雅克拉气田集气管线内腐蚀分析及材质选用  

Internal corrosion analysis and material selection of gas gathering lines in the Yakela Gas Field,Southwest Tarim Basin

作　　者：羊东明[1] 李亚光[2] 

机构地区：[1]中国石化西北油田分公司工程技术研究院,新疆维吾尔自治区乌鲁木齐市830011 [2]中国石油大学(北京)石油工程学院

出　　处：《天然气工业》2012年第10期74-77,116,共4页Natural Gas Industry

摘　　要：塔里木盆地雅克拉气田井流物具有高含CO2、高含Cl-、低含H2S、低pH值的特点,投产1年多后,集输管线距井口150m处相继出现爆管、穿孔、管壁减薄等腐蚀现象。随着气田开发时间的延长,气井含水量上升,腐蚀环境进一步恶化,腐蚀也逐渐从井口方向延伸至进站端。为此,分析了气田集气管线腐蚀环境、腐蚀规律特征、腐蚀影响因素(温度、CO2分压、pH值、Cl-含量、多相流流态及流速、水蒸气冷凝率),确定了集气管线腐蚀主要是CO2腐蚀,同时冲击流流态下高速气流的冲刷和Cl-的存在加剧了腐蚀进程。同时,对集气管线的管材进行了筛选,不同材质耐腐蚀性能分析表明:集气管材抗腐蚀性能由强到弱排序为22Cr、316L、玻璃钢、13Cr、1Cr13、06Cr13、3Cr、16Mn、L360;弯头抗腐蚀性能由强到弱排序为1Cr13、16Mn渗氮、15CrMo、16Mn。最后从技术可行、经济合理的角度分析认为:集气管材宜选用316L+20号钢的双金属管材和富含环氧树脂内衬高压玻璃管材,弯头宜选用1Cr13和16Mn渗氮高压直角弯头。The well fluids in the Yakela Gas Field,Tarim Basin,are of high CO2 and Cl-content,low H2S content,and low pH value.So only one year after the gathering lines in this field were put into operation,many kinds of corrosion problems occurred at the lines of 150 meters away from the well head,such as tube rupture,perforation and wall thinning,etc.The water content of the gas well became increasing and the corrosive environment was deteriorating as time went by.Meanwhile,corrosion gradually extended from the wellhead to the entrance to gas gathering stations.This paper hereby analyzes the corrosive environment of gas gathering lines,characteristics of corrosion,and corrosion factors including temperature,partial pressure of CO2,pH value,Cl-content,flow pattern and multiphase flow rate,and the condensation ratio of water vapor.It is found out that the main corrosion in the gas gathering lines is CO2 corrosion and the presence of high-speed air scour and Cl-flow aggravates the corrosion process.A study is also performed of the pipeline materials,the anti-corrosion performances of the materials for gas gathering lines have been determined from the best to the worst: 22Cr,316L,GFRP(glass fiber reinforced plastics),13Cr,1Cr13,06Cr13,3Cr,16Mn and L360;while that for elbow are 1Cr13,16Mn nitriding,15CrMo and 16Mn.Finally,from the perspective of technical feasibility and economic rationality,bimetallic steel pipes of 316L and 20# steel and high-pressure liner glass pipes rich in epoxy resin should be selected for the gas gathering lines,high pressure and right-angled elbows with 1Cr13 and 16Mn nitriding should be better selected.

关 键 词：塔里木盆地 雅克拉气田 CO2含量 Cl含量 H2S含量 高速气流冲刷 腐蚀分析 材质选用 

分 类 号：TE988.2[石油与天然气工程—石油机械设备]