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.