Design and Application of an Alkaline-Surfactant-Polymer Recovery System for the West Kiehl Field

SUMMARY The West Kiehl Unit, Crook County, Wyoming produces from the Minnelusa Lower "B" Sand reservoir. Original oil in place (OOIP) is estimated at 238, 481 m3. Estimated ultimate primary production is 27, 028 m3 or 11% OOIP. Four enhanced oil recovery methods were considered for application in this reservoir: conventional waterflood, polymer flood, an alkaline-polymer flood, and an alkaline-surfactant-polymer (ASP) flood. Estimated ultimate recoveries are 95, 392 m3 (40% OOIP), 95, 392 m3 (40% OOIP), 95, 392 m3 (40% OOIP), and 135, 934 m3 (56% OOIP), respectively. The polymer flood is expected to deplete the field faster than a conventional waterflood without an increase in ultimate recovery, while the ASP technology is expected to extend the field life and increase ultimate recovery dramatically. The ASP process has been implemented and early performance is very good. Two purposes are being served by implementation of the West Kiehl alkaline-surfactant-polymer flood. The first is to recover additional oil not recoverable by a waterflood or a polymer flood. The second is to pilot this potentially significant enhanced oil recovery (EOR) technique for other Minnelusa reservoirs. If this method proves successful, it will represent a sizable increase in ultimate recovery with the incremental oil recovery ranging as high as 25% OOIP. This paper discusses the goal for utilizing the alkaline-surfactant-polymer technology at the West Kiehl. Further, it details the development of the West Kiehl Field project including laboratory studies, reservoir parameters, initial injection and production history, facilities design, and operations of the flood.