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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 64 (1980)

Issue: 6. (June)

First Page: 960

Last Page: 960

Title: The Alsands Project--A Challenge in Petroleum and Mining Geology: ABSTRACT

Author(s): J. Douglas Feir

Article Type: Meeting abstract

Abstract:

A third mining operation in the Athabasca oil sands area of northern Alberta is planned by the Alsands Project Group, a consortium of nine petroleum companies.

The group is considering the use of large draglines to excavate oil sands from an open pit mine. This project contemplates separation of the bitumen and sand by a hot water process, followed by upgrading to synthetic crude oil. Production will begin in 1986; when design capacity of 140,000 b/d (22,250 m3/d) is reached, this project will supply over 10% of Canada's forecast crude producibility.

The bitumen occurs in a 300 ft (90 m) sequence of unconsolidated sands and clays of the Lower Cretaceous McMurray Formation, at or near the surface. A thin veneer of Recent and Pleistocene aeolian and glacial deposits overlie the McMurray. Devonian carbonates and evaporites occur below the Cretaceous. McMurray deposition took place in a mesotidal, coastal environment. The lowermost sands are fluvial, upper delta plain, overlain by tidal channel and tidal flat sands and muds of the lower delta plain. Some marine barrier bars and beaches have been identified. The highest bitumen saturations occur in the fluvial and tidal channel sands. However, the lowermost sands are frequently water saturated under artesian conditions. The rugged paleotopography of the Devonian erosional surface has s gnificantly influenced the depositional pattern of the overlying McMurray. This relief is, in part, due to the solution of Middle Devonian salt beds, with subsequent collapse of the overlying units.

This complex sequence of depositional patterns, varying lithologies, and fluid contents, combined with salt tectonics, has created the need for detailed geological and geotechnical studies to interface with mining engineering in developing a viable mine plan.

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Copyright 1997 American Association of Petroleum Geologists