| 1 | H & S Drilling Co Inc | Frazeysburg, OH 43822-0040-0040 | Oil & Gas Operator | Dec 2016 |
| 2 | Hall Energy Company LLC | Oklahoma City, OK 73120-5020 | Oil & Gas Operator | Jul 2022 |
| 3 | Harleton Oil & Gas Inc. | Tyler, TX 75710 | Oil & Gas Operator | Mar 2025 |
| 4 | Harman Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Dec 2007 |
| 5 | Hawkins Oil & Gas, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 6 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 7 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Nov 2024 |
| 8 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Mar 2025 |
| 9 | Hinton Production Company | MT Pleasant, TX 75455 | Oil & Gas Operator | Aug 1995 |
| 10 | Hopkins, T. M. Operating Co. | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2025 |
| 11 | Howell Oil & Gas, Inc. | Marshall, TX 75671 | Oil & Gas Operator | Oct 2019 |
| 12 | Hugus Investment Company, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Mar 2025 |
| 13 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Mar 2025 |
| 14 | Huntington Resources, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2006 |
| 15 | Hydrogeo, L.L.C. | Houston, TX 77074 | Oil & Gas Operator | Mar 2025 |