高腐蚀环境下油井管剩余抗挤强度的理论解  

A theoretical solution to the residual collapsing strength of the oil-well pipe under high-corrosion circumstances

作　　者：卢亚锋[1] 林元华[2] 赵铁[3] 唐庚[1] 孙永兴[4] 朱达江[2] 

机构地区：[1]中石油西南油气田公司采气工程研究院 [2]西南石油大学 [3]西南油气田公司川中油气矿 [4]中石油川庆钻探工程有限公司钻采工程技术研究院

出　　处：《石油机械》2010年第8期17-20,104-105,共4页China Petroleum Machinery

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"(NCET-08-0907);国家自然科学基金资助项目"基于数值模拟的复杂地层地应力反演研究"(50774063);中国石油天然气集团公司应用基础研究项目"非API标准油气井管材及管柱安全性与优化设计技术研究"(2008A-3005)中的部分内容

摘　　要：在高温高压高酸性气田中,油井管局部腐蚀或点蚀会产生应力集中,降低油井管强度,严重时会发展成穿孔泄漏。在本体应力集中系数应力分量表达式的基础上,推导了浅半球腐蚀孔、半球腐蚀孔及深半球腐蚀孔的应力集中系数表达式,并对油井管的剩余抗挤强度进行修正,同时应用推导的腐蚀孔应力集中系数公式对套管的剩余抗挤强度影响规律进行研究。结果表明,腐蚀孔直径d=2.5mm、深度h=1mm时,套管剩余抗挤强度下降近46%,而当h=1mm、d=5或7mm时,套管剩余抗挤强度分别下降30%和20%。In gasfields with high temperature,pressure and acidity,local corrosion or pitting will produce stress concentration and reduce oil-well pipe strength.When these conditions become serious,punched leakage will arise.On the basis of the expression for the stress component of the bulk stress concentration coefficient,the stress concentration coefficient expressions for the corrosion holes of shallow hemisphere,hemisphere and deep hemisphere were derived.And based on these,the residual collapsing strength of the oil-well pipe was revised.Meanwhile,the derived stress concentration coefficient formulae of the corrosion holes were applied to study the law to influence the residual collapsing strength.The result shows that,when the surface diameter of the corrosion hole is 2.5 mm and the corrosion depth is 1 mm,the casing residual collapsing strength will be reduced by 46%;when the depth is 1 mm and the diameter is 5 or 7 mm,the casing residual collapsing strength will drop by 30% and 20% respectively.

关 键 词：应力集中系数 抗挤强度 腐蚀孔 油井管 

分 类 号：TE931.2[石油与天然气工程—石油机械设备]