Paper submitted to 2nd EAGE/SBGF Conference on Deepwater Brazil Equatorial Margin, by Kyle Reuber (TGS)
Summary
The deepwater region of the Pará Maranhão Basin is considered underexplored but early analyses of high-quality 2D seismic surveys (Fig. 1) indicated that it likely holds significant hydrocarbon potential. Shallow water exploration results confirmed two working petroleum systems in the basin (exhausted oil field PAS-9/11 and sub-commercial oil well MAS-5)(Opdyke, S. and Balabekov, Y., 2018). The presence of source rock intervals across the neighboring equatorial basins in Brazil has also been confirmed. Recent deepwater oil discoveries in Ceará (Pecém) and Potiguar (Pitú and Anhangá) Basins targeted passive margin sedimentary units and illustrated deeper functioning petroleum systems in the region (Agência Petrobras, 2024). The northern continuation of the Equatorial Margin into Guyana and Suriname revealed to the world fantastic discoveries that are nowadays producing close to 1 MMbopd. The conjugate margin of Equatorial West Africa (Ghana and Ivory Coast) hosts a number of deepwater, stratigraphic trap discoveries that are analogous to the emerging play targets in Equatorial Brazil. This assessment is focused on the crustal nuances, volcanic structures and drift phase sedimentary units of the Pará-Maranhão Basin.
The Pará-Maranhão Basin of the Equatorial Atlantic Ocean is located between the Foz do Amazonas and Barreirinhas Basins of Brazil. This offshore basin covers approximately 100,000 km2 and has a range of water depths of 100 m to greater than 4,000 m, with the majority being greater than 1,500 m. The Harpia well (aka PAS-027) drilled in 2011 is the single well in the deepwater region of this basin. The well was drilled in 2,060 m of water and reached a total depth of 5,690 m (location in Fig. 1). The well’s bottom target penetrated allochthonous Miocene carbonate debris with shows of oil. Since the results of this wildcat were announced, no other deep water Pará-Maranhão wells have been drilled, despite evidence of a functioning petroleum kitchen.