| 1 | H & P Exploration Co. | Alice, TX 78333 | Oil & Gas Operator | May 2019 |
| 2 | Haigood, Danny | Portland, TX 78374 | Oil & Gas Operator | Mar 2008 |
| 3 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 4 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Oct 2025 |
| 5 | Haring Energy Company | Tuleta, TX 78162 | Oil & Gas Operator | Mar 2003 |
| 6 | Harper Hefte, Inc. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Oct 2025 |
| 7 | Harris Energy Services, LLC | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 8 | Harwood Exploration, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Aug 1995 |
| 9 | Hawn Brothers | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2003 |
| 10 | Hayes Oil & Gas Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2005 |
| 11 | Headwaters Energy Partners, LLC | Dripping SPGS, TX 78620 | Oil & Gas Operator | Oct 2025 |
| 12 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Oct 2025 |
| 13 | Houston Exploration Co, The | Houston, TX 77002 | Oil & Gas Operator | Apr 2017 |
| 14 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 15 | Hunter Petroleum Inc. | Alice, TX 78333 | Oil & Gas Operator | May 2014 |
| 16 | Huntington Energy LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Oct 2025 |
| 17 | Hurd Enterprises, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 18 | Hyquest Energy, Inc. | Midland, TX 79710 | Oil & Gas Operator | Mar 2015 |