Injection Rate Controlled Capillary Imbibition Transfer in Fractured Systems

Abstract

ABSTRACT In this paper, the effects of injection rate and fracture configuration on capillary imbibition transfer in fractured porous media were studied and analysed. Displacement experiments were conducted on artificially fractured rock samples and the experimental data were evaluated using a numerical simulator. The limiting value of injection rate and fracture capillary number were defined for an efficient capillary imbibition transfer. Some of the core flood experiments were enhanced with the fluid distribution measurements using CT-scan. Also, experiments on 2-D glass bead samples were conducted to scrutinize the influence of the fracture configuration on the matrix saturation distribution at different injection rates. Visualization studies on 2-D glass bead and CT scan of linear core flood experiments revealed that as the injection rate is increased, fracture pattern begins to become an effective parameter on the matrix saturation distribution. As the rate is lowered, however, the system begins to behave like a homogeneous system showing a frontal displacement regardless of the fracture configuration.