Exhibit 15.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the following Registration Statements:

(1) Registration Statement (Form S-8 No. 333-212796) pertaining to the CGG 2016 Stock Option Plan, and

(2) Registration Statement (Form S-8 No. 333-210768) pertaining to the CGG 2015 Stock Option Plan, and

(3) Registration Statement (Form S-8 No. 333-197785) pertaining to the CGG 2013 Stock Option Plan and the CGG 2014 Stock Option Plan, and

(4) Registration Statement (Form S-8 No. 333-188120) pertaining to the Compagnie Générale de Géophysique-Veritas 2012 Stock Option Plan and the Compagnie Générale de Géophysique-Veritas 2012 Performance Share Allocation Plan, and

(5) Registration Statement (Form S-8 No. 333-173638) pertaining to the Compagnie Générale de Géophysique-Veritas 2011 Stock Option Plan and the Compagnie Générale de Géophysique-Veritas 2011 Performance Share Allocation Plan, and

(6) Registration Statement (Form S-8 No. 333-166250) pertaining to the Compagnie Générale de Géophysique-Veritas 2010 Stock Option Plan and the Compagnie Générale de Géophysique-Veritas 2010 Performance Share Allocation Plan,

of our reports dated March 29, 2018, with respect to the consolidated financial statements of CGG and the effectiveness of internal control over financial reporting of CGG included in its Annual Report (Form 20-F) for the year ended December 31, 2017 filed with the Securities and Exchange Commission.

Paris-La Défense, France

March 29, 2018

/s/ Ernst & Young et Autres

By: Ernst & Young et Autres