This paper deals with high-velocity gas flow behavior in gas-liquid systems. It reports results of non-Darcy flow experiments in single and two-phase flow in porous media. The effect of both mobile and immobile liquids is significant in both decreasing the effective permeability, Keff, and increasing the effective non-Darcy coefficient, Beff. Mobile liquid seems to have greater effect on Keff and Beff than does immobile liquid, but the values are much more difficult to quantify. The Pe~ value for a serially connected composite core, as determined from a simple averaging equation, is experimentally validated. Finally, it is shown that resistivity measurement with material balance can be used to determine the brine saturation distribution along a composite core during an oil-going core flood test.