ABSTRACT: Oil Sands--The Key to Canada's Future Oil Supply
With the decline in conventional light oil resources in the Western Canada basin, oil sand and heavy oil deposits are being recognized as leading energy alternatives with the potential to fuel Canada's self-sufficiency in oil supply into the 21st century.
The Athabasca deposit in northeastern Alberta contains 900 × 109 bbl of bitumen; however, the initial oil viscosity is greater than 1 million cp. The bitumen must be heated to 212°F before the viscosity will drop below 1000 cp for flow to occur. To date there has been no successful, commercial in-situ recovery of this bitumen, but steam injection appears to be the most effective way to heat the reservoir.
The oil-bearing McMurray Formation of the Athabasca deposit consists primarily of unconsolidated sands and muds of the Lower Cretaceous Mannville Group. These sediments were deposited in a fluvial/estuarine environment, producing a complex series of interbedded-channel, off-channel, and marine sediments. To heat the bitumen by steam injection and to establish communication between wells through this heterogeneous reservoir requires a thorough understanding of the geology and the complex recovery mechanisms.
The Alberta Oil Sands Technology and Research Authority currently participates in two experimental pilots in the Athabasca oil sands and is the operator of a novel method using shaft and tunnel access and horizontal wells. Each of these pilots will be discussed to illustrate the impact of the geology on the recovery method being used.
AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990