River Scour Monitoring System for Pipeline Threat Prevention

Overview

Main Objective

The project will develop a River Scour Monitoring System capable of determining the degree of scour in a river bed thereby alerting pipeline operators should the amount of cover of the pipeline become reduced. The proposed technology is based on a temperature gradient decay method for monitoring a subject pipeline river crossing for scour conditions. Field demonstrations of the proposed technology will provide a validation of the applicability for detecting depletion of cover above an installed pipeline.

Public Abstract

Hazardous liquid pipelines are mandated to maintain a minimum cover depth below the river bottom at crossings of inland bodies of water with widths greater than 100 feet (30 meters) from high water mark to high water mark as per 49 CFR Part 195.248, Subpart D – Construction. These prescribed burial depths apply during the initial pipeline construction phase and not during system operation. Over time, river scour results in a reduction in the prescribed depth of cover that can compromise the pipelines. The objective of this research is the development of a "River Scour Monitoring System" to benefit society by serving as an "active" monitoring system capable of determining the degree of scour in a river bed thereby alerting pipeline operators should the amount of cover of the pipeline become reduced. The proposed technology is based on a temperature gradient decay method for monitoring a subject pipeline river crossing for scour conditions. Field demonstrations at crossing sites will provide a validation of the applicability for detecting depletion of cover above an installed pipeline. The Arizona State University-Pure Technologies Limited team brings complementary expertise to the project.

Summary and Conclusions

This report presents the development of a River Scour Monitoring Systems (RSS) that provides active monitoring of pipeline crossings to detect the presence of pipe exposure resulting from river scour. The field installation of the RSS at five pipelines in three different geographical locations demonstrated the ability to efficiently collect remote data on potential river scour. Future research should be funded aimed at developing models to predict potential future river scour from collected field data. These models could further help operators in better monitoring and reducing potentially costly pipeline damage and oil spills resulting from river scour. Additionally, continued refinement of the Vortex Induced Vibration models will enhance our understanding of pipeline failure mechanisms resulting from river scour effects.

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