Oil pipelines in Canada: the major systems and how they are regulated
Canada is one of the world's largest oil producers, and nearly all of that oil starts its journey in a pipeline. Most production comes from Alberta and Saskatchewan, far from the refineries and export markets it supplies, so a small number of large transmission pipelines carry crude oil east into Ontario and the U.S. Midwest, south to the U.S. Gulf Coast via connecting lines, and west to the British Columbia coast.
This guide summarises the main systems, what they carry, and who regulates them. Figures are taken from the Canada Energy Regulator (CER) and Natural Resources Canada, with the year of each figure noted, because capacities change as lines are expanded.
How much pipeline Canada has
According to Natural Resources Canada, there are about 825,000 km of transmission, gathering and distribution pipelines in Canada. Most of that is small-diameter gathering and local distribution pipe. The large interprovincial and international lines are regulated federally: the CER regulates over 73,000 km of pipeline, including roughly 48,000 km of operating gas pipelines and about 19,000 km of operating liquids pipelines.
Read more about the different kinds of line in our guide to the types of pipelines, and in the original Pipelines by the numbers page.
The major crude oil pipelines
The CER's 2021 report Canada's Pipeline System describes the main export pipelines out of Western Canada. The table uses the capacities it reported for June 2021, with the Trans Mountain figure updated for the expansion completed in 2024.
| Pipeline | Route | Capacity |
|---|---|---|
| Enbridge Canadian Mainline | Edmonton and Hardisty, Alberta, east across the Prairies to the U.S. Midwest, Ontario and Quebec (via connecting lines) | About 2.89 million barrels per day (2021) |
| Trans Mountain | Edmonton area to Burnaby, British Columbia, serving B.C., Washington State and export by tanker | About 890,000 barrels per day since the 2024 expansion (previously about 300,000) |
| Keystone | Hardisty, Alberta, to U.S. refining markets | About 591,000 barrels per day (2021) |
| Express | Hardisty, Alberta, to Casper, Wyoming, connecting to lines serving the U.S. Midwest | About 310,000 barrels per day (2021) |
Enbridge Canadian Mainline
The Mainline is a network of parallel pipelines rather than a single pipe. The CER reported that it carried about 58% of Canada's crude oil exports in 2021, mostly to refineries in the U.S. Midwest, with connecting lines delivering oil to Ontario and Quebec. Enbridge replaced its Line 3 across the Prairies, with the Canadian portion entering service in December 2019.
Trans Mountain
Trans Mountain is the only major pipeline carrying crude oil and refined products from Alberta to the West Coast. It has been owned by a federal Crown corporation since 2018. The expansion project twinned most of the route and, according to the CER, nearly tripled capacity to about 890,000 barrels per day. It entered service in May 2024, giving Canadian producers more access to markets in Asia and on the U.S. West Coast through the Westridge Marine Terminal.
Keystone
The Keystone system carries crude oil from Hardisty, Alberta, to refining markets in the United States. The separate Keystone XL expansion was cancelled after its U.S. presidential permit was revoked in January 2021.
Express
Express runs from Hardisty to Casper, Wyoming, where it connects with the Platte pipeline toward the U.S. Midwest. It is smaller than the other systems but gives shippers another route south.
Other important liquids pipelines
Several smaller federally regulated lines serve regional markets. Enbridge's Line 9 carries crude oil between Sarnia and Montreal, supplying Quebec refineries. The Norman Wells pipeline carries oil from the Northwest Territories to Zama, Alberta; Natural Resources Canada lists it at 870 km with a 12-inch diameter. Inside Alberta, a large network of provincially regulated pipelines moves oil sands crude, diluent and other liquids between production sites, upgraders and the hubs at Edmonton and Hardisty.
Who regulates oil pipelines
Jurisdiction depends on where a pipeline goes, not who owns it:
- Federal. Pipelines that cross a provincial or international border are regulated by the Canada Energy Regulator, which oversees their design, construction, operation, tolls and eventual abandonment.
- Provincial. Pipelines entirely within one province are regulated by that province, for example the Alberta Energy Regulator, the BC Energy Regulator or Saskatchewan's Ministry of Energy and Resources.
Natural Resources Canada provides an overview of pipeline safety regimes in Canada. The original pages Who regulates pipelines? and How is a pipeline route determined? explain the approval process in more depth.
How oil moves through a pipeline
Crude oil is pushed through transmission lines by pump stations spaced along the route. Different grades and products are often shipped in batches, one after another, through the same pipe. Control rooms monitor pressure and flow around the clock, and operators use in-line inspection tools, described in our guide to pipeline pigging, to check the pipe from the inside. For the full process, see How does a liquids pipeline work?
Sources
- Canada Energy Regulator, Canada's Pipeline System 2021: Introduction
- Canada Energy Regulator, Crude oil pipeline transportation system
- Natural Resources Canada, Pipeline safety regimes in Canada
Frequently asked questions
What is the largest oil pipeline in Canada?
Enbridge's Canadian Mainline. The Canada Energy Regulator describes it as the largest crude oil pipeline system in Canada, with about 2.9 million barrels per day of capacity in 2021, carrying the majority of Canada's crude oil exports to the U.S. Midwest and Ontario.
How many kilometres of oil pipelines are there in Canada?
The Canada Energy Regulator regulates about 19,000 km of operating liquids pipelines, which carry crude oil and other liquids across provincial and national borders. Many more kilometres of smaller gathering and feeder lines inside individual provinces are regulated provincially.
Who owns the Trans Mountain pipeline?
Trans Mountain has been owned by a federal Crown corporation since 2018. Its expansion project, which nearly tripled the system's capacity to about 890,000 barrels per day, entered service in May 2024.
Who regulates oil pipelines in Canada?
Pipelines that cross a provincial or national border are regulated by the Canada Energy Regulator. Pipelines that stay within one province are regulated by that province, for example by the Alberta Energy Regulator or the BC Energy Regulator.