An oil rig is lit up beside the coast near the village of Cojimar on the outskirts of Havana May 7, 2010. Spanish oil giant Repsol YPF has contracted with a unit of Italian oil company Eni SpA for a drilling rig that some sources said was bound for operation in Cuba's still untapped offshore fields. Cuba estimates it has 20 billion barrels of oil in its part of the Gulf of Mexico, which abuts the oil-rich U.S. and Mexican zones of the gulf, and Havana views its possible production as a godsend. The communist-led island produces about half its energy needs from onshore wells and gets the rest from oil-rich socialist ally Venezuela at favorable prices. REUTERS/Desmond Boylan (CUBA - Tags: ENERGY BUSINESS)