모세관 격리를 고려한 불균질 대염수층 내 CO2 저장 및 누출 분석

초록

Under circumstances where capillary entry pressure is larger than buoyancy pressure of CO2, a numberof capillary barriers can exist and CO2 accumulates below them. This is a new trapping mechanism called capillarytrapping. In this study, numerical simulations of CO2 sequestration were performed to estimate the amount ofCO2 storage and leakage under different heterogenous systems considering capillary trapping. Leverett J-functionwas applied so that every grid block had a different capillary pressure curve being physically consistent withits heterogenous properties. The flow pattern of CO2 plume was dependent not only upon permeabilityheterogeneity but also its correlation length. As the permeability variation increased, the total amount of trappedCO2 increased due to effect of capillary trapping, although CO2 trapped by residual and dissolution trappingdecreased. The lateral correlation length of permeability field affected spatial distribution of CO2 but did not havesignificant effect on the amount of CO2 storage and leakage.

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