Multiphysics gas transport in nanoporous unconventional reservoirs: Challenges of mathematical modelling

The flow behavior of fluids in nanoporous unconventional gas reservoirs is a multiphysics process making the mathematical modelling of such reservoirs challenging. Several vital forces and mechanisms are simultaneously playing a role in controlling the flow behavior in unconventional reservoirs. This comprehensive review aims to critically investigate the multiphysics flow dynamics in nanopores including viscous flow, diffusive and advective flow, adsorption and desorption phenomena, stress effect, and capillary and inertial effects. It also highlights a need for a combined approach to tackle such complicated fluid transport in unconventional reservoirs. The physics and characteristics of each transport mechanism are analyzed, and their significances are outlined to understand how the consideration of mechanisms is essential for accurately modelling a complex scenario. Finally, the challenges and prospects of unconventional reservoir modelling are discussed, and some suggestions are provided for the study of fluid mechanics of unconventional reservoirs. It is expected that this review will help researchers with a better understanding of the complexity of modelling of unconventional reservoirs. © 2022 The Authors