随着矿井采掘活动不断向深部延伸，碎软、低渗煤层瓦斯抽采难度增加，矿井瓦斯治理面临更大挑战。常规水力压裂煤层增透措施存在压裂不均匀、压裂排量低、压裂覆盖范围小及裂缝易闭合等不足。基于此，提出碎软煤层顶板定向长钻孔水力加砂分段压裂煤层增透区域瓦斯超前预抽的技术方案，研发了“定向喷砂射孔+加砂分段压裂”复合工艺技术，形成了多手段、多角度考察分段加砂压裂影响范围和压裂后煤层瓦斯抽采效果分析为一体的压裂效果评价方法。在山西阳泉矿区新景煤矿保安区北六、北七工作面开展工业性试验，完成2个压裂钻孔(孔深均为609 m)定向喷砂射孔、水力加砂分段压裂工程试验。累计定向喷砂射孔80次，其中1号压裂孔定向喷砂射孔30次，2号压裂孔定向喷砂射孔50次，砂比2%～3%、定向喷砂射孔压力22.6～28.6 MPa，共计注入射孔液1 072 m3，使用石英砂19.84 t。实施水力加砂分段压裂16段，1号压裂孔分6段压裂，2号压裂孔分10段压裂，单段注入压裂液153.76～235.11 m3、平均砂比2.02%～2.56%、共计注入核桃壳砂36.48 t、压裂液2 808.57 m3。采用孔内瞬变电磁法、微量示踪剂法等手段确定压裂影响半径20～38 m。统计压裂后1号钻场、2号钻场100 d瓦斯抽采数据，其中1号钻场平均瓦斯抽采体积分数43.97%，平均瓦斯抽采混合流量1.61 m3/min，日均瓦斯抽采纯量1 025.11 m3；2号钻场平均瓦斯抽采体积分数23.17%，平均瓦斯抽采混合流量8.56 m3/min，日均瓦斯抽采纯量2 810.6 m3。1号钻场、2号钻场较邻近区域顺层钻孔瓦斯抽采分数提高了3.36倍和6.38倍，百米钻孔瓦斯抽采纯量提高了16.44倍和45.14倍；较千米钻孔瓦斯抽采体积分数提高10.53倍和19.99倍，百米钻孔瓦斯抽采纯量提高了5.61倍和15.42倍。结果表明，该技术在煤矿井下实现大排量、高砂比，连续水力压裂作业，压裂后煤层透气性显著提高，为碎软煤层区域瓦斯治理提供技术借鉴。

With the continuous extension of mining activities to the depths, the difficulty of gas extraction in soft and low-permeability coal seams has increased, and the mine gas control is facing greater challenges. Conventional hydraulic fracturing coal seam permeability enhancement measures have some shortcomings such as uneven fracturing, low fracturing displacement, small fracturing coverage and easy fracture closure. Based on this, a technical scheme of advance gas pre-extraction in coal seam anti-penetration area fracturing by hydraulic sanding and staged fracturing with directional long drilling holes in the roof of crushed soft coal seam was proposed, and the composite technology of “directional sandblasting perforation + staged sand fracturing” was developed. and a fracturing effect evaluation method integrating multi-method and multi-angle inspection of the influence range of staged sand fracturing and analysis of coal seam gas drainage effect after fracturing has been formed. Industrial tests were carried out on the North sixth and North seventh working faces of the security area of Xinjing Coal Mine in Yangquan Mining Area, Shanxi Province, and two fracturing boreholes (both with a hole depth of 609 m) were completed, including directional sand blasting perforation and hydraulic sand adding staged fracturing engineering tests. A total of 80 times of directional sandblasting perforations have been carried out, including 30 times of directional sandblasting perforations for No.1 fracturing hole and 50 times of directional sandblasting perforations for No. 2 fracturing hole. The sand ratio is 2%～3%, and the directional sandblasting perforating pressure is 22.6～28.6 MPa. A total of 1 072 m3 of perforating fluid was injected, and 19.84 t of quartz sand was used. 16 stages of hydraulic sand fracturing were carried out. The No. 1 fracturing hole was divided into 6 stages, and the No. 2 fracturing hole was divided into 10 stages. Fracturing fluid 153.76～235.11 m3 was injected into a single stage, with an average sand ratio of 2.02%～2.56%. A total of 36.48 tons of walnut shell sand and 2 808.57 m3 of fracturing fluid were injected. The influence radius of fracturing is 20～38 m by means of borehole transient electromagnetic method and trace tracer method. The 100-day gas drainage data of Drilling Site 1 and Drilling Site 2 after fracturing were counted. The average gas extraction volume fraction of No. 1 drilling site is 43.97%, the average gas extraction mixed flow is 1.61 m3·min-1, and the daily average net gas extraction volume is 1 025.11 m3; The average gas extraction volume fraction of No. 2 drilling site is 23.17%, the average gas extraction mixed flow is 8.56 m3·min-1, and the daily average net gas extraction volume is 2 810.6 m3. Compared with the adjacent area, the gas drainage fraction of the bedding boreholes in the No. 1 and No. 2 drilling sites has increased by 3.36 times and 6.38 times, and the pure volume of gas drainage in the 100 meter boreholes has increased by 16.44 times and 45.14 times; The volume fraction of gas drainage increased by 10.53 times and 19.99 times compared with that of kilometer boreholes, and the net amount of gas drainage increased by 5.61 times and 15.42 times. The results show that this technology realizes large displacement, high sand ratio and continuous hydraulic fracturing operation in the coal mine, and the permeability of the coal seam after fracturing is significantly improved, which provides a technical reference for gas control in broken soft coal seam areas.