Hydro-Mechanical Modelling of Multiphase Flow in Coalbed by Computational Homogenization

A multiscale model is developed for the modelling of coalbed methane (CBM) production. CBM recovery is known to be a highly coupled and multiphase problem. The finite element square method is used to integrate a fracture-scale model in a multiscale scheme. This method consists to localize the macroscale deformation to the microscale, then resolve the boundary value problem on the microscale with finite elements, then homogenize the microscale stresses to compute macroscopic quantities, and finally resolve the boundary value problem on the macroscale with finite elements. This approach has the advantage that it does not require to write some constitutive laws at the macroscale but only at the REV-scale. The multiscale model is therefore appropriate for reservoir modelling. The model is developed and implemented in a finite element code and the simulation of a synthetic reservoir is considered.