Structural Assessment and Rehabilitation of Energy Pipes with Wrinkle-Corrosion Defect

石油和天然气行业约占加拿大GDP的8%，雇佣了超过10万名加拿大人。加拿大拥有世界上第二大的管道网络，拥有超过83万公里的管道，这些管道运输了加拿大99%的石油和天然气。这些管道大多埋在地下，因此，它们受到土壤的腐蚀环境和土壤（地面）运动产生的复杂载荷。腐蚀环境和载荷的共同作用导致管壁腐蚀、起皱等缺陷的发展。腐蚀导致管壁厚度损失，是埋地管道中最常见的缺陷。起皱缺陷是管壁向外凸起。这些缺陷或这些缺陷的组合可能导致管道破裂，这将产生深远的后果。根据管道提供的服务，石油或天然气可能会被释放，造成环境破坏、石油和天然气供应中断、财产损失、健康危害，甚至死亡。前人研究表明，已经形成腐蚀缺陷的管道段，在受到地面运动的作用下，腐蚀区域内也容易形成起皱缺陷，从而形成起皱-腐蚀复合缺陷。然而，由于进一步的地面移动和内部（操作）压力增加，油气管段受到应力时，没有研究人员对具有褶皱-腐蚀缺陷的油气管段的结构性能和安全性进行研究。因此，这项NSERC研究计划旨在进行详细的研究，以确定已形成褶皱-腐蚀联合缺陷的埋地管道的结构性能和失效条件。这项研究的结果将极大地帮助加拿大管道行业、工程师和监管政府机构，他们将能够正确评估当皱纹-腐蚀缺陷形成时破裂的可能性。此外，这项NSERC研究还将开发一种易于应用的修复技术，用于埋地管道的起皱腐蚀段。修复技术将使用柔性和无腐蚀性的纤维基织物。新的修复技术不需要任何焊接或高温应用，因此，这种修复技术不需要关闭管道运行，为管道行业和政府节省了大量收入，避免了对我们社区和工业的石油和天然气中断。通过对油气管道进行大量复杂且耗时的全尺寸试验，将实现本研究的目标。此外，将使用有限元程序进行计算机模拟，以便更好地了解故障的机理和原因。七名学生将在温莎大学S. Das博士的指导下完成研究工作。

The oil and gas industry adds about 8% of Canada's GDP and employ over 100,000 Canadians. Canada has the second-largest pipeline network in the world with over 830,000 km of pipelines which moves 99% of all the oil and gas that Canada produces. The majority of these pipelines are buried in the ground and hence, they are subjected to the corrosive environment of soil and complex loads resulting from the soil (ground) movements. The combined effect of the corrosive environment and loads cause the development of defects in the pipe wall such as corrosion and wrinkle. Corrosion causes a loss of pipe wall thickness and it is the most common defect found in buried pipelines. A wrinkle defect is an outward bulging in the pipe wall. These defects or a combination of these defects may cause the pipes to rupture, which would have far-reaching consequences. Depending on the service provided by a pipeline, oil or gas may be released, causing environmental damages, oil and gas supply interruption, property damages, health hazards, and even deaths. Previous research showed that the segment of pipeline that has developed a corrosion defect is also susceptible to the formation of a wrinkle defect within the corroded area when subjected to a ground movement and thus, the pipeline forms a combined wrinkle-corrosion defect. However, no previous researchers investigated the structural performance and safety of oil and gas pipe segments with a combined wrinkle-corrosion defect when it is stressed due to further ground movement and increased internal (operating) pressure. Hence, this NSERC research program is designed to undertake a detailed study to determine the structural performance and failure conditions of buried pipelines that have developed a combined wrinkle-corrosion defect. The outcomes of this research will immensely help the Canadian pipeline industry, engineers, and regulatory governmental bodies who will be able to correctly assess the possibility of ruptures when a combined wrinkle-corrosion defect has formed. Additionally, this NSERC research will also develop an easy-to-apply repair technique for wrinkle-corroded segments of buried pipelines. The repair technique will use flexible and noncorrosive fibre-based fabrics. The new repair technique will not require any welding or application of high heat and thus, this repair technique will not require a shutdown of the pipeline operation saving a significant amount of revenue for the pipeline industries and governments and avoiding interruption of oil and gas to our communities and industries. The goal of this research will be achieved through a large number of complex and time-consuming full-scale tests on oil and gas pipes. Additionally, computer simulations using a finite element program will be undertaken for better insight of the mechanics and reasons for the failures. Seven students will accomplish the research work under the supervision of Dr. S. Das at the University of Windsor.