Performance of a Thermal Horizontal Well Pilot

Abstract

Production performance of Esso Resources Canada Limited’s Horizontal Well Pilot I (HWPI), recovering10 degree API bitumen from Cold Lake, is described. The well has utilized a vertical steam injection well since 1980. Over 50,000 m3 of bitumen have been recovered at a cumulative oil-steam ratio (OSR) of over 0.35 during the first eight years of operation. A comprehensive field monitoring program of HWPI was undertaken including well bottomhole pressures and temperatures, reservoir temperatures, interwell radioactive tracer tests, surface seismic surveys and cased hole logs. Approximately 20 to 30 percent of the original bitumen in place in a thermally drained zone, inferred from measured surface seismic data, was recovered. A wellbore utilization of approximately 98 meters or 40 percent of the total horizontal slotted liner length was estimated based on the surface seismic anomalies and bitumen production data. This finding was confirmed from the results of a successful numerical simulation history match of this pilot. Analytical models have identified that pressure drive mechanisms dominated the early life of the well, with gravity drainage accounting for most of the production later in the well’s life.