焦作煤田瓦斯赋存规律及差异性原因分析

Gas Hosting Pattern and Discrepancy Analysis in Jiaozuo Coalfield

为厘清焦作煤田二1煤层瓦斯赋存规律及差异性原因,运用瓦斯赋存构造逐级控制理论,研究了焦作煤田瓦斯赋存规律及瓦斯生成与排放的过程,探讨了造成瓦斯赋存差异性明显的原因。深成变质作用叠加岩浆热液的岩浆变质作用是焦作煤田二1煤变质为三号无烟煤的主要原因,也是焦作煤田煤层瓦斯含量高的基础。煤层瓦斯的生、储、排过程研究表明,在喜马拉雅期之前整个焦作煤田的瓦斯赋存状态是相似的;喜马拉雅期形成的NW向峪河口正断层使两盘煤层上覆基岩厚度产生明显差异,是造成焦作煤田瓦斯赋存差异性的根本原因。峪河口断层将焦作煤田划分为东、西两个瓦斯地质单元,西部瓦斯地质单元瓦斯含量高、瓦斯突出灾害严重;东部瓦斯地质单元主要表现为低瓦斯区。

To clarify coal IIl gas hosting pattern and discrepancy cause in the Jiaozuo coalfield, through gas hosting tectonic gradual con- trol theory, has studied gas hosting pattern and gas generation and drainage processes, and discussed cause of obvious discrepancy in gas hosting. The study has considered that the plutonic metamorphism superimposed with magmatic-hydrothermalism could be the main cause of coal Ill metamorphosed into anthracite No.3 （WY3）, also the basis of high gas content in Jiaozuo coalfield. The study of coal gas generation, reservation and drainage processes have shown that the gas hosting status in whole Jiaozuo coalfield was similar be- fore the Himalayan stage, while the Himalayan NW Yuhekou normal fault made the overlying bedrock thicknesses in both wails obvi- ously different, thus the essential cause of gas hosting discrepancy. The fault has divided Jiaozuo coalfield into east and west two geolog- ical units. The west unit has higher gas content and serious gas outburst hazard; while the east unit is mainly showing low gaseous area.