Offshore Trinidad to French Guiana: A Regional Overview

Pate, Karen; Martinez, Wenceslao; Lall, Johan; Restrepo, Camilo¹; and Diez, Jorge
¹[email protected]

The recent exploration success on the West African margin has attracted a renewed exploration interest at the other side of the Atlantic, in particular at the Guyana-Suriname Basin, based on the concept of a mirrored geological setting on both sides of the Atlantic. However, this concept is only valid for a small portion of the South American coastal margin that is limited to French Guiana and a small portion of northern Brasil. Large expectations have been sold over the Guiana-Suriname Basin, but are yet to be tested and proved. This work reveals that the pursued play in the Guiana Basin presents more similarities with eastern Trinidad DW basins, where geological models are less understood.

To facilitate the evaluation of hydrocarbon systems in the offshore of this margin we generated regional cross-sections and an over 1200-kilometer-long conceptual, lithospheric-scale cross-section from the Tobago Trough to the Demerara plateau. The analyses include gravity and magnetics, interpretation of 2D and 3D seismic data, and a review of published literature.

The petroleum geological history of the Guiana-Suriname Basin began in the Jurassic when the North Atlantic rift system progressed southward to the Central Atlantic area. During the Early Cretaceous, South America and Africa rifted apart due to a counter-clockwise rotation of Africa relative to South America. The compression that occurred as a result of this rotation caused inversion of Lower Cretaceous-Jurassic sediments. The youngest evidence for this structural event is the Albian–Aptian Unconformity.

From the beginning of the Upper Cretaceous to recent times the margin became passive, characterized by the deposition of deep marine to shallow marine sediments. The development of submarine fans in the Turonian–Cenomanian has now captured the attention of explorationists for possible development of stratigraphic traps due to the lack of deposition of a mobile substratum capable of generating structural traps.

The Guiana-Suriname Basin is largely unexplored; however, the geological ingredients indicate the basin has prospectivity. The U.S. Geological Survey has estimated undiscovered resources for the basin to be an impressive 15.2 billion barrels of oil.

AAPG Search and Discovery Article #90166©2013 AAPG International Conference & Exhibition, Cartagena, Colombia, 8-11 September 2013