某气井超级13Cr完井管柱腐蚀及开裂原因分析  

Analysis Corrosion and Cracking in a Gas Well of Super 13Cr Completion Tubing Strings

作　　者：常泽亮[1] 李丹平 赵密锋[1] 吕祥鸿[3] 李岩[1] 薛艳 熊茂县 CHANG Zeliang;LI Danping;ZHAO Mifeng;LYU Xianghong;LI Yan;XUE Yan;XIONG Maoxian(Research Institute of Oil and Gas Engineering,PetroChina Tarim Oilfield Company,Korla 841000 Xinjiang,China;Xi＇an Maurer Petroleum Engineering Laboratory Co.,Ltd.,Xi＇an 710065,China;School of Material Science and Engineering,X i ＇ an Shiyou University,X i ＇ an 710065,China)

机构地区：[1]中国石油塔里木油田分公司油气工程研究院,新疆库尔勒841000 [2]西安摩尔石油工程实验室股份有限公司,西安710065 [3]西安石油大学材料科学与工程学院,西安710065

出　　处：《焊管》2018年第7期14-20,共7页Welded Pipe and Tube

基　　金：陕西省自然科学基金"高含H2S/CO2苛刻环境钛合金管材的耐蚀机理研究"(项目编号2016JM5064)

摘　　要：为了探究某气井超级13Cr完井管柱腐蚀及开裂的原因,通过腐蚀检测、裂纹分析等方法,对完井管柱腐蚀及裂纹问题进行了研究。研究结果表明,油管台肩面的局部腐蚀随着井深增加呈先增大后减小趋势,油管公扣与接箍连接处在拉应力下产生缝隙,流体在缝隙处滞留,发生缝隙腐蚀,井中部处于缝隙腐蚀的敏感区,腐蚀较严重。随井深增加,泥浆附着严重,阻挡了凝析水在内壁的附着,减缓了点蚀的发生,因此油管内壁点蚀深度随井深增加呈减小趋势,油管外壁点蚀无明显规律;超级13Cr材质和完井液的不匹配使油管在拉应力作用下发生应力腐蚀开裂,裂纹起源于外壁,呈树枝状、穿晶。In order to explore the causes of the corrosion and cracking of the Super 13 Cr completion tubing strings in a gas well,the corrosion and cracking problems of the completion tubing strings were studied by corrosion detection, crack analysis and other methods. The results showed that the local corrosion of the shoulder surface of the tubing rised first and then decreased as the depth of the well increased. The tubing pin and the coupling at the joint created a gap under tensile stress, the fluid stayed in the gap, and crevice corrosion occurred. The middle part of the well was in the sensitive area of crevice corrosion, and the corrosion was serious. With the increase of well depth, the mud adhered seriously, which obstructed the adhesion of the condensate waters on the inner wall and slowd down the occurrence of pitting corrosion. Therefore, the pitting depth of the inner wall of the tubing decreased with the depth of the well, and there was no obvious rule of pitting corrosion on the outer wall of the tubing. The mismatch between the super 13 Cr material and the completion fluid caused stress corrosion cracking of the tubing under tensile stress. The crack originated in the outer wall and was dendritic and transgranular.

关 键 词：油井管 超级13Cr 腐蚀 开裂 拉应力 完井液 

分 类 号：TE988.2[石油与天然气工程—石油机械设备]