松软低透气性煤层顺层钻孔全程套管预抽瓦斯技术
Gas Pre-Drainage Technology with Full Length Casing for Borehole Drilled Along Low Permeability Soft Seam
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摘要: 为了提高松软低透气性煤层的瓦斯抽采效果,针对潘一矿东区1252(1)首采工作面的特点,开展了松软煤层顺层钻孔全程瓦斯预抽技术实践,采取该措施后,单孔瓦斯抽采体积分数由原来的20%~40%提高到90%,瓦斯抽采纯量由原来的0.08 m3/min提高到0.25 m3/min,且最大单孔瓦斯抽采纯量达0.51 m3/min;评价单元瓦斯抽采纯量提升近35%,且流量稳定;单元抽采达标时间由传统预抽工艺的93 d,减少到采用顺层钻孔全程套管预抽瓦斯技术后的26 d,达到了快速消突和均匀消突的目的。Abstract: In order to improve the gas drainage effect of the soft and low permeability seam, according to the features of No.1252 (1) first coal mining face in the ea st block of Panyi Mine, the practices on the full length pre-drainage technology with the borehole along soft seam were conducted.After the measures conducted, the ga s drainage volume fraction of a single borehole increased from previous 20% ~40% to 90%, the pure gas drainage quantity was increased from previous 0.08 m3/min to 0.25 m3/min and the max pure quantity of a single borehole reached to 0.51 m3/min. The pure gas drainage quantity in per unit improved by 35% and the flow was stabl e.The gas drainage standard time per unit reduced from 93 days of the traditional pre-drainage technology to 26 days of the full casing pre-drainage technology with the borehole along seam. Thus the target for rapid outburst elimination and even outburst elimination was reached.