| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | Oasis Petroleum North America LLC | Houston, TX 77002 | Oil & Gas Operator | Aug 2025 |
| 2 | Omimex International Corporation | Fort Worth, TX 76103-2300 | Oil & Gas Operator | Jun 2025 |
| 3 | Omimex Petroleum Inc | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2022 |
| 4 | Orion Energy Partners LP | Denver, CO 80202 | Oil & Gas Operator | Nov 2010 |
| 5 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 6 | Ovaco Energy Inc. | Oil & Gas Operator | Nov 2009 | |
| 7 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 8 | Oxy Little Knife, LLC | Oil & Gas Operator | Jan 2016 | |
| 9 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |