Numerical Analysis of Non-Darcy CH4 Flow in Fracture Network of Coal Using Lattice Boltzmann Method

Abstract:

Coal seams comprise fractured coal that is naturally separated by discontinuous fractures or joints. These discontinuous fractures constitute a complicated fracture network that leads to the Non-Darcy CH₄ flow. It is intractable for conventional models to describe the behavior and its mechanism of Non-Darcy CH₄ flow in fractured coal. This paper reports a promising numerical analysis of the complex CH₄ flow in the fracture network of coal using Lattice Boltzmann Method (LBM). The flow properties of CH₄ flow, including viscosity distribution, average flow speed, permeability coefficient, are derived using the LBM model. The analysis is validated by comparing the LBM results with the experimental observation data.

Key words: Non-Darcy flow, CH₄, fracture network, Lattice Boltzmann Method, Coal, Permeability