Chevron Corp. (NYSE:CVX) has announced that it will lay off 15-20% of its global workforce and reorganize its business structure. The U.S. oil and gas major announced that it will consolidate its Oil, Products & Gas segment into Upstream and Downstream, Midstream & Chemicals segment, and be led by Mark Nelson, the current executive vice president of the Oil, Products & Gas unit. "Our new organizational structure and leadership appointments are designed to improve our operational efficiency and position Chevron for sustained...