Yes, we've actually gone so far in recent years.... It's not very economical most of the time, but we have put western oil on a tanker on the west coast. We've moved it through the Panama Canal and have brought it into Montreal to run, in part to test what Montreal's capability is with respect to western crude quality. So yes, those things are always possible when you're faced with a real shortage.
On February 2nd, 2012. See this statement in context.