Review of Carbon dioxide utilization and sequestration in depleted oil reservoirs

Climate change resulting from human-induced CO2 emissions is a critical global issue. To address its severe consequences, it is essential to reduce CO2 emissions and establish effective methods for capturing, utilizing, and storing CO2. Although previous efforts have focused on carbon capture and storage technologies to mitigate CO2 emissions from industrial processes, their limited feasibility, high costs, and security concerns necessitate exploring alternative approaches. One such approach involves using CO2 as a displacing agent for enhanced oil recovery and storing it in situ in depleted oil reservoirs. This comprehensive and authoritative review aims to provide an overview of experimental and modeling research on CO2 utilization in the EOR process and CO2 storage in depleted oil reservoirs. This review covers key aspects such as a comprehensive summary of CO2-EOR, including measurements of minimum miscibility pressure, screening criteria for candidate reservoirs, and injection modes for sandstone and carbonate oil reservoirs. It also assesses CO2 trapping mechanisms and storage capacity through diagrams and tables. The discussion covers experimental methods for dynamic characteristics, including injectivity, the relative permeability of water/CO2 and water/mixture phase systems, interactions within the CO2/brine/rock system, and CO2 solubility in water and oil. Furthermore, the review describes numerical modeling technologies for CO2 sequestration, encompassing CO2 migration, thermo-hydrological-mechanical processes, caprock stability, hydromechanical factors, geochemistry, and reactive transport modeling. Risk assessments for CO2 storage are also explored, including breakthrough pressure, sealing materials for leakage mitigation, and wellbore cement degradation and mitigation. Finally, the challenges and prospects of supercritical CO2 storage are discussed.