"Refineries tend to take crude from whatever source is available, oil being a very fungible product."
In sales, it might be fungible. In refining, no. Oils from different sources can very drastically in "refinability". California and Venezuelan crudes "are" more difficult to refine than many others.
23 posted on 05/31/2008 4:01:22 PM PDT by Wonder Warthog
(The Hog of Steel-NRA)