川渝气田FF-NL级采气井口阀门腐蚀失效分析  

Corrosion failure analysis of FF-NL level gas wellhead valves in Sichuan and Chongqing gas field

作　　者：江晶晶[1,2,3] 张强[1,2,3] 常宏岗[1,2,3] 蔡忠明[4] 张昌会[4] 袁曦[1,2,3] 张东岳[1,2,3] 莫林[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 [4]中国石油西南油气田公司川中油气矿

出　　处：《石油与天然气化工》2016年第3期76-81,共6页Chemical engineering of oil & gas

摘　　要：以川渝气田某FF-NL级采气井口阀门为例,对阀门进行机械切割分析。发现由阀体、阀板、阀座组成的流体介质通道处于井口高温高压高流速的气液混输腐蚀环境中,通道内表面容易受到电化学腐蚀和机械冲蚀的双重作用,冲刷腐蚀及点蚀现象比较明显。阀杆和阀板因选择材料不同,表现出电偶腐蚀特征,密封失效。轴承组件受力部位在腐蚀介质作用下,出现压应力诱导腐蚀。此外,阀座和阀体贴合面具备产生缝隙腐蚀的条件。室内模拟腐蚀评价实验结果表明,阀门主体材质12Cr13在模拟现场工况下腐蚀严重,与718镍基合金形成电偶后腐蚀速率明显增加。This paper focuses on the analysis of machine cutting on some FF-NL level valves used in wellheads in Sichuan and Chongqing gas field.Through analysis it is found out that the fluid medium channel,composed of valve,valve plate and valve base,is in corrosive and gas-liquid multiphase environment with high temperature,high pressure and high velocity,and the inner surface of the channel tends to be influenced by both of electrochemical and mechanical impact-corrosion,so the erosion and pitting corrosion relatively stand out.Because of the difference in material selection,valve rod and valve plate show the feature of galvanic corrosion and sealing failure.While in corrosive environment,bearing assemblies tend to show stress-induced corrosion.Furthermore,the binding face between valve base and body is qualified for crevice corrosion.The indoor results of simulated corrosion indicate that the main material 12Cr13 of valve has more severe corrosion in simulated working condition.After forming the galvanic couple by 12Cr13 and 718 nickel base alloy,the corrosion rate increases obviously.

关 键 词：含硫气田 腐蚀 阀门 电偶腐蚀 

分 类 号：TE983[石油与天然气工程—石油机械设备]