Venezuela’s official 300 billion barrels of proven oil reserves is largely the result of reclassification and political incentives, as most of the extra-heavy Orinoco crude is not economically recoverable due to high costs and infrastructure decay.
— Read on oilprice.com/Energy/Crude-Oil/Only-a-Fraction-of-Venezuelas-Oil-Is-Economically-Recoverable.amp.html