Print this pageAbstract: Facies Analysis Using Seismic Data, Coalinga Field, California
DELAUGHTER, JOHN1, JULIAN THORNE1, DALE BEESON1, LOUIS KLONSKY2, LEE WILLIAMS2, WILLIAM KEMPNER3, ED VONDOHLEN2, and KARLA TUCKER4
1
Chevron Petroleum Technology Company, San Ramon, CA; ,
2 Chevron North America Exploration and
Production, Bakersfield, CA;
3 Chevron USA Production Co, Bakersfield, CA;
4 California State U Long Beach, Long Beach, CA
Facies analysis and mapping is an integral part of the reservoir characterization process. Such analyses permit "high grading" selected zones in a well for completion and can also reduce the risk in well location; furthermore, recovery estimates and choice of facilities design can be strongly influenced by facies interpretations.
In order to map facies between wells automatically and reliably by treating geological concepts in a statistically rigorous fashion, Chevron has recently developed FaciesFinder, which uses well logs, and ASTRAL, which combines well logs with seismic attributes. With these tools, we have built an earth model for the Coalinga field in the central San Joaquin valley that includes facies, porosity and permeability predictions using well logs, 3D seismic and FaciesFinder 1D facies assignments.
Our task was complicated by the use of steam injection for enhanced oil recovery, which creates several significant challenges to seismic attribute analysis, such as: Collecting well logs and seismic data at different times, Noisy seismic data data due to steaming and pumping wells, and steam effects on velocity functions .
In this study, we attempted to address these challenges by including a "Steam/No-steam" flag as a well log and by grouping the layers with the greatest steam effects together during the analysis. The final results are encouraging and suggest that seismic attributes can aid in mapping facies between wells.
DELAUGHTER, JOHN, JULIAN THORNE, DALE BEESON, LOUIS KLONSKY, LEE WILLIAMS, WILLIAM KEMPNER, ED VONDOHLEN, and KARLA TUCKER
AAPG Search and Discovery Article #90911©2000 AAPG Pacific Section and Western Region Society of Petroleum Engineers, Long Beach, California