--> Offshore Exploration Opportunities in Brazil, Boyd, Kevin; Alexander, C. Shafe, #90100 (2009)

Datapages, Inc.Print this page

Offshore Exploration Opportunities in Brazil

Boyd, Kevin1
Alexander, C. Shafe2

1BP, Sunbury on Thames, United Kingdom.
2
BP,
Rio de Janeiro,, Brazil.

Though exploration drilling in Brazil began in the 1920’s, it was not until exploration stepped offshore into deepwater that world-class petreoleum provinces were discovered in Brazil with the first true giant oil field, Albacora, drilled in 1984. Since then many more large offshore discoveries have been made primarily in the Campos, Santos and Espirito Santo basins culminating with numerous recently announced pre-salt discoveries. The pre-salt promises to be the new great oil basin of the decade. However, outside of these basins much of Brazil remains largely under explored. Many exploration opportunities remain in offshore basins from Jequitinhonha basin northwards to Foz do Amazonas basin.

Regional syn-rift and post-rift Cretaceous source rocks are developed all along the Brazilian Atlantic margin, and these have been buried by varying thicknesses of Cretaceous-Tertiary overburden. 2D seismic profiles along Foz do Amazonas, Para Maranhão, Barreirinhas, Camamu-Alamada,
Jequitinhonha, Campos, Santos and Pelotas basins suggest significant variations on the thickness and extent of the underlying continental crust and the overlying syn-rift system. A deep seismic reflector is recognized in some basins and may be related to either a lower crustal detachment or the moho. Heat flow and thus source rock maturation level, timing and overall prospectivity will be controlled by the interpretation of this surface. Thick sequences of late Cretaceous and Tertiary deepwater clastics are observed in most of the basins providing multiple potential reservoir levels. Recent pre-salt drilling has revealed the reservoir potential of the non-marine and marginal marine syn-rift.

Future exploration in these basins will hinge upon further understanding of the position of the ocean-continent transition, crustal thickness, syn-rift extent and reservoir presence and effectiveness. This will have an impact on heat flow, source rock presence, distribution and maturity and hydrocarbon access to shallower trapped reservoirs. Gravity and magnetic data along with long record seismic should provide information on the exploration potential and extent of each basin. Comparing the Brazilian basins to their conjugate margins in
West Africa may also reduce some of the uncertainties in the crustal architecture.

AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil