--> ABSTRACT: Architectural Patterns Variability in Deepwater Reservoirs, by Oliveira, Tiago A.; Empinotti, Thaís A.; Moraes, Marco S.; Paraizo, Paulo B.; #90142 (2012)

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Architectural Patterns Variability in Deepwater Reservoirs

Oliveira, Tiago A.*1; Empinotti, Thaís A.2; Moraes, Marco S.3; Paraizo, Paulo B.2
(1) CENPES/PDGEO/GSEST, PETROBRAS, Rio de Janeiro, Brazil.
(2) CENPES/PDGP/CMR, PETROBRAS, Rio de Janeiro, Brazil.
(3) CENPES/PDGEO/PROMOB, PETROBRAS, Rio de Janeiro, Brazil.

The understanding of architectural pattern variations along the depositional tract and the stratigraphic succession of Deepwater systems is essential to improve reservoir quality and performance prediction of Deepwater reservoirs at both local and regional scales. Several controls have been proposed to explain the great variability of architectural styles found in those systems, including source area characteristics, shelf configuration, slope gradient, grain size, mud content, relative sea-level changes, among many others. In order to be effective, the prediction of architecture variations should be based on a few, essential and workable variables. In this study, we privileged the investigation of Deepwater reservoir architectural patterns from the eastern Brazilian margin basins including Campos, Santos, Espirito Santo and Sergipe-Alagoas, complemented by the equatorial basins offshore Brazil, the West Africa and the Gulf of Mexico basins. Several outcrop analog databases were also investigated, along with modern systems, especially from Brazilian margin. As a result, we propose a classification of the architectural types in which the main control on their development is a combination of gradient (i.e., position on the slope-to-basin profile - into which local variation can be imposed) and the position within the stratigraphic cycle (considered as reflecting mostly shoreline trajectory). Although recognizing that many other controls also play a role, we suggest that these two controls are the most applicable to subsurface investigation. The architectural variation trends obtained in such an analysis are comparable to those presented by the classical sequence stratigraphic models, but with significant refinement introduced by high-resolution seismic stratigraphic studies and outcrop analysis. In addition, modified trends caused by topographic confinement are also considered. As a result, the pathway for slope evolution and the role of confinement on the development of the architectural patterns is better understood.

 

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California