Key technology and application of surface life support hole demonstration project in Meihuajing Mine

In order to solve the problems of low drilling efficiency and poor target-hitting accuracy of ground life support hole, Meihua Mine was selected as the test site of rapid and accurate drilling technology project, through the analysis of geological conditions, the adaptability of complex strata and drilling technology, and the optimization of drilling technology, the construction technology is determined as compound drilling. The hydraulic truck-mounted drilling rig and large displacement mud pump are the key equipment, which are optimized from five aspects: well structure, PDC bit, bottom hole assembly, drilling parameters and trajectory control, rapid and accurate drilling technology for complex formation with large dip angle, medium soft rock and water inrush by optimizing PDC bit, adding hydraulic single-bend auger and using wireless MWD as key bottom hole assembly. The field test shows that the life support hole reaches the well depth of 670.5 m, takes 46.83 hours, the average drilling speed is 14.32 m/h and the horizontal displacement of bottom hole is 0.27 m, which meets the requirements of drilling hole in the golden rescue time of 72 hours for 600 m deep drilling, it has the important demonstration significance of mine emergency rescue.