Abstract The giant Wilmington oil field of Los Angeles County, California, on production since 1932, has produced more than 2.6 billion barrels of oil from basin turbidite sandstones of the Pliocene and Miocene. To better define the actual hydrologic units, the seven productive zones were subdivided into 52 subzones through detailed reservoir characterization. The asymmetrical anticline is highly faulted, and development proceeded from west to east through each of the 10 fault blocks. In the western fault blocks, water cuts exceed 96%, and the reservoirs are near their economic limit. Several new technologies have been applied to specific areas to improve the production efficiencies and thus prolong the field life. Tertiary and secondary recovery techniques utilizing steam have proved successful in the heavy oil reservoirs, but potential subsidence has limited their application. Case history 1 involves detailed reservoir characterization and optimization of a steamflood in the Tar zone of Fault Block II. Lessons learned were successfully applied in the Tar zone, of Fault Block V (4000 m to the east). Case history 2 focuses on 3-D reservoir property and geologic modeling to define and exploit bypassed oil. Case history 3 describes how this technology is brought deeper into the formation to capture bypassed oil with a tight-radius horizontal well.

Abstract The giant Wilmington oil field of Los Angeles County California, on production since 1932, has produced over 2.5 billion barrels of oil from Pliocene and Miocene age basin turbidite sands. The seven productive zones were subdivided into 52 subzones through detailed reservoir characterization to better define the actual hydrologic units. The asymmetrical anticline is highly faulted and development proceeded from west to east through each of the ten fault blocks. In the western fault blocks water cuts exceed 96% and the reservoirs are near the economic limit. Several new technologies have been applied to specific areas to improve the production efficiencies and thus prolong the field life. Tertiary and secondary recovery techniques utilizing steam have proven successful in the heavy oil reservoirs but potential subsidence has limited its application. Case history 1 involves detailed reservoir characterization and optimization of a steam flood in the Tar Zone, Fault Block II. Lessons learned were successfully applied in the Tar Zone, Fault Block V (4000 meters to the East). Case history 2 focuses on 3-D reservoir property and geological modeling to define and exploit bypassed oil. Case history 3 describes how this technology is brought deeper into the formation to capture bypassed oil with a tight radius horizontal well.

This field trip is designed to illustrate the changes that have occurred in the last ten years to the large oil fields in the Los Angeles Basin. In 1973 Truex and others showed the importance of environmental issues when oil fields are developed in an urban setting. A Geologic Field Guide to the Long Beach Area (Clarke and Henderson, 1987) was published in conjunction with the National AAPG meeting in Los Angeles. This guide will build upon update, and complement that work with as little repeat as possible. Wright (1991) gives an excellent overview of the structural geology and tectonic evolution of the Los Angeles Basin.