A new US assessment of Venezuela's oil reserves could give the country double the supplies of Saudi Arabia. Scientists working for the US Geological Survey (USGS) say Venezuela's Orinoco belt region holds twice as much petroleum as previously thought. The geologists estimate the area could yield more than 500 billion barrels of crude oil. Chris Schenk of the USGS said the estimate was based on oil recovery rates of 40 per cent to 45 per cent. Venezuela holds the largest oil reserves outside the Middle East.