无水泵反循环钻具的作用原理是,在钻进过程中,借钻具的上下提动,通过钻具内的球阀作用,促使冲洗液在钻具内自行循环.即当钻具提离井底,继而急速下落时,其本身对冲洗液有一个向下的作用力,与此同时液体将产生大小相等、方向相反的反作用力,顶开活门球阀,液体被压出,依此反复作用,便使液体在钻具内循环.为使液体循环,钻具对液体的作用力(液体反作用力)必须大于岩心阻力(包括岩心管与岩心间岩粉的阻力)、球在液体中的自重以及球阀上部液体压力等之和,且此循环作用良好与否, The function principle of the pump-less reverse circulation drilling tool is that during the drilling process, the drilling fluid is pushed up and down by the ball valve in the drilling tool to promote the circulation of the cleaning solution within the drilling tool. At the end, and then rapidly falling, its own flushing fluid has a downward force, at the same time the liquid will produce the same size, the opposite direction of the reaction force, the top open the valve, the liquid is pushed out, and thus repeated, So that the liquid circulates within the drill string.In order to circulate the liquid, the force (liquid reaction force) of the drill string to the liquid must be greater than the core resistance (including the resistance of the core tube to the core rock powder), the weight of the ball in the liquid, The upper part of the ball valve liquid pressure and so on, and this cycle is good or not,