Carbon dioxide sequestration through enhanced oil recovery: A review of storage mechanisms and technological applications

The carbon capture, utilization and storage (CCUS) technology is an effective approach for reducing carbon emissions and an important supporting method for achieving global goals of peak carbon emissions and carbon neutrality. The process of carbon dioxide (CO2) flooding, which refers to utilizing captured or stored CO2 through CCUS for the purpose of enhanced oil recovery (EOR), is one of the primary large-scale CO2 utilization techniques available. As global energy demand and CO2 emissions continue to rise, the use of captured CO2 for EOR is becoming more widely considered and applied to improve oil production from mature oilfields. This review presents a current perspective on the utilization of CO2-EOR and its technological requirements. Sources of CO2 available for CO2-EOR are identified and recent progress in CO2-EOR developments around the world are compared. The key mechanisms and technologies including carbonized water flooding, continuous CO2 injection, cyclic CO2 injection, gas-cyclic "huff-n-puff", and the involvement of nanoparticle-based additives are considered in detail. Environmental and economic factors influence the technical designs and suitability of CO2-EOR for specific subsurface reservoirs. These factors are insightful regarding future research and development requirements, particularly in respect of nanotechnology deployments. Recommendations are made regarding how CO2-EOR projects could be implemented and operated more efficiently, and how, for prospective projects, opportunities can be exploited and challenges overcome.