甲烷泄漏的可压缩流动分析与应用

Compressible Flow Analysis and Application of Methane Leakage

煤层气生产过程中的甲烷(CH4)泄漏属于非定常流动,其计算过程复杂,往往受压力、温度等多种因素的综合影响。为了定量掌握煤层气井口位置的泄漏情况,推导了可压缩定常流动的N-S方程,结合相关假设得到了用于煤层气泄漏计算的小孔模型,考虑现实情况总结出适用于煤层气泄漏计算的经验系数。对多个煤层气区块的实际案例进行计算,并开展对比分析。结果表明,小孔模型的计算平均误差相对较小,将该模型应用于煤层气井口泄漏的计算中是可行的。

Methane leakage in coalbed methane production is unsteady flow,and its calculation process is complicated,which is often affected by pressure,temperature and other factors.In order to grasp quantitatively the leakage situation of coalbed methane wellhead location,this paper deduced the N-S equation of compressible steady flow,combined relevant assumptions to obtain the small hole model for coalbed methane leakage calculation,and summarized the empirical coefficient suitable for coalbed methane leakage calculation considering the actual situation.The actual cases of several coalbed methane blocks were calculated and compared.The results show that the average error of the small hole model is relatively small,and it is feasible to apply the model to the calculation of coalbed methane wellhead leakage.