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Guarujá Formation

Coordinates: 26°6′S 43°43′W / 26.100°S 43.717°W / -26.100; -43.717
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Guarujá Formation
Stratigraphic range: Early Albian
~113–108 Ma
TypeGeological formation
Unit ofCamburi Group
UnderliesItajaí-Açu Fm., Juréia Fm.
OverliesAriri Formation
Thicknessup to 2,500 m (8,200 ft)
Lithology
PrimaryLimestone
OtherMarl
Location
Coordinates26°6′S 43°43′W / 26.100°S 43.717°W / -26.100; -43.717
RegionSantos Basin, South Atlantic
Country Brazil
Type section
Named forGuarujá

Location of the Santos Basin

The Guarujá Formation (Portuguese: Formacão Guarujá) is a geological formation of the Santos Basin offshore of the Brazilian states of Rio de Janeiro, São Paulo, Paraná and Santa Catarina. The predominantly calcarenite formation with marls dates to the Early Cretaceous period; Early Albian epoch and has a maximum thickness of 2,500 metres (8,200 ft). The formation is the second-most important post-salt reservoir rock of the Santos Basin.

Etymology

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The formation is named after the city of Guarujá, São Paulo.

Description

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The Guarujá Formation is 832 to 2,500 metres (2,730 to 8,202 ft) thick,[1] and consists of oolitic calcarenites, which laterally grade to greyish ochre and brownish grey calcilutites and grey marls. These facies are interbedded with the alluvial clastics of the Florianópolis Formation. The Guarujá name is restricted to the lowest limestone intercalation, previously named Lower Guarujá by Ojeda and Ahranha in Pereira and Feijó (1994). The microfacies indicate a tidal flat to shallow lagoon and open carbonate platform depositional environment. The age based on planktonic foraminifera and pollen is Early Albian.[2]

Petroleum geology

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The formation is the second-most important post-salt reservoir rock of the Santos Basin,[3] after the Itajaí-Açu Formation.[4][5]

Field Year Operator Reserves (in place, million barrels) Reserves (in place, million m3)
Notes
Cavalo Marinho 2001 Petrobras 25.04 3.981
Caravela 1992 Petrobras 48.81 7.760
Caravela Sul 1991 Petrobras 5 0.79
Coral 1990 Petrobras 22.57 3.588
Estrela do Mar 1990 Petrobras 15.16 2.410
Tubarão 1988 Petrobras 30 4.8

See also

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References

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  1. ^ Kiang Chang et al., 2008, p.32
  2. ^ Clemente, 2013, p.22
  3. ^ Contreras, 2011, p.34
  4. ^ a b c d e f "Santos Basin Fields". Archived from the original on 2017-09-07. Retrieved 2017-09-07.
  5. ^ Vieira, 2007, p.9
  6. ^ Juarez, 2013, p.14
  7. ^ ANP Yearbook, 2014, p.30
  8. ^ Coral Field: Case History in Oil Producing Albian Carbonates in Santos Basin, Brazil
  9. ^ Estrela do Mar, Cavalo Marinho oil output by 2007
  10. ^ Juarez, 2013, p.11

Bibliography

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