Geochemical clogging in fracture and porous rock for CO₂ mineral trapping

Geochemical trapping is regarded as one of the promising geologic sequestration of carbon dioxide (CO₂). Also carbonate mineralization takes advantage of permeability reduction to seal formations with decreasing CO₂ leakage risk and increasing storage safety. As precipitation rates tend to be faster and the solubility product shows lower value at higher temperature, the calcite- And kaolinite- rich rock produced through CO ₂-water-rock interaction is expected to form the scale in geothermal reservoirs. Ca2+ released from rocks could be removed as carbonate minerals (CaCO3) during CO₂ sequestration into aquifer rocks. However, when, where, and how much calcite deposits at the reservoir. For this reason, flow experiments and numerical calculation of advection-reaction model have been done to predict where and when the mineral deposits and permeability changes. The experimental and numerical results provided that fluid velocity change between fracture and porous media have more than one-order discrepancy at isothermal condition. When the fluid velocity in fracture exceeds the critical velocity, surface erosion allows re-entrainment. Critical velocity in porous media is likely to be larger than that in fracture because internal erosion might interrupt the migration of deposit by re-settlement in pore spaces.