[Petronski]

The question is irrelevant. Oil is a fungible commodity.

[MangoCrazy]

True, but it is still "titled" from the originating country because of the extreme variation in composition. Refiners need to know their source prior to "cracking" in order to maximize life of the catalyst. It is not like water. Canada leads and has had the lead for the last several years according to the DOE web site.