Failure Analysis of Drill Collar Box Fracture

被引：1

作者：

Li, Fang Po ^{[1
]}

Liu, Yong Gang ^{[1
]}

Lu, Cai Hong ^{[1
]}

机构：

[1] CNPC Tubular Goods Res Inst, Xian 710065, Shaanxi, Peoples R China

来源：

MANUFACTURING SCIENCE AND TECHNOLOGY, PTS 1-3 | 2011年 / 295-297卷

关键词：

drill string; drill collar; failure analysis; fatigue;

D O I：

10.4028/www.scientific.net/AMR.295-297.2129

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

One 203mm drill collar failed infrequently just after 200h of pure drilling time. This paper gives a systematic analysis in consideration of both material quality and loading condition on drill strings. Measurement and inspection were performed on configuration, chemical composition, mechanical performance, metallograghy and micro-fractograghy. It's thought that the drill collar failure accident was premature fatigue failure accident. Failure reason is the mechanical damage caused by improper manufacture process in the root of thread. Under the effect of fluctuating stress, fatigue cracks originated from mechanical damage position and grew rapidly. When cracks propagated through the wall thickness, drill collar fractured.

引用

页码：2129 / 2132

页数：4