By Arathy Somasekhar
HOUSTON (Reuters) - An oil spill that shut TC Energy's Keystone pipeline in the United States on Wednesday could squeeze crude inventories at the country's primary storage hub and in two main refining regions, the Midwest and Gulf Coast, analysts and traders said on Friday.
The Keystone line is a key artery bringing more than 600,000 barrels of Canadian crude per day (bpd) to various parts of the United States. It was shut late Wednesday after leaking more than 14,000 barrels of oil into a creek in Kansas, making it the largest crude spill in the United States in nearly a decade.
Canadian crude prices have already slumped on the news, widening on Thursday to a discount of roughly $33 per barrel to benchmark West Texas Intermediate crude futures (WTI) - which is currently trading at about $72 a barrel - from about $27 on Wednesday.
While TC Energy is yet to give details on when it will restart the pipeline, a previous Keystone spill had caused the pipeline to remain shut for about two weeks.
The line runs directly to the Cushing, Oklahoma, storage hub and delivery point for WTI, which is currently about 31% full with nearly 24 million barrels in stock. If the line is closed for more than a week, it could reduce Cushing stocks by about 2.5 million barrels, data analytics firm Wood Mackenzie said.
Refineries in the U.S. Midwest may be more affected depending on when the line is restarted.
The spill in Kansas took place downstream from a key junction in Steele City, Nebraska, where Keystone splits to run into Illinois. That stretch of the line could be restarted, but the other segment affected by the spill will not come back until regulators approve a restart.
By contrast, Gulf Coast refiners can draw on more sources for crude, both from offshore Louisiana facilities and from countries like Colombia, Mexico and Ecuador.
Still, volumes to the Gulf from Cushing have already dropped. Volumes on TC Energy's Marketlink pipeline, which flows from Cushing to Nederland, Texas, fell by about 300,000 bpd to less than 500,000 bpd, Wood Mackenzie estimates, after the leak was discovered.
That could leave the Gulf Coast refineries short of heavy Canadian barrels.
(Reporting by Arathy Somasekhar in Houston, Laura Sanicola in Washington, Nia Williams in Calgary and Shariq Khan in Bengaluru; Editing by Marguerita Choy)