关键词: 松软低渗煤层, 瓦斯, 超高压, 水力压裂, 水力割缝

Abstract: To solve the problem of efficient gas extraction from the soft and strongly adsorptive 2-1 coal seam of Zhaojiazhai Coal Mine in the western part of Henan Province，a combined fracturing and slot⁃ ting enhancement technology was proposed. This technology combines the technical advantages of hydrau⁃ lic fracturing and hydraulic slotting，conducting large-scale fracturing in the coal seam to open micro�cracks，and then using high-pressure water jetting to cut slots，achieving precise pressure relief and crack expansion，strengthening the macro and micro channels for gas flow，and improving the mechanical prop⁃ erties of the coal. A combined racturing and slotting enhancement test was conducted in the 14 mining area of the mine. The combined fracturing and slotting enhancement technology significantly improved the per⁃ meability of the coal seam，and the permeability coefficient increased to 25.5 times that of the original coal seam. This combined technology was applied to the 14201 working face. After 98 d of extraction，the gas content of the coal seam in the experimental area decreased from 8.62 m³/t to 5.35 m³/t. Compared with traditional technologies，the engineering volume was reduced by 33%，and the time for achieving extrac⁃ tion standards was saved by 39%，achieving efficient gas extraction from the coal seam. This technology provides a reliable path for the safe and efficient mining of soft and strongly adsorptive coal seams.

Key words: soft and low permeability coal seam, gas, ultra-high pressure, hydraulic fracturing, hy? draulic slotting