Multiscale Simulation and Analysis for Gas Flow in Deep-Seated Micronano Pore

Shale gas will become an important energy source in China in the near future. However, most shale gas in China is deeply buried, so the experience of shallow-seated shale gas exploitation in US can not be directly employed. A better understanding of shale gas transport mechanism can surely facilitate the precise prediction of production and the exploitation optimization of deep-seated shale gas. In this paper, we establish a multiscale simulation method named pore-field iteration. Field-scale problems such as inflow performance relationship and decline curve analysis are solved based on pore-scale simulation directly. In addition, the coupling between the high Knudsen number effect in micro flow and the non-ideal gas effect caused by the high pressure and temperature underground is investigated from a theoretical perspective. Finally, we incorporate the influence of the elastic structural deformation in our modeling and propose the characteristic pressure model to calculate apparent permeability, which supports shale gas exploitation by providing theoretical analysis.