钻井中的钻具事故,特别在旋转钻井中的钻具事故比较常见,其中又以钻杆细扣折断最发频繁。业已证明,无细扣钻杆也常常在扣根的第四、五扣处破断。从钻柱受力分析可知,钻柱工作时的拉力、弯曲应力等都在细扣末端形成应力集中, 同时经受交变应力的作用,所以,钻杆细扣末端经常产生疲劳破坏。另外,由于种种原因使钻杆丝扣发生严重磨损而造成的滑扣事故也是屡见不鲜的。为了尽量防止和避免这类事故发生,目前国内外都在加紧研究,寻求强化钻杆接头的方法,本文就此对几种方法和一些比较成功的实践经验作一概述。 Drilling in drilling accidents, especially in rotary drilling drilling accidents are more common, which in turn drill slender buckle the most frequent. It has been proven that no fine buckle drill is often broken buckle in the fourth, five buckle Department broken. Drill string stress analysis shows that the drill string work tension, bending stress and so on are formed at the end of the fine buckle stress concentration, while under the effect of alternating stress, therefore, the end of the drill pipe fine buckle often produce fatigue damage. In addition, due to various reasons, drill pipe threading serious wear and tear caused by the sliding accident is not uncommon. In order to prevent and avoid such accidents as far as possible, at home and abroad are stepping up research to find ways to strengthen the drill pipe joints. This article summarizes several methods and some successful practical experiences.