How can operators monitor and assess pipeline water crossings in the face of severe flooding?

Areas across North America have been impacted by flooding over the past month causing concern for pipeline owners and operators. Severe flooding, river scour and river channel migration can adversely impact the safe operation of a pipeline. Last month PHMSA issued an advisory to pipeline operators urging them to ensure the integrity of their pipelines in the event of flooding, scour and river channel migration. PHMSA suggests certain actions pipeline operators should take to ensure the safe operation of their pipelines, one of which is to evaluate pipeline crossings to determine if the pipeline has been exposed or undermined. This is typically done through a depth of cover survey, which is traditionally performed following flooding once safe river access becomes available.

To alleviate the safety concerns associated with depth of cover surveys at water crossings, PureHM operates autonomous water vessels, eliminating the need for manned boats to be on the water in adverse conditions. PureHM’s Spectrum XLI technology is deployed on autonomous boats to accurately measure depth of cover, depth of water and elevation profiles. Additionally, these unmanned vessels utilize multi-beam and side scan sonar with GPS to obtain full bathymetric profiles – providing operators with a clear picture of their underwater pipelines. Spectrum XLI can also perform a geotechnical evaluation of the land condition surrounding the pipeline, which provides insight as to whether the pipeline is under increased stress resulting from flood conditions.

To provide operators with continuous updates of any scour activity on pipelines operating through critical water crossings, PureHM has developed a semi-permanent river scour monitoring system that alerts operators of pipe exposure resulting from scour. Combining baseline depth of cover and depth of water surveys with this system can ensure that pipeline crossings with the highest risk are continuously monitored for scour. The river scour monitoring system provides operators with an easy, effective and consistent method for monitoring scour and helps to reduce the costs associated with regular surveys.