Upper corner gas control based on high level directional long borehole

In order to study the effect of the high level direction long borehole in upper corner gas control, a direction drilling equipment was applied to a directional long borehole drilling in the seam roof and the gas drainage effect inspection in Tangkou Mine. The results showed that a max depth of the high level direction borehole reached at 606 m, the effective section of the borehole was over 80% of the borehole, a direction auxiliary engineering amount of the high level directional drilling borehole was reduced over 60% in comparison with the conventional high level borehole and the cost reduction effect was obvious. In addition, the gas drainage concentration with the directional high level borehole was twice of the conventional high level borehole and the gas drainage pure volume was increased over 60%. The gas concentration in the upper corner and the air returning flow was effectively reduced and the effect was obviously improved.