(264g) Silica-Kaolinite Interface for Shale Gas Application: A Molecular Modeling Study

Methane mostly makes up the constituent of shale gas and it is currently being exploited in fulfilling the world’s energy demands. Molecular modeling techniques including Density Functional Theory (DFT) and Molecular Dynamics (MD) techniques are employed to understand methane transport in the pores at typical reservoir conditions. Herein, we study the interfacial phenomenon of methane adsorption on Silica-Kaolinite interface. This interface is created as it simulates a shale model which in reality is made up of clay (kaolinite) and quartz-like (silica) materials. The simulations revealed that the interface is formed by a chemical bond between a silicon atom from the silica surface and two oxygen atoms from the kaolinite surface. The adsorption of methane was studied at three different positions on the Silica-Kaolinite interface namely, silica-dominated region, interface region, and kaolinite-dominated region. The mode of adsorption of methane irrespective of its position on the interface was found to be physisorption with the kaolinite region having a greater adsorption. This is in agreement to previous studies which used experimental techniques for study methane adsorption. The results found herein which will be useful in shale estimating the original gas in place for shale reservoir application.

This work is funded by NPRP grant 12S-0130-190023 from from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.