Abstract: Application of Geostatistical Modeling and Reservoir Simulation in Management of a Turbidite Reservoir Waterflood, Elk Hills Oil Field, California
WIGHTMAN, JEFF, MALCOLM E. ALLAN, and MARK L. WILSON
The Elk Hills giant oilfield, located in the southern San Joaquin Valley of California, has produced 1.1 billion barrels of oil from Miocene and shallow Pliocene reservoirs. 65% of the current 60,000 BOPD production is from the pressure-supported, deeper Miocene turbidite sands.
The Main Body B turbidite sands of the 31S structure have been produced under peripheral waterflood. Large porosity and permeability variations in the Main Body B have led to early breakthrough of water in better quality sands and the bypassing of reserves in lower quality sands. Reservoir descriptions based on deterministic methods using cross-sections and traditional geologic mapping have not provided enough detail to capture the shore-scale stratigraphic heterogeneity needed for adequate reservoir simulation of the waterflood. An improved reservoir description was developed in this study using geostatistics which incorporated electric log and core data. This geostatistical description realistically depicted the sequences and lateral continuity of the sands and shales within the reservoir.
A reservoir simulation model with approximately 60,000 cells was constructed from the detailed geostatistical description to evaluate future waterflood strategies. A history match of rates and pressure was obtained through the twenty years of production history. The simulation model was used to quantify rate and reserve potential for infill drilling and conversion of the existing peripheral waterflood to a pattern waterflood.
Search and Discovery Article #90945©1997 AAPG Pacific Section Meeting, Bakersfield, California