Experimental Study of Oil Recovery by Water Alternating Gas (WAG) process in Microporous media

Abstract

Water alternating gas injection process (WAG) is a tertiary oil recovery technique commonly used to enhance the displacement efficiency of the residual oil which cannot be recovered during the primary and secondary recovery processes. In this study, experimental tests were conducted in a transparent water wet microporous model packed with glass beads and initially filled with crude oil. Alternate cycles of gas and water were injected to characterize the dynamics of three-phase flows and its associated oil recovery. The displacement of the residual oil at the end of each WAG injection cycles were studied in detail using the state of the art image processing techniques. It was observed that, the continuous cycles of WAG injection have helped the saturated residual oil to spread across the porous region and effectively displaced the residual oil that remained inside the water wet porous media after the initial water flooding. Obtained experimental results helps to understand the WAG process in detail and further it helps to validate future numerical models related to this process.