Goldman Downgrades Petrobras And Gran Tierra, Talks 'New Oil Order' By: Benzinga via Benzinga May 18, 2015 at 08:27 AM EDT In a report published Monday, Goldman Sachs analysts mentioned that oil prices have surged 31.6 percent, after having bottomed to ... Read More >> Related Stocks: Gran Tierra Energy Inc Petrobras - Petroleo Brasileiro S.A.