随着石油钻井、地质岩芯钻探技术的发展,钻进深度不断增加,所钻遇的地层更加复杂.在钻进过程中因井壁坍塌、掉块、井径扩大、缩径而产生的一系列卡钻、埋钻、钻杆折断等事故,轻者影响钻进速度、重者造成井的报废.例如,国外所谓的“Gumbo”页岩地层,即强粘土地层,被认为是十分复杂的地层.引起井壁不稳定的因素很多,有地质因索,也有工艺因素.岩层自身疏松,弱胶结或无胶结、破碎,在外力作用下很容易出现坍 With the development of oil drilling and geological core drilling technology, the drilling depth is increasing, and the strata encountered are more complicated. During the drilling process, due to the collapse of borehole walls, the falling of blocks, the expansion of borehole diameter and the reduction of diameter For example, the so-called “Gumbo ” shale formation in foreign countries, that is, strong clay formation, is considered to be very high Complex formation caused by a large number of unstable borehole wall factors, there are geological factors, but also process factors. Rock formation itself loose, weakly cemented or non-cemented, broken, under the action of external forces is prone to collapse