| 1 | H & P Partnership | La Vernia, TX 78121 | Oil Operator | Mar 2025 |
| 2 | H&K Energy | Stockdale, TX 78160 | Oil & Gas Operator | Jul 2005 |
| 3 | H. & J. Drilling Company | Fort Worth, TX 76114 | Oil & Gas Operator | Aug 2003 |
| 4 | H.K.E. | Stafford, TX 77497 | Oil & Gas Operator | Mar 2025 |
| 5 | Hankamer, Curtis Corporation,The | Houston, TX 77024 | Oil & Gas Operator | Mar 2025 |
| 6 | Hawn Brothers | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2003 |
| 7 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 8 | Hep Oil Company LTD | Gainesville, TX 76240 | Oil & Gas Operator | Mar 2012 |
| 9 | Hep Oil GP, LLC | Gainesville, TX 76241 | Oil & Gas Operator | Mar 2015 |
| 10 | Hibbard Energy, LP | Whitehouse, TX 75791 | Oil & Gas Operator | Mar 2025 |
| 11 | Holloway Oil Company | Austin, TX 78764 | Oil & Gas Operator | Feb 2004 |
| 12 | Hollub, Lambert Drilling Company | Seguin, TX 78155 | Oil & Gas Operator | Mar 2025 |
| 13 | Hominy Consulting, LLC | Canadian, TX 79014 | Oil & Gas Operator | Mar 2025 |
| 14 | Horizon Ridge Oil Company | Austin, TX 78738 | Oil Operator | Mar 2025 |
| 15 | Houston Gulf Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Mar 2025 |
| 16 | Houston Hydrocarbons, Inc. (A) | Houston, TX 77042 | Oil & Gas Operator | Sep 2004 |
| 17 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 18 | Hughes, Dan A. Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | Mar 2025 |
| 19 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Mar 2025 |
| 20 | Huntwood Resources, LLC | Huntsville, TX 77340 | Oil Operator | Mar 2025 |