Liberia

Why Liberia?

Liberia's Harper Basin has a geological history and petroleum system similar to those in Ghana, Côte d’Ivoire, and Guyana, which have seen recent oil discoveries.

Success in exploration along the northern South American coast has highlighted the potential for offshore Liberia whose coastline can be tectonically reconstructed to fit with the Guyana Basin, suggesting similar prospectivity.

The shelf area features typical syn-rift structures with growth sequences sourced from quartz-rich sediments eroded from onshore Precambrian outcrops. During the transition from syn-rift to drift in the Albian period, renewed erosion relocated some reservoir material to the slope, now pinching out against the basin-binding fault. This creates promising leads along the basin as these materials brighten into the up-dip trap.

Liberia Exploration Potential

Liberia boats strong play diversity from the syn-rift Lower Cretaceous to the deepwater Upper Cretaceous with multiple source rock intervals across the stratigraphy. The range of multi-client data available: 2D seismic, 3D seismic, and gravity and magnetic data, together with the well data, allows for a robust understanding of the plays and numerous prospect and leads are identifiable. Since 2023, TGS has undergone reprocessing of the “Block 8&9 3D” and part of the 2D surveys (primarily within the Liberia Basin). This has improved imaging quality, velocity modelling and amplitude and AVO confidence, de-risking certain prospectivity and improving trap and structural certainty.

Modelling predicts that the source rock maturity and expulsion post-dates the main tectonism in the basin, while rock data supports presence of effective seal horizons, comparable with West African Transform Margin analogues. Volumetric assessments of leads suggests that field sizes with over a billion barrels of oil in place could be present through a variety of stratigraphic and structural trapping mechanisms.

• 33 offshore blocks ranging from 2300 to 3500 km²
• 17 exploration wells drilled in both shelf and deepwater domains
• Proven petroleum system in the Cretaceous plays

Liberia's Geology

BSR (bottom simulation reflector) and OPAL boundaries (both chemical and mineralogical phenomena) were identified in the modern Sunfish 3D seismic survey and were used in the basin modeling to tie source rock (SR) maturation phase, pore pressure and burial basin temperature in the system. Models of various locations throughout the basin reveal that oil and gas have likely been generated and continue to be in active kitchens at present, with the Albian SR in the gas window and the well-extended Turonian-Cenomanian interval in the oil window. Their hydrocarbon generation timing is favorable for the stacked slope channel systems in the Late Cretaceous system, sealed by backfilling muds.