| 1 | D C Bintliff & W W F Oil Corp. | | Oil & Gas Operator | Dec 1989 |
| 2 | Dailey Oil And Gas LLC | | Oil & Gas Operator | Jun 2019 |
| 3 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 4 | Dan A. Hughes Company | | Oil & Gas Operator | Dec 2005 |
| 5 | Davis Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 1988 |
| 6 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Oct 2025 |
| 7 | Delta Operating Corporation | | Oil & Gas Operator | Feb 2024 |
| 8 | Denbury Management, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Dec 1999 |
| 9 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Oct 2025 |
| 10 | Denbury Resources Inc. | Plano, TX 75024 | Oil & Gas Operator | Dec 2003 |
| 11 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 12 | Destin Operating Company, Inc. | | Oil & Gas Operator | Jan 2023 |
| 13 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 14 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Oct 2025 |
| 15 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 16 | Dore-Dyn Production Co., Inc. | | Oil & Gas Operator | Jul 1993 |
| 17 | Duncan Energy Company | Denver, CO 80202 | Oil & Gas Operator | Mar 2008 |
| 18 | Dune Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2016 |
| 19 | Dunhill Resources, Inc. | | Oil & Gas Operator | Nov 2005 |
| 20 | Dynamic Exploration PTRS, LLC | | Oil & Gas Operator | Nov 2024 |
| 21 | Dynamic Offshore Resources, LLC | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |