Session: 04-03-03 Geohazard Management - Landslides - Part II

Paper Number: 87809

87809 - High Fidelity Distributed Fiber Optic Sensing for Landslide Detection 

Pipeline integrity management continues to adapt and improve with the adoption of new technologies. In 2016, Husky Midstream had a loss of containment incident on a 16-inch diameter pipeline on the south slope of the North Saskatchewan River in Saskatchewan, Canada which was determined to be caused by ground movement resulting from a landslide complex. The landslide complex on the south slope contains two deep-seated compound basal shear slides as well as a near surface translational slide in heavily over consolidated marine clays of the Upper Cretaceous Lea Park Formation.

A robust state-of-the-art instrumentation monitoring program was implemented that included real-time geotechnical instrumentation, high fidelity distributed fibre optic sensing (HDS), repeat ILI and weather data monitoring to identify, evaluate and monitor areas of ground and pipeline movement so that potential impacts to the pipelines could be mitigated. An early-warning system that included alarm thresholds was developed that identified when to proactively shut-in the pipeline.

The HDS monitoring comprised strain, acoustic and temperature sensing that revealed an excellent correlation to the geotechnical, ILI and weather station monitoring data on the actively moving landslide complex. This paper shows a number of these correlations over the HDS monitoring period from September 2017 to November 2018. The HDS monitoring showed increased strain magnitudes following a significant rainfall event that correlated to an acceleration in survey monument and slope inclinometer movement.  Locations of high strain accumulation correlated to ILI locations of bending strain. Accumulated strain magnitudes also correlated to LiDAR change detection results and visual observations of the ground surface. Diurnal and seasonal temperature variations from the temperature sensing data correlated to weather station data. Acoustic and strain accumulation correlated to construction activity on the right-of-way. 

As pipeline operators continue to include high fidelity fibre optic sensing as a continuous linear sensor along new and existing pipelines primarily as a leak detection tool, other critical applications, such as ground movement from landslides can be included as an important component of the integrity management system.    

Presenting Author: Carrie Murray Stantec Consulting Ltd.

Presenting Author Biography: Carrie Murray is a principal geotechnical engineer at Stantec with specialization in prairie geohazards, monitoring technologies for high-risk sites, remedial design, and construction for linear projects. She obtained her Bachelor degree in geological engineering at the University of Saskatchewan and her Master's degree in geotechnical engineering at the University of Alberta. She loves the outdoors and when not walking landslide slopes, she can be found hiking, fishing and canoeing with her family.