煤层气注气开采多组分流体扩散模型数值模拟

为了解决低渗透煤层气开发遇到挑战，依据双重介质扩散渗流和多组分吸附平衡理论，建立了注气开采煤层气多组分流体扩散渗流模型，利用数值方法研究了注气开采煤层气的增产机理．研究表明，注入二氧化碳气体不但减少了煤层甲烷的分压，加速了煤层甲烷的解吸，而且二氧化碳气体比甲烷气体更易吸附，竞争吸附置换煤层甲烷分子，从而提高了煤层气产量，结果表明注气开采煤层气是提高我国低渗透煤层气产量的有效途径。

Model and numerical simulation about multispecies fluid diffusion and seepage in exploitation coalbed methane by gas injection

In order to slove the eepage of exploitationEstablished dual porosity media mathematical model of multispecies fluid diffusion and seepage of exploitation coalbed methane by gas injection. the nonlinear mathematical model are investigated by using finite different method and got some valuable conclusions: Improved recovery of methane from coal beds can be achieved by injection of carbon dioxide .there are two main mechanisms that aid recovery of the coal beds methane content. Firstly, by reducing the partial pressure of the methane present in the fracture, the diffusion from the coal is enhanced,the second mechanism is the competitive adsorption of carbon into the coal matrix. molecules of CO2 preferentially absorb on to the surface adsorption sites, displacing methane.