Professional paper
Thief Zone Identification through Seismic Monitoring of a CO2 Flood, Weyburn Field, Saskatchewan
A.W. Araman
; Colorado School of Mines, Department of Geophysic, Golden Colorado
M. Hoffman
; Colorado School of Mines, Department of Geology, Golden Colorado
T.L. Davis
; Colorado School of Mines, Department of Geology, Golden Colorado
Abstract
Located in the Williston Basin (Figure 1) in Southeastern Saskatchewan, Weyburn Field implemented eight years ago a CO2 EOR project in order to maximize recovery from the fields main producing unit: a carbonate reservoir known as the Midale Beds. To date, Weyburn Field has produced 335 million barrels of oil and has an estimated 1.4 billion barrels OOIP.5 This paper demonstrates that Time-Lapse and Multi component seismic data analysis is an effective tool for monitoring CO2 injection through the detection of changes in reservoir properties such as porosity, fluid distribution, and fracture density. The monitoring of these changes directly informs the design of the EOR project, thus optimizing field recovery. Evaluation of P-wave Time-Lapse and S-wave data resulted in the following conclusions regarding production in Weyburn field:
1. The Midale reservoir is experiencing a downward loss in CO2 in the west corner of the study area. Shifting the location of the nearby injection well is recommended.
2. Throughout the field, P-wave time-lapse shows that CO2 is largely confined to NW-SE fracture orientation identified after interpretation of the 2000 S-wave data.
Keywords
CO2 flood; EOR strategy; multicomponent seismic analysis; seismic monitoring; time-lapse analysis
Hrčak ID:
49297
URI
Publication date:
28.11.2008.
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