Petrobras, the state-run oil company in Brazil, announced Tuesday it has made another discovery in what is proving to be one of the country's most productive offshore regions.

The new well is in the Santos Basin, where large pockets of oil are being found under a layer of salt deep beneath the ocean floor.

Located 144 miles off the coast of Sao Paulo state, the new well is more than 18,000 feet deep and holds good quality oil, Petrobras said. The well is in a region of the South Atlantic where seven of Brazil's 18 oil discoveries this year have been made. The well has still to be declared commercially viable, reported Bloomberg.

The well is still being drilled, with the aim of determining the lower limit of the reservoirs and identifying other possible zones of interest, said the company in a statement.

The U.S. Geological Survey assesses there could be as much as 100 billion barrels of offshore oil yet to be discovered in Brazil. The  Santos Basin could hold as much as 46 billion barrels.