Revenues from our major customers for the years ended December 31, 2013, 2012 and 2011 that contributed more than 10% of our total revenues are as follows:
| Year Ended December 31, | ||||||||||||
| Customer | 2013 | 2012 | 2011 | |||||||||
|
Petróleo Brasileiro S.A. |
33.6 | % | 33.3 | % | 35.0 | % | ||||||
|
OGX Petróleo e Gás Ltda. |
2.4 | % | 12.5 | % | 14.1 | % | ||||||