Lattice Boltzmann Method Simulations About Shale Gas Diffusion in Sinusoidal Channels

Abstract

Organic pores serve as the primary medium for the storage and transport of methane in shale formations. Furthermore, the diffusion behavior of methane within organic matter is crucial for enhancing shale gas production. Understanding the diffusion behavior of methane in nanopores is essential for unraveling the mechanisms of methane transport. In this paper, a lattice Boltzmann model was constructed to investigate the diffusion effects of methane in sinusoidal channels. The study examined the influence of the number, amplitude, and spacing of the protrusions in sinusoidal channels on methane diffusion. It was observed that methane is significantly influenced by large-amplitude protrusions, leading to an increase in diffusion velocity at the protrusion region. Before passing through a protrusion, methane concentration rises, while it decreases after passing through it. When multiple protrusions appear consecutively, methane struggles to form effective continuous diffusion pathways, resulting in significant variations in diffusion velocity. However, when the protrusions are misaligned, methane diffusion is affected only by the protrusions on one side, enabling the formation of continuous channels and maintaining high diffusion velocities. The LBM results provided in this paper will contribute to understanding the diffusion mechanisms of methane in irregular nano-channels.