Computational study of phase interface properties for energy extraction and storage process

Abstract

The interactions between gas and liquid have an important role in energy extraction and storage. For example, the interfacial tension (IFT) between the two phases has an important effect on developing crude oil in low-permeability reservoirs and compressed air energy storage in aquifers (CAESA). For the mechanism of two-phase fluid interaction in energy extraction and storage, the study of gas-liquid interface properties is carried out in the paper. Firstly, molecular dynamics simulations are used to study the molecular simulation progress of nitrogen and water under different environmental conditions, and the effects of different temperatures and pressures on IFT are studied. The results show that IFT increases with the temperature increase at constant pressure. When the temperature is constant, an increase in the pressure of the system will decrease the surface tension of the system. Then the effect of IFT on the distribution of gas-liquid phases in the pores of low-permeability rocks is studied by digital core technology and simulation methods. The results show that the lower the IFT of gas and liquid is, the better the displacement effect is and the higher the recovery ratio is in the low-permeability rocks. This study analyzes the IFT and influencing factors between the gas-liquid two-phase interface, and it guides the efficient development and utilization of energy extraction and energy storage.