The Influence of Pore Geometry on the Viscous Instability in Surfactant-polymer Flooding in Heavy Oil Reservoirs

Abstract

This study examines the effect of pore geometry on the viscous instability in surfactant-polymer flooding in an initially preferential water-wet porous medium filled with heavy oil and brine. Two approaches are used to characterize the effect of viscous instability. In both approaches, the dynamic mean pore-scale capillary number is considered as the foremost criterion to characterize the effect of viscous instability. In the first approach, which is a pore network approach, the effect of viscous instability on is neglected. In the second approach, the viscous instability effect is included by using the viscous instability theory to determine . The comparison between from the port network approach and viscous instability theory is used to show the effect of viscous instability. The change in was found to be an appropriate tool to characterize the effect of viscous instability in surfactant-polymer flooding.