Study on Apparent Permeability Model for Gas Transport in Shale Inorganic Nanopores

Inorganic nanopores occurring in the shale matrix have strong hydrophilicity and irreducible water (IW) film can be formed on inner surface of pores making gas flow mechanisms more complex. In this paper, existence inorganic is considered, and, based Knudsen number (Kn) correction pores, a apparent permeability model nano-pores established. The effect Kn permeability, ratio with pore radius IW are assessed. main conclusions as follows: (1) at low pressure (less than 10 MPa) for medium size (pore range nm–60 nm), should considered; (2) considering correction, bulk phase transport replaces diffusion slowly; IW, (3) increase pressure, decreases. Under where small, promotes fluid flow, while large hinders flow. conditions ultra-high