The Impact of Pore Pressure on Co2-Methane Displacement

The intricate behavior of carbon dioxide at supercritical conditions is considered to influence the ultimate recovery of additional hydrocarbon reserves through the application of CO2-enhanced gas recovery projects. Mixing in such a system is a diffusion-like process, which definitely depends on the physical properties of the displacing and displaced phases and the heterogeneity of the medium. The authors' aim was to experimentally investigate the consequence of pore pressure on the recovery efficiency and multiphase gas flow in a reservoirs porous medium. The displacement tests were carried out at five different pore pressures ranging from 10.34 to 40.68 MPa, temperature of 433.15 K, and displacement rate of 10 cm/hr. Results determined that improved recovery by approximately 40% can be obtained by applying the highest pore pressure in comparison with the test conducted at low pore pressure.