Brazil's state oil giant Petrobras said on Thursday that it had made four "important" new oil finds that should boost its oil reserves by about 1.4 percent. Petrobras said the discoveries in Brazil's northeast region would eventually increase reserves by more than 130 million barrels, or 1.4 percent. Brazil's current reserves are 9.278 billion barrels. The finds were made in four mature fields where production was thought to be declining. "In these basins, with infrastructure already installed and paid off, the costs are low and the deposits are quickly developed," Petrobras said in a statement. The finds were made in one offshore block in the Sergipe-Alagoas basin and three onshore blocks in the Espirito Santos, Reconcavo Baiano and Potiguar basins.