中文摘要：

本文基于Fick扩散定律,结合页岩气赋存形式和运移特点,针对干酪根有机质中溶解气扩散形式,建立干酪根中页岩气扩散数学模型.利用有限元分析方法进行数值求解,得到不同时刻干酪根内部页岩气浓度分布,分析干酪根内部不同位置浓度变化规律,内边界气体平均扩散通量变化规律,并通过计算得出给定符合页岩储层有机干酪根存在条件下干酪根扩散通量.同时在该扩散模型基础上改变边界条件,可以理论上计算多孔介质中气体有效扩散系数,为今后关于页岩气渗流理论和数值模拟研究奠定了基础.

英文摘要：

In order to describe dissolved gas diffusion form in organic kerogen, a shale gas diffusion mathemati- cal model has been established combining the shale gas occurrence modes and migration characteristics based on the Fick＇ s diffusion law. Finite element analysis method is employed for numerical solution of partial differential equa- tions. Obtaining the concentration distributions at different moments and analyzing the concentration changes at dif- ferent kerogen positions, the average gas diffusion flux change rules at inner boundary, cumulating the kerogen dif- fusion flux accordance with the shale reservoirs organic kerogen presence. Also the effective diffusion coefficient in porous media can be given through the numerical simulation by revising the diffusion model＇ s boundary conditions. It is a foundation work for the future shale gas percolation theory and numerical simulation research.