Flow characteristics and a permeability model in nanoporous media with solid-liquid interfacial effects

Abstract

Molecular dynamics simulations of water flow through nanotubes have demonstrated higher flow rates than the flow rates predicted using classical models and a significant change in flow patterns due to the thin film that forms on the solid wall of the tubes. We have developed a two-region analytical model that described the flow characteristics and permeability of fluid flow through nanoporous media and considered the solid-liquid interfacial effects. Our model considers the influence of various interfacial effects, including long-range van der Waals forces, double-layer repulsive forces, and short-range structure repulsive forces, and it establishes relationships between the permeability and the average pore diameter, porosity, surface diffusion, and contact angle by numerical calculations. Our results indicate that the permeability calculated using the present model (with interfacial effects) is more than 30 times the results that were calculated using the Kozeny-Carman equation (without interfacial effects). The thickness of the thin film significantly affects the flow characteristics. We have gained new insight and guidance regarding the development of nanoscale pore reservoirs, such as shale gas and shale oil.