Grant: Collaborative Research and Development Grants

The objective of the research described in this proposal is to develop models to characterize the growth of external metal-loss corrosion defects on transmission pipelines based on defect information obtained from multiple high-resolution inline inspections. The research will be carried out within a period of three years and will involve the training of one M.Sc. student (two years) and one PhD student (three years). The M.Sc. student will develop the growth models for maximum defect depth, average defect depth and maximum defect length by neglecting the temporal variability of the growth or spatial correlation between different defects. Both linear and nonlinear growth models will be considered. The PhD student will focus on developing sophisticated corrosion growth models that are capable of taking into account the spatial and temporal variability of the corrosion process. To this end, several general probabilistic deterioration models including the Markov process, Gamma process and multivariate Bayesian dynamic linear growth model will be explored. Accurate prediction of the corrosion growth rates will lead to increased safety and serviceability levels of pipeline operation as well as optimal allocation of limited resources for inspection and maintenance. The industry sponsor of the research, TransCanada, will therefore benefit from the research outcome. Given that external corrosion is a major integrity thereat to the overall Canadian pipeline network, the Canadian pipeline industry as a whole will also benefit from the research outcome, which will be disseminated through peer-reviewed technical journals and conferences. The proposed research further offers a unique training opportunity for the two graduate students involved in that they will carry out theoretical modeling of the pipeline corrosion process based on real defect information and will interact with experienced pipeline integrity engineers on a regular basis. This training will enable them to become the next-generation stewards of over 100,000 km of transmission pipelines owned and operated by the Canadian pipeline industry.