Chua Han Bing

CO2 storage in heterogeneous aquifer: A study on the effect of injection rate and CaCO3 concentration

Trapping mechanisms taken place during and after CO2 injection in a geologic storage medium are impacted by a number of parameters including injection rates together with rock and pore fluid compositions. There have been many studies on the factors controlling the capillary trapping and injectivity of CO2 storage sites. However, there are only few works carried out discussing on the effect of flow rate and rock and fluids compositions in controlling the trapping mechanisms. In this paper a CO2 storage site located in a heterogeneous aquifer is simulated to investigate the efficiency of structural, capillary and dissolution trappings as a function of injection rate and concentration of calcium carbonate. The results obtained from numerical analysis indicated that CO2 injection must be made within an optimum injection rate for having an effective storage in place. It was also found that concentration of CaCO3 is an important parameter to consider during the analysis as it drastically controls the fate of trapping mechanisms at high injection rates.