巨厚火成岩对下伏煤层瓦斯赋存的控制作用  

Controlling effect of extremely thick igneous rock on gas occurrence of underlying coal seam

作　　者：王伟[1] 程远平[1] 王亮[1] 王海锋[1] 卢守青[1] 蒋静宇[1] 

机构地区：[1]中国矿业大学瓦斯治理国家工程研究中心,安全工程学院,江苏徐州221116

出　　处：《采矿与安全工程学报》2014年第1期154-160,共7页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金青年基金项目(51004106);中国博士后科学基金项目(2012M510145);国家“十二五”大型油气田及煤层气开发重大专项项目;煤层气资源与成藏过程教育部重点实验室开放基金项目(2013-005)

摘　　要：为了研究巨厚火成岩对下伏煤层瓦斯赋存的控制作用,以海孜煤矿10煤层火成岩不同覆盖厚度区域所取5个煤样为研究对象,测定了坚固性系数、瓦斯放散初速度、瓦斯吸附常数、突出危险性指标K值等参数随火成岩覆盖厚度的变化,同时采用工业分析、CO2测微孔、电镜扫描、显微组分分析、镜质组反射率测定等方法研究了火成岩对煤质、孔隙结构的影响。结果表明:巨厚火成岩分布对下伏煤层煤质及瓦斯赋存具有控制作用,其热演化和热变质作用提高了10煤层变质程度,10煤层由无火成岩覆盖区的长烟煤逐渐演化为巨厚火成岩覆盖下的瘦煤;随上覆火成岩厚度增加,10煤层微孔发育,吸附和储集瓦斯的能力增强,瓦斯含量增加;火成岩侵入带来的挤压作用使厚覆盖层下煤层强度降低,局部更易形成软煤分层,增加了煤与瓦斯突出危险性。To study the controlling effect of extremely thick igneous rock on gas occurrence of under-lying coal seam, five coal samples had been selected in igneous rock covered areas with different thick-ness in No.10 Coal Seam of Haizi Coal Mine. The changes of coal firmness coefficient, initial methane diffusion velocity, methane adsorption constants, outburst risk index value, etc, as the increasing of ig-neous rock thickness were tested in this paper. Meanwhile, the proximate analyses, micro porous meas-ured by carbon dioxide, scanning electron microscopy and maceral were used to study the influence of igneous rock on the coal quality and pore structure. The results show that the distribution of extremely thick igneous rock plays a control role in the coal property and gas occurrence of underlying No.10 Coal Seam. The metamorphic degree of No.10 Coal Seam has been improved under the thermal evolution and thermal metamorphic effects of igneous rock. The underlying coal seam is gradually improved from long flame coal in without igneous rock covered area to lean coal under the extremely thick igneous rock. With the thickness increase of overlying igneous rock, the micro porous of No.10 Coal Seam developes, the ability of gas adsorption and reservoir enhances, and the gas content increases. The strength of underlying No.10 Coal Seam decreases under the squeezing action of igneous rock intrusion,coal layer can be easily formed in local area. Thus, the risk of coal and gas outburst increases.

关 键 词：巨厚火成岩 热变质作用 煤质 镜质组反射率 瓦斯赋存 

分 类 号：TD712[矿业工程—矿井通风与安全]