Brazil's state-owned oil company, Petrobras, says it has discovered a huge new offshore oil field off the coast of Rio de Janeiro state.
The Campos Basin region has recently attracted Lula's attention
The Papa-Terra field was found in the Campos Basin, which is already Brazil's most important oil-producing region.
Petrobras estimates it contains at least 700 million barrels of crude - about 10% of Brazil's current reserves.
The field, which is jointly operated with the US company Chevron, should start producing oil by the end of 2011.
Petrobras said the oil from the Papa-Terra field was heavier than the sweet light crude favoured by international markets, but the firm was investing $2bn in adapting its refineries to process heavy oil.
The new field is expected to help Petrobras achieve its goal of making Brazil self-sufficient in oil. Since 2003, the company has been meeting 91% of the country's needs.
The Campos Basin region already contains 40 other offshore oil fields producing more than 1.1 million barrels a day, amounting to more than 60% of Brazil's production.
Last month, Brazil's President Luiz Inacio Lula da Silva inaugurated the country's largest oil platform, named P-50, which is due to begin production in the basin's Albacoara Leste field early next year.
According to industry analysts, 75% of Brazil's oil reserves are under at least 400m of water.
As a result, Petrobras has built up expertise in deep-water drilling and operates the largest number of floating platforms in the world.
Chevron's local subsidiary will hold a 37.5% stake in the Papa-Terra field.