110SS碳钢油管和140ksi碳钢套管在钻井液中的腐蚀及电偶腐蚀行为  

Corrosion and Galvanic Corrosion Behavior of 110SS Carbon Steel Tubing and 140ksi Carbon Steel Casing in Drilling Fluid

作　　者：唐庚[1] 宋洋 王珏皓 郭梦龙 李玉飞[1] 罗伟 TANG Geng;SONG Yang;WANG Juehao;GUO Menglong;LI Yufei;LUO Wei(Engineering Technology Research Institute,PetroChina Southwest Oil and Gas Field Company,Chengdu 610017,China;Xi'an Maurer Petroleum Engineering Laboratory,Co.,Ltd.,Xi'an 710065,China)

机构地区：[1]中国石油西南油气田分公司工程技术研究院,四川成都610017 [2]西安摩尔石油工程试验室股份有限公司,陕西西安710065

出　　处：《热加工工艺》2022年第22期24-29,共6页Hot Working Technology

基　　金：四川盆地高温高压含硫深井超深井钻井、完井及试油技术研究与应用项目(2016E-0608)。

摘　　要：通过挂片失重腐蚀试验,研究了110SS碳钢油管及140ksi碳钢套管在聚磺钻井液中的腐蚀行为以及模拟井下油管、套管互相接触时的电偶腐蚀行为。结果表明:在120℃、密度为2.35g/cm^(3)的聚磺钻井液中,单独的110SS碳钢油管及140ksi碳钢套管的腐蚀速率极其轻微,分别为0.0078、0.0064 mm/a,最大点蚀深度分别为11.9、4.0μm。二者耦合腐蚀10、30 d后,腐蚀速率分别为0.0054~0.0049 mm/a、0.0033~0.0032 mm/a,均属于轻微腐蚀且腐蚀速率均随试验时间延长而减小,其次,二者的腐蚀速率差值逐渐减小;点蚀速率分别为0.1095~0.2482 mm/a、0.3906~0.0462mm/a,110SS碳钢的点蚀速率增大,140ksi碳钢点蚀速率减小。腐蚀产物中主要含有Fe_(x-1)S_(x)及SiO_(2)附着物,这表明110SS碳钢油管和140ksi碳钢套管之间的电偶腐蚀效应极小,且未以均匀腐蚀而以点蚀的方式体现。The corrosion behavior of 110SS carbon steel tubing and 140ksi carbon steel casing in polysulfonate drilling fluid and the galvanic corrosion behavior of simulated downhole tubing and casing contacting with each other were studied by weight-loss corrosion test. The results show that in the polysulfonate drilling fluid at 120 ℃ and a density of 2.35 g/cm^(3), the corrosion rate of the single 110SS carbon steel tubing and 140ksi carbon steel casing is extremely slight, which is 0.0078mm/a and 0.0064 mm/a, respectively, and the maximum pitting depth is 11.9 μm and 4.0 μm, respectively. After 10 days and30 days of coupling corrosion, the corrosion rates are 0.0054 mm/a-0.0049 mm/a and 0.0033 mm/a-0.0032 mm/a, respectively,which belongs to slight corrosion and the corrosion rates decrease with the extension of test time, secondly, the difference of the corrosion rates between the two decreases gradually. The pitting rate is 0.1095 mm/a-0.2482 mm/a and 0.3906 mm/a-0.0462 mm/a, respectively. The pitting corrosion rate of 110SS carbon steel increases and 140ksi carbon steel decreases. The corrosion products mainly contain Fe_(x-1)S_(x) and SiO_(2) attachments, which shows that the galvanic corrosion effect between 110SS carbon steel tubing and 140ksi carbon steel casing is very small, which is not reflected in the form of uniform corrosion but pitting corrosion.

关 键 词：110SS碳钢油管 140ksi碳钢套管 均匀腐蚀速率 最大点蚀深度 电偶腐蚀 

分 类 号：TG172.2[金属学及工艺—金属表面处理]