Brazil's Petrobras cites Franco and Sul de Tupi oil-gas prospects RIO DE JANEIRO, Dec. 20 (UPI) -- Brazil's Petrobras energy company said it sent notices to the Brazilian government advising that two offshore oil and gas prospects have commercial potential. Petrobas, formally known as Petroleo Brasileiro, said Thursday it submitted declarations of the commercial potential of the Franco and Sul de Tupi prospects in the energy-rich Santos Basin to the National Petroleum, Natural Gas and Biofuels Agency. Petrobas estimated the Franco prospect, which it wants to rename as the Buzios field, contains about 3.1 billion barrels of oil equivalent. Petrobras said it expects to have five production systems started in the field by 2020. The Sul de Tupi, which the company wants to name the Sul de Lula field, may contain as much as 128 million barrels of oil equivalent, the company said. Petrobas said first oil should come from the Sul de Lula field by the first quarter of 2017. Brazil ranks second behind Venezuela in proven oil reserves in South America.