Supposedly, oil consumption was going to consume more than production.
part:
In 2005, Matt Simmons wrote a book called Twilight in the Desert. In it, he summarized what he learned about Saudi Arabian oil production by reading 200 academic papers. He concluded from his analysis that the oil extraction techniques being used there were techniques that one might use if the fields were quite depleted.
Because of this, he doubted that we should believe stories that Saudi oil production can be greatly expanded. Instead, he raised the possibility that in the not too distant future, Saudi oil production will suddenly decline. Matt’s research underlying the book was no doubt behind his concern that oil reserves and oil production rates are not audited.
Twilight in the Desert: The Coming Saudi Oil Shock and the World Economy is a book by American investment banker Matthew Simmons. The text was initially published on June 10, 2005 by John Wiley & Sons. Wikipedia
Book Review, part:
Simmons has searched through hundreds of obscure SPE documents (Society of Petroleum Engineers) and found the paper trail that suggests the Saudi Oil Miracle may be entering its senescence, taking with it the capacity to produce more oil on demand.