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The effect of gas extraction would be significantly increased by the way of coal section drilling hole diameter expansion. For the existing technical problems and limitating of constructing large diameter borehole directly or using the reaming way of SKP high pressure water jet, and based on heterogeneous crushing mechanism of high pressure water jet, the integrative hydraulic drilling and reaming completely technology is proposed, the system structure of the technology is researched, the main equipments are integrative selected, and the process characteristics and application prospect of the technology are concluded. The results show that the integration technology of the integrative hydraulic drilling and reaming obvious improves the permeability of coal, promotes gas release, realizes continuous drilling between coal and seam and carried out simultaneously with drilling and reaming. It could significantly increase reaming efficiency and adaptability of evil working condition, which has important popularized and applied values.

According to the theory of gas flow in coal seams, and according to drainage standard and the other relevant laws and regulations, derived the calculating equation of efficient radium of drilling hole gas extracting in drill holes in coal seam and drill holes along seam. Efficient radium of drilling hole gas extracting was calculated, combining with field practice of coal seam named 1 in Xinji No. 2 coal mine, the comparison with efficient radium of drilling hole gas extracting tested in field. Analysis on influencing factors of efficient radium of drilling hole gas extracting, and obtain the influence law on the efficient radium of drilling hole gas extracting.

In this paper,in the case of upper protective layer mining of a mine for the engineering background, based on the model of semi-infinite plane body in elastic mechanics, the theoretical calculation model of verticalhorizontalshear stress of floor coal rock is established, and it is concluded that the stress expression of any point in the impact of distributed force. By introducing the rock strength index I and generalized Hooke's law, it is concluded that the discrimination criterion of guide gas fissure zone and pressure relief desorption belt of underlying coal rock with upper protective layer mining. The pressure relief scope of protection with the mining of upper protective layer is determined. Theoretical analysis shows that: the "pressure relief desorption zone" of the underlying protected coal seam that the vertical distance to the protective layer is 40m lags behind 22.2m.Through field test, the results show that the obtained pressure relief scope of protection is 26.98m,and the theoretical analysis results are basically similar.

Mine into the deep mining, the power disaster occurs mechanism more complex features fuzzy disasters and hazards common. Outburst and rock burst and other disasters are common differences, the use of traditional coal seam outburst hazard identification method has limitations. According to the kilometers deep test area, the individual indicators law 13-1 coal seam the outburst hazard identification,13-1 coal seam first mining area were identified as non-prominent seam. While outburst identification test area seam burst tendency identification,13-1 coal seam has a strong burst tendentious. The test mine disaster prevention should also consider bumping prevention and control not only consider the gas control. Project research results have important reference conditions similar to mine.

Test mine is a large modern mine, the 13-1 coal-seam original permeability coefficient was low, gas pressure and content were higher, coal seam outburst danger of serious, directly extracting coal gas is difficult. Using a new type of high pressure water jet reaming technology, can achieve the expansion of borehole diameter, increase coal seam exposed area and pressure relief range, thereby improving the coal seam permeability, increased coal seam drainage radius. Investigated on the basis of determination of the original coal seam gas pressure and content of the coal extraction radius after the hydraulic reaming. Provide the basis for the seam of the test area borehole design

In Xinji Coal Mine under complicated geological conditions, regional faults. Experimental zone for near coal seam group mining(6-1,7-1,7-2,8 seam), The objective conditions with protective layer . The minefield of soft broken coal seam, Soft layered coal firmness coefficient f = 0.18. In the test area of 210601,210603 6-1seam protective layer mining face during the period, there were 8 abnormal gas dynamic phenomenon, To the coal mine safety production brought hidden trouble. On the basis of dynamic phenomenon occurring phenomenon, analysis of the dynamic phenomena, combined with the test area actual situation, summed up the6-1coal power causes, for guiding the 6-1safety mining and provide a theoretical basis, has important significance.

In view of the Huai Nan mining area deep mine Dingji mine fully mechanized mine head face low-index outburst suddenly extrusion the region gas geological feature, analysis mechanism of the suddenly extrusion frictional sliding instability. The research gain sensitive index critical value drilling bits S and depth of hole coefficient S′, drilling gas inrush initial velocity q and attenuation coefficients Cq, its innovative index S′ the forecast enhanced the rate of accuracy take the ground stress as the leading role low- index outburst. The results show that the forecasting non-outbursting risk rate is 87%, and the forecasting non-outbursting accuracy rate is 100% during 2000m tunnel driving in test area.