在苏联很多研究者证明:快速下降钻具对孔壁能补充产生很大的液动压力,使岩层产生裂缝,导致钻孔冲洗液的漏失;当提升钻具时,发现液动压力明显下降,引起孔壁岩层的坍塌(即人工坍塌)。 Many researchers in the Soviet Union proved that the rapid descent drilling tool can supplement the hole wall with a lot of hydrodynamic pressure and cause cracks in the rock formation, leading to the loss of drilling fluid. When the drilling tool is raised, the hydrodynamic pressure is obviously decreased, Cause the hole wall rock collapse (ie, artificial collapse).