Formation of carbonates and PH variations in conditions representative of deep saline aquifers

CO₂ sequestration in saline aquifers has been of interest as an option to reduce concentration of CO₂ in the atmosphere. Of all the mechanisms of sequestration, mineral sequestration is proved to be the most secure one. In this study, formation of carbonates is investigated through monitoring of PH of the medium consist of sand+synthetic brine+ supercritical CO₂ and sand+synthetic brine+ supercritical CO₂. The experiments are conducted at pressures of 1100 and 1300 psi (CO₂ at supercritical state) and temperatures ranged from 70-150. The results indicated that salinity of brine, pressure and temperature of the system directly affect the PH of solution and therefore formation of carbonates.