ASKER, NORWAY and HOUSTON, December 20, 2017—TGS and Schlumberger today announced a new 2D seismic project offshore Egypt.

The project will comprise acquisition of a 10,000 km 2D long-offset broadband multiclient seismic survey. Advanced new acquisition and imaging techniques will provide better illumination of complex subsalt structures. The project will integrate all legacy seismic and non-seismic data. Acquisition will commence mid-December and is expected to complete in late Q1 2018.

This project is part of an agreement entered with South Valley Egyptian Petroleum Holding Company (GANOPE) in which Schlumberger and TGS have a minimum 15-year period of exclusive multiclient rights in a ~70,000 km² open area offshore the Egyptian Red Sea.

“The unexplored offshore Egyptian Red Sea area is made up of large, untested structures and well-established hydrocarbon systems, which offer exceptional growth opportunities for oil companies. New imaging technologies are required to improve subsurface understanding and increase exploration success rates. The upcoming new multiclient 2D seismic acquisition program is the initial step in mitigating the complex salt imaging challenges of this unique opportunity,” said Kristian Johansen, CEO, TGS.

Maurice Nessim, president, WesternGeco, Schlumberger, added: “Our comprehensive geological understanding, innovative seismic imaging techniques and full integration of non-seismic methods will define new exploration trends in these prospective basins. The Schlumberger unique play-to-prospect integrated subsurface evaluation capabilities will enable customers to develop new prospectivity insight and accelerate their exploration decisions in this structurally complex area. Our program will have significant impact on the exploration potential for the entire Red Sea (600,000 km² across 5 countries). Our collaborative approach will help customers to identify high potential play segments, assess exploration risks and accelerate hydrocarbon maturation cycles.”

GANOPE is responsible for managing the hydrocarbon resource potential at South Valley. This project is supported by industry funding.

About TGS

TGS-NOPEC Geophysical Company (TGS) provides multiclient geoscience data to oil and gas Exploration and Production companies worldwide. In addition to extensive global geophysical and geological data libraries that include multiclient seismic data, magnetic and gravity data, digital well logs, production data and directional surveys, TGS also offers advanced processing and imaging services, interpretation products, and data integration solutions.

For more information visit TGS online at www.tgs.com.

Forward-looking statements and contact information

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 TGS' reliance on a cyclical industry and principle customers, TGS' ability to continue to expand markets for licensing of data, and TGS' ability to acquire and process data products at costs commensurate with profitability.

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.

TGS-NOPEC Geophysical Company ASA is listed on the Oslo Stock Exchange (OSLO:TGS). TGS sponsored American Depositary Shares trade on the U.S. over-the-counter market under the symbol "TGSGY".

About Schlumberger

Schlumberger is the world's leading provider of technology for reservoir characterization, drilling, production, and processing to the oil and gas industry. Working in more than 85 countries and employing approximately 100,000 people who represent over 140 nationalities, Schlumberger supplies the industry's most comprehensive range of products and services, from exploration through production, and integrated pore-to-pipeline solutions that optimize hydrocarbon recovery to deliver reservoir performance.

Schlumberger Limited has principal offices in Paris, Houston, London and The Hague, and reported revenues of $27.81 billion in 2016. For more information, visit www.slb.com.

For further information, contact:

Investors and Media
Sven Børre Larsen – TGS, Chief Financial Officer
Tel: +47 90 94 36 73
sven.larsen@tgs.com

Will Ashby – TGS, VP HR & Communication
Tel: +1 713 860 2184
will.ashby@tgs.com

Media
Susan Ganz – Schlumberger, Public Relations Manager-Western Hemisphere
Tel: +1 713 939 2997
sganz1@slb.com