Steady-state supercritical CO 2 and brine relative permeability in Berea sandstone at different temperature and pressure conditions
In this study, we measure steady-state two-phase supercritical CO 2 -brine relative permeabilities in a 61 cm-long Berea sandstone core at three different conditions (408C and 12.41 MPa, 408C and 8.27 MPa, and 608C and 12.41 MPa) under primary drainage. We use pressure taps to obtain pressure drops of individual sections of the core, and X-ray Computed Tomography (CT) to obtain in situ saturation profiles, which together help to mitigate the capillary end effect. We include previously measured relative permeabilities at 208C and 10.34 MPa, and compare all the data using both an eye-test and a statistical test. We find no appreciable temperature and pressure dependence of CO 2 relative permeability within 20–608C and 8.27–12.41 MPa. We find slight changes in the brine relative permeability between supercritical CO 2 conditions (40–608C and 8.27–12.41 MPa) and the liquid CO 2 condition (208C and 10.34 MPa). The temperature and pressure independence of CO 2 relative permeability has been previously recognized and reassured in this work using a capillary-effect-free method. This allows one to use a single CO 2 relative permeability curve in modeling two-phase CO 2 flow within 20–608C and 8.27–12.41 MPa.