Application and Research Progress of CO₂ Stimulation Technology in Unconventional Oil and Gas Reservoirs: A Review and Prospect

Efficient exploitation of unconventional oil and gas resources plays an indelible role in meeting national development requirements and daily consumption and ensuring national resource security, but it is difficult to achieve efficient exploitation by traditional fracturing and oil displacement methods. Carbon dioxide (CO2) fracturing technology and flooding technology have become important means to enhance oil recovery of unconventional oil and gas reservoirs because of advantages of the significant effect on the production increase, small damage to the reservoir, large scope of application, and low cost. In this paper, the mechanism and technology of CO2 in fracturing, flooding, and storage are analyzed on the basis of the current research status of CO2 in the field of unconventional oil and gas production. The application examples and related research of CO2 fracturing technology, flooding technology, and storage technology used in oil and gas reservoirs both domestically and internationally are reviewed. The related application technologies and technical bottlenecks are discussed. Eventually, the related technologies of CO2 are prospected. It is expected to provide scientific advice for CO2 capture, flooding, and storage technologies.