Three-Phase Gas/Oil/Brine Relative Permeabilities Measured Under CO2 Flooding Conditions

Abstract

Summary Steady-state three-phase gas/oil/brine relative permeabilities were measured in a carbonate core under CO2 flooding conditions. Results show that the relative permeability of each phase depends only on the saturation of that phase instead of on two saturations, as many previous studies have concluded. All previously reported gas/oil/brine relative permeability studies have been conducted with low-pressure N2 gas or air. In this work, CO2 gas, oil, and brine were injected into a carbonate core at 71°C and 9.65 MPa so that the phase behavior and flow would be similar to reservoir conditions. Results show that significant differences exist between the three-phase gas/oil/brine relative permeabilities measured when the gas is CO2 and those measured when the gas was N2.