Evaluation of the diffusive tortuosity by analyzing the molecular thermal motion displacement

Abstract

Molecular thermal motion is a very meaningful process. Plenty of useful information can be extracted from molecular travel displacement. In this paper, a kerogen model with a random and complex pore network is constructed. Based on the molecular thermal motion process, the diffusive tortuosity caused by the confined pore network is investigated by the molecular dynamics simulations. The influence of thermodynamic parameters on the diffusive tortuosity is carefully studied. The results showed that the diffusive tortuosity ranges from 1.57 to 2.70 depending on the pressure. However, with the variation of temperature and porosity, the diffusive tortuosity has a little change, mainly distributed from 1.79 to 1.95. The thermal diffusive tortuosity of the complex pore network is successfully calculated by analyzing molecular thermal motion property.