| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | Oak Valley Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2015 |
| 2 | Ok-La-Tex Production, Inc. | Oil & Gas Operator | Jan 1982 | |
| 3 | Oleum Operating Company, L.C. | Longview, TX 75606 | Oil & Gas Operator | Dec 2021 |
| 4 | Olympic Oil & Gas Co., Inc. | Oil Operator | Apr 1991 | |
| 5 | Oracle Oil, LLC | Oil & Gas Operator | Jul 2013 | |
| 6 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 7 | Osr Oil & Gas Corp | Oil & Gas Operator | Dec 2024 | |
| 8 | Oxy Petroleum Inc | Oil & Gas Operator | Jan 1986 | |
| 9 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Sep 2026 |