煤层气-水两相三孔介质渗流规律研究

Study on coalbed methane-water two-phase seepage law in triple porosity medium

我国煤层气资源丰富,为研究煤层气开采机理,探讨了煤层气基质孔隙及裂缝系统的双孔孔渗动态变化规律,建立气-水两相渗流模型。气体在基质微孔中的吸附遵循Langmuir定律,由基质微孔向基质孔隙中的扩散视为拟稳态并服从Fick第一定律。应用COMSOL Multiphysics进行数值模拟研究,并进行参数敏感性研究,同时研究开采过程中基质及裂缝系统孔渗的变化规律。本研究对煤层气储层结构孔隙认识及煤层气开采具有重要意义。

China is rich of coalbed methane resources. In order to study the mining mechanism of coalbed methane,discussed the coal seams dual poroelastic porosity-permeability dynamic model, builded numerical simulation of gas-water two-phase flow. The gas adsorption on matrix micropore follows Langmuir＇s law,the diffusion from matrix micropore to matrix porous is regarded as pseudo steady state and obeys Fick＇s first law.Numerical simulation and parameter sensitivity analysis were conducted with COMSOL Multiphysics,and porosity and permeability＇s variation in the mining process were also discussed.This study has important significance for understanding coalbed methane reservoir structure pore and coalbed methane mining.