| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | O'Brien, Owen | Saint Paul, KS 66771 | Oil Operator | Jan 2026 |
| 2 | O'Connell, James P. | Vacaville, CA 95687 | Oil Operator | Nov 2009 |
| 3 | Oil & Gas Servic | Oil Operator | Jun 1983 | |
| 4 | Oilfield Truck Service | Oil Operator | Jun 2014 | |
| 5 | Onyxx Oil Corpor | Oil Operator | Jul 1992 |