Experimental Studies of Injectivity Reduction Due to Carbonate Mineralization

Geochemical trapping has been regarded as the safest process to transfer carbon dioxide (CO2) gas into carbonate mineral during geological sequestration. Carbonate mineralization takes advantage of permeability reduction to seal formations, thereby leading to decreasing CO2 leakage risk and increasing storage safety. As precipitation rates tend to be faster, and the solubility product shows lower values at higher temperatures, CO2-saturated groundwater reacts with calcite- and kaolinite-rich rocks to form the carbonate deposits in geothermal reservoirs. In the laboratory-scaled experiments, supersaturated carbonate fluid flowed into a column over a wide range of temperature, pH, and concentration of CO2, which affected the further growth rates of carbonates. The reduction of injectivity controls the fluid flow velocity that governs the distribution of the deposit amounts, and the SI product and CO2 concentration of reactants can be effective for predicting the required time for clogging phenomena to occur.