With more than 8,500 rivers that traverse the country, Canada’s energy highways sometimes have to cross under rivers in order to deliver the petroleum products Canadians use every day.
Pipeline companies take extra precautions when crossing rivers (known as watercourse crossings) to ensure the river’s ever-changing geology does not affect the pipeline buried below. By protecting the pipeline from the river, companies are also protecting the river from the product in the pipeline.
“We want to make sure, should the pipeline become exposed, that the pipeline has special characteristics that will withstand those extra forces,” explained Colin Gagne, vice-president of pipeline services at SECURE Energy Services, a company that works with operators on pipeline integrity at watercourse crossings.
Gagne shared his expertise on five ways pipeline companies work to keep pipelines safe at watercourse crossings (PDF).
Gagne explained that the best and first line of defense against pipeline damage is “depth of cover” – burying the line far below the surface so it will be unaffected by scouring of the riverbed.
“With the construction techniques available, for instance horizontal directional drilling, we can get lines much deeper than we could in the past. Lines can go down as deep as 50 feet,” said Gagne, who explained that it would take a very rare and substantial flood event to impact a pipeline buried that far below the ground.
Pipelines that cross under water are sometimes 30 to 50 per cent thicker than the pipe used for the rest of the route, explained Gagne.
“Extra wall thickness will help us keep the product within the pipeline and maintain the pipeline integrity,” he said.
To prevent damage from rocks and debris in the soil and in the moving water, Gagne explained that companies use specialized pipeline coatings that are impact resistant, abrasion resistant and highly durable.
“We know we’re probably going to have some sort of rocks against the pipeline, and we want to prevent (damage) as much as possible, and part of those preventive measures are to put in an impact-resistant coating,” said Gagne.
Companies use block valves on either side of a crossing so the line can be shut off or isolated if its integrity is at risk. These block valves can be controlled remotely, Gagne explained.
“If the control centers for the operations of the pipelines see something is going on, they can shut those valves remotely and vastly increase the response time to a potential event,” he said.
“The other option available to us is to put mechanical protection, such as rock armouring or concrete coating, on the water crossing itself,” said Gagne.
Gagne explained companies sometimes place rocks along the riverbank and position concrete mats overtop the pipeline to prevent erosion.
Want to learn more about how companies work to protect pipeline integrity at watercourse crossing? Take a look at these blog posts:
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.