U.S. sanctions on Venezuela’s oil industry have made winners out of Royal Dutch Shell Plc and BP Plc, Gulf of Mexico offshore heavyweights, as refiners in need of substitutes are scooping up oil produced in the region.  Those two companies produce notable amounts of crude oil that refiners have settled on as the immediate replacement for the heavy Venezuelan crude that U.S. refiners relied on for years. Trading volumes in these grades of oil have surged to the highest in months, and prices touched five-year peaks after sanctions were imposed. U.S. production has surged to a record 12 million barrels a day, but less than 5 percent of that is heavy oil. The sanctions have hamstrung refineries in the United States, […]