The Kuparuk River oil field has had a "miscible" water-alternating-gas (MWAG) enhanced-oil-recovery (EOR) pilot in place since 1988. This original pilot was implemented on two drillsites previously on waterflood. The pilot was expanded to a third drill site in 1993 to test the MWAG process in an area previously flooded by an "immiscible" water-alternating-gas (lWAG) recovery technique. Large-scale application of MWAG at Kuparuk is in progress, with a project that will more than triple current MWAG injection. Full implementation is slated for mid-1996. When completed, the Kuparuk large-scale EOR (LSEOR) project will be among the largest of its kind in the world. This paper covers the basic aspects of moving the EOR process at Kuparuk from pilot to large-scale application. A number of hurdles had to be overcome, including scaleup of field and simulation results in a consistent manner and the need to use existing infrastructure to ensure economic viability.
The Kuparuk River field is on Alaska's North Slope, approximately 260 miles north of the Arctic Circle and 30 miles west of the Prudhoe Bay field (Fig. 1). On the basis of remaining reserves and a current production rate of nearly 300,000 BOPD, Kuparuk is the second largest field in North America. From the time of first production in 1981, Kuparuk has operated under a variety of recovery mechanisms, including primary depletion, waterflood, lean-gas reinjection, and both IWAG and MWAG injection. Reservoir development decisions are often complex and interrelated, requiring the integration of reservoir recovery mechanisms and surface facility constraints. This was especially true for the Kuparuk LSEOR project.