Geology and petroleum habitat for Brazilian east Atlantic margin basins

Sergipe-Alagoas, Jequitinhonha, Espirito Santo, and Campos basins are located along the east Brazilian continental margin in South America. These basins present 3 major Mesozoic and Cenozoic sedimentary sequences ranging from continental to open-marine environments. Two structural styles produced 3 major exploratory plays, both structural and stratigraphic. Structures are related, first, to an early tectonic framework of the basins caused by extensional forces, when an irregular hinge line was developed, and later, to gravity sliding and sedimentary loading when an entire set of structures that depict complex structural and sedimentary patterns from the border of the basins toward the hinge line, and from the hinge line down to the basins. The tectonic-structural model defines trends for hydrocarbon exploration. More than 80 oil and gas fields have been discovered in both onshore and offshore portions of the east Brazilian margin basins. Oil-field data plus a large amount of subsurface and seismic reflecting data support the proposed model used to establish the global exploratory strategy for the east Brazilian margin basins. Such a model can also be useful for homotaxial analogy in areas where similar geologic conditions occurred; however, it is necessary to keep in mind that each basin has unique features.