Altering Capillary Pressures Using Anionic Surfactants for Geological Carbon Storage Applications: Micro-Scale Observations

Abstract Carbon dioxide is the well-known green-house gas responsible for the global warming. Geological carbon storage utilizes readily available technique to store CO 2 in a large scale. The CO 2 storage efficiency of geological carbon storage depends on the CO 2 injection rate and the sweep efficiency. Surfactants have been utilized to enhance sweep efficiency by modifying capillary pressure, recently in geological carbon storage. In this study, the performance of anionic surfactants for enhancing the sweep efficiency during geological carbon storage has been investigated in lab scale. Micromodel and pore network model results have shown that the use of anionic surfactants can significantly lower the interfacial tension and thus the capillary pressures and enhance the sweep efficiency, demonstrating the significant potential of anionic surfactants for increasing CO 2 storage capacity in geological carbon storage.