渤海某油田L80油管腐蚀机理研究

发布时间：2018-06-01 07:26

本文选题：渤海油田 + L油管　；参考：《表面技术》2017年03期

【摘要】：目的研究渤海某油田L80油管腐蚀机理,对分析该油田油管腐蚀特点、确定油管腐蚀类型、证实井底腐蚀环境、评估油管腐蚀程度和推荐油管防腐材质具有重要意义。方法基于L80油管宏观腐蚀形貌观察做出的初步判断,首先进行材质分析,其次进行微观腐蚀形貌分析,然后进行腐蚀产物分析,再进行腐蚀程度分析,最后进行电化学试验。结果该L80油管理化性能及金相组织符合标准,其内外壁腐蚀行为不一致,外壁以均匀腐蚀为主且腐蚀轻微,内壁有一定程度局部腐蚀且腐蚀较严重。腐蚀产物主要含有Fe、S、O和C元素,主要成分为Fe1-xSx、Fe CO3和Fe_2O_3。其外壁点蚀坑深度在15~50μm之间,内壁点蚀坑深度在80~150μm之间,内壁微裂纹宽度在20~70μm之间。CO_2分压、H_2S分压、含水率和温度对L80油管腐蚀行为有重要影响。结论该油田井底CO_2和H_2S共存,L80油管发生了CO_2/H_2S共存的电化学腐蚀,但点蚀、应力腐蚀开裂(SCC)整体上比较轻微,且L80油管表现出良好的抗硫化物应力开裂(SSC)能力。根据研究结果,推荐现场可以继续使用L80油管。
[Abstract]:Objective to study the corrosion mechanism of L80 tubing in a certain oil field in Bohai Sea. It is of great significance to analyze the corrosion characteristics of tubing, determine the corrosion type of tubing, confirm the corrosion environment of bottom hole, evaluate the corrosion degree of tubing and recommend the anticorrosive material of tubing. Methods based on the preliminary judgment of macroscopic corrosion morphology of L80 tubing, material analysis, micro-corrosion morphology analysis, corrosion product analysis, corrosion degree analysis and electrochemical test were carried out. Results the physical and chemical properties and metallographic structure of the L80 oil pipe were in accordance with the standard. The corrosion behavior of the inner and outer wall was not consistent. The external wall was mainly corroded uniformly and the corrosion was slight. The inner wall had a certain degree of local corrosion and serious corrosion. The corrosion products mainly consist of Feo and C, and the main components are Fe1-xSxTiFe CO3 and FeS2O3s. The depth of pitting pit in outer wall is between 15 渭 m and 50 渭 m, the depth of pitting pit in inner wall is between 80 and 150 渭 m, and the width of microcrack in inner wall is between 2070 渭 m and 2070 渭 m. The partial pressure of H _ 2S and temperature have important influence on corrosion behavior of L80 tubing. Conclusion the electrochemistry corrosion of CO_2/H_2S coexisting in L80 tubing has occurred in the bottom hole of the oilfield, but the pitting corrosion and stress corrosion cracking (SCC) are relatively slight, and the L80 tubing has good ability to resist sulphide stress cracking. Based on the results of the study, it is recommended that the L 80 tubing can continue to be used on site.
【作者单位】：中海石油(中国)有限公司蓬勃作业公司;中国石油大学(北京)石油工程教育部重点实验室;
【基金】：总公司科技重大专项(YXKY-2013-TJ-01,YXKY-2015-TJ-04)~~
【分类号】：TE985

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