保持天井导向孔钻进方向的准确性并防止其偏斜,比提高钻孔速度,降低成本更为重要,因为,为了降低成本而进行高速钻孔,往往会造成钻孔偏离“孔标”(target)的严重后果。目前大多数其他钻进作业都致 Maintaining the accuracy of the pilot hole in the direction of the pilot hole and preventing its deflection is more important than increasing the drilling speed and reducing the cost because high speed drilling to reduce costs often results in the deviation of the hole from the “hole” target) serious consequences. Most other current drilling operations are caused