The Guarujá Formation () 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 . The formation is the second-most important post-salt reservoir rock of the Santos Basin.
Etymology The formation is named after the city of Guarujá, São Paulo.
Description The Guarujá Formation is thick,Kiang Chang et al., 2008, p.32 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.Clemente, 2013, p.22
Petroleum geology The formation is the second-most important post-salt reservoir rock of the Santos Basin,Contreras, 2011, p.34 after the Itajaí-Açu Formation.Vieira, 2007, p.9
Field Year Operator Reserves (in place, million barrels) Reserves (in place, million m3) Notes Cavalo Marinho 2001 Petrobras Caravela 1992 Petrobras Caravela Sul 1991 Petrobras Coral 1990 Petrobras Estrela do Mar 1990 Petrobras Tubarão 1988 Petrobras
See also
Campos Basin
References
Bibliography