Molecular simulations were used to model the extraction of gas from porous materials.

Reducing the environmental impact of fracking

Abstract

Existing fluid transport frameworks struggle to describe hydrocarbon recovery from unconventional shale gas reservoirs due to the nanoporosity and extremely low permeability of shale. We reported molecular dynamics simulations showing that methane recovery from a hydrophobic nanoporous membrane is a thermally activated process in the presence of water at the external surface. The increase in interfacial free energy as water is displaced by hydrocarbon results in an energy barrier. We use a simple thermodynamic model describing the critical hydrocarbon nucleus to build a statistical model of the long-time kinetics of gas recovery that explains rapid and variable declines in shale gas production. The simulations also suggest that supercritical carbon dioxide could be used to both enhance the producivity of shale gas wells and reduce wastewater.

Publication
Activated desorption at heterogeneous interfaces and long-time kinetics of hydrocarbon recovery from nanoporous media
Date