泥浆膜在大气环境下对钻杆的腐蚀机理研究  

Study on Drill Pipe with Mud Membrane Corrosion Mechanics Under Atmospheric Environment

作　　者：刘婉颖[1,2] 施太和[1] 曾德智[1] 朱泽华[2] 贾华明[3] 卢强[3] 刘鹏[3] 

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,成都610500 [2]西南石油大学材料科学与工程学院,成都610500 [3]塔里木油田公司工程技术部,新疆库尔勒841000

出　　处：《材料工程》2011年第8期19-23,共5页Journal of Materials Engineering

摘　　要：采用高温高压釜模拟研究塔里木油田现场环境所用聚磺体系钻井液对S135钻杆的腐蚀行为及腐蚀机理。通过对表面黏附有泥饼的挂片进行XRD和SEM观察,分析钻杆表面黏附的泥饼形貌特征及腐蚀行为。结果表明:S135钻杆发生了局部氧腐蚀,特征为溃疡状腐蚀、局部连片腐蚀和深坑蚀。腐蚀产物主要是正交(斜方)晶系的针铁矿。钻杆腐蚀的主要原因是起钻时未刮泥浆,黏附在钻杆外壁的泥浆膜在空气中因水分挥发而形成泥饼壳后,留下铁矿粉、重晶石、土粉、碳酸钙粉等作为骨架的固相物,该固相物称为垢层。垢层与钻杆表面接触,产生三种相互关联的局部腐蚀,即供氧差异微电池腐蚀、电偶腐蚀和缝隙腐蚀。High temperatures and pressures autoclave were used to simulate the field environment of Tarim oil deposit.And corrosion behavior and mechanism of S135 drill pipe in lignosulfonate mud were studied.Topographic features of mud cake adhereing to the drill pipe and the corrosion product of drill pipe were analyzed by XRD and SEM.The results showed that S135 drill pipe emerged local oxidation corrosion.Features were ulcer-like corrosion and local contiguous corrosion and pit corrosion.Main corrosion products were orthorhombic crystal system＇s allcharite.The main reason of drill pipe corrosion was unscraped mud while hoisting.Moisture from mud membrane volatilized on the air and formed mud cake shell.Then iron hematite,barite,bentonite powder,and calcium powder were left as the framework for solid phase substrates.That was called scale buildup.It contacted drill pipe＇s surface and three interrelated local corrosions,which were differential oxygen concentration,bimetallic corrosion and crevice corrosion,were produced.

关 键 词：泥浆膜 钻杆 腐蚀 磺化泥浆 

分 类 号：TG172.4[金属学及工艺—金属表面处理]