An analytical model for calculating gas velocity profiles and predicting gas apparent permeability enhancement factors in nanopores of shale with nanometer scale characteristic dimensions of different geometries (slit pores and circular pores) is proposed. The proposed model considers the presence of a mobile high-viscosity water film by modifying boundary conditions at a liquid-solid interface and a gas-liquid interface has good agreements with experimental data, and confirms that a mobile high-viscosity water film enhances gas flow capacity. The importance of a mobile highviscosity water film is further evaluated with a varying pore size, pressure, and surface wettability. In the case of smaller pores and higher pressure, a mobile high-viscosity water film makes more positive contributions to both the gas velocity and a gas apparent permeability enhancement factor. Increasing the contact angle at a solid-water interface implies a reduction in molecular attractions and a decrease in gas flow resistance and thus leads to enhanced gas flow capacity. This study is extended to the case of multiphase flow in nanopores of shale and provides a better explanation of the fluid flow pattern in actual reservoir conditions.