QGEP, operator and 30% stakeholder, said it would release further details including the expected budget later this week.
The BS-4 block is 185 kilometres offshore in Brazil's Santos Basin.
State oil firm Petrobras in November signed a $270 million deal its 40% stake in Atlanta and sister field Oliva to independent OGX, an agreement still subject to approval by authorities.
Barra Energia holds the remaining 30% stake in the block.
Upstream
