套管全管壁屈服挤毁压力计算  

Calculation of Yield Collapse Pressures for Casing Through-Wall

作　　者：孙永兴[1,2] 林元华[2] 施太和[2] 刘素君 陈丽萍 张帆 

机构地区：[1]中国石油川庆钻探工程有限公司钻采工程技术研究院,四川广汉618300 [2]CNPC石油管工程重点实验室(西南石油大学),四川成都610500

出　　处：《石油钻探技术》2011年第1期48-51,共4页Petroleum Drilling Techniques

基　　金：国家新世纪优秀人才支持计划项目“高含H2S气藏完井管柱设计及其可靠性研究”(编号:NCET-08-0907);四川省杰出青年学科带头人培养基金项目“石油膨胀管关键技术研究”(编号:06ZQ026-028)资助

摘　　要：分析了API屈服挤毁公式和ISO全管壁屈服挤毁压力公式,认为:API Bulletin 5C3屈服挤毁设计的基本原理是管内壁屈服即失效,实际上,内壁开始屈服时套管还有很大的抗挤余量,对于D/t<15的厚壁及特厚壁套管,若按API提供的这种最小屈服挤毁公式计算,会造成管材浪费或选择套管难的问题;而ISO全管壁屈服挤毁压力公式并非是全管壁屈服公式,可能并不适合所有壁厚段套管强度的计算。为此,根据弹塑性力学理论推导出了任意屈服半径处及全管壁屈服时的挤毁强度公式。通过计算对比可知,对于D/t≤15的厚壁管(API Bulletin5C3用屈服公式计算套管强度)用von Mises屈服准则计算的套管内壁起始屈服挤毁强度值,要比现行的API Bul-letin 5C3屈服挤毁值高15.45%,而全管壁屈服挤毁值至少要比API Bulletin 5C3屈服挤毁值高出32.78%。The analysis of API 5C3 yield collapse formula and ISO through-wall yield collapse formula shows that the basic design principle of API 5C3 is the failure of inner wall. In fact,casing wall still has a great of collapsing when yielding. For casing （D/t〈15） and special thick casing, the formula for determination of minimum yield collapsing provided by API will result in the casing waste or the difficulty in choosing casing. While the ISO through-wall yield collapse formula is not completely through-wall yield collapse formula which cannot be used for all casing. The yield collapse formula for arbitrary radius and the through-wall yield is obtained by elastic-plastic mechanics theory. The comparison shows that for casing （D/t〈15）, initial yield collapse strength for inner casing calculated by von Mises yield criterion is 15.45% higher than that of using API 5C3, and the through-wall yield collapse strength is 32. 78%higher than that of using API 5C3＇s.

关 键 词：套管 屈服应力 抗压强度 

分 类 号：TE925.2[石油与天然气工程—石油机械设备]