| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | O. D. Maybrier | Oil Operator | Dec 2011 | |
| 2 | Oil Country Management, Inc. | Oil & Gas Operator | Jan 2005 | |
| 3 | Oil Lift, Incorporated | Metairie, LA 70002 | Oil & Gas Operator | Apr 2020 |
| 4 | Oleum Operating Company, L.C. | Longview, TX 75606 | Oil & Gas Operator | Dec 2021 |
| 5 | Olympic Natural Gas Company | Oil & Gas Operator | Oct 1990 | |
| 6 | Olympic Production Company | Oil & Gas Operator | Jul 1994 | |
| 7 | Opmi Operating Company | Houston, TX 77057 | Oil & Gas Operator | Jun 2008 |
| 8 | Optimistic Oil Co. | Oil & Gas Operator | Dec 1991 | |
| 9 | Orb Exploration, L.L.C. | Oil & Gas Operator | Jun 2017 | |
| 10 | Oxy Petroleum Inc | Oil & Gas Operator | Jan 1986 |