| 1 | D L Operating | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 2 | D. A. B. Oil Service, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Nov 2012 |
| 3 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 4 | Dahab Energy Inc. | Dallas, TX 75225 | Oil & Gas Operator | Feb 2026 |
| 5 | Daily, Carroll | Loving, TX 76460 | Oil & Gas Operator | Sep 2023 |
| 6 | Daleco Resources, Inc. | Lewisville, TX 75067 | Oil & Gas Operator | Mar 2008 |
| 7 | Dales Oil Company | Loving, TX 76460 | Oil Operator | Feb 2026 |
| 8 | Dallas Petroleum Group, LLC | Dallas, TX 75379 | Oil & Gas Operator | Feb 2026 |
| 9 | Dallas Production Company LLC | Dallas, TX 75206 | Oil & Gas Operator | Feb 2026 |
| 10 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 11 | Dallas Royalty, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2012 |
| 12 | Davis, Gowin | Wichita Falls, TX 76308 | Oil & Gas Operator | Mar 2001 |
| 13 | Davis, R. E. Oil & Gas, Inc. | Graham, TX 76450 | Oil & Gas Operator | Oct 2015 |
| 14 | Davis, Robert E. | Graham, TX 76450 | Oil & Gas Operator | Apr 1997 |
| 15 | Dearing, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2021 |
| 16 | Decleva, Paul | Wichita Falls, TX 76302 | Oil & Gas Operator | Dec 2020 |
| 17 | Dedica Energy Corporation | Mattoon, IL 61938 | Oil & Gas Operator | Mar 2008 |
| 18 | Deen Drilling Company | Archer City, TX 76351 | Oil & Gas Operator | Feb 2026 |
| 19 | Del Mar Energy, Inc. | Van Alstyne, TX 75495 | Oil & Gas Operator | Feb 2026 |
| 20 | Delfin Operating, LLC | Dallas, TX 75243 | Oil & Gas Operator | Feb 2026 |
| 21 | Delong, Horace | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 22 | Delta Exploration Company Inc | Denver, CO 80202 | Oil & Gas Operator | Feb 2026 |
| 23 | Demoss, L. V. | Graham, TX 76450 | Oil & Gas Operator | May 2004 |
| 24 | Denton Exploration, Inc. | Dallas, TX 75219 | Oil & Gas Operator | Feb 2026 |
| 25 | Desana Development Corporation | Midland, TX 79701 | Oil & Gas Operator | Feb 2026 |
| 26 | Devon Energy Operating Co., L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2009 |
| 27 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2026 |
| 28 | Devon Gas Services, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Nov 2015 |
| 29 | Diamond S Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Feb 2026 |
| 30 | Diasu Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 31 | Dimock Operating Company | Frisco, TX 75034 | Oil & Gas Operator | Feb 2026 |
| 32 | DJ Resources Inc | Bowie, TX 76230 | Oil & Gas Operator | Nov 2017 |
| 33 | DM Backhoe Service | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 34 | Doc'S Tank Trucks | Jacksboro, TX 76458 | Oil Operator | Jun 2007 |
| 35 | Domestic Crude | Graham, TX 76450 | Oil & Gas Operator | Jul 2000 |
| 36 | Dominion Natural Resources LLC | Dallas, TX 75367 | Oil & Gas Operator | Feb 2026 |
| 37 | Don Bar Investment Company | Windthorst, TX 76389 | Oil & Gas Operator | Feb 2004 |
| 38 | Don Peterson Company, LLC - | Loving, TX 76460 | Oil Operator | Feb 2026 |
| 39 | Dooley, Jeff | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2012 |
| 40 | Double Eagle Exploration Inc | Windthorst, TX 76389 | Oil Operator | Sep 2025 |
| 41 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Feb 2026 |
| 42 | Double L Operating | Graham, TX 76450 | Oil & Gas Operator | Nov 2018 |
| 43 | Douglas Investments Inc | Fort Worth, TX 76137 | Oil Operator | Jan 2020 |
| 44 | Dove Drilling, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Nov 1997 |
| 45 | Drennan, D. E. | Graham, TX 76450 | Oil & Gas Operator | Dec 2011 |
| 46 | Dry Creek Operating, LLC | Fort Worth, TX 76109 | Oil & Gas Operator | Feb 2026 |
| 47 | Dry Fork Production Co., LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 48 | Dte Gas Resources, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2007 |
| 49 | Dte Gas Resources, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2014 |
| 50 | Dual Quiver Oil & Gas Op, LLC | Flower Mound, TX 75027 | Oil & Gas Operator | Feb 2026 |
| 51 | Dynamic Production, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2026 |