Abstract: The Importance of Quantification of Reservoir Mineralogy in Thermally Enhanced Recovery Projects: A Study Via Computer Simulations

Craig H. Moore, Jon S. Dudley, Ann Cochran

The local mineralogy of most reservoirs varies, over a moderate range, in the amount, grain size and composition of the mineral constituents. Computer simulations of steamflooding of a bitumen deposit suggest that these variations can significantly affect the induced diagenesis of the reservoir.

Detailed petrography of rocks from one bitumen deposit in the Clearwater formation of Alberta indicates that there are approximately 40 different modal mineralogies. X-ray diffraction, SEM, and electron microprobe work provides reasonably detailed identities and chemical compositions of the fine-grained minerals present. These data, some experimental data, and thermodynamic and kinetic data from the literature, were used to simulated the effects of steamflooding using the REACTRAN computer code. The results of the simulations show that different systems behave in significantly different ways even though some of their modal mineralogies are similar. The different types of behavior may have a dramatic influence on formation damage caused by thermally enhanced recovery.

Not all 40 modal mineralogies behaved differently and, in this case, they could be categorized into 16 groups, the rocks within each showing similar behavior. Correlation of these groups with zones and facies in the reservoir can help determine the most efficient strategies for production and the least-damaging techniques to use for thermally enhanced recovery in particular wells.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994