Brazil, already the second largest oil reserve holder in South America, is opening the biggest play in that country’s history in the deep pre-salt formations below its major producing basins.

The new world-class oil province lies under the Espirito Santo, Campos and Santos basins, and the discovery opened with the Tupi accumulation.

According to Petrobras, Tupi “which represents but a small part of the new frontier, may boost Brazil’s current 14-billion-bbl oil and gas reserves by more than 50%.” So far, Petrobras is the only operator that has drilled deep enough to test pre-salt sediments.

The company analyzed and tested the zone in the Tupi area at the second well in Block BM-S-11 in the Santos Basin. That analysis show 5 billion to 8 billion boe including gas and 28º gravity oil. Petrobras holds a 65% working interest in the tract with BG as a 25% partner and Portugal’s Petrogal Galp Energia holding 10%.

To date, Petrobras and its partners have invested US $1 billion in the play over the past couple of years drilling 15 wells to the pre-salt. It tested eight of those wells for high commercial volumes                                                                                                   of oil and associated gas.

During that period, the Brazilian company developed efficient techniques to drill through more than 6,562 ft (2,000 m) of salt to depths between 16,405 and 22,967 ft (5,000 and 7,000 m).  

The first well took more than a year to drill at a cost of $240 million. Newer wells take 60 days and costs $60 million to drill.

The drilling program was part of a major mapping effort that allowed the company to delineate an are 497 miles (800 km) long and 124 miles (200 km) wide from a point off the coast of Espirito Santo to the state of Santa Catarina. Water depths range from 6,562 to 9,843 ft (2,000 to 3,000 m).

Although only Petrobras has been active in the area, several oil and gas companies hold exploration blocks and production concessions over the pre-salt play.