PORE-SCALE 3D MODELING OF VISCOUS FINGERING FOR NON-NEWTONIAN HEAVY OIL RECOVERY

Abstract

Heavy oil recovery faces significant challenges due to the unstable displacement of oil by water, known as viscous fingering (VF). This occurs when low-viscosity fluids displace high-viscosity fluids, leading to inefficient oil recovery and increased water production. These issues reduce efficiency and increase environmental and economic costs, highlighting the need for improved simulation techniques to better understand and manage VF dynamics. This study examines the use of non-Newtonian Carreau fluids in modeling VF phenomena, offering more realistic simulations than Newtonian fluids. The shear-thinning behavior of Carreau fluids allows injected fluids to penetrate smaller pores effectively, influencing finger formation and growth. Current work, which incorporates non-Newtonian fluid characteristics, provides a more accurate representation of viscous fingering, including key features such as finger formation, merging, coalescence, blocking, tip-splitting, and expansion. Three porosity values (0.29, 0.5, and 0.7) are simulated to represent diverse reservoir conditions. A 3D computational fluid dynamics (CFD) model is utilized, employing the volume of fluid (VOF) approach to capture immiscible displacement processes. The model is validated using experimental data from coreflood studies. The results demonstrate that porosity significantly influences VF behavior, with lower porosities resulting in more pronounced finger formation, splitting, and coalescence. Non-Newtonian fluids decrease instability by moderating VF growth dynamics, enhancing displacement efficiency. These findings emphasize the importance of incorporating non-Newtonian fluid properties and porosity variations into VF simulations to optimize oil recovery processes. This study provides insights into VF dynamics, advancing the development of sustainable and efficient heavy oil recovery technologies.