Predicting bitumen recovery from steam stimulation. [Alberta]

Alberta's bitumen reserves occur in 4 major deposits that contain 980 billion bbl of bitumen in place. The Cold Lake deposit, 150 miles northeast of Edmonton, contributes in excess of 125 billion bbl of high viscosity, low gravity in-place bitumen. This deposit is confined within a large area, roughly 3000 sq miles in E.-Central Alberta, and is buried to a depth of 1000 to 1500 ft. Due to bitumen's high viscosity at virgin conditions, conventional oil field recovery techniques cannot be applied and surface mining techniques are impractical due to excessive overburden. Esso Resources has been experimenting with in situ recovery methods in the Cold Lake deposits since the early 1960's with major emphasis on steam stimulation. Esso's Leming pilot project is the most successful and largest in the area, and its performance under steam stimulation is discussed in this work. Total investment at Leming exceeds $50 million and has provided sufficient steam stimulation definition for Esso to propose a commercial development based on this recovery process. The pilot project begun at Cold Lake (later expanded to include 80 wells) has resulted in a technique for forecasting oil recovery from a full-scale project.