摘要
Abstract
In light of the regional pressure relief problem in severe rockburst mines,taking Mengcun Coal Mine as an example,which is a severe rockburst mine,the return airway of the 401104 working face is a gob-side driving roadway.During the reverse excavation phase,conventional rockburst prevention measures were adopted.The working face exhibited characteristics such as high-frequency microseismic events,large energy releases,rockburst manifestations,significant floor heave,and low single-advance excavation rates.Subsequently,an innovative rockburst control method was introduced.First,surface horizontal well fracturing was carried out 60 m above the coal seam of the 401103 working face.The fractures extended east-west,covering the entire 401103 working face,and north-south,covering both the 401103 working face and the return airway of the 401104 working face to the north.After mining of the 401103 working face was completed,and before excavation of the 401104 return airway,surface horizontal well staged fracturing was implemented 40 m above the coal seam in the middle of the 401104 working face,further weakening the key layer 40 m above the coal seam in the 401104 return airway.In the underground,directional long-distance hydraulic fracturing was carried out ahead of the excavation face in the coal pillar zone of the 401104 return airway,20 m above the coal seam,to achieve pre-pressure relief.Thus,the weakening of the three key layers—"high,medium,and low"—was accomplished.During the excavation of the 401104 return airway,the pressure relief workload was reduced by 20%,the concentrated stress decreased by 15%,the microseismic monitoring energy decreased by 18%,and the single-advance rate increased by 130%,achieving a dual improvement in quality and efficiency.关键词
双台阶压裂/地面水平井压裂/冲击地压/定向长钻孔水力压裂Key words
double step fracturing/surface horizontal well fracturing/rock burst/directional long borehole hydraulic fracturing分类
矿业与冶金
