The monopoly said the field was discovered on the coastal shelf in the southeastern state of Espirito Santo, and preliminary data suggests there are huge reserves in this sector of the Atlantic shelf.
Petrobras announced in November a massive oil and gas deposit had been discovered on the coast south of the country's capital, which it said could contain between 5 and 8 billion barrels of light oil.
If results of the initial research into the quantity of oil and gas are confirmed, Brazil will increase its hydrocarbon reserves by over 50%, becoming a global leader.
The country is currently unable to meet domestic demand for natural gas and was forced to import additional gas from Bolivia and Argentina in 2006.
Petrobras reserves are currently estimated at 13 billion barrels.
