| 1 | D & S Oil Company | Corsicana, TX 75151 | Oil & Gas Operator | Oct 2025 |
| 2 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 3 | Dahlia Operating LLC | Petrolia, TX 76377 | Oil & Gas Operator | Apr 2018 |
| 4 | Dallas Petroleum Group, LLC | Dallas, TX 75379 | Oil & Gas Operator | Oct 2025 |
| 5 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 6 | Davis, Gowin | Wichita Falls, TX 76308 | Oil & Gas Operator | Mar 2001 |
| 7 | Dawson, B G Oil & Gas LTD | Dallas, TX 75205 | Oil & Gas Operator | Jul 2024 |
| 8 | DDC Production Company | Archer City, TX 76351 | Oil Operator | Oct 2025 |
| 9 | De Larios, R. V., LTD. | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 10 | Decleva, Paul | Wichita Falls, TX 76302 | Oil & Gas Operator | Dec 2020 |
| 11 | Deen Drilling Company | Archer City, TX 76351 | Oil & Gas Operator | Oct 2025 |
| 12 | Delek Energy Systems Us Inc | Denver, CO 80202 | Oil & Gas Operator | Oct 2011 |
| 13 | Demers - Fleming | Wichita Falls, TX 76305 | Oil & Gas Operator | Mar 2008 |
| 14 | Demers Oil Production | Byers, TX 76357 | Oil & Gas Operator | Apr 2002 |
| 15 | Denton Exploration, Inc. | Dallas, TX 75219 | Oil & Gas Operator | Oct 2025 |
| 16 | Diamond Energy, Inc. | Sherman, TX 75091 | Oil & Gas Operator | Oct 2025 |
| 17 | Diamond Operating, LLC | Wichita Falls, TX 76308 | Oil & Gas Operator | Aug 2010 |
| 18 | Dixie Drilling Company, Inc. | Sherman, TX 75090 | Oil & Gas Operator | Nov 2011 |
| 19 | DJ Resources Inc | Bowie, TX 76230 | Oil & Gas Operator | Nov 2017 |
| 20 | DJD Drilling Corporation | Graham, TX 76450 | Oil Operator | Jan 2010 |
| 21 | DM Backhoe Service | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 22 | Dominion Natural Resources LLC | Dallas, TX 75367 | Oil & Gas Operator | Oct 2025 |
| 23 | Double Barrel Operating Limited Liability Company | Wichita Falls, TX 76308 | Oil Operator | Oct 2025 |
| 24 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Oct 2025 |
| 25 | Double S Operating Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 26 | Dove Creek Resources, LLC | Arlington, TX 76012 | Oil Operator | Oct 2025 |
| 27 | Dry Creek Operating, LLC | Fort Worth, TX 76109 | Oil & Gas Operator | Oct 2025 |
| 28 | Dry Fork Production Co | Wichita Falls, TX 76301 | Oil Operator | Apr 2003 |
| 29 | Dry Fork Production Co., LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 2025 |
| 30 | DWP Oil & Gas | Wichita Falls, TX 76309 | Oil & Gas Operator | Oct 2025 |
| 31 | Dym Energy, Inc. | Celina, TX 75009 | Oil & Gas Operator | Apr 2018 |
| 32 | Dynamic Production, Inc. | Fort Worth, TX 76106 | Oil & Gas Operator | Oct 2025 |