A model for pseudo-steady and non-equilibrium sorption in coalbed methane reservoir simulation and its application

Coalbed methane (CBM) reservoir simulation is vital in CBM development. Production of CBM is controlled by a three-step process: gas desorption from the coal matrix, gas diffusion to the cleat system, and gas flow through fractures. This process follows the Langmuir's law, Fick's first law and Darcy's law. In this work, we suggested a three-dimensional, dual-porosity, two-phase, pseudo-steady, non-equilibrium sorption mathematical model for overall progresses from desorption to flow by the help of petroleum reservoir numerical simulation method and this complex mathematical model is approximated and solved by finite-difference and fully implicit method. The CBM reservoir simulation software, CBMRS 1.0 in Korean interface was developed by C++. It was compared with COMET 3D and evaluated and it could be exclusive software for CBM reservoir simulation.