US oil prices continued to close the gap on benchmark Brent crude on Friday following news on Thursday of an outage at the Keystone pipeline.
The pipeline, owned and operated by TransCanada Corporation, runs crude oil from the Canadian sedimentary basin to refineries in Illinois and Texas and ruptured last week, spilling 200,000 gallons of crude in South Dakota.
Damage caused by the rupture may mean the pipeline could be closed for several weeks.
The news caused Nymex West Texas Intermediate (WTI), the US crude benchmark, to climb 1.1% to $58.63 a barrel - its highest level since July 2015.
WTI is now closing the gap on Brent crude, currently the global crude benchmark, which was up just 0.17% to $63.65 a barrel. The spread is now down to $5.02 - its lowest since August.