Effect of Permeability on CO2 Storage and Injectivity in Low-Permeability Saline Aquifers

This study quantitatively evaluates CO 2 injectivity under low-permeability conditions using a homogeneous reservoir model.In Case 1, the optimal CO 2 injection per unit thickness and effective limiting permeability were estimated to maximize cumulative injection, whereas Case 2 determined the minimum injectable permeability that allows injection without exceeding the reservoir maximum allowable pressure.The effects of applying a porosity-permeability-dependent correlation and pressure sensitivity on injectivity were also examined.Without the correlation, optimal injection converged near 20 mD, and the effective limiting permeability was approximately 3 mD.When the correlation was applied, increased porosity enhanced injectivity, raising the effective limiting permeability to approximately 47 mD.The minimum injectable permeability increased with injection rate and decreased with the reservoir maximum allowable pressure.These indicators provide practical guidance for assessing CO 2 injection feasibility and defining operating conditions in low-permeability reservoirs.