关键词: 深部矿井, 低透煤层, 树状钻孔, 穿层钻孔, 抽采半径

Abstract: Aiming at the problems of small extraction radius and low extraction efficiency in the gas gas extraction of deep-permeability coal seams in deep mine, taking the Shoushan No. 1 coal mine of Pingdingshan mine areas test sites, Experimental research on permeability improving technology of tree-type through layer borehole. The test used a self-propelled hydraulic jet tree drilling process.A total of 34 sets of tree-type through layer borehole were constructed in low gas extraction lane which under the seam. 7 per group, total 238 boreholes. The results showed that,compared with hydraulic punching borehole, the application of tree-type through layer borehole in deep low-permeability coal seams, significant increase in extraction influence radius. The average gas drainage concentration increased by 1.30 ~ 1.80 times. And the high-concentration extraction cycle is prolonged. The average daily extraction volume of a single hole is 3.47 ~ 5.30m3 /d. Compared with hydraulic punching and drilling, it is 1.58~3.66 times. The effect of the application of tree-type through layer borehole to the pre-extraction of the cross-strip strip in the deep mine face is obvious. Provided permeability improving technology reserves for gas drainage in deep low-permeability coal seams of pingdingshan mining area.