—、管钻的应用及其效率在工农业供水、城建供水以及厂基建筑的勘测中,需要经常在卵石与砾石岩层中进行冲击钻探工作。在这种地层钻探所用的主要工具是管钻(抽筒)。管钻在钻孔中的工作是借人力或机械动力作不断的向孔底岩石冲击。将岩石抽取至管筒内然后取出地面来,在抽取的同时使套管逐渐向地下深进,直至所要求的深度。管钻工作效率的快慢是取决于地质岩石的构造及管钻本身的结构。目前在各勘察部门所采用的管钻为一普通式管钻。这种管钻适用于一般砂土层钻探使 -, Drill pipe applications and their efficiency In the industrial and agricultural water supply, urban water supply and survey of plant-based buildings, the need for frequent pebble and gravel rock drilling operations. The main tool used for drilling in this formation is tube drilling (casing). Drill pipe in the drilling work is by human or mechanical power for continuous rock bottom hole impact. The rock is drawn into the tube and then removed from the ground, drawing it while gradually deepening the casing down to the required depth. Tube drilling efficiency depends on the speed of geological rock and pipe structure of the drill itself. Currently used in various surveying departments of the pipe as a common pipe drill pipe. This pipe drill is suitable for general sand drilling