The expansion of oil exploration in the Amazon River mouth is gaining momentum with new blocks under study, sparking debates over environmental impact and energy sovereignty.
The Amazon Equatorial Margin is consolidating itself as a new hub of interest for the fossil fuel industry.
Recently, the National Agency of Petroleum, Natural Gas and Biofuels (ANP) approved the inclusion of 86 new oil blocks in the study phase.
Of these, 36 are in the Foz do Amazonas (Amazon River Mouth) basin, 25 in Pará-Maranhão, and 25 in Barreirinhas.
While these blocks are not scheduled for this year’s auction, they will be evaluated in the first half of 2027
to provide technical input for future offering cycles.
A key focal point in this new expansion is that 27 of these blocks under study extend—either partially or fully—beyond the Exclusive Economic Zone (EEZ). This is possible due to a March 2025 decision that expanded the Brazilian continental shelf by 360,000 square kilometers in the region.
This territorial expansion, equivalent in size to Germany, grants Brazil exclusive rights
over natural resources in the seabed and subsoil, even beyond the EEZ
in areas previously considered international waters.
New Territories and Exploratory Potential
Extending exploration beyond the EEZ is a significant milestone.
Brazil now holds jurisdiction over a vast submarine region, paving the way to offer new blocks to interested companies.
George Mendes, an environmental engineer and geosciences manager at the Arayara International Institute,
notes that the ANP is actively working to provide more options
to attract investment and jumpstart exploration.
The ANP’s strategic planning for 2026 and 2027 includes re-aligning exploration sectors
according to the new limits of the Brazilian continental shelf.
Expectations are that the equatorial margin, which encompasses the Foz do Amazonas, Pará-Maranhão, Barreirinhas, Ceará, and Potiguar basins, holds reserves estimated at 30 billion barrels of oil.
An Old Plan Reaches a New Frontier
Brazil’s interest in expanding its continental shelf dates back to the 1980s.
In 2017, the Brazilian government formally submitted its expansion request to the UN, with technical support from Petrobras.
The process for approving offshore blocks is complex,
involving evaluations by the ANP, Ibama, ICMBio, MMA, and MME,
in addition to public hearings and review by the Federal Court of Accounts (TCU).
Petrobras already holds concessions for 32 blocks in the equatorial margin and, in October 2025, obtained its first environmental license for block 59 in the Foz do Amazonas.
The discovery of oil in the Morpho well, with a daily investment of approximately US$ 1 million,
has reinforced the state-owned company’s plans to invest US$ 2.5 billion in the region between 2026 and 2030,
including the drilling of 15 new wells.
Environmental and Social Impacts Under Debate
Despite the economic potential, the expansion of oil exploration in the Foz do Amazonas
raises environmental and social concerns. The Federal Public Prosecutor’s Office (MPF) has questioned Ibama
regarding the duration and impact of drilling activities, pointing to potential damage to marine fauna,
artisanal fishing, and the way of life of indigenous and traditional populations.
Organizations such as the Arayara Institute and 350.org warn of the risks of oil spills
and rising sea temperatures and levels, which affect already vulnerable communities.
Despite local resistance and environmental concerns, international market interest in Brazilian oil has grown.
The 5th Permanent Offer Cycle auction, held in June 2025, attracted several foreign companies
that acquired blocks in the region.
The approval of the General Environmental Licensing Law is also seen as a factor loosening the process,
intensifying the debate over the future of oil exploration on the equatorial margin.
