"In 1956, Shell Oil geologist M. King Hubbert discovered a grand illusion in the American oil industry. For tax purposes, he noted, American oil companies regularly delayed the declaration of new oil reserves by years and even decades. The result was a false impression that new oil was being found all the time. In fact, discoveries had peaked in 1936."
"Simmons had become suspicious of the Saudis' claims about the vastness of their oil supply. In his four decades of working in the oil and gas industry, everyone he had ever talked to had taken it as gospel that the Saudis had enough oil to bail the world out when other supplies ran short. If that wasn't true, Simmons believed, the era of cheap oil was over. Demand for crude was on the rise worldwide, and supplies were getting tighter all the time. If the Saudis were pushing up against the limits of their oil production, the world needed to know.
"In his typically analytical fashion, Simmons went hunting for data. He found it in the form of hundreds of technical papers submitted by Saudi oil geologists to the Society of Petroleum Engineers over the past 50 years. Simmons spent the month of August 2003 sitting on his porch in Maine and grinding his way through the minutiae of technical accounts of, for instance, reservoir pressure and water-cut percentages, trying to piece together the challenges that the Saudi geologists had encountered in managing their precious oilfields. In the end, his conclusion was clear. "I finished reading the last paper on a Sunday afternoon," says Simmons, "and I sat back and I thought, Holy crap, this is unbelievable. I've just discovered the biggest energy illusion ever in the world. We're in big trouble. I'm going to write a book."
So he did:
"Twilight in the Desert: The Coming Saudi Oil Shock and the World Economy"