| 1 | D & B Oil Company | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 2 | D & H Investments | Jacksboro, TX 76458 | Oil & Gas Operator | Oct 2025 |
| 3 | D & L Operating Co. | Bangs, TX 76823 | Oil & Gas Operator | Nov 2022 |
| 4 | D L Operating | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 5 | D.J. & T. Energy | Abilene, TX 79601 | Oil & Gas Operator | Oct 2025 |
| 6 | D.J.F. Services, Inc. | Holdenville, OK 74848 | Oil & Gas Operator | Oct 2025 |
| 7 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 8 | Dain Oil | Graham, TX 76450 | Oil & Gas Operator | Dec 2007 |
| 9 | Dallas Operating Corp. | Dallas, TX 75205 | Oil & Gas Operator | Nov 2006 |
| 10 | Dallas Production Company LLC | Dallas, TX 75206 | Oil & Gas Operator | Oct 2025 |
| 11 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 12 | Dartex Energy Inc | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 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 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Oct 2025 |
| 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 | Oct 2025 |
| 19 | Delray Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 20 | Delta Oil & Gas Company | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2003 |
| 21 | Delta Oil & Gas LTD. | Breckenridge, TX 76424 | Oil & Gas Operator | Oct 2025 |
| 22 | Demoss, L. V. | Graham, TX 76450 | Oil & Gas Operator | May 2004 |
| 23 | Denman-Friesen Co. | Lufkin, TX 75901 | Oil & Gas Operator | Nov 2006 |
| 24 | Denoco Inc. | Plano, TX 75086 | Oil & Gas Operator | Mar 2008 |
| 25 | Denton Exploration, Inc. | Dallas, TX 75219 | Oil & Gas Operator | Oct 2025 |
| 26 | Derby Oil Of Texas | Ventura, CA 93003 | Oil & Gas Operator | May 1996 |
| 27 | Devon Energy Operating Co., L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2009 |
| 28 | Diamond M DRLG & Expl Co. | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2025 |
| 29 | Dick Lindsay Oil Company, Inc. | Graham, TX 76450 | Oil Operator | Oct 2025 |
| 30 | DJ & T Services, LLC | Abilene, TX 79601 | Oil & Gas Operator | Oct 2025 |
| 31 | DJD Drilling Corporation | Graham, TX 76450 | Oil Operator | Jan 2010 |
| 32 | DM Backhoe Service | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 33 | Dolberry Energy Resources Corp. | Dallas, TX 75252 | Oil Operator | Oct 2025 |
| 34 | Domestic Crude | Graham, TX 76450 | Oil & Gas Operator | Jul 2000 |
| 35 | Dominion Natural Resources LLC | Dallas, TX 75367 | Oil & Gas Operator | Oct 2025 |
| 36 | Don Bar Investment Company | Windthorst, TX 76389 | Oil & Gas Operator | Feb 2004 |
| 37 | Don Peterson Company, LLC - | Loving, TX 76460 | Oil Operator | Oct 2025 |
| 38 | Donnell, Bill | Graham, TX 76450 | Oil & Gas Operator | May 1995 |
| 39 | Donnell, Louis, Jr. | South Bend, TX 76481 | Oil & Gas Operator | Mar 2008 |
| 40 | Dooley, Jeff | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2012 |
| 41 | Double J Enterprises | Loving, TX 76460 | Oil Operator | Oct 2025 |
| 42 | Double K Production | Graham, TX 76450 | Oil & Gas Operator | Sep 2014 |
| 43 | Double L Operating | Graham, TX 76450 | Oil & Gas Operator | Nov 2018 |
| 44 | Double M Petroproperties, Inc. | Haskell, TX 79521 | Oil & Gas Operator | Oct 2025 |
| 45 | Drake Petroleum, LLC | Cypress, TX 77429 | Oil & Gas Operator | Jun 2023 |
| 46 | Drennan, D. E. | Graham, TX 76450 | Oil & Gas Operator | Dec 2011 |
| 47 | Dry Fork Production Co., LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 2025 |
| 48 | Duncan Land & Exploration, Inc. | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |