Comparative analysis of the efficiency of various forms and technologies of CO2 injection for geological storage and enhanced oil recovery

To reduce anthropogenic carbon dioxide (CO₂) emissions, it is necessary to implement carbon capture projects followed by CO₂ injection into reservoir formations for geological storage and enhanced oil recovery. This paper examines the main CO₂ injection methods applied in reservoir systems for both enhanced oil recovery and long-term carbon sequestration. The analysis includes the injection of supercritical CO₂, water-alternating-gas (WAG) technology, and carbonated water injection. Several studies indicate that CO₂ retention is most efficient when it is injected in dissolved form within formation water compared to other methods; however, the total mass of CO₂ injected under such conditions is lower. In the supercritical state, a higher mobility of the displacement front is observed, leading to improved sweep efficiency. The WAG process demonstrates intermediate performance in terms of both sweep efficiency and oil displacement effectiveness.

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