TGS Commences 3D Multi-client Onshore Survey in Central Alberta, Canada

CALGARY, CANADA (7 January 2013) - TGS, through its wholly-owned subsidiary Arcis Seismic Solutions, has commenced acquisition of a 3D multi-client onshore survey, Ille Lake, covering 180 km(2) (70 mi(2)) in the deep basin of Central Alberta, Canada. The Ille Lake survey is optimized and designed to evaluate multiple zones from the Cardium and the Upper & Lower Mannville (Glauconite, Ostracod & Basal Quartz Oil), through to the newly emerging Duvernay unconventional play.  In addition to the survey's optimal acquisition parameters, Arcis provides proprietary tools that will enhance imaging and rock property assessments for even greater assistance with the placement of horizontal wells. The seismic data will be processed by Arcis and final data will be available to the industry in Q1 2013. The survey is supported by industry funding. Company summary TGS-NOPEC Geophysical Company (TGS) provides multi-client geoscience data to oil and gas Exploration and Production companies worldwide.  In addition to extensive global geophysical and geological data libraries that include multi- client seismic data, magnetic and gravity data, digital well logs, production data and directional surveys, TGS also offers advanced processing and imaging services, interpretation products, permanent reservoir monitoring 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 principal 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). For additional information about this press release please contact: Kristian Johansen Chief Financial Officer Office: +47 667 69931 Cell: +47 47 60 33 34 Email: kristian.johansen@tgs.com Will Ashby Director Investor Relations and M&A Office: +1 713 860 2184 Email: will.ashby@tgs.com Rod Starr Senior VP Western Hemisphere Tel: +1 713 860 2100 Email: rod.starr@tgs.com This information is subject of the disclosure requirements acc. to §5-12 vphl (Norwegian Securities Trading Act) This announcement is distributed by Thomson Reuters on behalf of Thomson Reuters clients. The owner of this announcement warrants that: (i) the releases contained herein are protected by copyright and other applicable laws; and (ii) they are solely responsible for the content, accuracy and originality of the information contained therein. Source: TGS via Thomson Reuters ONE [HUG#1668348]