The West African transform margin (WATM) stretches from Sierra Leone in the west to Benin in the east. What was once frontier territory for oil and gas exploration has had some of the most exciting discoveries in recent years.


Our Data Coverage

Data Coverage in the West African Transform Margin

Sierra Leone

  • Over 11,000 km² of multi-client 3D seismic
  • Over 16,000 km of dense multi-client 2D seismic
  • Gravity and magnetics surveys
  • License round opportunities


  • 31,350 km² of 3D seismic (key reprocessing in 2022)
  • 50,487 km of multi-client 2D seismic
  • Gravity and magnetic data
  • 33 offshore blocks


  • 17,874 km regional 2D multi-client seismic reprocessed in 2019
  • 2,048 km legacy 2D seismic
  • 82,000 km² Multibeam and Seafloor Sampling (MB&SS)
  • 1,223 active hydrocarbon seeps detected)
  • Interpretation products and drop coring


  • Regional 2D multi-client seismic
  • Recently reprocessed and merged into a 22,482 km dataset
  • Tano Basin remains the most prolific petroleum basin in Ghana
  • Proven, successful plays offshore Ghana


  • Recently reprocessed 2D seismic 4,946.5 km
  • Pre-Stack Time & Depth (PSTM/PSDM) products
  • Gravity and magnetic shipborne data
  • Oil has been discovered, and source rock material tested in wells on the shelf


  • 6,000 km² multi-client 3D seismic data
  • 5,854 km deepwater multi-client 2D reprocessed seismic
  • Pre-Stack Time and Depth Migrated products (PSTM/PSDM)
  • Gravity and Magnetics data
Sierra Leone License Round

Sierra Leone 5th License Round

In 2022, the Petroleum Directorate of Sierra Leone (PDSL) launched its 5th License Round. It also reiterated its multi-point plan to streamline the petroleum license process that awards within 85 days of application. It also provides an investment environment to encourage international O&G companies to explore Sierra Leone's offshore waters. Studies of the extensive seismic coverage in the area indicate potential multi-billion barrel prospects, presenting an exceptional exploration opportunity.

The formal bid submission deadline closed on 29 September 2023. The PDSL will now evaluate the interested parties that expressed an interest. 

Liberia Direct Negotiations

The LPRA has announced an indefinite extension to direct negotiation on all blocks over the Harper and Liberia basins within the offshore Liberia acreage. Thirty-three blocks are open for negotiation.  The new block demarcation followed an update to the petroleum bill in 2019, with a maximum block size of 3,500 km². TGS holds a range of multi-client seismic data across the tendered acreage to support the blocks on offer in both basins, including recently reprocessed 3D seismic. 

Liberia Map THUMB

Other Subregions

  • Northwest Africa
  • West African Salt Basins
  • Southwest Africa
  • East Africa
  • Mediterranean and Middle East

Northwest Africa

Northwest Africa

Northwest Africa has been the shining light of African exploration. That light was cast upon the region through world-class discoveries in Senegal and Mauritania.

TGS offers 2D and 3D seismic in continuous coverage from MSGBC to Liberia, with supporting MBSS geochemistry, and continues to prove a working hydrocarbon system here. 


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West African Salt Basins

West Africa

West Africa contains an intriguing mix of mature and frontier areas, presenting many exciting opportunities for significant discoveries.


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Southwest Africa

Southwest Africa

We hold the largest and most extensive 2D library in Namibia and South Africa with over 97,500 km and are adding to it by tieing recent discoveries to explore analogous plays.


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East Africa

East Africa

East Africa contains several offshore basins, some of which are still unexplored for oil and gas.

TGS offers comprehensive seismic coverage of the region, combined with well data, gravity and magnetic surveys, and other geoscience data.


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Mediterranean and Middle East

Mediterranean & Middle East

Significant 2D and 3D in the Red Sea providing exploration insights into an emerging region.

In addition, significant key areas of the Mediterranean and North Africa are covered with regional tie lines and a tight grid of 2D. 


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