松软突出煤层穿层洞穴完井钻孔瓦斯抽采实践

Practices on Gas Drainage with Cavity Completion Borehole Passing Through Soft and Outburst Seam

基于地面煤层气井裸眼洞穴完井的抽采实践经验,探讨了煤矿井下穿层洞穴完井钻孔煤层瓦斯抽采增产机理,分析了松软突出煤层穿层钻孔的造穴工艺技术和注意事项,并在呼鲁斯太矿区进行了现场试验考察。试验结果表明,穿层洞穴完井钻孔在扩大抽采钻孔影响范围、提高瓦斯抽采量和延长钻孔有效抽采时间等方面具有优势。在200 d的抽采时间内,穿层洞穴完井钻孔的瓦斯抽采量为穿层钻孔的6.6倍;抽采200 d后,穿层洞穴完井钻孔的瓦斯抽采量为61.6 m3/d,而穿层钻孔的瓦斯抽采量为3.68 m3/d。

Based on the gas drainage practice experiences with an open hole completion of the surface coal bed methane well, the seam gas drainage production increasing mechanism with the cavity completion borehole through seam in underground mine was discussed and the cavity technology and the noted items of the borehole through the soft and outburst seam were analyzed. A site test and investigation was conducted in Hulu Sitai Mining Area. The test results showed thai the cavity completion borehole through the seam could enlarge the influence scope of the drainage boreholc, improve the gas drainage production, prolong the effective drainage time of the borehole and have other advantages. Within the 200 days＇ drainage period, the gas drainage quantity with the cavity completion horehole through seam would be 6. 6 times higher than the borehole through seam. After 200 days＇ gas drainage, the gas drainage quantity with the cavity completion borehole through seam would be 61.6 m^3/d and the gas drainage quantity with the borehole through seam would be 3.68 m^3/d.