TGS Q3 2025 Operational Update

OSLO, Norway (8 October 2025) - TGS ASA ("TGS"), a leading global provider of energy data and intelligence, routinely publishes a quarterly operational update six working days after quarter-end.

The table below shows TGS' normalized Ocean Bottom Node (OBN) crew count¹:

+---------------------------------------+---------+---------+ |   | Q3 2025 | Q3 2024 | +---------------------------------------+---------+---------+ | Normalized crew count Contract(1) | 1.8 | 3.8 | +---------------------------------------+---------+---------+ | Normalized crew count Multi-client(1) | 1.0 | 0.0 | +---------------------------------------+---------+---------+

(1) The table shows the average number of crews in operation when assuming a normalized crew size. )

The table below shows TGS' allocation of active seismic streamer 3D vessel capacity(2):

+-------------------+---------+---------+ |   | Q3 2025 | Q3 2024 | +-------------------+---------+---------+ | Contract | 45% | 20% | +-------------------+---------+---------+ | Multi-client | 28% | 57% | +-------------------+---------+---------+ | Steaming | 10% | 6% | +-------------------+---------+---------+ | Yard | 8% | 2% | +-------------------+---------+---------+ | Stacked/Standby | 9% | 15% | +-------------------+---------+---------+ | Number of vessels | 6 | 6 | +-------------------+---------+---------+

(2) The statistics include only active seismic 3D streamer vessels (capacity working on New Energy Solutions projects are excluded). )

Based on preliminary financial review TGS expects multi-client investment to be approximately USD 86 million in Q3 2025, compared to USD 129.4 million in Q3 2024.

Kristian Johansen, CEO of TGS commented: "Asset utilization in Q3 exceeded expectations, with a normalized OBN crew count of 2.8 and streamer vessel utilization at 73%, compared to our previous indications of approximately 2.5 and 65%, respectively. The stronger performance was mainly driven by optimized vessel scheduling as well as securing more streamer and OBN work than expected."

TGS will release its Q3 2025 results at 07:00 a.m. CEST on 23 October 2025. CEO Kristian Johansen and CFO Sven Børre Larsen will present the results at 09:00 a.m. CEST, webcasted live.

The webcast can be followed live via this link: https://channel.royalcast.com/landingpage/hegnarmedia/20251023_4/

For more information, visit TGS.com (http://www.tgs.com) or contact: Bård Stenberg, VP IR & Business Intelligence Tel.: +47 992 45 235 E-mail: investor@tgs.com

About TGS TGS provides advanced data and intelligence to companies active in the energy sector. With leading-edge technology and solutions spanning the entire energy value chain, TGS offers a comprehensive range of insights to help clients make better decisions. Our broad range of products and advanced data technologies, coupled with a global, extensive and diverse energy data library, make TGS a trusted partner in supporting the exploration and production of energy resources worldwide. For further information, please visit www.tgs.com (https://www.tgs.com/).

Forward Looking Statement All statements in this press release other than statements of historical fact are forward-looking statements, which are subject to a number of risks, uncertainties and assumptions that are difficult to predict and are based upon assumptions as to future events that may not prove accurate. These factors include volatile market conditions, investment opportunities in new and existing markets, demand for licensing of data within the energy industry, operational challenges, and reliance on a cyclical industry and principal customers. Actual results may differ materially from those expected or projected in the forward- looking statements. TGS undertakes no responsibility or obligation to update or alter forward-looking statements for any reason.