影响煤层气富集的因素是多方面的，而且不是所有因素均具有同等重要的作用，某些因素是充分条件，某些因素则仅是一种必要条件，而水文地质条件是其中最为重要的条件之一。通过对国内外低煤阶煤层气勘探和开发资料的对比研究，发现美国粉河盆地的甲烷风化带很浅，而中国西北地区的煤层甲烷风化带却很深，通过对这一现象的分析发现，不同的水文地质条件导致了中美两国在低煤阶煤层气富集成藏方面的巨大差异；中国西北地区很大范围内的煤层气勘探开发潜力较前者小，但是在局部地区仍然存在一些较为有利的煤层气勘探区带。

There are many factors that affect the coalbed methane enrichment, and not all of them have the same effect. Some of them are sufficient conditions and others are necessary conditions. Exploring experiments show that the hydrological condition is an important factor affecting the methane enrichment. This paper carries out a contrast study between the Powder River basin(PRB) and the Northwest China coal basins and finds that the methane oxidation zone in the Northwest China coal basins is much deeper than that in PRB. It results from the different hydrological conditions. The Northwest coal basins in China have a smaller potential of exploration and development than the PRB, but areas with wet climate in the basins have favorable prospects. 