ABSTRACT: Coupled Reaction Transport Modeling of Oil Sand Steam Stimulation

DUDLEY, JON S., Esso Resources Canada Limited, Calgary, Alberta, Canada, and CRAIG H. MOORE, C. H. Moore Research & Applications, Bloomington, IN

It has been well established through a combination of post-steam core analyses, experiment, pilot fluid analyses, and theory that artificial diagenesis occurs during steam stimulation of oil sands. The impact of this rock-fluid interaction on production is less clear. Simulations of steam stimulation, using a numerical code that couples reactions including reaction kinetics and fluid transport, promises to resolve this question by addressing the nature and extent of mineral changes and their spatial and temporal distribution.

As a test of this modeling approach, simulations have been conducted of thermal (265 degrees C) core-flow experiments designed to investigate the effect of steam stimulation on the Clearwater Formation heavy oil reservoir.

The Clearwater Formation of the Western Canada sedimentary basin is a mineralogically complex feldspathic (volcanic) lithic arenite containing about 14 authigenic minerals including both silicates and carbonates that undergoes extensive artificial diagenesis during steam stimulation. Numerical simulations of thermal core-flow experiments show a reasonable match to the reported mineral changes indicating that the code is robust enough to handle such mineralogical complexity.

Preliminary results suggest that these simulations can be used to aid in the design of experiments and identify critical reaction interdependencies that would not be readily obtainable from experiment. These reaction couplings can identify potentially critical geological parameters that control production-limiting reactions and must, therefore, be evaluated in order to assess potential reservoir performance. Also, it is hoped in future to apply this knowledge to control critical reactions and, thereby, improve heavy oil recovery.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)