| 1 | H And H | Gonzales, TX 78629 | Oil Operator | Feb 1999 |
| 2 | H&K Energy | Stockdale, TX 78160 | Oil & Gas Operator | Jul 2005 |
| 3 | Ha.P.C. Oil, Inc. | Gonzales, TX 78629 | Oil & Gas Operator | Aug 2006 |
| 4 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 5 | Hampton Resources Corporation | Houston, TX 77010 | Oil & Gas Operator | Mar 1996 |
| 6 | Haring Energy Company | Tuleta, TX 78162 | Oil & Gas Operator | Mar 2003 |
| 7 | Harrier Holdings, LTD. | Burnet, TX 78611 | Oil Operator | Oct 2025 |
| 8 | Hart Petroleum Services, Inc | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Jul 2025 |
| 9 | Harvey, Robert E., Jr. | Nixon, TX 78140 | Oil & Gas Operator | Oct 2003 |
| 10 | Hat Creek Energy LLC | Denver, CO 80209 | Oil & Gas Operator | Jun 2019 |
| 11 | Hawn Brothers | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2003 |
| 12 | Heritage Expl. & Prod. Co., Inc. | Stafford, TX 77497 | Oil & Gas Operator | Dec 2000 |
| 13 | Hibbard Energy, LP | Whitehouse, TX 75791 | Oil & Gas Operator | Oct 2025 |
| 14 | Hicks Exploration, LLC | Dover, OK 73734 | Gas Operator | Feb 2025 |
| 15 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Oct 2025 |
| 16 | Hinton Production Company | MT Pleasant, TX 75455 | Oil & Gas Operator | Aug 1995 |
| 17 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Oct 2025 |
| 18 | Hopco Operating, Inc. | Stafford, TX 77497 | Oil & Gas Operator | Dec 2016 |
| 19 | Horizon Exploration Services | El Paso, TX 79922 | Oil Operator | Oct 2025 |
| 20 | Houston Exploration Co, The | Houston, TX 77002 | Oil & Gas Operator | Apr 2017 |
| 21 | Houston Hydrocarbons, Inc. (A) | Houston, TX 77042 | Oil & Gas Operator | Sep 2004 |
| 22 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |