Maximizing CO2 Storage in Anticlinal Structures, a Numerical Simulation Study in the Middle East

Summary Anticlines are often preferred for carbon sequestration due to their ability to provide a secure containment, similar to oil and gas traps. However, the availability and storage capacity of anticlines can be limited, prompting the exploration of alternative options, such as open aquifers or unconfined reservoirs, which rely on residual trapping and dissolution to sequester injected CO2. This paper aims to demonstrate that injecting CO2 into the flanks of an anticlinal structure can enhance the overall CO2 sequestration capacity by leveraging the trapping mechanisms of open aquifers, specifically residual trapping and dissolution. A case study comparing two injection strategies is presented. The first scenario involves injecting CO2 into the structural closure, where it remains primarily in a mobile phase, with a limited storage capacity of 400 million tons. In contrast, the second scenario involves placing injectors on the flanks of the structure, at the lowest possible point within the fetch area, allowing the CO2 plumes to migrate upward and eventually become trapped in the structural closure. Notably, this approach doubles the storage capacity, highlighting the potential benefits of flank injection in optimizing CO2 sequestration.