Abstract: A Method of Integrating Capillary Pressure and Relative Permeability Data into a Fullfield Numerical Simulation of Main Body "B" Reservoir, Elk Hills Field, California

HAMPTON, THOMAS, Holditch Reservoir Technologies; S. SINGH, Occidental of Elk Hills, Inc

There are several major reservoirs within Elk Hills Field with a large dataset of capillary pressure and relative permeability data. Several major reservoir studies are underway to assist in the further development of this world class field recently acquired by Oxy. A fullfield simulation has been tasked to quickly enhance the reservoir management of upper Main Body "B" Reservoir.

The challenge is to have an accurate reservoir description that efficiently utilizes the wide range and large data set that is available. This is needed to fully model this complex, layered, turbidite reservoir (Stevens sandstone in Miocene Monterey formation). Also needed, is the ability to integrate additional laboratory data as it becomes available since modern core has recently been obtained. Main Body "B" has 30 sets of Capillary Pressure (Pc) from 7 wells, 18 sets of relative permeability to water from three wells, and 16 sets of relative permeability to gas. The laboratory capillary pressure was obtained in brine, gas, or mercury fluids. Most of the data was obtained in the 1970's.

By using an emerging innovative SCAL software program, some of the major tasks performed were the following: prepare a database of special core analysis, perform quality control, effectively convert the measured data to consistent units and field conditions, generate Leverette J-function, calculate height of saturation plane above free water level, group multi-phase rock fluid data according to hydraulic flow units, transform laboratory data into "rock" curves for input into ECLIPSE simulator and automatically assign curves to grid cells.

This feature resulted in significant time savings to Oxy in developing an integrated large model of Main Body "B" Reservoir at Elk Hills, where many different flow units are observed. Further, the quality of reservoir description is significantly improved by using this tool. Also, as additional data becomes available, it can quickly be incorporated into the model. By improving the quality of the reservoir model, accuracy in development planning is expected.

AAPG Search and Discovery Article #90911©2000 AAPG Pacific Section and Western Region Society of Petroleum Engineers, Long Beach, California