Performance of Hawkins Field Unit Under Gas Drive-Pressure Maintenance Operations and Development of an Enhanced Oil Recovery Project

Abstract

ABSTRACT In-depth studies of the Hawkins Field Unit revealed that gas drive-gravity drainage had a recovery efficiency of over 80 percent whereas the recovery efficiency from water drive was about 60 percent. These studies led to unitization of the Hawkins Field on January 1, 1975 and initiation of a gas injection project using produced gas and inert gas. This gas injection project has been very successful in converting the combination gas drive - water drive recovery mechanism to essentially all gas drive. Recent studies indicate that immiscible gas drive of the water invaded portion of the reservoir should recover additional oil. These studies show that the minimum residual oil saturation from gas displacement of water invaded oil column is essentially the same as that from gas displacement of original oil column. Thus, potential exists for reducing the average residual oil saturation in the water invaded oil column from 35 percent to about 12 percent by gas drive-gravity drainage. The process of gas displacement of a water invaded oil column has been termed Double Displacement Process (DDP). This paper reviews the performance of the Hawkins Field Unit under the existing gas drive-pressure maintenance project. It also discusses the development work recently completed supporting the Double Displacement Process and the initiation of an enhanced recovery project using DDP in the East Fault Block.