(Reuters) — The Canadian energy sector has proposed several major oil pipeline projects in the last decade, but only the Trans Mountain expansion project was completed.

Here, a look at three other pipelines that never came to be:

Energy East - A proposed C$15.7-billion project (US$11.0 billion), Energy East would have carried oil cross-country from Alberta to the Atlantic province of New Brunswick. It was cancelled in 2017 by TC Energy in the face of regulatory hurdles and opposition from environmental groups, particularly in Quebec.

Northern Gateway - This pipeline was proposed by Enbridge in 2006 to carry oil from Alberta to British Columbia's northwest coast. The C$7.9-billion project (US$5.5 billion) faced opposition from local and Indigenous communities who feared the risk of a marine spill. The project died in 2016 after Prime Minister Justin Trudeau's government cancelled its permits.

Keystone XL - This proposed TC Energy project would have carried oil from the oilsands of northern Alberta to the major U.S. crude storage hub at Cushing, Oklahoma and then on to U.S. Gulf Coast refineries. The project was rejected on environmental grounds by former U.S. President Barack Obama's administration, then revived during President Donald Trump's first administration. Former President Joe Biden revoked the pipeline's permit on his first day in office in 2021.

TC Energy spun off its oil pipeline business in October last year into a new company named South Bow Energy Trump said on Monday he wanted the pipeline built, but South Bow said it had moved on.

TC Energy has sought to recover more than $15 billion from the U.S. government for cancellation of the project.