State-owned energy giant Petrobras announced Wednesday it has located petroleum and gas reserves in ultra-deep waters of the Sergipe-Alagoas basin, calling the discovery a "new oil province" for Brazil.

"The information obtained thus far is sufficient to confirm the discovery of a new oil province in the basin," Brazil's largest company said in a statement.

The accumulations of oil and gas were found at a water depth of 2,311 meters (7,580 feet) and located some 58 kilometers (36 miles) off the coast of the northeastern state of Sergipe.

Petrobras said the discovery was made at its first ultra-deep exploration project in the section of that basin facing Sergipe's coastline.

The company added in a statement to regulators that tests confirm the reserves located at sub-surface depths of between 5,050-5,400 meters (16,550-17,700 feet) have excellent porosity and permeability conditions.

High-quality crude with an American Petroleum Institute gravity of 43 degrees was extracted from the upper areas of the reserve, while slightly lower-quality, heavier crude with an API gravity of 32 degrees was found at deeper levels.

The reserve was discovered at the SEAL-M-426 block, in which Petrobras is the operator with a 60 percent stake and IBV-Brasil has the remaining 40 percent interest.

Petrobras, one of the fastest-growing oil companies in recent years and a world leader in deep-water drilling, currently gets close to 80 percent of its output from the Campos basin, located off the coast of southeastern Brazil.

In recent years, the company has discovered massive offshore reserves in the Atlantic Ocean that could transform Brazil into a major oil exporter.

The pre-salt region is a vast area 800 kilometers (500 miles) long and 200 kilometers (125 miles) wide that encompasses the Santos, Campos and Espirito Santo basins and is estimated to hold as much as 80 billion barrels of crude.

But accessing those fields will be very costly and pose an enormous technical challenge because they are located some 150 kilometers (93 miles) offshore at depths of between 5,000-7,000 meters (16,400-22,950 feet) and under a layer of salt up to 2 kilometers (1.2 miles) thick.

Drastic changes in temperature as the oil is brought to the surface add to the technical complexity of developing the reserves.

Petrobras estimates that the pre-salt reserves' share of national oil production will climb from 2 percent in 2011 to 40.5 percent in 2020.