Assessing surfactant influence on CO2 injection efficiency in geological storage: A pore network approach

• Developed a pore network model for CO 2 injection efficiency . • Validated model with experimental data showing similar trends. • Surfactants enhance CO 2 injection efficiency by reducing capillary pressure . • Achieved up to 28 % increase in injection efficiency with surfactants. • Emphasized interfacial tension and contact angle impacts on CO 2 injection. Carbon capture and storage (CCS) involves the sequestration of carbon dioxide (CO 2 ) in specific geological formations. During this process, injected CO 2 displaces the existing brine, creating capillary pressure at the interface due to the immiscibility of the two fluids. As this capillary pressure counteracts the injection force, the efficiency of CO 2 injection decreases. Previous research has indicated that surfactants can lower capillary pressure and increase the efficiency of CO 2 injection. Despite these findings, comprehensive quantitative analyses of the interfacial properties and the effects of surfactants on CO 2 storage remain limited. In this study, a pore network modeling technique was developed to assess the efficiency of CO 2 injection with surfactant use. The model was validated through comparison with experimental data. Using the validated model, the efficiency of CO 2 injection was examined under various conditions of interfacial properties. The study also reviewed existing literature to analyze the differences in CO 2 injection efficiency with and without surfactants. The findings suggest that the use of surfactants could improve CO 2 injection efficiency by approximately 28% under CCS conditions. The modeling technique introduced in this research offers a promising tool for analyzing fluid flow in porous media and could support future studies in this field. Moreover, the results demonstrate the potential of surfactants to enhance injection efficiency in CCS applications.