A Brief Tectonostratigraphic Account of the Guyana Basin, Offshore Guyana—In Search of the Fabled Canje-Saramacca Cretaceous Petroleum System
Business Development Geoscientist, PGS Multi-Client NSA
The Guyana Basin is principally an offshore basin located along the northeast coast of South America, comprising ~ 350,000 km² across Suriname, Guyana, and French Guiana. The basin is considered a frontier component of the Equatorial Atlantic Margin play, which it shares with West African countries Ghana, Liberia, Sierra Leone and the Ivory Coast where a significant commercial Cretaceous petroleum system has recently been realized (e.g. Tullow Oil's Jubilee discovery).
Most exploration to date has focused on the onshore and shallow-water Guyana Basin, with only the onshore component of the Bakhuis Horst providing commercial accumulations (Tambaredjo and Calcutta Fields). Approximately 40 exploration wells have been drilled offshore, all on the continental shelf and most testing structural targets.
The primary source kitchen of the Guyana Basin is the Canje-Saramacca petroleum system (Cenomanian-Turonian) located offshore in deep waters. A secondary, untested source from rocks of Jurassic/Early Cretaceous age might also exist (Staatsolie). Modelling work by Mobil in the shelf area suggests that the oil window is reached at 4,000 m, however the North Coronie-1 well indicates that source beds encountered at 4,600 m are only marginally in the oil window.
Regional mapping of the deep and ultra-deep water of the Guyana Basin offshore Guyana utilizing modern 2D seismic suggests potential reservoirs are Cretaceous carbonate build-ups and sands (turbidites/fans) of Cretaceous and Tertiary age in stratigraphic and structural traps. Stacked reservoirs are common. Seal is not considered an issue in deep and ultra-deep water, but is a high risk in shallow waters.
AAPG Search and Discovery Article #90203 © AAPG Geoscience Technology Workshop, Trinidad and Tobago Deep Horizon and Deep Water Frontier Exploration in Latin America and the Caribbean, March 9-11, 2014, Port of Spain, Trinidad