Investigating the interplay of fracture inclination and rock properties on supercritical CO2-foam flow in porous media

Abstract

Natural and induced fractures in porous media pose significant challenges in subsurface applications such as carbon storage, hydrocarbon production, and aquifer contamination mitigation. These highly permeable fractures disrupt the natural flow in porous formations, leading to issues including reduced pressure buildup and early fluid breakthrough. To address these challenges, foam injection serves as an effective method for fluid diversion, offering enhanced mobility control in fractured media. However, the foam's performance must be carefully optimized considering factors such as reservoir conditions, in-situ fluid compatibility, rock properties like pore structure, permeability, and mineralogy, as well as fracture roughness, homogeneity, and orientation. This study investigates the effects of inclination angles (0°, 5°, 10°, and 15°) of smooth, saw-cut fractures on the performance of supercritical carbon dioxide foam in three distinct carbonate rocks: Indiana limestone, Fond Du Lac dolomite, and Alabama Silver limestone. These rocks exhibit a wide range of permeabilities, from 0.4 mD to 5.4 D. The findings are compared with previous research on Berea sandstone. It is demonstrated that optimal foam performance is more readily achieved in fractured porous media with higher permeability, larger pore throat sizes, and mineralogically compatible formations. Unlike previous work where studies focused on the individual impact of specific parameters, including a previous study conducted by our group to explore the effect of fracture orientation, the novelty of this paper is that it addresses multiple parameters at the same time and the interconnected roles that they play. This interplay of fracture orientation, rock type, and flow properties is what determines the ideal conditions that must be optimized to achieve the required foam performance.