An unmentioned factor here, is the oil shale fields of our country. At current price levels of a barrel of oil that shale is getting more and more reasonable to go after. The Saudis are aware of this fact.
We lived in CO during the 1970s. We are very aware of the oil shale on the Western Slope. During the Carter years, some of the majors had started setting up facilities to extract the shale for further refining. Even the ads on tv showed a guy burning a piece of shale.