Post-Rift Cretaceous Exploration in the South Atlantic – Key Factors Influencing Exploration Performance

Westwood’s South Atlantic Margin Study, announced in June 2026, considers the geological drivers behind exploration performance for post-rift Cretaceous reservoirs in the South Atlantic over the past two decades.  

The study provides data-backed insights into what drives exploration success and failure across the Equatorial, Central and Austral segments. It is based on more than 400 exploration wells drilled between 2007 and 2025 targeting post-rift Cretaceous stratigraphy, drawn from Westwood’s Wildcat solution and supplemented with paleo-bathymetry and crustal domain information from Getech. 

As well as providing detailed overviews of the key basins, plays and information on wells drilled, the project investigated six key factors influencing exploration performance on a quantitative basis.

Paleo-Slope Gradient – Tano-Ivorian Basin Example (Slope Influenced by Structural Domain). Source: Westwood South Atlantic Margin Study 2026

1. Crustal domain uses Getech data to divide the South Atlantic Margins into six key domains – Rifted Continental Fragment, Attenuated Continental Crust, Transitional (subdivided in to Strike Slip, Magma Poor and Magma Rich) and Oceanic Crust. Despite technical success across all crustal types, significant differences in commercial success are apparent.

2. Source rock considers the importance of source rock presence, effectiveness and maturity, as well as variation at local and basin scale for both syn- and post-rift Cretaceous source rocks.

3. Kinematic style categorises the Equatorial Margin of the Atlantic into three kinematic styles: Normal, Oblique and Strike Slip, and highlights differences in exploration performance across these styles.

4. Depositional slope type analyses exploration performance for clastic turbidites according to whether the slope can be considered to be “ponded” or “unponded”, to highlight the importance of slope topography and its impact on exploration performance.

5. Angle of paleo-slope uses Getech’s paleo-bathymetry model at stage level to consider all clastic turbidite tests by slope angle, allowing quantitative analysis of exploration performance by slope gradient.

6. Distance to paleo-coastline uses Getech’s depositional environment model at stage level to assess the relationship between a well’s location and its proximity to the paleo-coastline, identifying significant differences across South Atlantic segments and, in some cases, at basin level.

Detailed technical work has previously been completed on each of these factors, but the value of the study lies in the breadth and consistency of the dataset, which brings together more than 400 offshore exploration wells, regional geological context and decades of industry experience. This allows exploration performance to be assessed across comparable geological settings, rather than relying on isolated well outcomes or individual basin analogues.

In some cases, the results reinforce established industry interpretations, particularly around charge effectiveness, depositional setting and basin maturity. In others, the quantitative analysis highlights less obvious controls and regional contrasts, providing a more robust framework for comparing performance across the Equatorial, Central and Austral South Atlantic margins.

Jamie Collard, Senior Exploration Research Manager

Further information on Westwood’s South Atlantic Margin Study is available  here.

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