| 1 | H & H Operating | Olney, TX 76374 | Oil & Gas Operator | Sep 2025 |
| 2 | H & O Operating Co | Odessa, TX 79764 | Oil & Gas Operator | Mar 2008 |
| 3 | H L Brown Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Jun 2025 |
| 4 | H&P Oil & Gas LLC | Mertzon, TX 76941 | Oil & Gas Operator | Sep 2025 |
| 5 | Hadson Energy Resources Corp. | Houston, TX 77056 | Oil & Gas Operator | Dec 1994 |
| 6 | Halbouty, Michel T. | Houston, TX 77056 | Oil & Gas Operator | Aug 1997 |
| 7 | Hallwood Energy Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Feb 2005 |
| 8 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 2025 |
| 9 | Ham Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Feb 2000 |
| 10 | Hamon Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2011 |
| 11 | Hampton, Jno. W. & Son | Wichita Falls, TX 76302 | Oil & Gas Operator | Nov 1998 |
| 12 | Hank Oil & Gas, Inc. | Houston, TX 77056 | Oil & Gas Operator | Oct 2023 |
| 13 | Hanley Petroleum Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2017 |
| 14 | Hannathon Petroleum II, LLC | Midland, TX 79705 | Oil & Gas Operator | Sep 2025 |
| 15 | Hannathon Petroleum, LLC | Midland, TX 79705 | Oil & Gas Operator | Sep 2025 |
| 16 | Hardy Oil & Gas USA Inc. | Houston, TX 77079 | Oil & Gas Operator | Jun 1996 |
| 17 | Harper, Wayne | Dallas, TX 75206 | Oil & Gas Operator | Mar 2008 |
| 18 | Headington Energy Partners, LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Sep 2025 |
| 19 | Hec Petroleum, Inc | Midland, TX 79705 | Oil & Gas Operator | Mar 2006 |
| 20 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | May 2025 |
| 21 | Henderson & Erickson, Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2025 |
| 22 | Hendrix, John H. Corporation | Midland, TX 79705 | Oil & Gas Operator | Sep 2018 |
| 23 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 24 | Henry Petroleum LP | Midland, TX 79701 | Oil & Gas Operator | Dec 2008 |
| 25 | Henry Resources LLC | Midland, TX 79703 | Oil & Gas Operator | Sep 2025 |
| 26 | Hexp Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Sep 2025 |
| 27 | Hi - Mountain Energy Corporation | Odessa, TX 79762 | Oil & Gas Operator | Sep 2025 |
| 28 | Hibernia Resources III, LLC | Houston, TX 77056 | Oil & Gas Operator | Nov 2023 |
| 29 | Highmark Energy Operating, LLC | Dallas, TX 75222 | Oil & Gas Operator | Sep 2025 |
| 30 | Hillin-Simon Oil Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2013 |
| 31 | Holliday Drilling, Inc. | Stephenville, TX 76401 | Oil & Gas Operator | Dec 2020 |
| 32 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Oct 2024 |
| 33 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 34 | HPPC, Inc. | Midland, TX 79701 | Oil & Gas Operator | Feb 2023 |
| 35 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Sep 2025 |
| 36 | Hufo Production Corporation | Midland, TX 79702 | Oil & Gas Operator | Jul 2002 |
| 37 | Hugoton Energy Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Dec 2019 |
| 38 | Hulsey Larry O & Co | Graham, TX 76046 | Oil & Gas Operator | Jun 2012 |
| 39 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2025 |
| 40 | Hydrocarbon Management, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Dec 1996 |