INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

Abstract

The project involves using advanced reservoir characterization and thermal production technologies to improve thermal recovery techniques and lower operating and capital costs in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., Calif. Through September 2001, project work has been completed on the following activities: data preparation; basic reservoir engineering; developing a deterministic three dimensional (3-D) geologic model, a 3-D deterministic reservoir simulation model and a rock-log model; well drilling and completions; and surface facilities on the Fault Block II-A Tar Zone (Tar II-A). Work is continuing on research to understand the geochemistry and process regarding the sand consolidation well completion technique, final reservoir tracer work, operational work and research studies to prevent thermal-related formation compaction in the Tar II-A steamflood area, and operational work on the Tar V steamflood pilot and Tar II-A post-steamflood projects. The project team spent the Fourth Quarter 2001 performing routine well work and reservoir surveillance on the Tar II-A post-steamflood and Tar V pilot steamflood projects. The Tar II-A post-steamflood operation started in February 1999 and steam chest fillup occurred in September-October 1999. The targeted reservoir pressures in the ''T'' and ''D'' sands are maintained at 90 {+-} 5% hydrostatic levels by controlling water injection and gross fluid production and through the bimonthly pressure monitoring program enacted at the start of the post-steamflood phase. The project team ramped up well work activity from October 2000 through November 2001 to increase production and injection. In December, water injection well FW-88 was plug and abandoned and replaced by new well FW-295 into the ''D'' sands to accommodate the Port of Long Beach at their expense. Well workovers are planned for 2002 as described in the Operational Management section. Expanding thermal recovery operations to other sections of the Wilmington Oil Field, including the Tar V horizontal well pilot steamflood project, is a critical part of the City of Long Beach and Tidelands Oil Production Company's development strategy for the field. The steamflood operation in the Tar V pilot project is mature and profitable. Recent production performance is below projections because of wellbore mechanical limitations that were being addressed in 2001. As the fluid production is hot, the pilot steamflood was converted to a hot waterflood project in June 2001.