| 1 | H & H Star Energy Inc | Traverse City, MI 49684 | Oil & Gas Operator | Aug 2016 |
| 2 | Hamon Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2011 |
| 3 | Hanna Oil And Gas Company | Fort Smith, AR 72901 | Oil & Gas Operator | Feb 2025 |
| 4 | Hazlewood Oil & Gas Co Inc | Oklahoma City, OK 73139-9353 | Oil & Gas Operator | Apr 2022 |
| 5 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Feb 2025 |
| 6 | Henry Petroleum Of Oklahoma LP | Midland, TX 79703-5000 | Oil & Gas Operator | Feb 2017 |
| 7 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 8 | HK Energy Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 9 | Hoover & Wilson Exp & Prod Inc | Fort Smith, AR 72913-5171 | Gas Operator | Jul 2013 |
| 10 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Oct 2024 |
| 11 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 12 | Hosco Operating Inc | Seminole, OK 74868-2447 | Oil & Gas Operator | Aug 2017 |
| 13 | Houston Exploration Co, The | Houston, TX 77002 | Oil & Gas Operator | Apr 2017 |
| 14 | Hsumy Oil & Gas Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2007 |