1. Baker Hughes Company
2. Calfrac Well Services Ltd.
3. Cudd Energy Services
4. FracChem LLC
5. Franklin Well Service LLC
6. Halliburton Energy Services Inc.
7. NexTier Oilfield Services Inc.
8. NOV Inc.
9. Patterson-UTI Energy Inc.
10. Schlumberger Limited
11. Tacrom Services S.R.L.
12. TechnipFMC PLC
13. Trican Well Service Ltd.
14. U.S. Silica Holdings Inc.
15. Weatherford International PLC