基于风险检查的海洋立管腐蚀失效分析

摘要

在收集海洋立管数据和最后1次检查数据的基础上,确定其主要失效类型；根据相关规范和文件确定其腐蚀率.根据检查出的缺陷尺寸和腐蚀率,采用改进的一次二阶矩法计算海洋立管在新缺陷下的失效概率,绘出失效概率随时间变化的曲线.根据立管失效概率的可接受标准,确定何时需要对哪个部位进行检查和维修,并将检查结果作为下次风险分析的基础数据.应用风险检查方法制定的检查计划同时满足经济性和安全性的要求,可为水下生产系统的其他管线腐蚀失效分析提供参考.%Based on detail information of riser and last inspection data, main degradation mechanisms were determined. Corrosion rate was assessed according to relevant standards and documents. Based on the defect detected and the corrosion rate,failure probability of riser under new developed defect was calculated by Ameliorated First-Order Second-Moment (AFOSM). Curve of failure probability of riser varying by time was delineated. According to the accepted criterion of riser failure,inspection plan involved. In addition,new inspection results were viewed as the information of next analysis. Safety and economy were both satisfied by this risk inspection method. Moreover,references can be provided to corrosion failure analysis of other pipes used in sub-sea production system.