First Published: GEO ExPro - World of Foldouts, April 2025, by Kyle Reuber, Pedro Zalan and Henri Houllevigue, TGS
Abstract
On February 11, 2025, the ANP announced and launched the 5th Round of Permanent Offer Blocks in the Concession Regime sparking renewed interest in the Equatorial Margin Basins. Shallow water commercial fields and deepwater discoveries are limited but evidence of multiple deep- and ultra-deep water prospects and two proved petroleum systems are present.
Introduction
The Equatorial Margin of Brazil (EMB) could be on the brink of an oil and gas exploration boom. A string of wildcat discoveries in the adjacent margin (Guyana / Suriname) and on the conjugate margin (Ghana / Ivory Coast) suggest a high probability for similar discoveries in the EMB. Last year’s Potiguar Anhangá well and the 2011 French Guiana Zaedyus discoveries serve as “bookends” to a deepand ultra-deep water frontier margin segment. These data points are
important, as they point to a distal and deeper functioning petroleum system in the EMB. The
2024 Anhangá discovery in the Potiguar Basin was the first successful ultra-deep water well
in the region. Prior to Anhangá, many of the previous exploration phases in the region had targets in the shallow and deep waters, aiming for rift-related units.
The 5th Concession Round of Brazil’s Permanent Offer (OPC) contains 64 exploratory blocks in the region totaling over 58,000 km2 (Figure 1). In the circa 600,000 km2 equatorial margin forty-seven blocks are in the Foz do Amazonas (Amapá sub-basin) and Pará-Maranhão Basins with water depths ranging from 200 - 2,000 m. The remaining 17 blocks are in the Ceará and Potiguar Basins in water depths ranging from 1,000 - 3,000 m.
Figure: Calculated Spectral Decomposition attributes of Late Cretaceous fans and channels complexes from the Amapá 3D Phases I(A) & II(B). A special thanks to NKDeep for their contribution of these to attribute images.
Exploration in the Equatorial Margin of Brazil has ebbed and flowed over time with the earliest exploration activities starting in the 1960s. The 1970 - 1980s were periods of intense exploration in the EMB resulting in a small number of discoveries. In the last 15 years, the conjugate margins and nearby basins have emerged as prolific oil and gas provinces. Here we highlight prospective features within the newly offered blocks. It is expected that the move of exploration targets to deeper waters will net a higher commercial success rate, as has been the case in many other frontier basins. Vast amounts of 2D and 3D seismic data to support exploration have been acquired overtime in the EMB. The TGS seismic data library in the EMB is unmatched with >82,000 km2 of 3D, >423,000 km of 2D and 270,000 km2 of 2DCubed seismic products.
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