Petrobras’ oil production from frontier fields offshore is soaring. Pictured, a platform prepares for its first day working a ‘pre-salt’ field in 2010. Associated Press RIO DE JANEIRO—When Brazil’s state-run oil company Petroleo Brasileiro SA disclosed its biggest-ever oil find, in 2007, then-president Luiz Inácio Lula da Silva quipped that the discovery proved that God is Brazilian. New production figures are making believers out of many in the industry. Output from the “pre-salt” fields has passed 500,000 barrels of oil a day, nearly triple that of 2012, and now accounts for nearly a quarter of the company’s total production of two million barrels a day. It is a quick ramp-up for Petrobras, and is taking place in one of the most challenging oil patches in the world. The deposits lie nearly 200 miles off Brazil’s southeastern coast, buried deep below the sea floor under a thick layer of salt, […]