Repsol gives up on Cuba MADRID, May 31 (UPI) -- The risk of exploring for oil off the coast of Cuba is too great to continue in current blocks, a spokesman for Spanish energy company Repsol said. Repsol spent roughly $100 million on its latest search for oil about 30 miles off the coast of Cuba. Kristian Rix, a spokesman for the company, told the BBC that 80 percent of its efforts were unsuccessful. "At this point we don't think it is worth continuing to drill, at least not in our blocks," he said. Offshore drilling is very expensive and there is quite a risk involved. Cuba produces half of the oil it needs to meet overall energy demand. It relies on imports that it gets at a subsidized rate from the Venezuelan government for the rest. The U.S. Energy Department's Energy Information Administration estimates that, as of 2009, there are around 1 billion barrels of oil reserves in Cuba's economic zone. The country aims to cut the amount of oil it imports from Venezuela through development of offshore reserves. Malaysian energy company Petronas aims to take over from Repsol, the BBC reports.