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

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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.