--> ABSTRACT: Active Tectonics and Petroleum Accumulations in Brazil, by Claudio Coelho de Lima and Aline Theophilo Silva; #90906(2001)

Datapages, Inc.Print this page

Claudio Coelho de Lima1, Aline Theophilo Silva2

(1) Petrobras Research Center, Rio de Janeiro, Brazil
(2) Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil

ABSTRACT: Active tectonics and petroleum accumulations in Brazil

The South America Plate (SAP) is nowadays in horizontal compression and shortening. This is foreseen by plate force models and shown by stress data compilations and by spatial based geodetic results as well. The compression/shortening is due to the tectonic context of SAP, which is mostly dominated by the convergence with the Nazca and the Caribbean plates and the divergence from the African plate. This context has been mostly established since the Upper Cretaceous, and slightly modified during Tertiary, in response to global plate re-organizations. In response to the compression, the lithosphere as whole (or only the crust if thermal gradients are high enough) tends to buckle. This tendency is controlled by the previous lithospheric/crustal structure. The concepts that firstly passive margins are relaxed (submitted only to minor faults) and secondly that the formation of structures have been terminated a long time ago are deeply seated within the oil industry. For exploitation the perception of the ongoing compression opens up new perspectives for well design and secondary recovery. For exploration, we infer that the ongoing compression has an important role in the distribution and preservation of petroleum accumulations since: a strong positive correlation exist between permeability and maximum stress; accumulations are ephemeral in a geological time scale, being strongly dependent on seals fine geometry and biodegradation; the disruption of the kitchens of generation is a positive factor to primary migration; and, the source rocks of the most important south American petroleum systems are still in the oil generation window

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado