The newly announced oil province is located in a new exploratory frontier, where the pre-salt layer was reached for the first time. To date, Petrobras is the only company, with operator status, with or without partnerships, that has drilled, tested, and evaluated pre-salt rocks.
Petrobras analyzed and tested the Tupi area. The formation test analyses undertaken for the second well in the BM-S-11 block, located in the Santos basin, allows the recoverable volume of 28 degree API light oil to be estimated at 5 to 8 billion barrels of oil and natural gas. Petrobras is the area's operator and holds 65% of the working interest, while British outfit BG holds 25%, and Portuguese company Petrogal - Galp Energia, 10%.
With $1-billion in investments made over the past couple of years, 15 wells were drilled and reached the pre-salt layers, eight of which duly tested and evaluated based on the best oil industry techniques. These wells produce high commercial value light oil (28 degree API) and a large amount of associated natural gas.
Petrobras developed new drilling techniques to reach the pre-salt layers, at depths of 5,000 to 7,000 meters: more than 2,000 meters of salt have already been crossed. The first well took more than a year and cost $240 million to be drilled. Nowadays, Petrobras drills an equivalent well in 60 days for $60 million.
The data obtained from these wells, integrated with a major mapping effort, allowed the company to determine, with a high degree of accuracy, that the pre-salt rock formations range from an area extending from the State of Espirito Santo to the State of Santa Catarina. It is about 800 km long and 200 km wide, and is found in water depths between 2,000 to 3,000 meters.
The National Oil, Natural Gas and Biofuels Agency has already granted about 25% of the pre-salt rock areas to several oil companies in the form of exploratory blocks and production concessions.
The analysis and interpretation of the production data obtained from the eight tested wells, which have extremely high productivity, provided concrete elements that allow the company to guarantee Brazil is before the country's biggest oil province, comparable to the world's most important oil-bearing areas.
Petrobras has already discovered 25 billion barrels of oil
Since its creation, Petrobras has discovered 25 billion barrels of oil and natural gas in Brazil, of which 11 billion have already been lifted. The current Brazilian proved reserves are 14 billion barrels. Most of this oil and natural gas is located in the so-called "post-salt" geological layers, 80% of which in the Campos Basin, where heavy oil predominates.
As of 2003, Petrobras expanded its activities and sought new exploratory frontiers. As a result of its efforts, the company has appropriated 9 billion barrels in reserves in the past five years.
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