Oil & Gas Petrobras chalks up another findBRAZIL'S Petrobras has made a new discovery of good-quality oil in the pre-salt reservoirs of Block BM-S-9, in the ultra deepwater Santos Basin. February 7th 2011, 2:53 am 1 min read Facebook An icon of a facebook f logo. LinkedIn An icon of the LinkedIn logo. Twitter An icon of the Twitter logo. BRAZIL'S Petrobras has made a new discovery of good-quality oil in the pre-salt reservoirs of Block BM-S-9, in the ultra deepwater Santos Basin.