TGS and Viridien begin seismic survey in ‘strategic area of underexplored’ Brazilian basin

September 5, 2025, by Nadja Skopljak

Norwegian energy data and intelligence company TGS and France-based geophysical services company Viridien, formerly known as CGG, have begun a 5,300 square kilometers multi-client 3D seismic survey offshore Brazil.

Ramform Tethys; For illustrative purposes only. Source: TGS

The joint venture partners announced on September 4 the commencement of the Megabar Extension Phase I survey in the Barreirinhas Basin offshore Northern Brazil.

TGS will deploy the purpose-built streamer vessel Ramform Tethys, equipped with the GeoStreamer technology. Imaging of the survey will be conducted by Viridien, leveraging the Time-Lag Full-Waveform Inversion (TL-FWI) and Reverse Time Migration (RTM) imaging technologies.

According to TGS, the survey, supported by industry funding, will be acquired in a promising area with proven geological potential but no existing 3D data.

The Barreirinhas Basin features proven petroleum systems and giant discoveries in adjacent Guyana and Suriname basins that demonstrate analogous deepwater play components, the Norwegian company said, noting that recent licensing activity along the equatorial margin, coupled with the success of Brazil’s 5^th Cycle Permanent Concession Offer, supports growing momentum for the region.

“We are pleased to commence this new Megabar Extension survey as part of our long-term commitment to unlocking high-potential frontier areas for new exploration opportunities in Brazil. Megabar Extension will give our clients an unmatched early-mover advantage in a strategic area of the underexplored Barreirinhas Basin in one of South America’s most promising exploration plays,” said Sophie Zurquiyah, CEO of Viridien.

“With exclusive access to the first ultramodern 3D seismic data set in this area, explorers will be able to identify opportunities faster, make more confident decisions, and position themselves ahead of the competition for upcoming bid rounds.”

Acquisition is expected to conclude by late November, with initial imaging products expected by Q3 2026 and final data in Q1 2027.

“TGS remains committed to support the energy industry with high quality data for exploration activities in Brazil’s equatorial margin basins. Geology in these basins share characteristics with discoveries in Guyana and Suriname, and Megabar Extension Phase I will represent a significant step forward in understanding geology in the Barreirinhas Basin,” said Kristian Johansen, CEO of TGS.

Furthermore, Viridien reported on September 2 that it had taken ownership of seismic field data from the Momentum survey, set to be incorporated into Laconia, Viridien’s ocean bottom node (OBN) program in the U.S. Gulf.

The new coverage will extend Viridien’s OBN footprint by approximately 143 Outer Continental Shelf blocks, around 3,343 square kilometers.