The state-owned Cuban oil company Cubapetroleo says the country may have more than 20bn barrels of oil in its offshore fields – more than double the previous estimate. Cubapetroleo’s exploration manager said drilling in the offshore wells would begin as early as the middle of 2009. Such reserves would place Cuba among the top 20 oil producing nations. Cubapetroleo’s estimates are based on comparisons to known oil reserves found within similar geological structures off the coasts of the USA and Mexico. The company said Cuba had undersea geology “very similar” to that surrounding Mexico’s giant Cantarell and Poza Rica oil fields in the Bay of Campeche. The US Geological Survey recently estimated that as much as 9bn barrels of oil and 21 trillion cu/ft of natural gas could lie within that zone, in the North Cuba Basin. However, Cubapetroleo exploration manager Rafael Tenreyro Perez said his company’s estimate was higher because it had better information about Cuba’s offshore geology. Mr Tenreyro said he expected the first production well to be drilled before the middle of next year by a consortium led by the Spain-based oil company, Repsol, and that more wells could be started before 2010.