MAP 30.1 Worldwide Oil Reserves, 1980

Data produced by geologists and engineers enable experts to estimate the size of “proved oil reserves,” quantities that are recoverable with existing technology and prices. In 1980, total worldwide reserves were estimated at 645 billion barrels. Recovery of reserves depends on many factors, including the location of the oil. Large portions of U.S. reserves, for example, lie under the Gulf of Mexico, where it is expensive to drill and where hurricanes can disrupt operations.