The Northern Brazilian Equatorial Margin, including Foz do Amazonas, Pará-Maranhão, Barreirinhas and Ceará Basins, covers an area of approximately 620,000 km2 up to the 3,000m isobaths. The basins are directly related to the breakup of the African and American plates during Aptian-Albian times. Recent giant hydrocarbon accumulation in deep and ultra deep waters in Guyana (Zaedyus well) and Venus, Jupter, Narina and Jubilee in West Africa Equatorial Margin suggesting that large oil/gas accumulations must also be present in the deep to ultra-deep water realm of the Brazilian margin. In the Pará-Maranhão Basin, most of the exploration activity took place during 70’s and 80’s where most of its 34 offshore wells were drilled. Only two wells have been drilled in water depths deeper than 83m. Direct evidence of at least three active oil and gas petroleum systems were obtained by the recovery of gas and light oil in several exploration wells The Barreirinhas Basin covers an area of approximately 50,000 km2 of which 20% is onshore. The presence of onshore gas and light oil discoveries proved the presence of at least three active oil & gas petroleum systems in the Basin. The Ceará Basin spans over an area of 62,983 km2 between the Tutóia and Fortaleza highs. The exploratory history of the basin started at the end of the 60’s with the first seismic survey done by Petrobras, and this initial exploration effort gave first results with the discovery of the Xaréu field (1977), followed by the discoveries of Curimã and Espada (1978), and Atum (1979) fields. By 2012, Petrobras made its first large oil discovery (Pecém oil field) in the deep water region of the basin. By 2013, 117 exploratory wells were drilled in the basin with its vast majority concentrated in the Mundaú sub-basin. During the last license lease of the basin in 2013, 6 exploration blocks were awarded to companies such as Exxon, Total, Chevron and Premier, indicating that these companies envisage a high exploration potential of the basin. This multi-client 2D Petroleum System Modeling and Exploration Risk Assessment of Equatorial Margin including Para-Maranhão, Barreirinhas and Ceará Basins Brazil, allowed for the reconstruction and characterization of the active petroleum systems present in the area. The integration of its elements and processes which look into oil and gas migration, trap formation, thermal evolution of source rocks and oils, oil and gas accumulation and preservation of the new frontier leads and prospects targets, are critical in tower the drilling exploratory risk in such unexplored deep waters. Full references of all images are listed in the reports