Print this pageSalt Provinces Offshore Brazil and West Africa — Regional Seismic Lines
Regional seismic programs of the last decade, including massive 2D and 3D data acquisition processed in time and depth, have brought in the modern technological era to the reservoir characterization and deepwater drilling of the continental margins off east Brazil and west Africa.
The main salt basins off the South Atlantic are situated in deepwater, within the Aptian salt provinces bordering the continental margins. This paper discusses the role of modern seismic regional lines in the assessment of structural and stratigraphic salt features, exploration plays and the development of deepwater oilfields based on the new data that in the deep and ultradeep water settings targets at the mapping of new reservoirs and their relationship with post-rift and syn-rift source rocks.
Major pre-salt structures consist of seaward and landward-tilted faulted blocks in the highly compartmentalized lacustrine syn-rift section, or to anticline features associated with volcanic and basement highs. Recent discoveries in the pre-salt section of the Santos and Campos Basins have established Brazil and the South Atlantic marginal basins as having the best world-class risk exploration opportunities.
The deepwater turbidite plays of the post-rift marine sediments are found mostly on Miocene-Eocene-Maastrichian reservoirs along the continental slope and basin. Interpretation in time (PSTM) and depth (PSDM) has posted the correct geometries of Tertiary strata and of the deeper Aptian salt structures. Beneath the autochthonous salt bodies this procedure has uncovered the underlying sub-salt reservoirs as well as the syn-rift sequences that encompass the source rocks and the newly discovered oil bearing carbonate reservoirs in deep waters. Future offshore exploration will continue aiming at better seismic resolution of the deepwater prospects and into the ultra deepwater plays of the salt wall provinces, including mini-basins, sub-salt and pre-salt plays, and along volcanic highs at the outermost continental crust petroleum provinces.
AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil