Modeling the confined fluid flow in micro-nanoporous media under geological temperature and pressure

Understanding the fluid flow in confinement space is the important task for CO2 storage and unconventional gas production. The high temperature and pressure in geological formation proposed a challenge to the traditional model, which ignores the influence of temperature and pressure on the confined single-phase flow and two-phase flow. In our work, an analytical model is proposed to characterize the liquid flow and two phase flow in tight porous media with further considering the influence of temperature and pressure on fluid transport in confinement space. The results demonstrate that solid-liquid interactions will rise up the flow resistance of confined water and reduce the liquid permeability of tight porous media. Additionally, as the burial depth increases, the increasing temperature will not only increase the fluidity of bulk water but also weaken the effect of solid-liquid interactions, and the coupled effects can increase the water volume flux in geological formation. For two-phase flow in the formation, the high temperature and pressure result in small Knudsen number and low gas relative permeability branch while the high temperature increases the water fluidity and rises up the water relative permeability branch. The output of gas can increase Knudsen number, promoting the gas flow capacity and rising up the gas relative permeability branch. (C) 2019 Elsevier Ltd. All rights reserved.