Characterization of CO2-brine migration with criteria for detection of CO2 leakage in the porous media

The issue of global warming and the proposed geological carbon sequestration have increased the interests in the supercritical CO2 (scCO2) and brine/water as two-phase flow system in porous medium. Like other two-phase flow systems in porous media, the capillary pressure (Pc), relative permeability (Kr) and electrical properties (e.g., bulk electrical conductivity (σb) and bulk dielectric constant (εb) ) of the fluid-fluid-porous media systems can be used as the characterization parameters since they are all functions of water saturation (S). But the non-uniqueness of these functions pose challenges to their applications in the efficient and reliable monitoring of the subsurface processes involving two-phase flow system, especially CO2-water/brine system. This work invetsigates the non-uniqueness in the Pc-S, εb-S and σb-S relationships for scCO2-brine/water system in silicate and carbonate media. The work further explore the application of silicone rubber as membrane in the detection of CO2 leakage in the subsurface.Finally, simple criteria is established to distinguish the presence of various gases in the subsurface and design simple household application of the leakage detection system.