| 1 | D H & L Operating, Inc. | | Oil & Gas Operator | Sep 1983 |
| 2 | D. B. Braddock | | Oil & Gas Operator | Jan 1986 |
| 3 | D. B. McConnell | | Oil & Gas Operator | Oct 1991 |
| 4 | D. B. McConnell Et Al | | Oil & Gas Operator | Nov 1993 |
| 5 | D. J. Fritz | | Oil & Gas Operator | Feb 1982 |
| 6 | D.J.F. Petroleum Corporation | | Oil & Gas Operator | Oct 1992 |
| 7 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 8 | Dallas DRLG. & Development Co. | | Oil & Gas Operator | Apr 1987 |
| 9 | Danos Oil & Gas LLC | | Oil & Gas Operator | Oct 2024 |
| 10 | Decker & Associates | | Oil & Gas Operator | Mar 1991 |
| 11 | Delhi Gas Pipeline Corporation | Palestine, TX 75802 | Oil & Gas Operator | Feb 1998 |
| 12 | Desoto Gas Corporation | | Oil & Gas Operator | Oct 1986 |
| 13 | Desoto Gas Prod Co Inc-Zadeck | | Gas Operator | Jan 1990 |
| 14 | Desoto Gas Producing Co. Inc | | Oil & Gas Operator | Jan 1990 |
| 15 | Desoto Oil & Gas Corporation | | Oil & Gas Operator | Dec 1990 |
| 16 | Desperation Oil & Gas Co. | | Gas Operator | Jan 1989 |
| 17 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 18 | Diversified Natural Res., Inc. | | Oil Operator | May 2000 |
| 19 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Oct 2025 |
| 20 | Dome De Sel LLC | | Oil & Gas Operator | Nov 2024 |
| 21 | Dominion Midstream Services, LP | | Oil Operator | Dec 2006 |
| 22 | Donald J. Zadeck | | Oil & Gas Operator | Feb 1998 |
| 23 | Dorchester Exploration, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 2001 |
| 24 | Dorothy F. Hamlin | | Oil Operator | Dec 1985 |
| 25 | DRD Operating Company | | Oil & Gas Operator | Feb 2014 |
| 26 | Dual Energy, Inc. | | Oil & Gas Operator | Oct 2022 |
| 27 | Duke Energy Field Services Inc | | Oil Operator | Mar 2000 |
| 28 | Duke Energy Field Services LLC | | Oil Operator | Dec 2006 |
| 29 | Dzurik Interests, Inc. | | Oil & Gas Operator | Dec 2024 |