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%，雇用了超过10万加拿大人。加拿大拥有世界第二大管道网络，管道总长超过83万公里，输送了加拿大99%的石油和天然气。这些管道大多埋在地下，因此，它们受到土壤腐蚀性环境和土壤(地面)运动产生的复杂载荷的影响。在腐蚀环境和载荷的共同作用下，管壁会产生腐蚀、起皱等缺陷。腐蚀会造成管道壁厚的损失，是埋地管道中最常见的缺陷。起皱缺陷是指管壁向外鼓起的缺陷。这些缺陷或这些缺陷的组合可能会导致管道破裂，这将产生深远的后果。根据管道提供的服务，可能会释放石油或天然气，造成环境破坏、油气供应中断、财产损失、健康危害，甚至死亡。以往的研究表明，管道中出现腐蚀缺陷的管段在地面运动时也容易在腐蚀区域内形成起皱缺陷，从而形成起皱-腐蚀复合缺陷。然而，由于地面进一步移动和内部(操作)压力的增加，油气管段在承受应力时，其结构性能和安全性还没有人研究过。因此，NSERC的这项研究计划旨在进行一项详细的研究，以确定具有皱折-腐蚀组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在形成组合皱纹腐蚀缺陷时破裂的可能性。此外，NSERC的这项研究还将开发一种易于应用的埋地管道褶皱腐蚀段修复技术。这项修复技术将使用柔软且无腐蚀性的纤维织物。新的修复技术将不需要任何焊接或应用高热，因此，这种修复技术将不需要关闭管道操作，为管道行业和政府节省大量收入，并避免石油和天然气对我们的社区和行业造成中断。这项研究的目的将通过对石油和天然气管道进行大量复杂和耗时的全尺寸试验来实现。此外，还将使用有限元程序进行计算机模拟，以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.