高瓦斯碎软煤层超高压水力割缝增透机理及合理技术参数研究

针对云南省大坪矿区某煤矿开采C_9煤层期间面临的煤层透气性差、瓦斯含量高、预抽达标时间长、生产接续失调等问题,提出超高压水力割缝增透强化抽采技术。采用理论分析、实验考察的方法对其增透机理、合理技术参数分别进行了分析研究,得到C_9煤层合理割缝压力为75 MPa,单缝合理排屑量为0.36t,缝槽半径约为1.66m,单缝合理割缝时间为7min,缝槽合理间距为5m。在此基础上开展了工业试验,试验结果表明:C_9煤层采用超高压水力割缝后,钻孔抽采瓦斯浓度、瓦斯纯流量提高约2.14倍、2.74倍,煤层抽采达标时间缩短约63.7%,解决了某煤矿C_9煤层瓦斯治理难题,有效地保障了煤矿的安全高效生产。

Study on the rational technical parameters and antireflection mechanism of ultra-high pressure hydraulic slitting in high gas and soft coal seam

According to the mining of C9 coal seam in Daping Coal Mine, Yunnan Province, the coal seam is faced with the problems of poor permeability, high gas content, long time of pre drainage reaching the standard, and maladjustment of production continuity, etc. Theoretical analysis and experimental investigation are used to analyze the mechanism of increasing permeability and reasonable technical parameters respectively, find the reasonable cutting pressure of C9 coal seam is 75MPa, the reasonable chip removal amount of single seam is 0.36t, the radius of slot is about 1.66m, the reasonable cutting time of single seam is 7min, and the reasonable spacing between slots is 5m. The test results show that: after adopting ultra-high pressure hydraulic slotting in C9 coal seam, the concentration and pure flow of gas extracted by drilling are increased by about 2.14 and 2.74 times, and the time of reaching the standard is shortened by about 63.7%, which effectively guarantees the safety and efficiency of the mine Production.