不渗透小断层群瓦斯异常赋存特点及防治研究

Research on the abnormal occurrence characteristics of gas in impermeable small fault group and its control technology

基于地质构造对瓦斯灾害的控制作用,研究了不渗透小断层群的瓦斯赋存及抽采特点,总结出精细预测不渗透小断层群的还原对比法,提出了穿层钻孔定点旋转割缝强化抽采瓦斯方法.通过对平煤股份八矿井田内大型断裂和小断层的调查分析,确定了区域煤体受压扭性构造应力场控制,结合穿层钻孔施工数据,对己15-14140机巷区域煤层底板进行了高精度还原,与瓦斯动力现象对比分析后,预测巷道Ⅶ区(465～525m)存在不渗透小断层群,并在该区域采用定点旋转割缝强化抽采瓦斯方法进行了现场试验.结果表明:不渗透小断层群存在区域超量瓦斯富集现象,采用穿层钻孔定点旋转割缝强化抽采瓦斯方法后,构造区域煤体整体卸压,裂隙系统生长、扩容,煤体透气性增大至原来的297倍,70d单孔累计抽采瓦斯达9 750m3,取得了显著的效果.

Based on the control effect of geological structure on gas disaster, extraction characteristics of impermeable small fault group were researched. relation method for fine forecast of impermeable small fault group and enh technology using rotatory slotted borehole were proposed. Field trials were gas occurrence and The reduction-cor- anced gas drainage carried out in a re- lated mine. Through the investigation of the large fracture and small faults in the No. 8 mine of Pingdingshan, the fact that the coal is controlled by transpressional tectonic stress is con- firmed. According to the drilling data, the seam floor around Ji15-14140 was restored with high precision. Contrasted with gas dynamic phenomenon, we forecast that there exist small imper- meable faults in ~[ area （465--525 m）. The field test was also carried out in the region by the reduction-correlation method. The results show that there is regional excess gas in the imper- meable small fault group. After using the enhanced gas drainage technology, coal pressure in structure area is entirely released and the fracture system expands which makes the coal seam permeability increases to 297 times of the original. Accumulative drainage quantity of one bore- hole reaches 9 750 m3 in 70 days which shows that the technology has significant effect.