ABSTRACT
ABSTRACT: Carbon-dioxide geological storage has an important issue-the interaction of gas-coal interaction in micro-scale. In this report, micro-scaling modeling is implemented for the gas-coal interaction in coalbed seam. First, the mathematical model for the gas-coal interaction is formulated. This model considers the interaction of gas flow, density change of gas due to pressure and deformation of coalbed seam. The absorption /desorption of gas on coal matrix is also incorporated into the framework. Then, the evolution of porosity is developed based on the gas absorption and compaction of coal skeleton. Third, an input method is developed to describe the local heterogeneity through local porosity. Fourth, two examples are numerically simulated to investigate the effect of fracture-induced heterogeneity on gas flow in coalbed seam. Finally, an idealized micro-structure model is investigated to consider the swelling-induced permeability change in coalbed seam.
