A model for flows in low permeability porous media with nano scale pores has been derived with assumptions including homogeneity

the Darcy's law

ideal gas model and the Klinkenberg effect. Numerical simulations are carried out for pressure pulse decay experiment with spherical crushed samples using the finite difference method with suitable boundary conditions. Non-dimensional parameters Z

Z* and bK are introduced when the governing equations are non-dimensionalized. Various pressure decay curves are investigated numerically when various parameters Z

Z* and bK are applied. A data processing method for the present pressure pulse decay experiment is proposed. Porosity

permeability and the Klinkenberg coefficient can be determined by combining both the measured pressure decay curves at the sample boundaries and the numerical solutions of the governing equations. The permeability and the Klinkenberg coefficient of a porous medium sample cannot be determined using only one pressure decay curve.