| 1 | H.E.R. Operating, LLC | Silsbee, TX 77656 | Oil & Gas Operator | Apr 2024 |
| 2 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2023 |
| 3 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Apr 2024 |
| 4 | Hanson Minerals Co. | Houston, TX 77042 | Oil & Gas Operator | Oct 1993 |
| 5 | Hanson Production Company | Cuero, TX 77954 | Oil & Gas Operator | Jul 2009 |
| 6 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | Apr 2024 |
| 7 | Harrison, Dan J III&Bruce F Est | Houston, TX 77002 | Oil & Gas Operator | Apr 2024 |
| 8 | Harrison, Dan J. III&Bruce F. | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 9 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 10 | Hec Petroleum, Inc | Midland, TX 79705 | Oil & Gas Operator | Mar 2006 |
| 11 | Hemco Development, LLC | Dallas, TX 75201 | Oil & Gas Operator | Nov 2020 |
| 12 | Hemco Production, L. L. C. | Dallas, TX 75201 | Oil & Gas Operator | Apr 2016 |
| 13 | Henderson, Peter Oil Co. | San Angelo, TX 76906 | Oil & Gas Operator | Feb 2020 |
| 14 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Apr 2024 |
| 15 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Apr 2024 |
| 16 | Houston Energy Operating, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jul 2020 |
| 17 | Houston Gulf Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Apr 2024 |
| 18 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 19 | Houston Oil Prod Enterprises,Inc | Houston, TX 77006 | Oil & Gas Operator | Apr 2024 |
| 20 | Howard Exploration, Inc. | Houston, TX 77069 | Oil & Gas Operator | Apr 2024 |
| 21 | HS Resources, Inc. | Denver, CO 80202 | Oil & Gas Operator | Dec 2005 |
| 22 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Apr 2024 |
| 23 | Hurley Petroleum Corporation | Baton Rouge, LA 70821 | Oil & Gas Operator | Feb 2000 |
| 24 | Hydrocarbon Management, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Dec 1996 |