Q3 2017 Earnings Release

CEO CFO 26 October 2017

Kristian Johansen Sven Børre Larsen

Forward-Looking Statements

All statements in this presentation 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.

Q3 2017 Highlights

Q3 net revenues of 142 MUSD, up 25% from Q3 2016
Net late sales of 79 MUSD, up 18% from 67 MUSD in Q3 2016
Net pre-funding revenues of 62 MUSD were up 58% from Q3 2016, funding 54% of TGS' operational multi-client investments for the quarter
Operational multi-client investments of 114 MUSD in addition to 1 MUSD from risk sharing arrangements
Operating profit for the quarter was 26 MUSD compared to 11 MUSD in Q3 2016
Cash flow from operations at 86 MUSD compared to 91 MUSD in Q3 2016
Cash balance of 205 MUSD in addition to undrawn 75 MUSD Revolving Credit Facility
Quarterly dividend maintained at USD 0.15 per share

Operational Highlights

Q3 2017 Operations

Q3 Activity – U.S. Gulf of Mexico

Fusion M-WAZ reimaging program

M-WAZ reimaging program in collaboration with Schlumberger in Mississippi Canyon, Atwater Valley and Ewing bank areas
~27,000 km2 (1,166 OCS blocks ) 3D M-WAZ data previously acquired by TGS and Schlumberger between 2008 and 2012
Reimaging is >70% complete with final data delivery mid-2018

Otos multibeam and seep study

~289,000 km2 multibeam acquisition completed in early Q2; acquisition of 350 cores and associated advanced geochemistry analysis will complete in Q4
Designed to mirror the successful Gigante multibeam and seep study in the Mexican GOM

Q3 Activity – East Canada

Newfoundland Labrador 2D – 2017 Season

• 22,000 km multi-client 2D survey infilling and extending existing JV* data in the region; targeting 2019 and 2020 Sectors of the Scheduled Land Tenure

Newfoundland Labrador 3D

~18,000 km2 multi-client 3D covering a mix of held and open acreage within the 2018 and 2019 Sectors of the Scheduled Land Tenure
Long Range 3D
East Flemish Pass 3D Phase II
Harbour Deep 3D
Cape Broyle 3D

Well positioned for future licensing rounds

• Following the most active year ever in this region, the TGS/PGS JV library will exceed 175,000 km of 2D data and 29,250 km2 of 3D data in addition to 83,700 km of TGS vintage data, an expansive well log library and advanced multi-client interpretation products

* In JV with PGS

Q3 Activity – Norway

AM17 Atlantic Margin 3D

40,000 km2 project in the central-southern Norwegian Sea largest 3D survey carried out by any company in Northern Europe
Covers largely open blocks in a relatively under-explored area with limited drilling to date
Several underlying blocks included in the 24th licensing round
Acquisition in 2017 and 2018

Carlsen 3D

5,490 km2 multi-client survey located in the Southwest Barents Sea
Open acreage with blocks included in the 24th licensing round
Acquisition completed in Q3 2017

Q3 Activity – Ireland

Crean 3D - Ireland

~5,400 km2 multi-client survey located in the South Porcupine Basin between the Porcupine High and the Irish Mainland Platform
Adding to TGS's Atlantic Margin offering building on the exploration success on the Newfoundland Labrador conjugate margin coupled with historical exploration in Atlantic Ireland
Acquisition completed in October 2017

Q3 Activity - U.S. Land

West Kermit 3D

1,050 km2 high-resolution 3D multi-client project in Loving and Winkler counties, TX, in the Delaware basin
Data acquisition expected to complete in Q4 2017

Geary 3D

200 km2 high-resolution 3D multi-client project in the SCOOP & STACK play in the Anadarko Basin, OK
Data acquisition expected to complete in Q4 2017

Permian Well Database

Comprehensive Permian well database announced to clients in Q1 2017
Expanded to ~460,000 wells in Q3 2017 (including validated well headers and digital LAS) supported by multiple interpretive products

Financials

Net Revenues

Late sales revenues

26 ¹⁵ ²⁷ 58% Y/Y

Prefunding revenues

Q4 2015 Q1 2016 Q2 2016 Q3 2016 Q4 2016 Q1 2017 Q2 2017 Q3 2017

Proprietary revenues

Total revenues

Net Revenue Breakdown

Operating Expenses, EBIT, Free Cash Flow

230 ⁶² ⁶⁹ ⁷⁴ ⁹² ⁶² ⁶⁹ ⁹⁵ 0 50 100 150 200 250 Q4 2015 Q1 2016 Q2 2016 Q3 2016 Q4 2016 Q1 2017 Q2 2017 Q3 2017 67% - rate

Amortization and impairment

* Defined as cash flow from operational activities minus operational cash investments in multi-client projects

