OTOTT, GEORGE E., JR., and BOB RUNGE, THUMS Long Beach Company, Long Beach, CA, DON CLARKE, City of Long Beach Department of Oil Properties, Long Beach, CA, and GARY WOODLING, ARCO Long Beach Inc., Long Beach, CA

ABSTRACT: Reservoir Description Needs for Layered Waterflood Surveillance Long Beach Unit, Wilmington Field

Recent California legislation has paved the way for the state of California, the city of Long Beach, ARCO, and THUMS Long Beach Company to work together on interdisciplinary teams to design and implement an optimized waterflood plan for the Long Beach Unit of the Wilmington oil field. Four engineering/geologic teams each manage specific reservoir formations using data from 1500 wells.

Initially, work began on a sand level using a large volume of existing reservoir description work from equity determination. Major stratigraphic units were delineated into individual sand bodies, each with an oil-water contact, ranging from 10 to 60 ft thick and separated by shales 5 to 30 ft thick. Fault planes were also mapped. These efforts resulted in sand body resolution from four to ten-fold finer than previous mapping.

A large amount of engineering data, including spinner surveys, sand splits, pressure monitoring, and RFT, was combined with the reservoir description to assess flood performance and to plan drilling locations. Injection "thief" sands were correlated and omitted from new well completions. The data were collected and organized in a computerized data management system.

The first success was achieved with a 7-spot pilot waterflood in the Ranger West reservoir. Four injection wells were drilled as a result of the reservoir description and engineering work. Oil production in the area increased from 2700 to 3600 bbl/day during the first six months.

The challenge for the reservoir teams is to extend the waterflood plan to a flow unit level. A reservoir zonation workstation system has been installed to provide rapid sand-body correlation and visualization.

AAPG Search and Discovery Article #90992©1993 AAPG Pacific Section Meeting, Long Beach, California, May 5-7, 1993.