资源环境科技发展态势分析平台

A model commonly applied to the estimation of water relative permeability k(rw) in porous media is the Burdine-Brooks-Corey model, which relies on a simplified picture of pores as a bundle of noninterconnected capillary tubes. In this model, the empirical tortuosity-connectivity factor is assumed to be a power law function of effective saturation with an exponent (mu) commonly set equal to 2 in the literature. Invoking critical path analysis and using percolation theory, we relate the tortuosity-connectivity exponent mu to the critical scaling exponent t of percolation that characterizes the power law behavior of the saturation-dependent electrical conductivity of porous media. We also discuss the cause of the nonuniversality of mu in terms of the nonuniversality of t and compare model estimations with water relative permeability from experiments. The comparison supports determining mu from the electrical conductivity scaling exponent t, but also highlights limitations of the model.