腐蚀海底管道评估

Assessment on Corroded Pipeline

管道缺陷可能在管道制造、运输、预制、施工和管道腐蚀(运行期)中发生。为确保管道完整性,管道运营者必须能够对缺陷进行检测和评估。近年来,科研机构和学者对缺陷检测和评估技术有广泛研究。国内在老管道的设计中,通常将腐蚀缺陷直接在管道壁厚中全部扣除,使用通用的环向内压进行管道强度分析.这种方法只是简单考虑缺陷深度的影响,并不能完全正确评估腐蚀管道。以DNV RP-F101腐蚀管道设计规范为主,对目前国际上管道缺陷评估技术进行总结。应根据相关规范对腐蚀管道进行评估设计。对腐蚀管道各不确定性因素的敏感性也进行了分析。

Defects in pipelines can be introduced during manufacturing （e.g. laminations）, transportation, fabrication （e.g. weld defects） and installation （e.g. dents）, and can occur due to corrosion. To ensure the integrity of the pipeline, operators must be able to detect and to assess the significance of pipeline defects. Much effort has been involved in assessment on the corroded pipeline. Subtraction of the corrosion allowance from nominal wall thickness of pipe is a simple method for the in-service assessment for pipeline in China. However, this simple method is not entirely correct and is without sufficient support by theory. This paper summarizes the assessment methodology based on the standard of DNV RP-F101. And sensitive analysis for various elements uncertainty is also included in this paper.