The U.S. is on track to become a net petroleum exporter by 2021 and will soon after surpassing Russia and rival Saudi Arabia, currently the world’s largest oil exporter, the International Energy Agency said Monday. The U.S. is expected to double its gross crude oil exports to 4.2 million barrels a day by 2024, while total exports of crude and refined products should reach 9 million barrels a day, the IEA said in its annual five-year oil outlook report. …