A Renewed View on the Petroleum Potential of the Eastern Margin of Brazil

Abstract

The Eastern Margin of Brazil (EMB) extends from the Pernambuco-Paraíba Basin (PEPB) in the northeasternmost part of Brazil to the southernmost Pelotas Basin (PB) bordering with Uruguay. From North to South, the EMB is constituted by the PEPB, Sergipe-Alagoas (SEAL), Jacuípe (JAC), Camamu-Almada (CAMAL), Jequitinhonha (JEQ), Cumuruxatiba (CUM), Espírito Santo (ES), Campos (CAM), Santos (SAN) and Pelotas Basins (PEL). They are all typical passive margin basins formed during the breakup of Western Gondwana and opening of the South Atlantic. Extensional stresses dominated their formation and development. The EMB is well known to the international petroleum industry due to the prolific Campos Basin that produces around 1,700,000 boepd from post-salt turbidites and carbonates. In the last 8 years, another EMB basin (SAN) has dazzled the world with the huge discoveries of oil reserves (such as Lula and Buzios fields) in an uncommon carbonate reservoir in the pre-salt section (microbialites, also present in CAM). However, the large petroleum potential of the EMB is not restricted to these two basins. Recently, large discoveries of light oil, condensate and gas (sourced from Cretaceous marine shales) in late cretaceous turbidites were reported in the SEAL. The basin that is a traditional producer in shallow waters has now become one of the most promising frontiers in ultra-deep waters. In the ES, another traditional producer from cretaceous and cenozoic turbidites in shallow and deep waters, presents the potential for sub-salt discoveries associated to allochthonous salts (similar to those in GOM) in its ultra-deep waters. In the PEL attention is now focused to stratigraphic plays associated to late cretaceous/paleogene turbidites and cretaceous marine source rocks within a very thick drift section resting upon huge piles of seaward-dipping reflectors (SDRs). Several exploratory blocks in the adjacent margin of Uruguay had been acquired by companies in the last bid round. Recent studies carried out by ANP, including regional and detailed interpretation and mapping of extensive seismic grids, pointed out several exploratory opportunities in diverse areas of the EMB. Bright/flat spots and stratigraphic pinch-outs/incised channels associated to turbidite sandstones are the most common leads. Turtleback structures in albian carbonates also comprise a common play. This renewed view indicated that there is a significant petroleum potential remaining in the EMB.

AAPG Datapages/Search and Discovery Article #90216 ©2015 AAPG Annual Convention and Exhibition, Denver, CO., May 31 - June 3, 2015