Compared with water, CO2 has larger expansibility, lower viscosity and lower reaction degree with rock.As an enhanced geothermal system (EGS) seepage heat transfer fluid, CO2 has higher heat transfer efficiency than water.This paper summarizes the research status of fluid/rock interaction in CO2-EGS from three aspects: theoretical research, experimental research and numerical simulation.The changes of reservoir rock properties are evaluated from mineral composition, micro pore structure and mechanical properties.The results show that the main reaction minerals of CO2-water-rock interaction are quartz and feldspar, and the precipitation minerals are montmorillonite, illite and calcite.The interaction of CO2-water-rock will lead to the decline of mechanical properties of reservoir rocks and the change of pore structure characteristics.Finally, the existing problems and development trend of CO2-water-rock interaction in CO2-EGS are discussed, which provides a reference for the development and research of CO2-EGS in the future.
