Cold Lake: A Giant Heavy Oil Field from Cretaceous Incised Valleys of Alberta, Canada
G. Glen McCrimmon1 and Howard R. Feldman2
1 Imperial Oil Resources - presently seconded to Hibernia Management and Development Company, St. John's, NF
2 ExxonMobil Exploration Company, Houston, TX
The Cold Lake heavy oil field, Alberta, Canada contains in-place bitumen resources estimated at 20.7 Billion barrels. The primary reservoir occurs within large incised valleys of the Albian (Cretaceous) Clearwater Formation. To date 771 Million barrels of 10° API bitumen have been produced with recent rates between 120,000 and 150,000 barrels per day. Bitumen is recovered via in situ steam stimulation which requires closely-spaced wells (4-8 acre). As a result, there is a rich collection of well log and core data. This presents a unique opportunity to investigate reservoir continuity in great detail using over 1000 wells and 400 cores over an area of 3,200 km2. Prominent well log markers, and the abundance and density of well logs allows unambiguous correlation of incised valley fill successions.
The Clearwater Formation consists of at least 10 discrete incised valley's with depths of incision ranging from 30 to 120 m. Each incised valley fill shows a predictable updip to downdip transition from sandstone-dominated fluvial or upper estuarine deposits to mudstone-prone estuarine or marine facies. The detailed stratigraphic framework has resulted in improved recognition and prediction of reservoir quality intervals and has provided a basis for prioritization of future development opportunities.