煤层气在低渗透储层中传输非线性规律研究

考虑气体滑脱效应条件下，建立了煤层气在低渗透储层中渗流的数学模型，采用Laplace变换和留数计算方法进行解析求解，得出了气体非线性渗流的压力分布规律，并将其与达西渗流条件计算的结果进行对比分析，结果表明：滑脱效应对气体非线性渗流过程有较大影响，且随着抽气量的增大，其差别越明显。因此，在低渗透储层中进行煤层气资源化开发计算时，应充分考虑到气体滑脱效应对气体渗流的影响。这不仅对于可为煤层气资源开发潜力的评价和开发工程方案的优化提供科学决策依据，而且对于低渗透油气藏工程开发过程中水平试井数据的确定具有重要的参考价值。

Study on non-linear seepage flow of coal bed methane in low permeability formation

A mathematical model of coal bed methane seepage flow has been established under presumption of the effect of gas slippage. The approximate analytic solutions to the nonlinear mathematical model are accomplished by the Laplace transformation method. The distribution law of gas pressure in low permeability formation has been presented under the conditions of considering and neglecting slippage effect. Results show that gas slippage effect has a large impact on gas non-linear seepage flow, and with the increase of gas extraction rate, the difference becomes more obvious. It cannot be ignored slippage effect for gas nonlinear seepage flow in the low permeability formation resources exploitation and utilization. The theoretical basis is provided for evaluating the potential of coal bed methane resources exploitation and the optimum of engineering design. The solutions give specific evidence to analyzing well test data in the process of low-permeability oil gas reservoir exploitation.