A dynamic multi-component transport model for CO2 enhanced coalbed methane recovery

摘要: This paper presents a dynamic multi-component transport (DMCT) model for better understanding and prediction of CO2-enhanced coalbed methane (CO2-ECBM) recovery. is coupled system dealing with different processes: gas sorption equilibrium; diffusion flow; matrix shrinkage swelling. The was developed based on the bidisperse mechanism Maxwell-Stefan (MS) theory, which provides an improved simulation dynamics. equilibria determined using ideal adsorbed solution-real (IAS-RG) approach Langmuir isotherm. variations fracture porosity permeability effective stress were considered in Shi & Durucan (SD) model. Experimental data obtained from series core flush tests employed to examine predictive capability proposed DMCT simulations show good agreements experiments, predicted microand macro-pore diffusivities are comparable measurements achieved by other researchers. These then used triplecomponent simulating flue injection enhanced (FG-ECBM) calculated results suggest that CH4 recovery profiles mixed injections lay between lines pure N2 CO2 injections. have same breakthrough time as injection. However, composition has significant effect produced composition.