| 1 | H-S Exploration | Gunnison, CO 81230 | Oil & Gas Operator | Sep 2026 |
| 2 | H.E.R. Operating, LLC | Silsbee, TX 77656 | Oil & Gas Operator | Sep 2026 |
| 3 | H.K.E. | Stafford, TX 77497 | Oil & Gas Operator | Sep 2026 |
| 4 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Sep 2026 |
| 5 | Hankamer, Curtis Corporation,The | Houston, TX 77024 | Oil & Gas Operator | Sep 2026 |
| 6 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | Sep 2026 |
| 7 | Hat Oil & Gas, Inc. | Slaton, TX 79364 | Oil & Gas Operator | Feb 2002 |
| 8 | HD Operating Co, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2026 |
| 9 | Heisey Ventures, Inc. | Houston, TX 77019 | Oil & Gas Operator | Sep 2026 |
| 10 | Helis Oil & Gas Company, L.L.C. | New Orleans, LA 70130 | Oil & Gas Operator | Oct 2023 |
| 11 | Helis,WM.G.,Est., A Partnership | New Orleans, LA 70130 | Oil & Gas Operator | Aug 2003 |
| 12 | Hemco Development, LLC | Dallas, TX 75201 | Oil & Gas Operator | Nov 2020 |
| 13 | Hennig Production Co., Inc. | Tyler, TX 75701 | Oil & Gas Operator | Sep 2026 |
| 14 | Hicks Exploration, LLC | Dover, OK 73734 | Gas Operator | Oct 2024 |
| 15 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Sep 2026 |
| 16 | HNG Storage Company | Houston, TX 77042 | Oil & Gas Operator | Mar 2002 |
| 17 | Hollimon Oil Corporation | Castroville, TX 78009 | Oil & Gas Operator | Nov 2016 |
| 18 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Sep 2026 |
| 19 | Horizon Exploration Company | Houston, TX 77019 | Oil & Gas Operator | Aug 2002 |
| 20 | Horizon Prod. And Operating, LLC | Alvin, TX 77511 | Oil & Gas Operator | Sep 2026 |
| 21 | Houston Energy Operating, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jul 2020 |
| 22 | Houston Energy, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jan 2014 |
| 23 | Houston Expl. & Prod. Co., Inc. | Austin, TX 78746 | Oil & Gas Operator | Aug 2003 |
| 24 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 25 | Houston Oil Prod Enterprises,Inc | Houston, TX 77006 | Oil & Gas Operator | Sep 2026 |
| 26 | Houston Petroleum Company | Houston, TX 77027 | Oil & Gas Operator | Sep 2026 |
| 27 | Houston Resources Corp. | Houston, TX 77002 | Oil & Gas Operator | Apr 2003 |
| 28 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Sep 2026 |
| 29 | Hughes Oil Operating, LLC | Spring, TX 77387 | Oil & Gas Operator | Sep 2026 |
| 30 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 31 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2026 |
| 32 | Hunt, WM. Herbert, Trust Est. | Dallas, TX 75201 | Oil & Gas Operator | Sep 1998 |