Oil
| Amerada Hess Corporation | |
| Apache Corporation | |
| Ashland, Inc. | |
| Austvik Ole Gunnar Energy | |
| Baker Hughes Incorporated | |
| Benton Oil and Gas Company | |
| Berry Petroleum Company | |
| BJ Services Company | |
| Black Hills Corporation | |
| Blue Dolphin Energy Company | |
| Burlington Resources, Inc. | |
| Caltex Petroleum Corporation | |
| Caltex SPIC | |
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| Chesapeake Energy Corporation | |
| Chevron Corporation | |
| CITGO Petroleum Corp. | |
| Devon Energy Corporation | |
| Eastern Enterprises | |
| Empire Energy Corporation | |
| Energen Corporation | |
| Equity Oil Company | |
| Forest Oil Corporation | |
| Fox Energy Corporation | |
| GeoDiamond | |
| Global Petroleum Corp. | |
| Hunting PLC | |
| Imperial Oil Limited | |
| IndigoPool.com | |
| Ira D. Conklin & Sons, Inc. | |
| Key Energy Services, Inc. | |
| Kuwait National Petroleum Company | |
| Lakehead Pipe Line Partners, L.P. | |
| Lasmo PLC | |
| Lyondell Petrochemical Company | |
| Marathon Oil Company | |
| Midcoast Energy Resources | |
| Mitchell Energy and Development Corp. | |
| Newpark Resources, Inc. | |
| North Coast Energy, Inc. | |
| Nuevo Energy Company | |
| Occidental Petroleum | |
| Ocean Energy, Inc. | |
| OSCA Inc. | |
| Petróleos Mexicanos (Pemex) | |
| Premier Oil | |
| Slovene Oil Company | |
| Statoil | |
| Sunoco Inc. | |
| Swift Energy Company | |
| Tesoro Petroleum Corporation | |
| Texaco, Inc. | |
| TotalFina | |
| TransCoastal Marine Services, Inc. | |
| Unocal | |
| Vaalco Energy | |
| Valero Energy Corporation | |
| World Fuel Services Corporation | |
| BlackRock Ventures Inc. | |
| Irving Oil Limited | |
| Niko Resources Ltd. | |
| Oil Directory, The | |
| Petro-Canada | |
| Ranger Oil Limited | |
| Ridel Resources Ltd | |
| Shell Canada | |
| Talisman Energy | |