Pilot test of CO2-EOR and Storage in Extra-Low-Permeability Reservoirs in the Liaohe Oilfield, Northeast China

Geological storage of carbon dioxide (CO2) is an important way to mitigate global warming, making CO2 enhanced oil recovery (CO2-EOR) and storage technology with sequestration and economic benefits a hot research topic and making positive progress in medium- to high-permeability reservoirs. However, the research on extra-low-permeability reservoirs is still poorly understand, facing the dual challenges of high cost and low efficiency. In order to clarify the potential of CO2-EOR and storage in extra-low-permeability reservoirs, this study takes the extra-low-permeability reservoir in Liaohe Oilfield, Northeast China, as an example, and integrates experimental analyzes, numerical simulations, and on-site trial injections to carry out a pilot test study of CO2-EOR and storage. The results show that the production capacity of natural energy development decreases rapidly and the recovery rate is low ( 7.5