| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | O S & J Operatin | Oil Operator | Nov 1984 | |
| 2 | Oast, Thomas H. | Greenville, NC 27835 | Oil Operator | Nov 1985 |
| 3 | Oil Prop Investm | Oil Operator | Dec 1995 | |
| 4 | Oil Property Man | Oil & Gas Operator | Jun 1995 | |
| 5 | Oilfield Search | Oil Operator | Mar 1990 | |
| 6 | Oilfield Services, LLC | Winfield, KS 67156 | Oil Operator | Nov 2017 |
| 7 | Ol' Oily LLC | Oil Operator | Dec 2023 | |
| 8 | Olympic Petroleu | Oil & Gas Operator | Jul 1993 | |
| 9 | Osborn Heirs Com | Oil & Gas Operator | May 1995 | |
| 10 | Osborn Oil & Gas | Oil & Gas Operator | Jun 1991 |