1. 3M Company
2. Anton Oilfield Services Group
3. Baker Hughes Company
4. China Oilfield Services Limited
5. Halliburton Energy Services Inc.
6. KATT GmBH
7. Mitchell Industries
8. NOV Inc.
9. Oil States International Inc.
10. RPC Inc.
11. Schlumberger Limited
12. Siao Petroleo
13. Superior Energy Services Inc.
14. Tendeka by Abu Dhabi National Energy Company
15. Weatherford International PLC