[link|http://www.naseo.org/Committees/energyproduction/oil/Refining.htm|Refining]:

The U.S. has the largest and by far the most complex refining system in the world, reflecting its being the world\ufffds largest consumer of both oil and transportation fuels (see Graph). However, only Africa has a lower average capacity per refinery than the U.S. level of 94 thousand B/D. The pressing need to minimize unit costs and refining\ufffds pronounced economies of scale strongly suggest that the number of refineries in the U.S. will continue to decline, while those that remain will continue to expand their capacity through debottlenecking.


IOW, if refining doesn't make the companies money, they won't invest in it.

:-(

Cheers,
Scott.