A single figure sets Venezuela apart from the rest of the world: 303 billion barrels of so-called proven oil reserves. But experts say the country's estimate is inherently problematic and far from proven — rooted in exaggerated, aging data from a corrupt government.

The number has long been touted by politicians and investors as an important measure of untapped energy potential, most recently by President Donald Trump 's administration in detailing a sweeping deal for the U.S. to take control of some Venezuelan reserves.

But a more realistic estimate of the country’s proven reserves — a gold standard metric, representing the amount of oil that can reasonably be extracted under current conditions — is about one-third of what it has reported, half a dozen experts told The Associated Press. They put the likely figure at 60 to 120 billion barrels, a vast amount but not enough for Venezuela to remain the world’s largest holder of reserves.

The distinction is an important one as Venezuela and the U.S.…