How large are Russia's oil reserves?
Like many things in post-Soviet Russia it is supposed to be a state secret. But that does not stop the world's oil majors from hotly debating exactly how big Russia's crude oil resrves are.
Estimates of proven reserves vary wildly, from the U.S. Oil and Gas Journal's 48.6 billion barrels to analyst estimates which are three times higher.
The experts agree on one thing. Russia's oil reserves are big enough to support booming oil exports for decades to come.
Oil output hit eight million barrels a day in November - some three billion barrels a year - for the first time in a decade. Russia exports half as crude oil and a quarter as products, making it the second exporter after Saudi Arabia.
But the Middle East producers still dwarf Russia in terms of reserves with Saudi Arabia holding some 261.8 billion barrels and Iraq 112.5 billion, according to BP estimates.
"Russia could get production to nine (million barrels a day) or perhaps higher by 2010," said Ian Woollen, an analyst from Wood Mackenzie, who puts Russia's proven reserves at 120 billion barrels
So they do have a few drops of the stuff...