Lithological Discrimination and Correlation in Oil Sands Using Rock Magnetic Properties

MORRIS, WILLIAM A., McMaster University, Hamilton, Ontario, Canada

The Lower Cretaceous McMurray Formation, which contains most of the bitumen reserves of the Athabasca oil sands, comprises uncemented quartz sands with siltstone, shale, and local ironstones. The sequential fluvial, estuarine, and marine depositional environments of the McMurray drainage basin have resulted in the complex juxtaposition of differing lithofacies. Horizontal continuity of lithofacies is limited. Sand body geometries are many and varied. Prediction of sand body geometry has important economic applications; a strong positive correlation exists between sand facies and oil grade.

An investigation of the magnetic property variations in specimens from five closely adjacent boreholes within the McMurray Formation has shown that it is possible to: (1) document objective magnetic property parameters to differentiate distinct lithological units; (2) use these same magnetic parameters to establish between borehole lithostratigraphic correlations; and (3) to show that the magnitude of some magnetic parameters bears a direct relationship to the oil content of a lithology.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)