大牛地气田集输管道低洼处腐蚀机理研究  

Study on the Corrosion Mechanism of Low-Lying Area of Gathering Pipeline in Daniudi Gas Field

作　　者：刘诗桃 周军 刘岳龙[2] 韩杰林[3] 彭思洲 万伟[3] 梁光川[1] LIU Shitao;ZHOU Jun;LIU Yuelong;HAN Jielin;PENG Sizhou;WAN Wei;LIANG Guangchuan(Petroleum Engineering School,Southwest Petroleum University,Chengdu 610500,China;Petroleum Engineering Technology Research Institute,Sinopec North China Oil and Gas Branch,Zhengzhou 457001,China;No.1 Gas Production Plant,Sinopec North China Oil and Gas Branch,Yulin 719000,China)

机构地区：[1]西南石油大学石油与天然气工程学院,四川成都610500 [2]中国石化华北油气分公司石油工程技术研究院,河南郑州457001 [3]中国石化华北油气分公司采气一厂,陕西榆林719000

出　　处：《材料保护》2024年第8期122-129,共8页Materials Protection

摘　　要：为了研究大牛地气田集输管道低洼处腐蚀机理,通过模拟管道沿线积液分布,确定距起点1207 m的管道低洼处为重点监测点,在现场开展管段开挖与挂片安装工作。采用失重测试计算挂片腐蚀速率,结合扫描电镜(SEM)、能谱(EDS)、X射线衍射(XRD)等手段表征腐蚀产物微观结构和成分。结果表明:采气树处挂片均匀腐蚀速率为0.0035 mm/a,腐蚀程度轻微,无明显局部腐蚀倾向;低洼处挂片均匀腐蚀速率为0.0599 mm/a,局部腐蚀速率为0.1380 mm/a,孔蚀系数为2.3,局部腐蚀程度严重。低洼处管段试样表面腐蚀产物结构疏松,腐蚀产物主要由FeCO_(3)、FeS、Fe_(2)O_(3)组成,推测腐蚀主要由CO_(2)和H_(2)S 2种腐蚀性气体引起,积液中的Cl^(-)起到加速作用。To investigate the corrosion mechanisms of low-lying areas in the gathering and transportation pipelines of the Daniudi Gas Field,the distribution of accumulated liquid along the pipeline was simulated.A low-lying section of the pipeline located 1207 m from the starting point was identified as the primary monitoring point.Excavation of pipeline sections and installation of coupons were conducted on-site.Weight loss testing was used to calculate the corrosion rates of the coupons,and the microscopic structure and composition of the corrosion products were characterized using scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD).Results showed that the uniform corrosion rate of the coupons at the gas tree was 0.0035 mm/a,the corrosion degree was slight,and no obvious local corrosion tendency was observed.The uniform corrosion rate of the low-lying coupon was 0.0599 mm/a,the local corrosion rate was 0.1380 mm/a,the pitting corrosion coefficient was 2.3,and the degree of localized corrosion was severe.The structure of the corrosion products on the surface of the low-lying pipe samples was loose,and the corrosion products were mainly composed of FeCO_(3),FeS and Fe_(2)O_(3).It was speculated that the corrosion was mainly caused by the corrosive gases CO_(2)and H_(2)S,with Cl^(-) in the effluent playing an accelerating role.

关 键 词：管道内腐蚀 腐蚀机理 管道积液分布 表面分析 

分 类 号：TG172.3[金属学及工艺—金属表面处理]