在研究变形双重介质煤层气渗流问题的压力动态特征时,不仅考虑了煤层的双重介质特征和煤层气的吸附特征,而且考虑了介质的变形,还引入渗透率模数建立了变形双重介质拟稳态渗流的定产量内边界的无限大地层及有限封闭地层的数学模型。渗透率依赖于孔隙压力变化的流动方程是强非线性的。对于双重介质拟稳态渗流的数学模型采用直接隐式差分法进行离散,用Newton迭代法求解离散后的非线性方程组,获得了无限大地层及有界封闭地层的双重介质拟稳态渗流模型的数值解。讨论了变形参数和双重介质参数变化时压力的变化规律,给出了不同情况下的典型压力曲线图。这些结果为油田开发提供了理论依据和试井方法。

In this paper,the pressure behavior of the flow problem with deformed  double porosity is studied, not only considering the double porosity and absorption of coal seams but also the deformation of medium. The new mathematical models  of pseudosteady state flow problem with deformed double porosity are built by introducing the permeability module. The dependence of permeability on pore  pressure makes the flow equation strongly nonlinear. The numerical solutions for pseudosteady state flow models are obtained by using Newtonian iterative method  in an infinitely large system and the finite closed system. The change rules of pressure are discussed when the parameters of the models change. The plots of  type pressure curves are given, and the results can be provided to theoretical basis and well-test method for oil field.