Injecting CO2 into the saline aquifer is considered to be an effective strategy to mitigate CO2 emissions. Saline aquifers are known to have a wide range of salinities and several evidences showed that different brine salinities give rise to different CO2-brine-rock wetting behaviors as well as different CO2 solubility potential. This will ultimately influence the CO2 plume migration behavior and the overall performance of a CO2 sequestration project. However, associated field-scale CO2 capacity predictions in different saline aquifers received little attention. This study conducts field-scale numerical simulations to analyze the effect of aquifer salinity on the CO2 storage potential. Different CO2-brine flow behaviors undervariablebrine salinities were considered. The results showed that an increase in the plume migration distance was observed in a higher salinity aquifer.While an increase in the brine salinity would result in an increase in residual trapping but a decreased solubility trapping capacities.Also, higher salinity formation observed more mobile CO2 and thus exhibit a worse sealing efficiency. We point out that residual trapping capacity evaluation should consider both residual CO2 saturation and the CO2 occupied volume, which both are strong functions of brine salinity.

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