| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | O'Malley Production Co. Inc. | Oil & Gas Operator | Apr 1988 | |
| 2 | Oilwell Acquisition Co. | Oil & Gas Operator | Jun 1999 | |
| 3 | Onyx Energy Corporation | Oklahoma City, OK 73157 | Oil & Gas Operator | May 1994 |
| 4 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 5 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |