Were:
1. Shell , Great Britain/The netherlands
2. Exxon-Mobil , USA
3. BP , U.K
4. Petrochina/Sinopeck , China
5. Chevron , USA
6. Lucoil , Russia
7. Fuchs, Germany
8. Nippon oil , Japan
9. Valvoline , USA
10. Idemitsu , Japan
11.Conoco-Philips, USA
12. CPC , Taiwan
13. PDVSA, Venezuela
14...