Multiseam coalbed methane (CBM) exploitation can not only reduce single-well investment but also increase the length of service of the well and significantly enhance the CBM economic recovery of the entire basin. To compare with and further to guide the actual project of CBM production, this study proposed a conceptual gas-water two-phase separate flow model for single coal seam considering the solubility of gas. This mathematical model was solved analytically by separation of variables and verified through history matching of the production data from the No. 3 seam of 1# test well of Jincheng and then applied to investigate the effect of gas solubility on the gas pressure. Furthermore, based on the coupled two-phase separate flow model of single seam, another two-phase separate flow model for the development of multicoal seam development was established. Similarly, the analytical solution of this model for multicoal seam layers was matched with the in situ data of TS-1 well of Liupanshui coal mine. It is found that the height difference and pressure difference between the two seams play key roles in the multiseam CBM development comprehensively.

中文翻译：

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多煤层煤层气生产中气水两相流的解析解

多煤层煤层气的开采不仅可以减少单井投资，而且可以增加井的服务年限，并显着提高整个盆地的煤层气经济恢复能力。为了与煤层气生产的实际项目进行比较并进一步指导实际工作，本研究提出了一种考虑了气体溶解度的概念的单煤层气水两相分离流模型。通过变量分离分析求解该数学模型，并通过对晋城1＃试井3煤层生产数据的历史记录进行历史拟合验证，然后用于研究瓦斯溶解度对瓦斯压力的影响。此外，基于单缝耦合两相分离流动模型，建立了多煤层开发的两阶段分离流动模型。同样，该模型对多煤层的解析解与六盘水煤矿TS-1井的现场数据相匹配。研究发现，两个煤层之间的高度差和压力差在多煤层煤层气开发中起着关键作用。