Steam Stimulation Heavy Oil Recovery At Cold Lake, Alberta

Abstract

Abstract This paper describes the application of steam stimulation techniques for economic recovery of extremely viscous, low temperature, sour bitumen at Cold Lake, Alberta, Canada. These techniques were developed through an extensive fifteen year program which included engineering studies, laboratory research and a succession of experimental field pilot projects which currently produce 800 m /day projects which currently produce 800 m /day (5000 bbl/day). Cold Lake wells cannot be produced without thermal stimulation, nor produced without thermal stimulation, nor can fluids be injected into the bituminous sand matrix at moderate pressures. With high pressure steam injection, however, the formation breaks down to accommodate large volumes of hot fluid, penetrating vertically through the zone and laterally in a generally preferred northeast-southwest direction from preferred northeast-southwest direction from each well. After steam injection and a short soak period, heavy oil is produced at rates up to 30 m3 per day (190 bbl/day). Production rates have been found to be Production rates have been found to be related to reservoir parameters controlled by the Lower Cretaceous depositional environments (sand continuity, grain size, fines content and fluid distribution) and to the volumes of steam injected. With multiple cycles, recovery is expected to be 20 percent, but is dependent on completion practices, well spacing and pattern orientation. High regulatory pattern orientation. High regulatory approval, Esso Resources Canada Limited plans to develop a 25 000 m3 per day plans to develop a 25 000 m3 per day (160,000 bbl per day) raw bitumen production operation. The project will production operation. The project will include upgrading facilities at the field site to yield a widely marketable synthesized crude oil product. Introduction Cold Lake is one of the four major Alberta oil sands deposits highlighted in Figure 1. It contains an estimated 25 × 10(9) m3 (160 billion barrels) of low gravity, highly viscous oil in place. The resource is deposited over approximately 800,000 hectares (two million acres) in east-central Alberta, some 290 km or 180 air miles from the city of Edmonton. It occurs in thick Lower Cretaceous sand sequences buried to depths ranging from 300 to 600 metres (1100 to 2000 feet). The oil or "bitumen" is too deep to be recovered by conventional surface mining and too viscous to flow or be pumped to surface at native conditions. Esso Resources Canada Limited and its Parent Company, Imperial Oil Limited, began Parent Company, Imperial Oil Limited, began laboratory and engineering studies in the early 1960's, progressing to small-scale field pilot recovery trials in 1964. Since that pilot recovery trials in 1964. Since that time, pilot operations have been expanded, extensive reservoir description information has been compiled and economic potential has been demonstrated. Current prospects for a major commercial development encompassing an area of 140 km2 (55 square miles) is now view with a high level of interest and anticipation by industry, regulatory bodies, communities and governments. RESOURCE DESCRIPTION As shown in Figure 2, oil sands at Cold Lake occur in the Lower Cretaceous Manville Group which consists of the McMurray, Clearwater and Grand Rapids formations with the Grand Rapids divided into upper and lower members. The sediments are deposited on a Paleozoic erosional surface and are overlain by at least 300 m (1000 feet) of total overburden consisting largely of shales and about 120 m (400 feet) of glacial drift.