在山前地带和山地钻进时的主要障碍,是钻井的自发弯曲。岩层的倾斜大、软硬岩石的频繁交替等经常是造成钻井弯曲的原因。这使地质人员不得不认为,在上述地区每钻进一百米,井筒方位角变化到7-10°是允许的。目前所使用的预防和纠正钻井弯曲的方法(减少管柱重量的同时增大钻头的转数、在井筒内安置定心器、降低钻头载荷,向井内下 The main obstacle to drilling in the foreland and mountains is spontaneous drilling of wells. The rock slope is large, frequent alternation between soft and hard rocks and other reasons is often caused by the drilling bend. This made the geologists have to think that it would be permissible to change the wellbore azimuth to 7-10 ° for every 100 meters drilled in these areas. Currently used methods to prevent and correct drilling bends (to reduce the weight of the string while increasing the number of bits to be rotated, centering the core within the wellbore, reducing the bit load, moving down the well