AS President George W Bush strolled around his Prairie Chapel ranch in Texas last week with Saudi ruler Crown Prince Abdullah, oil prices were high on the agenda during talks between the leaders of the world's biggest energy consumer and largest oil exporter.
At the same time, Matt Simmons, one of Bush's energy advisers, was at a conference in Edinburgh, spelling out harsh facts on Saudi oil production which, if proved true, would have severe repercussions for the global economy.
Simmons's belief is that Saudi has been overstating its oil reserves for years, its biggest oil fields are in decline and it will struggle to live up to its promise to crank up daily output from around 10 million barrels a day to 12 million by 2009 and later 15 million to meet global demand.
He visited Saudi in 2003 as part of a US energy delegation. By the time he left, six days later, he was convinced that the rosy picture the Saudis had painted of their key strategic resource was deeply flawed but he could not yet prove it.
"On the plane back from Riyadh I said `Something doesn't meet the smell test ...' I have made my career out of uncovering illusions and I thought, wouldn't it be odd if the biggest energy country in the world proved to be an illusion," he says.
Chairman of Simmons & Co, the independent energy investment bank he founded in 1974, Simmons is about to publish a book - Twilight In The Desert: The Coming Saudi Oil Shock And The World Economy- in which he outlines the fruits of his painstaking research into the true extent of Saudi oil reserves.
Simmons studied some 200 petroleum engineering reports on the biggest oil fields in Saudi, a nation which boasts 25% of world reserves.
"It was the most exhausting project of my life ... like putting together a complex patchwork quilt," he says. He found "a smoking gun" - no evidence of major new finds beyond a limited "golden triangle" and clear evidence of major fields entering decline.
Global data on oil reserves is a sensitive topic. The big oil-producing nations, members of the Organisation of Petroleum Exporting Countries (OPEC) production cartel, are particularly sensitive about revealing data as any downward revision in oil wealth would have ramifications on economic and political stability. Simmons claims that OPEC members frustrated attempts to get real data over the past two decades because the higher their reserves seemed, the bigger the quota they obtained.
In the 1980s, Middle East reserves jumped by some 43% in three years, despite there being no major new finds.
Oil nations and oil companies alike have a motive to exaggerate reserves. Shell admitted last year that it had overstated reserves by a whopping 20%, sending its shares crashing. "Sure, there are other bombshells out there still to come," Simmons claims.
He is calling for the world to adapt a new standard of disclosure of oil reserves, which he refers to as "13 points of light". The idea has support from the International Energy Agency, International Monetary Fund and G8 leaders of the world's richest economies.
The Sunday Herald
Presentation to the Boston Committee on Foreign Relations (pdf)