Petrobras has drilled one well at Potiguar, and is in the process of drilling a second one, but lacks environmental permits to drill more, said Mendes on the sidelines of the CERAWeek energy conference.
In January, Petrobras confirmed it had found hydrocarbons in its first Equatorial Margin well, Pitu Oeste, but said its economic viability was inconclusive.
The potential of the second well still needs to be evaluated, said Mendes.
"We will be finishing this well and maybe we will take the rig to the southeast of the country, to Campos and Santos Basin," he told Reuters, adding that the rig is expensive and so it cannot stay idle while waiting for new permits.
Potiguar is located in the so-called Equatorial Margin, an extensive area in northern Brazil that is seen as the most promising frontier for oil and gas exploration for Petrobras.
Petrobras plans to drill 16 wells in the Equatorial Margin in five years, said Mendes, but Brazilian environmental regulator Ibama, whose workers are striking, has been slow to issue new permits, delaying exploration projects.
