Review on technologies of geological resources exploitation by using  carbon dioxide and its synchronous storage

Fossil fuels with coal as the main body currently account for more than 80% of the energy consumptionin China. The carbon dioxide capture and storage (CCS) is the key to reduce carbondioxide (CO2) emission at large scale, thus help us reaching the “carbon peaking” and realizing the goal of “carbon neutrality” in the whole world. The progress of CCS projects of countries across the globe are compared. There are 164 CCS projects around the world (distributed in 28 countries), and 56 on-going CCS projects (distributed in 15 countries). The United States, China and Britain are the top three countries on sum of CCS projects, and for on-going projects, the United States, China and Canada are top three countries. The technical principle of CO2 used in the development of petroleum, brine, natural gas, combustible ice and other geological resources and simultaneously realizing different degrees of geological storage is introduced CO2 flooding technology is less carbon-intensive than traditional production methods, and at the same time can use crude oil goafs to achieve CO2 storage.The theoretical storage capacity for CO2 in deep saline aquifer is adequate to keep the atmospheric CO2 concentration around 450 ppm, saline and mineral elements could be potentially benefit to offset the cost for CO2 storage to some extent. While CO2 is applied to displace methane and other gases, the formation characteristics, injection pressure and temperature determine the production efficiency, and the tightness of the natural gas storage formation helps reduce the diffusion and loss of CO2 in the vertical direction. Furthermore, technologies for CO2 geological storage with synergistic high-salinity water treatment, CO2 for hot-dry-rock driven power generation and underground coal gasification are discussed. CO2 storage with synergistic high-salinity water treatment could realize simultaneous cut of emission for both, and high hardness in the water could accelerate carbonation of CO2. CO2 is also used as a gasification agent, which can adjust the composition of syngas, but the gasification process is difficult to control, and the formation space generated by coal gasification can be used for CO2 storage. The use of CO2 in the development of hot dry rock can save water and reduce pipeline scaling, but the high loss rate of CO2 may lead to unsatisfactory sequestration effects.Finally, the problems of lack of complete equipment development, lack of understanding of technical principles, high technology costs, and lack of laws and regulations faced by CCS are summarized, and its application potential is prospected.