Exhibit 8

List of CGG subsidiaries (December 31, 2017)

(Certain dormant or small subsidiaries of the Group have not been included in the list below)

French Companies	Head Office	% of interest
CGG Services SAS	Massy, France		100.0
CGG Explo SARL	Massy, France		100.0
Geomar SAS	Massy, France		100.0
Sercel Holding SAS	Carquefou, France		100.0
Sercel SAS	Carquefou, France		100.0
Foreign Companies	Head Office	% of interest
CGG Holding BV	The Hague, Netherlands		100.0
CGG Marine BV	The Hague , Netherlands		100.0
CGG Services (NL) BV	The Hague, Netherlands		100.0
CGG International SA	Geneva, Switzerland		100.0
CGG Data Services SA	Geneva, Switzerland		100.0
CGG Services (Norway) AS	Oslo, Norway		100.0
Exploration Investment Resources II AS	Oslo, Norway		100.0
Exploration Vessel Resources II AS	Oslo, Norway		100.0
CGG Services (UK) Limited	Crawley, United Kingdom		100.0
CGG do Brasil Participaçoes Ltda	Rio do Janeiro, Brazil		100.0
Veritas do Brasil Ltda	Rio do Janeiro, Brazil		100.0
LASA Prospeccoes SA	Rio do Janeiro, Brazil		100.0
CGG Mexico, SA de CV	Mexico City, Mexico		100.0
Geoinnovation Corporativa S. de RL de CV	Mexico City, Mexico		100.0
CGG Holding (U.S.) Inc.	Houston, United States		100.0
CGG Services (U.S.) Inc.	Houston, United States		100.0
CGG Land (U.S.) Inc.	Houston, United States		100.0
CGG Canada Services Ltd	Calgary, Canada		100.0
CGG Services (Canada) Inc.	Calgary, Canada		100.0
CGG Services (Australia) Pty Ltd	Perth, Australia		100.0
CGG Aviation (Australia) Pty Ltd	Perth, Australia		100.0
CGGVeritas Services (B) Sdn Bhd	Bandar Seri Begawan, Brunei		100.0
PT CGG Services Indonesia	Jakarta, Indonesia		95.0
CGG Services India Private Ltd	Navi Mumbai, India		100.0
CGG Technology Services (Beijing) Co. Ltd	Beijing, China		100.0
CGG Services (Singapore) Pte Ltd	Singapore		100.0
CGG Services (Malaysia) Sdn Bhd	Kuala Lumpur, Malaysia		100.0
CGG Vostok	Moscow, Russia		100.0
Sercel-GRC	Tulsa, United States		100.0
Sercel Inc.	Houston, United States		100.0
Hebei Sercel-Junfeng Geophysical Prospecting Equipment Co. Ltd	Hebei ,China		51.0
Sercel Singapore Pte Ltd	Singapore		100.0
De Regt Marine Cables BV	Krimpen Aan de Lek, Netherlands		100.0

Each of our subsidiaries listed above is organised in the country in which its head office is located, and each such subsidiary does business under its registered name.