油气井套管侧向屈曲分析与井下加强工具探讨  

Lateral buckling analysis of oil and gas well casing and design of downhole reinforcement tool

作　　者：尹飞[1] 高德利[1] 

机构地区：[1]中国石油大学石油工程教育部重点实验室,北京102249

出　　处：《中国石油大学学报（自然科学版）》2014年第6期67-71,共5页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金创新研究群体项目(51221003);国家'973'项目(2010CB226703);国家科技重大专项(2011ZX05009-005)

摘　　要：针对油气井套管挤毁的研究多局限于强度分析,忽视了套管侧向稳定性问题。除小直径或特厚壁的套管外,常用套管的失效形式应属于失稳损坏。基于外压作用下套管侧向屈曲机制,分别采用API标准和圆筒屈曲分析的方法,计算套管侧向屈曲的临界压力。另外,对减小套管计算长度的井下加强工具进行探讨和设计。结果表明:套管纵向长度对侧向屈曲的临界压力具有重要影响;若把套管的计算长度减小到某一范围,可有效地提高套管的抗失稳能力。结果为提高套管抗失稳能力提供了一种新途径,可作为完井后高挤毁风险套管的加强补救措施。The current researches on casing collapse are mainly confined to strength analysis, while the problems caused by lateral buckling are less considered. In fact, the most failures of oil and gas well casing, except casings with small diameter or thick wall, can be attributed to the mode of buckling failure. The mechanisms of casing buckling under external pressure were revealed. The critical pressure of casing lateral buckling was calculated using two methods, including an API standard and a cylinder buckling analysis technique. Subsequently, the downhole casing reinforcing tool was designed. The results in-dicate that the casing length used in the calculation has a great influence on the critical pressure for lateral buckling of cas-ings, and the anti-instability of casings increases with the decrease of the values of casing length adopted in the calculation. The findings can efficiently increase the anti-instability of casings and provide a new remedial measure for casings with high collapse risks after well completion.

关 键 词：钻井 井筒完整性 套管挤毁 屈曲分析 井下工具 结构设计 

分 类 号：TE21[石油与天然气工程—油气井工程]