| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | O I L Energy Corp | Oil & Gas Operator | Oct 2017 | |
| 2 | O I L Niagaran LLC | Oil & Gas Operator | May 2017 | |
| 3 | Okemah Production Inc | Oil Operator | Dec 2005 | |
| 4 | Omega Operating, Inc. | Odessa, TX 79769 | Oil & Gas Operator | Mar 2001 |
| 5 | Omega Resources Inc | Oil & Gas Operator | Nov 1998 | |
| 6 | Omimex Energy, Inc. | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2025 |
| 7 | Omni Petroleum Corporation | Austin, TX 78738 | Oil & Gas Operator | Dec 2025 |
| 8 | Onco Petroleum USA Inc | Oil Operator | Dec 2009 | |
| 9 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 10 | Ososki Edward D Dba Federal Oil Company | Oil & Gas Operator | Sep 2025 |