Quantification of Uncertainties in Crack Growth Model and Operating Pressure for the Integrity Management of Pipelines Subjected to Stress Corrosion Cracking

应力腐蚀开裂（SCC）是加拿大油气管道失效的主要原因之一。根据加拿大能源管道协会的数据，2017年加拿大管道事故总数的17%是由于SCC。由于氢脆增强的腐蚀疲劳，SCC缺陷会随着时间的推移而增长，如果不加以缓解，可能导致管道破裂，在人类安全和环境破坏方面造成严重后果。由于管道工作压力、土壤环境和SCC固有随机性的不确定性，SCC缺陷的增长存在显著的不确定性。拟议的研究项目是西安大略大学的周文星博士和加拿大自然资源部CanmetMaterials研究中心的科学家之间的合作。合作的长期目标是开发方法，模型和决策支持工具，用于遭受SCC的管道的基于风险的完整性管理。 拟议的研究项目是这项多年合作的第一步，其目标是量化SCC缺陷和石油和天然气管道内部运行压力增长模型的不确定性。在实际操作压力和土壤环境下，从全尺寸管道试样获得的SCC生长试验数据将用于表征SCC生长模型的模型不确定性。将采用加拿大管道运营商提供的石油和天然气管道的工作压力时程记录来表征管道内部压力的不确定性。拟议的项目将培训两名教育科学硕士学生，为期一年。研究结果将为在基于风险的管道完整性管理框架中实施SCC增长模型提供关键知识。

Stress corrosion cracking (SCC) is one of the leading causes of failure for oil and gas pipelines in Canada. According to the Canadian Energy Pipeline Association, 17% of the total pipeline incidents in Canada were due to SCC in 2017. SCC defects grow over time due to corrosion fatigue enhanced by hydrogen embrittlement, and, if unmitigated, can lead to pipeline ruptures with serious consequences in terms of human safety and environmental damage. There are significant uncertainties in the growth of SCC defects due to uncertainties in the pipe operating pressure, soil environments and inherent randomness of SCC. The proposed research project is a collaboration between Dr. Wenxing Zhou at the University of Western Ontario and scientists at CanmetMATERIALS research centre of Natural Resources Canada. The long-term objective of the collaboration is aimed at developing methodologies, models, and decision-support tools for risk-based integrity management of pipelines subjected to SCC. The proposed research project is the first step of this multi-year collaboration with the objective of quantifying the uncertainties in the growth models for SCC defects and internal operating pressures of oil and gas pipelines. SCC growth test data obtained from full-scale pipe specimens under realistic operating pressure and soil environments will be used to characterize the model uncertainties of SCC growth models. Operating pressure time-history records for oil and gas pipelines provided by pipeline operators in Canada will be employed to characterize the uncertainties in the pipe internal pressure. The proposed project will train two MESc students for a duration of one year. The research findings will provide the key knowledge for the implementation of SCC growth models in a risk-based pipeline integrity management framework.