A new model for gas transport in fractal-like tight porous media

Abstract

A new gas transport model for fractal-like tight porous media is proposed by simultaneously considering the microstructural complexity of real porous media, the compressibility of gas, and the gas slippage effect. This model clarifies the gas transport mechanisms in porous media: the total gas flow volume is governed by the weighted addition of viscous flow and slippage flow, and the distribution weighting factor depends on the capillary diameter and the mean free path of the gas. Based on the proposed model, a new permeability model was derived for gas transport in fractal-like tight porous media. The new permeability model does not have any empirical constants, and every parameter in the model has clear physical meaning. The predictions from the model were then compared with experimental data to show that the model is valid. Furthermore, the parameters influencing gas permeability were analyzed.