Modeling Coupled Effects of Dissolved Salts (Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl^-, SO<inf>4</inf>^2-) concentration on multiphase flow and dissolution of CO<inf>2</inf> in saline aquifer

Dissolution trapping plays imperative role in immobilization of injected CO2 in saline aquifer. However, dissolved salts concentration in saline brine plays critical role in influencing solubility of CO2. The present work numerically investigates the effect of dissolved salts concentration in brine on dissolution of CO2. The present work also investigate the coupled effect of injection induced flow and distribution of CO2 in brine and brine salinity on solubility of CO2. Towards objective, a numerical model governing two phase immiscible fluid flow with associated capillary interphase has been developed. The solubility of CO2 into brine at the interphase is computed by the developed solubility model. Validated numerical model has been used to investigate the coupled effect of flow and dissolution. The observed results suggest that as pressure of the system increases solubility increases, whereas salinity of brine has inverse effect on solubility. It has been observed that, injection of CO2 in porous system results in drastic pressure buildup at the near well bore region and CO2phase propagates along the length of the porous media. The coupled effect of flow and distribution has significant effect on dissolution and it has been observed that about 15.95% of dissolved mass fraction has been dissolved after 96 hours in injection.