Development and Applications of CO-Responsive Gels in CO Flooding and Geological Storage.

Gel systems are widely used as plugging materials in the oil and gas industry. Gas channeling can be mitigated by reducing the heterogeneity of the formation and the mobility ratio of CO to crude oil. Cracks and other CO leaking pathways can be plugged during the geological storage of CO to increase the storage stability. By adding CO-responsive groups to the classic polymer gel's molecular chain, CO responsive gel is able to seal and recognize CO in the formation while maintaining the superior performance of traditional polymer gel. The application of CO responsive gels in oil and gas production is still in the stage of laboratory testing on the whole. To actually achieve the commercial application of CO responsive gels in the oil and gas industry, it is imperative to thoroughly understand the CO responsive mechanisms of the various types of CO responsive gels, as well as the advantages and drawbacks of the gels and the direction of future development prospects. This work provides an overview of the research progress and response mechanisms of various types of CO responsive groups and CO responsive gels. Studies of the CO responsive gel development, injectivity, and plugging performance are comprehensively reviewed and summarized. The shortcomings of the existing CO responsive gels system are discussed and the paths for future CO responsive gel development are suggested.