黔西县官寨井田4、9号煤层瓦斯分布规律探讨

官寨井田位于贵州省黔西县东部，4、9号煤层为井田全区可采煤层。根据大量瓦斯地质资料分析，发现4号煤层大部分区块瓦斯含量大于15．0mL／g·daf，其中大于20．0mL／g·daf的区块主要分布在井田西部边缘；在井田西部瓦斯含量一般为10．0～15．0mL／g·daf；西部煤层露头和张性断层附近含量均小于10．0mL／g·daf。9号煤层瓦斯含量大于20．0mL／g·daf分布于井田中东及北东部，并由往西南及中部逐渐降低的趋势；其含量小于10．OmL／g·daf分布于井田南部煤层露头附近。由于井田构造复杂，瓦斯含量明显受断层和煤层埋深影响，数据显示：闭合断层附近瓦斯含量明显增高，张性断层附近含量变小，同一煤层随埋藏深度增加瓦斯含量增大。

Discussion on Nos.4 and 9 Coal Seams Gas Distribution Pattern in Guanzhai Minefieid,Qianxi County

The Guanzhai minefield is situated at eastern Qianxi County, Guizhou Province, Nos.4 and 9 coal seams are mineable in the whole minefield. Based on analysis of large amount gas geological data, found that gas content of most blocks of No.4 coal seam is 〉 15.0ml/g·daf, in which, blocks with gas content 〉 20.0ml/g·daf mainly in western margin of the minefield; in western part of the minefield gas content is generally 10.0-15.0ml/g·daf; near the western part coal seam outcrops and extension faults, gas content 〈 10.0ml/g·daf. No.9 coal seam gas content 〉 20.0ml/g·daf blocks are distributed in the middle east and northeast part of minefield, gradually decreasing toward southwest and middle part; 〈10.0ml/g·daf near the southern part coal seam outcrops. Due to complex minefield structures, gas content is obviously impacted by faults and coal seam buried depths, relevant data demonstrated： gas content increasing distinctly near sealed faults, decreasing near extension faults; in same coal seam, gas content increasing along with the increasing of buried depth.