| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | Oilwell Acquisition Co | Oil & Gas Operator | Jun 1999 | |
| 2 | Okie Operating Company, LTD. | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2026 |
| 3 | Oleum Operating Company, L.C. | Longview, TX 75606 | Oil & Gas Operator | Dec 2021 |
| 4 | Orb Exploration, L.L.C. | Oil & Gas Operator | Jun 2017 | |
| 5 | Orx Resources, Inc. | Oil & Gas Operator | Dec 2009 | |
| 6 | Orx Resources, L.L.C. | Houston, TX 77067 | Oil & Gas Operator | Sep 2026 |
| 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 |