess:

– the risk of leakage (containment risk) from the intended reservoir– the capacity of the site to store the intended mass of CO2 at the planned rates (effectiveness risk)

• Specific aims to provide outputs that help BP to:– understand and communicate containment risk

• understand and communicate effectiveness risk• identify knowledge gaps• develop strategies to reduce risk

• URS Risque process used, – Externally acceptable, benchmarked on a number of projects

• Gorgon, Otway, Weyburn, Zerogen– Independent review process using external managed process

• URS and CO2CRC representatives– Rigorously defined base case, and probabilistic scales

• Further plans– Risk workshop highlighting different processes as communication to European regulatory people,

DNV, Shell, Risque.– In Salah planning to benchmark risk processes

• RISQUE Process• CCP Certification Process UT and LBNL• CO2 PENS LANL• DNV

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Risk Assessment Process

Establish the context

Identify risks

Analyse risks

Likelihood Consequences

Estimate level of risk

Evaluate risks against targets

Strategy to treat risks

The specific aims were to provide outputs that help BP understand and communicate containment risk and effectiveness risk, and to identify knowledge gaps and develop strategies to reduce risk.

In light of updated monitoring data, review characterisation and re evaluate risks

Risk = Likelihood x consequences

(rate volume)Estimated rate of CO2 seepage (t/an)Log normal distribution

High estimate: CL 95% 60Best estimate: CL 50% 30

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KB-502 Injection OverviewKB-502 Injection Overview

• CO2 injections began in April 2005

– Slow start-up of ~200 MMscf per month through Aug 2007

• CO2 Injections ramp up to a maximum of 907 MMscf in December 2007

– Steady decline in injection volume through August 2006 (468 MMscf)

• Two additional periods of injection ramp-up and decline after September 2007

– Steep decline in injection volume after May 2007

• CO2 identified in adjacent well KB-5 in early August 2007

• CO2 injections were shut-in August 2007

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Track 65: 11-29-2003 to 01-22-2005Track 65: 11-29-2003 to 01-22-2005

Note the temporal decorrelation due to sand movement. This feature is not filtered out within these SVD optimized interferograms to preserve near-well

deformation magnitudes.

Pinnacle Technologies March 26,2009

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Track 65: 11-29-2003 to 09-24-2005Track 65: 11-29-2003 to 09-24-2005

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Track 65: 11-29-2003 to 03-18-2006Track 65: 11-29-2003 to 03-18-2006

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Track 65: 11-29-2003 to 03-22-2008Track 65: 11-29-2003 to 03-22-2008

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Track 65: 11-29-2003 to 05-31-2008Track 65: 11-29-2003 to 05-31-2008

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Track 65: 11-29-2003 to 05-31-2008Track 65: 11-29-2003 to 05-31-2008

NE-SW lineation near KB-14 (seen in

JGI images) not observed in these

datasets

Believed to be a atmospheric artifact carried through from

the 7-31-2004 master image NW-SE lineation

(fault?)

• Delineates western margin of deformation at KB-501

• Trend passes through a “deformation trough” at KB-502Zoom in on KB-501 and KB-503

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Modelling Tasks for 2009

Jan 09 Jul 09Apr 09 Dec 09Oct 09

Model convergence

E300 simulations

MPath simulations

Flow Simulation

Stars coupled modelCO2/CH4

mixing

Coupled modelling workshop with R&D partners

Long-term CO2 storage

Input to R&D Partners (LLNL, LBNL, Pinnacle, CO2ReMoVe)

R&D Model insights

Improved parameterization

Validation and peer review

Monitor/Model coupling

Microseismic, Timelapse seismic, Satellite/surface, Chemical monitoring, Production monitoring, Hydrogeology

Model updates

Structural restoration and fracture prediction (MVE)

Characterisation

Update datasets (JV/JIP)

Fracture modelling (History Match DFM of kb502/kb5 area)

Generate model grids

Rock mechanical modelling and properties

Laboratory analyses (U of L., LLNL, JIP)

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Monitoring Overview

Year 2009 involves a major effort in monitoring activities at Krechba ($12M)• 3D/4D Seismic – Northern field area (improved imaging and time-lapse)• Microseismic test well – KB601 drilled to 500m with geophone string)• Tiltmeters/DGPS – in the KB501 area; 64 tiltmeter and 3 DGPS stations• Satellite Imagery – whole field; monthly acquisition programme• Observation wells to monitor potable aquifer – two to be drilled in 2009• Surface gas flux, Lineament Analysis, microbiology – being done by

CO2ReMoVe (BGS, BRGM, Uiv. Rome)• Wellhead Annulus Monitoring – continual (from 2006) gas composition and

tracer analysis (IFP and IFE)• Data acquisition from development/water wells – KB-15, KB-16 and KB-17

– Cuttings analysis, headspace gas– Electric logs, behind casing sonic (MSIP)