PRESSURE DISTRIBUTION MEASUREMENTS FOR CO2 FOAM FLOW IN POROUS MEDIA

CO2 foam technology has found wide application in enhanced oil recovery and carbon dioxide geological storage. To predict its flow behavior in underground reservoirs, pressure distributions for CO2 foam flow in porous media were measured by setting pressure transducers along the samples cores. In the meantime, the transient propagation process was visualized and the water saturation variation histories were obtained with the help of computed tomography (CT) technology. As a comparative study, N-2 foam flow resistance characteristics were also investigated in this paper. It is found that CO2 foam has nonlinear pressure distribution in porous media, with lower-pressure drop in the inlet region while a steeper pressure gradient in the region close to the sample outlet, while N-2 foam gives a much higher pressure drop compared to CO2 foam and the pressure distribution stays almost linear along the porous media. CT measurement results clearly show pistonlike propagation behavior and indicate an obvious entrance effect for CO2 foam flooding due to the high water saturation in the inlet region of the porous media.