Evaluation of CO2 enhanced oil recovery and CO2 storage potential in oil reservoirs of petroliferous sedimentary basin, China

Carbon Capture, Utilization, and Storage (CCUS) technology has emerged as the bottom-line technology for achieving carbon neutrality goals in China. The development of Carbon Dioxide Enhanced Oil Recovery (CO2-EOR) not only increases revenue for high-investment CCUS projects but also enables permanent CO2 storage in the oil reservoir. However, the basin is used as the research object to evaluate the CO2 storage potential of the oil reservoir. The evaluation results are inaccurate and unable to support the implementation of later CCUS projects. Here, more accurate oil reservoir data is employed as the evaluation object. It is the first time at the national level to screen oil reservoirs to distinguish between CO2 miscible and immiscible, and evaluate the potential of CO2-EOR and CO2 storage in the reservoir. The research results show a total of 2570 suitable oil reservoirs in 4386 candidate oil reservoirs nationwide. About 1.26 billion tons of additional crude oil can be produced by CO2-EOR technology. This includes approximately 580 million tons of additional oil from CO2 miscible flooding and 680 million tons from CO2 immiscible flooding. The study further refines the CO2 geological utilization data and provides a theoretical basis for CCUS project site selection in China.