Abstract: Revitalizing the Isobo Field, Offshore Nigeria

KOFRON, BRUCE M., CHIKWE E. EDOZIEM, PAUL A. HEGER, KOLA B. ALOFE, ABIYE H. MEMBERE, MICHAEL D. GUERRA, BYRON M. CLANCY, and GEORGE L. FISHER

The Isobo Field, Offshore Nigeria, came on stream in 1982. From 1993-1995, the field was shut-in due to low wellhead pressure and back pressure from the production platform, the central gathering point for 5 other fields. Before shut-in, peak production was approximately 20,000 BOPD and cumulative oil production was 26 MMBO. In 1995, the field was revitalized by installing a Mobile Production Facility (MPF) in conjunction with a reservoir description study to ensure an extended field life.

Installation of the MPF quickly brought production back on line to 23,000 BOPD surpassing the previous peak rate. This was accomplished by increasing the pressure differential between the formation/well bore and surface facilities. The reservoir description study identified 8 separate Upper Miocene Biafra Member reservoirs that can be exploited by an additional seven well development program. Peak production under the new development scheme may be as high as 45,000 BOPD.

A 3D seismic survey shot in 1991 was the cornerstone for the reservoir description study. It was integrated with wire-line logs from 10 wells, PVT data, and production history data to quantify reserves and identify undrained sands. Integration of these data sets identified fluid communication across faults and unconformities between reservoirs that were previously considered compartmentalized.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria