Тип бассейна: Платформ
Подтип бассейна: Пассивных окраин (перикратонно-океанический)
Класс бассейна: Периокеанический
Возраст бассейна: Зрелый - Мезозойский
Тип полезных ископаемых:
Геологический возраст начало:
Геологический возраст конец:
Площадь: 92884.25 км²
Espirito Santo Basin
The Espirito Santo Basin is located on the eastern Brazilian margin and is limited to the south by the Vitória High, to the north by the Mucuri paleocanyon, to the west by the crystalline basement and to the east by the volcanic complex of Abrolhos. Its area covers approximately 41,500 km², of which 3,000 km2 onland, where 4 geological provinces are recognized: (I) São Mateus Platform; (II) Regência Platform; (III) Fazenda Cedro Paleo-canyon and (IV) Regência Paleo-canyon (Figure 1)
Figure 1: Location map of the study area showing the main provinces of the onshore Espírito Santo Basin.
The Espírito Santo basin was formed in the context of the Gondwana supercontinent break-up and the formation of the Atlantic Ocean.
Espírito Santo basin’s tectonic-stratigraphic evolution is interpreted as a passive rift with a N-S axis, including volcanic and sedimentary rocks ranging from the early Cretaceous (Valanginian- Aptian) up to the Neogene (França et al. 2007). The main hydrocarbons source rocks in the basin are the shales from Cricaré Formation, deposited in a lacustrine environment from the rift phase. Source rocks from this age are related to the Pre-Salt, that is responsible for three out of four barrels of oil already discovered in Brazil (Milani & Araújo 2003; Mohriak 2003; 2006).
Tectonic quiescence from the Post-rift phase (Alagoas stage, Aptian) allowed the deposition of the Itaúnas evaporites. Its salt has begun to move in the late AptianLower Albian (Fiduk et al. 2004; Mohriak 2003) and reaches thicknesses from 50 m onshore to more than 5,000 m in deep and ultra-deep waters (França et al. 2007). It deforms and controls sedimentation up to the present, conditioning paleocanyons, trapping turbidites, forming mini-basins (Fiduk et al. 2004; Mohriak 2003), folding the surrounding sediments and providing traps for the oil and gas industry.
Drift phase comprises the rocks deposited from Albian to the present. It can be subdivided into two phases: the Initial Drift (with marine and transgressive sequences, with depositions of sandstones, limestones, shales and turbidites) and the Late Drift (with regressive character, with deposition of shallow carbonate platform and fluvial deposits).
The latest magmatic phase recorded in the basin occurred during the Eocene. The Abrolhos volcanic complex covers an area of 30,000 km2 (França et al. 2007; Fiduk, et al. 2004; Mohriak 2006) being formed by the passage of the Trindade Hot Spot in the northern portion of the Espírito Santo Basin (Mohriak 2006). Magmatic bodies in the sedimentary column increases towards the Abrolhos Plateau and may have locally affected the thermal maturation of the rocks and, consequently, the potential for oil and gas generation.
The accumulations of hydrocarbons in the Espírito Santo Basin can be classified according to the ages of the reservoir rocks: (i) Alagoas sandstones located mainly on structural traps at the São Mateus platform (Ii) Aptian calco-siliciclastic reservoirs located on structural traps at the Regência Platform and (iii) Cretaceous / Tertiary turbidite reservoirs that are located within the paleocanyons mainly in stratigraphic traps (Wolff et al., 1986). Most of the sandstone reservoirs of this basin are found in uplifted and/or tilted blocks affected by the rift tectonics. In the paleo-canyons, truncation features predominate against walls of canyons forming stratigraphic traps (Figure 2). However, recent studies after drilling new exploratory wells in the Inhambu Field (Neves et al., 2016), shows that the Urucutuca Formation can be very thin and in some areas non-existent, while hydrocarbon indications are present at the fluvial sandstones of the São Mateus and Mariricu Formations.
Figure 2: Geological section of the Espírito Santo Basin, showing the main compartments of the Basin.
Data source:Seismostratigraphic analysis in the Inhambu Field, Espírito Santo Basin, Brazil. Igor Andrade Neves, Wagner Moreira Lupinacci, Cleverson Guizan Silva. 2017
Oil Seep Detection Using Microwave Remote Sensing at Espírito Santo Basin, Eastern Brazil. Lucas dos Anjos Correa do Espirito Santo, Marcelo dos Santos Salomão, Enrico Campos Pedroso, Ciro Jorge Appi. 2021
Следующий Бассейн: Puerto Montt