含H_(2)S天然气管道内腐蚀直接评价方法的改进  

Improvement of Direct Evaluation Method for Internal Corrosion of Natural Gas Pipelines Containing H2S

作　　者：李欣[1] 王松[1] LI Xin;WANG Song(PetroChina Pipeline Engineering Company Limited,Langfang 065000,China)

机构地区：[1]中国石油天然气管道工程有限公司,廊坊065000

出　　处：《腐蚀与防护》2024年第8期77-83,共7页Corrosion & Protection

摘　　要：为了确定H_(2)S对天然气管道内腐蚀的影响,对NACE SP0110-2010标准提出的天然气管道内腐蚀直接评价方法(包括预评价、间接评价、直接评价、后评价四个环节)进行改进,即在该方法的间接评价环节引入了CO_(2)-H_(2)S腐蚀速率预测模型和积水概率参数,提高了推荐开挖点管道腐蚀程度的准确性。并以某含H_(2)S天然气管道为例,对改进后的评价方法进行了演示。结果表明:根据间接评价(多相流腐蚀模拟计算),极严重腐蚀出现在管道前500 m处,23%管段的积水概率为1;根据直接评价(现场开挖),5个开挖点处管道均属于极严重腐蚀,最大腐蚀速率为0.337 mm/a,与间接评价的预测结果一致;根据后评价确定了管道再评估时间间隔为1 a。改进后评价方法对预测多相流含H2S天然气管道内腐蚀高危点具有一定的借鉴意义。In order to determine the influence of H_(2)S on internal corrosion of natural gas pipelines,the direct evaluation method for internal corrosion of natural gas pipelines proposed by NACE SP0110-2010 standard(including pre-evaluation,indirect evaluation,direct evaluation and post-evaluation)was improved by introducing CO_(2)-H_(2)S corrosion rate prediction model and ponding probability in the indirect evaluation of the method,which improved the accuracy of the corrosion degree of pipeline at recommended excavation points.Taking a natural gas pipeline containing H_(2)S as an example,the improved evaluation method was demonstrated.The results show that according to indirect evaluation(multiphase flow corrosion simulation calculation),extremely severe corrosion occurred 500 m in front of the pipeline,and 23%of the pipeline sections had a ponding probability of 1.According to the direct evaluation(on-site excavation),the pipelines at all 5 excavation points were severely corroded,with a maximum corrosion rate of 0.337 mm/a,which was consistent with the predicted results of the indirect evaluation.According to the post-evaluation,the pipeline reassessment interval was determined to be 1 a.The improved evaluation method can provide certain reference for predicting high-risk corrosion points in multiphase flow natural gas pipelines containing H_(2)S.

关 键 词：天然气管道 H_(2)S 内腐蚀直接评价 改进 

分 类 号：TG174[金属学及工艺—金属表面处理]