The main beneficiaries of more than $700 billion of federal energy incentives over the past five decades have been the oil and natural gas industries, a new study reveals. The oil and natural gas industries together garnered 60 percent of federal incentives between 1950 and 2006, with 46 percent of the roughly $725 billion in federal support going to the oil sector, according to the report by the consulting firm Management Information Services Inc (MISI).