EBIT *

Multi-Client Library

Operational investments* and prefunding ratio

*Operational investments excluding risk-sharing arrangements

Investments – year of completion

Net revenues vs net book value – year of completion

Q3 2017 Income Statement

USD million, except EPS		Q3 2017	Q3 2016	Change in %
Net revenues		142	113	25%
Cost of goods sold – proprietary and other		0.2	5	-97%
Amortization of multi-client library	67%	95	74	27%
Gross margin		47	34	38%
Personnel costs		13	12	10%
Other operating expenses		6	8	-23%
Cost of stock options		0.1	0.2	-75%
Depreciation		2	3	-37%
Operating profit	18%	26	11	140%
Net financial items		1	2	-48%
Profit before taxes	19%	27	13	108%
Taxes		18	11	56%
Net Income	7%	9	2	441%
EPS, Undiluted		0.09	0.02	441%
EPS, Fully Diluted		0.09	0.02	441%

Q3 2017 Cash Flow Statement

USD million	Q3 2017	Q3 2016	Change in %
Received payments from customers	115	110	4%
Payments for operational expenses	(26)	(25)	-4%
Paid taxes	(2)	6	-141%
Operational cash flow	86	91	-6%
Investments in tangible and intangible assets	(1)	(2)	15%
Investments in multi-client library	(105)	(62)	-69%
Interest received	0.8	0.7	18%
Interest paid	(0.04)	(0.03)	-52%
Dividend payments	(15)	(17)	9%
Proceeds from share issuances	-	-	N/A
Change in cash balance	-35	11	-411%

Balance Sheet

USD million	Q3 2017	Q2 2017	Change in %	Q4 2016
Assets
Cash and cash equivalents	205	239	-14%	191
Other current assets	272	268	1%	353
Total current assets	477	508	-6%	544
Intangible assets and deferred tax asset	82	84	-2%	86
Other non-current assets	0.5	2	-73%	11
Multi-client library	838	812	3%	812
Fixed assets	21	21	-3%	23
Total Assets	1,418	1,426	-1%	1,477
Liabilities
Current liabilities	223	227	-2%	262
Non-current liabilities	5	5	-8%	6
Deferred tax liability	33	33	-1%	39
Total Liabilities	261	265	-2%	307
Equity	1,157	1,161	0%	1,169
Total Liabilities and Equity	1,418	1,426	-1%	1,477

Dividend stable at USD 0.15 per share

Shareholder authorization to distribute quarterly dividend payments
Aim to keep a stable quarterly dividend through the year
Actual quarterly dividend level paid will be subject to continuous evaluation of market outlook, cash flow expectations and balance sheet development
Q4 2017: USD 0.15 per share to be paid on 16 November 2017
Shares will trade ex-dividend on 2 November 2017

Outlook

Oil market uncertainty to persist in the short-term

Early indications of modest E&P spending growth in 2018

Most market analysts expect E&P spending growth of 0 to 10% in 2018
Flattish development in offshore spending expected but substantial variation (i.e. uncertainty) in estimates

Current exploration activity not sustainable

Upstream cost is coming down

Base-case estimate of Brent price required to remain cash flow neutral (accumulate no additional debt) between 2017 and 2019 for more than 50 of the world's leading oil companies, as estimated by Wood Mackenzie. Includes upstream costs and pro-rated shareholder distributions. Excludes downstream cash flow
Year-to-date for 2017

Backlog down following busy quarter

Historical Backlog (MUSD) 2013 - 2017

2017 Projects Schedule*

EUR AMEAP NSA

*Acquisition schedule excludes Fusion M-WAZ Reprocessing, other processing projects and GPS investments

License Round Activity and TGS Positioning

North & South America

Central & Western GOM Mar & Aug (2017-22 Plan)
Newfoundland Labrador 2017 round delayed; call for 2018 nominations open
Nova Scotia Dec 2017 (3-Year Rolling Plan)
Canada Onshore at least monthly
Brazil Pre-salt rounds Oct 2017; 15th Round H1 2018
Mexico Round 2.4 (deep water)- Jan 2018; Round 3.1 (shallow) Mar 2018

Africa, Middle East, Asia Pacific

Ongoing uncertainty on timing of African licensing rounds
Australia Feb & Mar 2018 (bids due)
New Zealand May 2018 (nominations due)
Indonesia Nov 2017 (bids due)

Europe / Russia

Norway APA early 2018 (awards due)
Norway 24th Round Nov 2017 (bids due)
UK 30th Round Nov 2017 (bids due)
Greenland Dec 2017 & 2018 (bids due)

Summary

Q3 net revenues of 142 MUSD
Q3 EBIT of 26 MUSD
Cash balance of 205 MUSD in addition to undrawn 75 MUSD Revolving Credit Facility
Quarterly dividend maintained at USD 0.15 per share
Oil market uncertainty to persist in short-term
Long-term future of asset-light, focused multi-client business remains strong
Cost control, disciplined counter-cyclical investment and balance sheet strength positions TGS to enhance its leading position
2017 guidance (as updated 23 May 2017):
New multi-client investments of approximately USD 260 million
Additional multi-client investments expected from sales of existing surveys with risk sharing arrangements
Pre-funding of new multi-client investments expected to be approximately 40%-45%