The Namibian government and a Brazilian energy firm on Tuesday announced the first discovery of oil off the coast of Namibia, although not in commercial volumes.
Reporting findings from an exploratory well in the Walvis Basin off the southwest African country's central coast, Rio de Janeiro-based HRT said there were promising signs.
The company discovered "two well-developed source rocks" and "several thin-bedded sandy reservoirs that are saturated by oil".
Work will begin with 15 days at a second exploration location 15 kilometres (nine miles) to the west, HRT added.
The find, although not commercially viable, will raise hopes that Namibia could become the latest southern African country to strike oil reserves.
Angola to the north is Africa's second-biggest producer of crude, after Nigeria.
Namibia currently has no oil production and no proven reserves.
However, it does have proven gas reserves of two trillion cubic feet (56.6 billion cubic metres).
HRT is just one of a number of companies with concessions in Namibia's deep Atlantic waters.
Spain's Repsol and Brazil's Petrobras also have production licenses.