深井强突出煤层揭煤下向钻孔瓦斯抽采成套技术
Completed gas drainage technology with downward borehole for high outburst seam opening in deep mine
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摘要: 为解决顾桥矿-943—-1 000 m北翼二水平回风斜巷及深部进风井井筒在穿过6煤时的瓦斯涌出异常问题,针对深井存在的煤层松软、透气性低、地应力高、瓦斯压力和瓦斯含量高等特点,提出在顶板巷施工下向穿层钻孔,配套使用掏穴、全程套管跟管钻进、快速封孔等工艺,并进行了现场应用。结果表明:回风斜巷揭6煤措施孔共抽采瓦斯17.2万m3,揭煤区域预抽率45.3%,揭煤区域原始瓦斯压力5.18 MPa,残余瓦斯压力0.22 MPa,原始瓦斯含量10.24 m3/t,残余瓦斯含量5.06 m3/t,残余瓦斯压力和瓦斯含量均未超过国家规定和该矿区的临界值。该技术也成功应用于深部进风井井筒揭6煤,大幅度缩短了工期,实现了深井强突出煤层的安全高效揭煤。Abstract: In order to solve the gas abnormal problem occurred when air retuning gateway in No. 2 Level of-943- -1 000 m North Wing of Guqiao Mine and deep air in take shaft passed through No.6 seam,according to the soft seam,low permeability,high geostress,high gas pressure and high gas content features of the deep mine,the do wnward passed through strata borehole was provided for the construction of the roof gateway,including the cutting,full length casing drilling,rapid borehole sealing and othe r techniques and were applied to the site practices. The results showed that the downward boreholes in No. 6 seam of the air retuning gateway had drainaged gas of 172 0 00 m3 and the pre-drainage rate in the seam opening area was 45. 3%. An in-situ gas pressure of the seam opening area was 5. 18 MPa,the residual gas pressure was 0. 22 MPa,the in- situ gas content was 10. 24 m3/ t,the residual gas content was 5. 06 m3/ t. Neither the residual gas pressure nor the gas content was over the critical value of the state and the mining area. The technology was also successully applied to open No. 6 seam in a deep mine air intake shaft,the construction period was highly reduc ed and the safety and high efficient seam opening in high outburst seam in deep mine was realized.