In June 2013, Canadians watched as surging floodwaters destroyed highways, bridges and homes across Alberta. Floods pose a serious risk to community safety and to critical infrastructure, like pipelines.
Although pipeline infrastructure is buried below the ground, floods can threaten pipelines, especially where they cross under rivers and streams. That’s why pipeline companies are continuously improving the way they prepare for and respond to floods.
“A lot of companies are shutting in (stopping flow to a section of line) and purging their pipelines right away when they start to see events happening,” explained Colin Gagne, vice-president of pipeline services at SECURE Energy Services, a company that works with operators on pipeline integrity at watercourse crossings (PDF).
This week, Gagne explains how pipeline companies prepare for high-flow events, such as floods.
Companies monitor each of their pipelines 24-7 from sophisticated control rooms (PDF). Gagne explained that these control centres can now access real-time flow data from rivers near their pipelines. Pipeline companies know that rushing floodwater may remove soil (this is called scouring) or other protective materials covering the pipeline, so once river flows reach a certain level, companies take proactive steps to prevent an incident.
“Once we see a threshold is reached, we can shut down pipelines as a precautionary measure because we think scour is occurring over (the pipeline) and it’s close to being exposed or in a state of threat,” Gagne said.
From the control centre, the company can shut off or isolate a section of the pipeline using block valves, which are installed at either side of a watercourse crossing, if the pipeline’s integrity is at risk.
So how do companies determine how much rushing water will threaten the pipeline’s integrity? That’s where pipeline modeling comes in.
Gagne explained that companies can use sophisticated computer modeling to help predict how often a flood will occur, and if it does occur, how much the water will scour the bed and banks of the pipeline watercourse crossing. To create these models, companies plot out a river’s topography, gradient and channel shape and then use information on current and historical water flows as well as bank stability to help them predict how a flood will affect the pipeline.
“They can take the depth of the pipeline and they can figure out, by modeling, ‘the pipe will become exposed if we see this much flow in a river,’ ” said Gagne.
“If we model events on a pipeline, and we look at the terrain models, then we can determine where the flow will go, should an event (or leak) occur,” said Gagne. “Then we can start to stage our response equipment in the appropriate places.”
CEPA’s member companies operate approximately 115,000 kilometres of pipeline in Canada. Between 2002 and 2013, these companies achieved a 99.999 per cent safety record on all of those lines. They did this through rigorous monitoring and maintenance and by working to mitigate all threats to the pipelines’ integrity.
Want to learn more about how companies keep pipelines safe? Check out this fact sheet (PDF).
The Canadian Energy Pipeline Association represents Canada’s transmission pipeline companies who operate approximately 115,000 kilometres of pipelines in Canada. In 2013, these energy highways moved approximately 1.2 billion barrels of liquid petroleum products and 5.3 trillion cubic feet of natural gas. Our members transport 97 per cent of Canada’s daily natural gas and onshore crude oil from producing regions to markets throughout North America.