A consortium formed by Brazil's state oil company Petrobras and Portugal's Galp said it concluded the drilling of the Jupiter well off Brazil's coast, confirming an important find first announced in January.
The companies said the reserve contained large quantities of natural gas and light oil, but more wells and analysis were necessary to determine the size of the reserve and to say how much of it is crude.
Stocks in Galp which holds a 20 percent stake in the Santos basin block, jumped around 3 percent in early trade on Thursday to 13.25 euros before paring gains to trade 1.9 percent higher.
The partners had to abandon drilling in January after the initial discovery of natural gas to perform rig maintenance, and have now completed the well, 5,773 metres from the ocean surface.
Jupiter is close to the super-giant Tupi find, where Petrobras last November put recoverable reserves at between 5 billion and 8 billion barrels. Petrobras has said the area covered by the Jupiter accumulation is similar in size to Tupi.
Some analysts estimate 50 to 80 billion barrels of oil may lie deep below a thick layer of salt under the seabed along a 500-mile (800-km) stretch off Brazil's southern coast.
The investments required to exploit the subsalt oil and gas are estimated at anywhere from $200 billion to $600 billion.
Source
