State-run oil firm Petrobras has begun studies for the implementation of a new oil platform in Brazil's Buzios field, three sources with knowledge of the matter told Reuters.

Each Buzios platform has an average cost of $3.5 billion, said a source, adding that the one under study would be a FPSO (floating production storage and offloading) vessel to expand gas production in Buzios.

Petrobras did not immediately comment.

Buzios is the second largest field in Brazil by production, behind Tupi field, both in Santos Basin. Buzios produced around 875,000 thousand barrels of oil equivalent per day (boed) in June, out of a total of 4.35 million boed produced in the country, according to data from the regulatory agency ANP.

The Buzios project currently includes 11 units, with five already set up and six more to be added by 2028, according to Petrobras' 2024-2028 strategic plan.

A 12th FPSO would increase capacity by at least 150,000 boed, according to one of the sources.

"There will be the 12th unit, studies are already underway," said the source.

With the 11 units planned to date, Petrobras expects production of around 2 million barrels of oil per day by 2030, according to a statement released in April.

Buzios represents something close to 20% of the national oil and gas production, and is set to become the largest field in the country.

(Reuters - Reporting by Rodrigo Viga Gaier, Writing by Fabio Teixeira; editing by David Evans)