In coal and gas outburst mines, regional gas control must be carried out before heading and stoping at the working face. In the soft coal seam with Platt coefficient f < 1, hole collapse and pressure drilling are e...In coal and gas outburst mines, regional gas control must be carried out before heading and stoping at the working face. In the soft coal seam with Platt coefficient f < 1, hole collapse and pressure drilling are easy to occur in directional drilling through layers, which may cause drilling accidents. Through the research on the matching combination of directional drilling rig, mud pump, screw drilling tool and other equipment, sliding drilling and compound drilling technology, the accurate and efficient drilling of directional cross-layer drilling can be realized. The directional cross-layer drilling rock segment is between 70 and 90 m. If there is geological structure in the drilling rock segment or cracks appear due to the increase of rock stress around the roadway, the attenuation of borehole gas concentration will increase rapidly. Through secondary plugging grouting at the borehole opening and reverse grouting in the borehole, the borehole gas extraction concentration will be effectively increased, and efficient extraction and release of coal seam gas will be achieved. The directional drilling rig random measurement system can control the drilling construction orientation, solve the technical problems of deviation of drilling trajectory, crack coal and gas outburst mines, construct long-distance cross-layer drilling and gas extraction blank zone, and realize outburst elimination in outburst coal seam area. The adoption of the outburst prevention and control plan for directional cross-layer drilling area can reduce the tunneling work amount of the rock roadway at the bottom plate of the working face, reduce the safety accident rate of the mine gas disaster and the safety cost expenditure, and will produce huge economic and social benefits in the aspect of mine gas prevention and control.展开更多
文摘In coal and gas outburst mines, regional gas control must be carried out before heading and stoping at the working face. In the soft coal seam with Platt coefficient f < 1, hole collapse and pressure drilling are easy to occur in directional drilling through layers, which may cause drilling accidents. Through the research on the matching combination of directional drilling rig, mud pump, screw drilling tool and other equipment, sliding drilling and compound drilling technology, the accurate and efficient drilling of directional cross-layer drilling can be realized. The directional cross-layer drilling rock segment is between 70 and 90 m. If there is geological structure in the drilling rock segment or cracks appear due to the increase of rock stress around the roadway, the attenuation of borehole gas concentration will increase rapidly. Through secondary plugging grouting at the borehole opening and reverse grouting in the borehole, the borehole gas extraction concentration will be effectively increased, and efficient extraction and release of coal seam gas will be achieved. The directional drilling rig random measurement system can control the drilling construction orientation, solve the technical problems of deviation of drilling trajectory, crack coal and gas outburst mines, construct long-distance cross-layer drilling and gas extraction blank zone, and realize outburst elimination in outburst coal seam area. The adoption of the outburst prevention and control plan for directional cross-layer drilling area can reduce the tunneling work amount of the rock roadway at the bottom plate of the working face, reduce the safety accident rate of the mine gas disaster and the safety cost expenditure, and will produce huge economic and social benefits in the aspect of mine gas prevention and control.
