You have to be careful to differentiate the yields from oil production and oil refining. On the production side you can pull a barrel of oil out of the ground for a cost of $15 and sell it for $145. Ka-ching!
Refining, however, means you buy this $145 dollar barrel of oil and then try and make a profit by turning it in to various products and make a small spread on the difference. Right now, that difference is so small that many refineries are barely turning a profit.
Go look at some of the stocks of companies that primarily refine and you'll see what I mean. Look up FTO or ALJ for instance. They are near 52 week lows. The companies that do both refining and production are doing great, but those companies that are mostly refining focused are getting hammered.
http://blogs.wsj.com/marketbeat/2008...