Brazil's oil and gas regulator, the ANP, approved on Friday (2) the delimitation of 501 new exploratory blocks in the country's Equatorial Margin, an offshore stretch running from the coast of Amapá state to Rio Grande do Norte. The blocks cover about 380,000 square kilometers, an area the size of Japan, spread across five sedimentary basins: Foz do Amazonas, Pará-Maranhão, Barreirinhas, Ceará and Potiguar. Offering these areas to investors, however, has not been confirmed and still depends on reviews by other branches of the government.

The blocks, grouped into 11 new sectors, only became possible because in 2025 the UN Commission on the Limits of the Continental Shelf granted Brazil sovereignty over roughly 360,000 square kilometers of additional seabed in the region, beyond the 200 nautical miles (370 kilometers) previously recognized, according to O Globo. The additional area has been nicknamed the Amazônia Azul (Blue Amazon) for its potential in natural and mineral resources. "With the conclusion of Brazil's claim, the area over which the country exercises sovereign rights to explore the natural resources of the seabed and subsoil has been expanded," the ANP said in a statement.

The announcement came on the same day that state-run Petrobras confirmed a second oil discovery at the Morpho well in the Foz do Amazonas basin, the first in ultra-deep waters off the coast of Amapá. The basin is the company's main bet for renewing Brazil's reserves. According to Folha de S.Paulo, there are currently 51 exploratory blocks under active concession in the Equatorial Margin: 29 in Foz do Amazonas, nine in Barreirinhas, nine in Potiguar and five in Pará-Maranhão. The industry sees the region as the leading candidate to succeed the pre-salt fields, which are expected to enter production decline in the next decade, according to O Globo.

Any auction still needs environmental review

The agency stressed that mapping out blocks does not mean automatically taking them to auction. In its statement, the ANP said:

"Any eventual designation of blocks for bidding will depend on specific analysis and must follow the applicable regulatory process, including the assessments and opinions required for that purpose, from the ANP and other bodies involved."

In practice, a future offering requires input from the Mines and Energy Ministry and the Environment Ministry, plus approval from the CNPE, the national energy policy council, Folha reports. The ANP said the socio-environmental analysis behind the new boundaries took the region's conservation units into account and found no overlaps that would make the proposed blocks unworkable. The agency also adjusted the limits of three existing sectors to match the new continental shelf, without affecting contracts in force, since the new areas have not yet been tendered.

Environmental organizations oppose expanding the oil frontier in the Equatorial Margin and see a contradiction with President Luiz Inácio Lula da Silva's pro-sustainability rhetoric, Folha reports. The region, home to sensitive coastal ecosystems from Amapá to Rio Grande do Norte, has become the main arena of the clash between Brazil's hydrocarbon policy and its climate agenda. Next week, the ANP will hold two auctions of exploratory areas, with 13 blocks in the pre-salt and hundreds of blocks elsewhere in the country.