The effect of fracture aperture and flow rate ratios on two-phase flow in smooth-walled single fracture

This work experimentally examines the cocurrent flow of oil and water in moderately oil-wet smooth-walled single fractures. The focus of our investigation is on studying the effects of varying fracture aperture and flow rate ratios on relative permeability to oil and water. The phase distribution and flow regimes within the fracture were closely monitored and found to vary with the flow rate ratio and total flow rate, and appeared to have a direct impact on the relative permeability. Experimental relative permeability data exhibited variations in shape indicating the effects of fracture aperture and flow ratios. Also, the data show the effects of oil-water phase interference, and phase saturation changes on the relative permeabilities for each fracture configuration. A couple of two-phase relative permeability models, namely, viscous coupling model, and homogenous single-phase approach, were tested against the experimental relative permeability data. This work provides insight into the nature of two-phase flow in a single fracture and could help in better modeling of more complex fracture networks.