Carbon Capture, Utilization, and Storage (CCUS) Hybrid CO₂ Sequestration and Enhanced Oil Recovery: A Sustainable Approach Assessment of CO₂ injection strategies that maximize hydrocarbon recovery while ensuring long-term geological storage stability

Carbon Capture, Utilization, and Storage (CCUS) technologies are pivotal in mitigating climate change by reducing CO₂ emissions from industrial sources. Among the most promising CCUS approaches is the integration of CO₂ sequestration with Enhanced Oil Recovery (EOR), which not only aids in reducing atmospheric CO₂ but also enhances hydrocarbon recovery from mature oil reservoirs. This evaluates hybrid CO₂ sequestration and EOR strategies, focusing on the optimization of CO₂ injection methods that maximize oil recovery while ensuring the long-term geological stability of the stored CO₂. CO₂ injection into oil reservoirs enhances oil recovery through mechanisms such as miscible displacement, oil viscosity reduction, and swelling effects. The study examines various CO₂ injection strategies, including continuous, cyclic, and water-alternating-gas (WAG) injection, and their effectiveness in improving oil recovery efficiency. Additionally, advanced methods like foam-assisted CO₂ injection are explored for their potential in increasing sweep efficiency and reducing CO₂ mobility, thus enhancing both hydrocarbon recovery and storage security. Ensuring the long-term stability of stored CO₂ is critical to the success of CCUS projects. The study assesses the factors influencing CO₂ retention, including capillary trapping, mineralization, and solubility trapping, and highlights the role of advanced monitoring techniques, such as 4D seismic imaging and pressure monitoring, to detect potential leakage and ensure the integrity of storage sites. This emphasizes the environmental and economic benefits of hybrid CCUS-EOR systems, which offer a dual advantage of climate change mitigation and extended hydrocarbon production. The review concludes with an analysis of the challenges and future directions for large-scale deployment, including technological advancements, cost barriers, and regulatory considerations, ultimately advocating for policy support and investment in CCUS technologies for sustainable energy production.