煤层气保存条件是评价低煤阶煤层气成藏条件的重要方面之一。硫磺沟矿区及周边地区侏罗系西山窑组发育多层煤层，且煤层厚度大，煤变质程度低，受喜马拉雅运动等影响，地质条件复杂。从区域构造、煤层盖层两个方面对低煤阶煤层气的保存进行研究，认为构造对煤层气含量及分布影响较大，构造控气样式中在逆冲断层与向斜缓翼组合，越靠近向斜轴部其含气量越大，且越靠近断层附近，含气量随深度增大的增速越大；叠瓦式逆冲断层与其间的褶皱组合中，越靠近逆冲的前端，其含气量越大。通过统计分析煤层顶板岩性及厚度两个因素，得出14-15号煤层盖层封盖性能最好，其次为9-10号煤。%CBM preservation condition is one of important aspects in low rank coal CBM reservoiring evaluation. The Jurassic Xishan⁃yao Formation in the Liuhuanggou mine area and periphery has developed multiple coal seams with large thickness, but low degree of coal metamorphism. Impacted by Himalayan and other movements, caused complex geological conditions. From tectonics and coal over⁃burden two aspects carried out studies on low rank coal CBM preservation, considered that impact from structures on CBM content and distribution is larger. In structural control of CBM pattern thrust and syncline gentle limb assemblage, the near to the syncline axis, the larger the CBM content, especially the near to faults, the speedup of CBM content will be larger. In assemblage of imbricate thrusts and folds between, the near the thrust front, the larger the CBM content will be. Through statistic analysis of coal roof lithology and thick⁃ness two factors, have educed the sealing performance of coal No.14-15 overburden is the best, No.9-10 the second.
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