Monitoring and Prediction of Pipe Wrinkling Using Distributed Strain Sensors

As exploration of energy resources develops further into the remote Canadian North, pipeline construction is being pushed further into the unknown. The new pipeline construction in the North has generated a great need for understanding and predicting the behaviour of pipelines under harsh northern environmental conditions. Continuous real-time monitoring technology using distributed strain sensors has become a possible method for monitoring the performance of these pipelines in the field. The aim of this research is to find the correlation between the distributed strains along the line pipes and the local buckling (wrinkling) of these pipes, and to study the contribution of these distributed strains to the detection of initial wrinkle of buried pipelines. Both experiments and finite element analyses (FEA) concluded significant findings in the current research. Conventional strain gauges and advanced Brillouin Scattering fibre optic sensors (BSFOSs) were employed in the experimental programs. BSFOSs can measure the distributed strains spacing as close as 50 mm along the line pipes, so that these sensors can detect the wrinkle location along the monitored pipeline. The distributed strains measured from the BSFOSs and from conventional strain gauges in longitudinal direction are presented in this paper. The methodology for detecting the initiation of pipe wrinkling and finding the optimal positions of installation of the distributed sensors are proposed.