Masoud Karimnezhad - M.Sc. in Petroleum Engineering, Department of Petroleum Engineering, Shahid Bahonar University of Kerman, and Young Researchers Society, Kerman, Iran
Hossein Jalalifar - Ph.D. in Rock Mechanics, Department of Petroleum Engineering, Shahid Bahonar University of Kerman,Kerman, Iran
Mosayyef Kamari - M.Sc. in Petroleum Engineering, National Iranian South Oil Company

carbon dioxide sequestration in depleted reservoirs is a mitigation strategy for reducing greenhouse gasemissions to the atmosphere and minimizing the detrimental impacts. As Iran is one of the main CO2 producingcountries in the world, the country’s options for long-term CO2 storage must be identified and studied. Thus, asouthwest Iranian oil reservoir is selected to study its CO2 sequestration feasibility. Caprock integrity is a criticalfactor for the long-term safe storage of CO2 in geological formations. In this study, a three-dimensionalgeomechanical modeling was performed by using a general finite element program (Abaqus software) to studythe geomechanical effects of CO2 injection on the caprock and to estimate the risk of caprock shear and tensilefailure. The results show that the caprock remains stable during the injection period under the consideredconditions. However, high injection rates may lead to caprock tensile failure. Thus, the maximum allowableinjection rate to preserve caprock mechanical stability was estimated through a sensitivity analysis, which isequal to 0.28 Mt/year. Results of the numerical model were validated against the analytical method of solution.Finally, a sensitivity analysis was performed to determine the effects of caprock internal friction angle andcohesion on its failure tendency.

CO(2) injection, Iranian reservoir, numerical simulation, geomechanical model, caprock integriy