PERMEABILITY MODELS FOR TWO-PHASE FLOW IN FRACTAL POROUS-FRACTURE MEDIA WITH THE TRANSFER OF FLUIDS FROM POROUS MATRIX TO FRACTURE

Abstract

Study of transport mechanism of two-phase flow through porous-fracture media is of considerable importance to deeply understand geologic behaviors. In this work, to consider the transfer of fluids, the analytical models of dimensionless relative permeabilities for the wetting and non-wetting phases flow are proposed based on the fractal geometry theory for porous media. The proposed models are expressed as functions of micro-structural parameters of the porous matrix and fracture, such as the fractal dimension ([Formula: see text] for pore area, the fractal dimensions [Formula: see text] for wetting phase and for non-wetting phase, porosity ([Formula: see text], the total saturations ([Formula: see text], the porous matrix saturation ([Formula: see text] of the wetting and non-wetting phases, fractal dimension ([Formula: see text] for tortuosity of tortuous capillaries, as well as the ratio ([Formula: see text] of the maximum pore size in porous matrix to fracture aperture. The ratio ([Formula: see text] has a significant impact on the relative permeabilities and total saturations of wetting phases. The results reveal that the flow contribution of wetting phase from the porous matrix to both the seepage behavior of the fracture and total wetting phase saturation can be neglected as [Formula: see text]. The models may shed light on the fundamental mechanisms of the wetting and non-wetting phase flow in porous-fracture media with fluid transfer.