山西沁水盆地煤层气有利开采区块研究

摘要

Colabed methane system is a natural system that consists of coal seams, coalbed methane in them and surrounding rocks. As an unconventional natural gas, the generation, reservoir and conservation of coalbed methane are different from those of conventional hydrocarbon. The Qinshui basin in southeastern Shanxi Province, has abundant coalbed methane resources in the Carboniferous Taiyuan Formation and Permian Shanxi Formation. In this study, we reported geophysical features, structural deformation and tectonic evolution of coalbed meathane system in the Qinshui basin. Relationships between structural deformation and the formation of coalbed methane reservoir in Qinshui basin were also discussed. The results show that the Yangquan-Shouyang area in the north part of the basin and the Tunhu-Xiangyuan area in the east are favorable for formation coalbed methane system. In contrast, the Jincheng-Qmshui area in the south part of basin and the Qinyuan area in the middle of basin are favorable for both the formation of coalbed methane reservoirs and high yields as well.%煤层气系统是一个由煤层、煤层中所含甲烷及其围岩组成的天然系统.作为一种非常规天然气,煤层气的生成、聚集和保存不同于常规油气系统.山西沁水盆地作为我国一个特大型石炭-二叠纪含煤盆地,具有非常丰富的煤层气资源.本研究通过对盆地地球物理特征和地质构造演化的深入分析,阐明了地质构造条件对煤层气富集的控制作用.研究结果表明:沁水盆地经历了多期构造演化,地质构造与煤层气成藏之间具有密切关系.在构造次级向斜部位含气量增高,而背斜部位含气量降低,在正断层附近含气量也明显降低.综合分析还表明,盆地北部阳泉-寿阳区域,是煤层气成藏有利区域之一,但不利于煤层气高产；盆地南部晋城-沁水一带及其以北,不仅是煤层气成藏有利区域,而且利于煤层气高产；盆地中部沁源地区是煤层气成藏和高产的有利区域；盆地东部的屯留-襄垣区域是煤层气成藏有利区域之一,但可能不利于煤层气高产.