In this paper we examine how residual oil trapping by mobile water affects the recovery performance of miscible EOR processes. The objectives of the study are (1) to develop a multiphase, numerical model to investigate factors affecting water-blocking and the release of oil from dendritic states; (2) to evaluate performance of miscible processes and forecast displacement efficiency and recovery under a variety of operating conditions, and (3) to determine the "optimum" water-solvent ratio to be used in a miscible Water-Alternate-Gas (WAG) process. Using the multiphase flow model, we considered the oleic phase as two parts, a mobile phase and a trapped phase, and studied the effects of capillary forces, solvent viscosity, fraction of trapped oil, dispersion and mass transfer coefficients on recovery performance. Guidelines for determining the optimum water-solvent ratio to be used in a miscible WAG process are discussed.

You can access this article if you purchase or spend a download.