井下油管腐蚀失效分析  

Corrosion failure analysis of downhole oil tube

作　　者：吴贵阳[1,2,3] 余华利[1,2,3] 闫静[1,2,3] 刘志德[1,2,3] 杜国滨[1] 霍绍全[1,2,3] 曹军[1,2,3] 

机构地区：[1]中国石油西南油气田公司天然气研究院 [2]国家能源高含硫气藏开采研发中心 [3]中国石油天然气集团公司高含硫气藏开采先导试验基地

出　　处：《石油与天然气化工》2016年第2期50-54,共5页Chemical engineering of oil & gas

摘　　要：油气井增产、投产常采用酸化技术,在酸化过程中,油井管腐蚀失效是油管失效的主要形式之一。通过化学成分分析、金相分析、残余应力测试、腐蚀区域微观分析和油管耐蚀性能评价对酸化过程中呈现规律状螺旋腐蚀失效油管进行的分析表明,失效油管的化学成分、抗拉强度、延伸率、屈服强度、硬度均符合技术协议要求;金相组织由回火索氏体组成,但存在带状偏析,且内部存在拉应力。螺旋状内部拉应力存在形成其特有腐蚀形貌,腐蚀产物主要由CaCO_3、Fe_2O_3组成。现场工况下使用转向酸,在105℃时会发生严重腐蚀,腐蚀速率可达到126.45g/m^2·h。Acidizing technology was commonly used in oil and gas well stimulation and production,and corrosion failure of oil tube during the acidification process was a main form of tubing failure.Chemical composition analysis,metallography analysis,residual stress test,microstructure analysis at corroded areas and the adaptability evaluation of oil tube were used to investigate the helical corrosion failure of oil tube during acidification process.The analysis results showed that chemical composition,tensile strength,elongation,yield strength and hardness of the failure oil tube were agreed with technology agreement,and microstructure was tempered sorbitic,but ribbon segregation and residual stress existed in oil tube.Corrosion unique topography was formed by helical internal tensile stress,the products were mainly composed of CaCO_3,Fe_2O_3.Severe corrosion would happened at 105 ℃when diverting acid were used on site.The corrosion rate could reach 126.45g/m^2·h.

关 键 词：失效分析 残余应力 井下油管 油气田 螺旋状腐蚀 

分 类 号：TE983[石油与天然气工程—石油机械设备]