Thermal reservoir simulation is used to develop an operational strategy for the Tulare sand of the South Belridge field. History matching of an ongoing steamflood that has been in operation since 1981 is used to test the validity of the model. The primary purpose of the simulation study is to evaluate and design the optimum steamflood for an expansion project in the undeveloped, southern portion of the field. The simulation model also is used to study operating policy options for current operations as well as for new development. This study results in the recommendation that a 5-acre, nine-spot pattern be developed for the Southern Expansion Project. Study of operating policy shows that steamflood performance can be improved by shutting in marginal producing layers and optionally cutting back the steam-injection rate.
South Belridge field ranks among the five largest producing fields in the U.S. The Pleistocene age Tulare formation is the main reservoir at South Belridge and currently produces under steamdrive. Mobil Oil Corp. operates the southern portion of the field area, and Shell Oil Co. operates the northern portion. The primary area of interest in this paper is the Mobil-operated portion of the field. All reservoir properties and production history discussed in this paper will be for that property only. The shallow, heavy-oil reservoir consists of unconsolidated sediments deposited in a fluvio-deltaic geologic setting. Correlation of reservoir sands at South Belridge has always been difficult owing to reservoir discontinuity and rapid lithofacies change. Few published results exist concerning steamflooding in reservoirs with similar highly layered and stratigraphically discontinuous sands.