The obvious slippage effect for gas flow has been found due to the low gas permeability, and the effect of coal matrix shrinkage on the permeability is also indispensable.

Methods of experiment, theory and calculation were used to establish a new nonlinear flow law. Experiment results of gas flow in low permeability pore-fissure media were analyzed.

This paper presents a new method of steady flow to solve the problem that the injection rate into cores is difficult to get steady, especially for gas in measuring relative permeability.