| 1 | D. C. Bintliff | | Oil & Gas Operator | Mar 1987 |
| 2 | D.C.Bintliff-McCormick Oper Co | | Oil & Gas Operator | May 1984 |
| 3 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 4 | Darsey Operating Corporation | | Oil & Gas Operator | Sep 1990 |
| 5 | David L. Whittington Inc | | Gas Operator | Sep 2022 |
| 6 | Davis-Goodman Oil Company | | Oil & Gas Operator | Jun 1980 |
| 7 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Oct 2025 |
| 8 | Deblin Operating LTD | | Oil & Gas Operator | Jan 1997 |
| 9 | Deck Oil Company | Tulsa, OK 74101 | Oil & Gas Operator | Jun 2020 |
| 10 | Delta Development Co. Inc. | | Oil & Gas Operator | Dec 1988 |
| 11 | Delta Petroleum Corp Of Co | | Oil & Gas Operator | Oct 2010 |
| 12 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 13 | Desco Oil Company | Houston, TX 77056 | Oil & Gas Operator | Feb 2017 |
| 14 | Di Energy Inc. | Houston, TX 77067 | Oil & Gas Operator | Jan 2004 |
| 15 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Aug 2025 |
| 16 | Dome De Sel LLC | | Oil & Gas Operator | Nov 2024 |
| 17 | Dow Intrastate Gas Company | | Oil Operator | Dec 2023 |
| 18 | Duer Wagner & Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 1998 |
| 19 | Dune Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2016 |
| 20 | Dunn Exploration Company, LLC | | Oil & Gas Operator | Jan 2025 |
| 21 | Dynamic Exploration PTRS, LLC | | Oil & Gas Operator | Nov 2024 |
| 22 | Dynamic Exploration, Inc. | | Oil & Gas Operator | Oct 2003 |