高压水射流水力扩孔抽采半径考察研究

潘三矿为大型现代化矿井,13-1煤层原始透气性系数低且瓦斯压力及含量均较高,煤层突出危险性严重,直接抽采煤层瓦斯难度大。采用新型高压水射流扩孔技术,可达到扩大钻孔直径、增加煤层暴露面积和卸压范围的目的,从而提高煤层的透气性,增大煤层的抽采半径。在测定煤层原始瓦斯压力及含量的基础上,采用瓦斯压力和含量降低法考察水力扩孔后的煤层抽采半径,为试验区煤层抽采钻孔设计提供了依据。

Investigation and Study on Gas Extraction Radius of Borehole Expanded by High-pressure Water Jet

The test mine is a large modern mine,its 13-1 coal seam has low original permeability coefficient,higher gas pressure and content,and serious outburst hazard,so the direct gas drainage from this seam is more difficult.The use of the new hole enlargement technology by high-pressure water jet can achieve the goal of enlarging the hole diameter,increasing the exposed area of the coal seam and pressure releasing range,and thereby improve the permeability of the coal seam and increase the gas extraction radius from the seam.On the basis of measuring the original gas pressure and content of the seam,investigation was made on the gas extraction radius from the seam after hole enlargement by using the reduction method of gas pressure and content,this thus provided a basis for the design of gas extraction holes in the test area.