An integrated approach for gas-water relative permeability determination in nanoscale porous media

摘要

This paper provides an integrated approach to simulate gas-water relative permeability in nanoscale porous media with interfacial effects using fractal theory. The calculation results with present model considering the interfacial effects match the laboratory results very well. The characteristics of relative permeability were analyzed under different values of Hydrogen bond (Pi(h)), Double layer repulsive force (Pi(e)), Long-range van der Waals force (Pi(w)) and Short-range structure repulsive force (Pi(s)). The result shows that the interfacial effects can promote the fluid flow in the nanoporous media and the relationship is as follows: Pi(h) Pi(e) Pi(w) Pi(s). Pi(h) and Pi(e) improve spreading obviously, which are accounted for more than 70%. Then the Pi(w) affects spreading accounts for 1/5 nearly. In addition, the analysis of fractal dimension on relative permeability is carried out to indicate that the gas-water relative permeability decreases with the increase of the fractal dimension. While the capillary force has impact on relative permeability slightly. The new insight and theoretical basis could be obtained for CO2 geological storage and shale gas extraction from nanoscale porous media.