Investigation on foam-assisted chemical flooding for enhanced oil recovery

Abstract

Foam-assisted chemical flooding (FACF) is a novel enhanced oil recovery (EOR) methodology that combines the injection of a surfactant slug, to mobilize previously trapped residual oil, with foam generation for drive mobility control, thus displacing the mobilized banked oil. The main goal of this study concerns the understanding of oil mobilization and displacement mechanisms that take place in a FACF process. At first, in order to promote understanding of the incremental benefits FACF can provide one with, we get ourselves familiar with immiscible gas flooding and water-alternating-gas (WAG) injection. Subsequently, we study the effect of aqueous phase salinity, drive foam quality, and method of drive foam injection, on the oil mobilization and displacement processes in FACF, at both model-like conditions and in a reservoir setting. We present novel insights, on the dynamic physical processes that take place within the porous media during FACF, which could only be obtained through the assistance of a medical CT scanner. Moreover, in order to identify the main controlling parameters that determine incremental oil recovery in WAG and FACF, we develop several mechanistic models for the aid of history-matching laboratory observations.