SAO PAULO -- Brazilian state-controlled oil company Petrobras said the drilling of another well in the Tupi area has served to confirm expectations surrounding that massive field located deep below the ocean floor.
In a statement Thursday, the company said the new well, which is still in the drilling phase and known as Iracema, provides proof that the Tupi field, in the Santos Basin, holds between five and eight billion barrels of recoverable light oil and natural gas.
Petrobras said this third well is 2,210 meters (7,245 feet) deep and located 250 kilometers (155 miles) off the coast of Rio de Janeiro state.
The discovery of the "presence of good quality reservoirs and of oil similar to that found in the Tupi pioneering well" was communicated to the ANP petroleum regulator, Petrobras said.
The contractor group for the block where Tupi is located is made up of Petrobras, with a 65 percent stake; Britain's BG Group, with 25 percent; and Portugal's Galp, with 10 percent.
The partners announced the start of commercial oil production at Tupi last month.
Tupi was the first discovery in the pre-salt area, so-called because the up to 80 billion barrels of recoverable light crude it is estimated to contain are located under a thick layer of salt far beneath the floor of the Atlantic Ocean.
The discoveries in the pre-salt region, first announced in late 2007, could eventually lead to a nearly six-fold increase in Brazil's current proven reserves of 14 billion barrels and transform that nation into a major oil exporter.
However, the fields pose an enormous technical and financial challenge due to the depth and thickness of the salt and the drastic changes in temperature as the oil is brought to the surface.
Acknowledging that Petrobras alone is not capable of developing the massive pre-salt reserves, Brazil announced last month that it will invite international oil companies to bid for concessions in that region beginning next year.
The country had previously halted the sale of concessions after the massive finds were made.
Petrobras, an integrated energy company and the global leader in deepwater oil exploration and production, operates in 27 countries in the Americas, Africa, Asia and Europe.
Shares of Petrobras, Brazil's largest corporation, trade on the Sao Paulo, New York, Madrid and Buenos Aires stock exchanges, but the Brazilian government retains control through a golden share.