Evaluating the potential of depleted oil reservoirs for CO2 sequestration through simulation modeling

Leading to achieve net zero emissions, performing carbon capture and storage (CCS) on a large scale is becoming more necessary, especially for developing countries, which are highly affected by the continuously increasing release of carbon dioxide (CO₂). It has also been observed that developing countries does not participate much in the release of CO₂ in the atmosphere but are highly influenced by global warming because of geological location. Therefore, addressing challenges of climate changes and its impacts requires high-capacity storage in safe and reliable locations. Depleted oil and gas reservoirs offer a valuable option to store CO₂ due to their adequate porosity and permeability. In this research, an effort has been made to provide a simulation study and comprehensive analysis of CO₂ storage through reservoir simulation in subsurface oil reservoir. In contrast to prior works, this research article introduces a simulation approach to assess the feasibility of CO₂ storage in an oil reservoir. Storage in an oil reservoir was modeled using a commercial compositional simulator. CO₂ behavior during injection is examined using gas injection profiles throughout the injection duration and injection rate. Results of the study demonstrate that reservoir pressure changes equally in all layers and grid blocks making the evaluated reservoir suitable for CO₂ storage. Bottom hole pressure (BHP) behavior during injection shows the feasibility of CO₂ storage. The analysis revealed that continuous injection of CO₂ at a rate of 3500 Mscf/day over a period of 10 years led to a successful storage scenario, with the reservoir reaching its space limit and the injection rate dropping to zero. These results suggest the viability and effectiveness of CO₂ storage as a means of mitigating greenhouse gas (GHG) emissions.