Theoretical studies of methane adsorption on Silica-Kaolinite interface for shale reservoir application

Abstract

Shale gas is mostly made up of methane and is currently being exploited in fulfilling the world's energy demands. Density Functional Theory (DFT) and Molecular Dynamics (MD) techniques are employed for understanding methane transport in the pores at typical reservoir conditions. Shale, which is made up of clay and quartz-like material, is represented in this study by a combined silica-kaolinite surface. The simulations revealed that the interface is formed by a chemical bond between silicon to two oxygen atoms from the kaolinite surface. Physisorption is the mode of adsorption of methane irrespective of the position of the gas on the interface. However, methane has stronger adsorption on the kaolinite region than the silica region.