February 16, 2012. Syncrude oil's discount plunged the most on record after Enbridge Energy Partners LP shut two pipelines that help deliver oil from Alberta to U.S. and Canadian refineries following a leak on one of the lines. Enbridge closed the 491,200-barrel-a-day Line 5 after a release near Sterling, Michigan, that is estimated to be less than three barrels. It also shut Line 1, which delivers oil from Edmonton, Alberta, to Superior because of high inventories at the terminus.