Research progress on characterization and simulation of shale oil flow in microscale

Abstract

Clarifying the mechanisms of confined fluid flow in nanoscale space and calculating the permeability and other microscopic parameters are crucial to enhance the recovery of shale oil, which have attracted great attention in recent years. We review the micro flow mechanisms and numerical methods of shale oil, and discuss the effects of the solid-liquid molecular interaction force which leads to boundary slip and viscosity/density heterogeneity on the shale oil flow behaviors. Firstly, we introduce the four analytical models of confined fluid flow in nanopores which are the region-separation model, the effective viscosity model, the apparent viscosity model and the apparent slip length model. Then, we summarize the simulation methods and the applications in the study of fluid flow in nanoporous media Among them, the direct simulation methods are the molecular dynamics simulation (MDS) method and the pore-scale lattice Boltzmann simulation method (LBM), and the indirect simulation methods are the pore network model (PNM) and the coupled direct-indirect simulation method . We discuss the advantages and disadvantages of each simulation method. Finally, on the basis of summarizing the advantages and disadvantages of research results, the future research directions are put forward.