| 1 | D And N Natural Gas Op. Co. Inc. | Plano, TX 75075 | Oil & Gas Operator | Feb 2026 |
| 2 | D-Mil Production Inc | Argyle, TX 76226 | Oil & Gas Operator | Feb 2026 |
| 3 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 4 | Dallas Production Company LLC | Dallas, TX 75206 | Oil & Gas Operator | Feb 2026 |
| 5 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 6 | Dallas Royalty, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2012 |
| 7 | Dedica Energy Corporation | Mattoon, IL 61938 | Oil & Gas Operator | Mar 2008 |
| 8 | Delong, Horace | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 9 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Feb 2026 |
| 10 | Denbury Resources Inc. | Plano, TX 75024 | Oil & Gas Operator | Dec 2003 |
| 11 | Desana Development Corporation | Midland, TX 79701 | Oil & Gas Operator | Feb 2026 |
| 12 | Devon Energy Operating Co., L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2009 |
| 13 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2026 |
| 14 | Devon Gas Services, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Nov 2015 |
| 15 | Diamond Energy, Inc. | Sherman, TX 75091 | Oil & Gas Operator | Feb 2026 |
| 16 | Diamond S Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Feb 2026 |
| 17 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Feb 2026 |
| 18 | DJ Resources Inc | Bowie, TX 76230 | Oil & Gas Operator | Nov 2017 |
| 19 | Doc'S Tank Trucks | Jacksboro, TX 76458 | Oil Operator | Jun 2007 |
| 20 | Dogwood Operating Company, Inc. | Houston, TX 77069 | Oil & Gas Operator | Feb 2026 |
| 21 | Dooley, Jeff | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2012 |
| 22 | Double Diamond Energy Corp. | Granbury, TX 76048 | Gas Operator | Apr 2013 |
| 23 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Feb 2026 |
| 24 | Dte Gas Resources, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2007 |
| 25 | Dte Gas Resources, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2014 |
| 26 | Dual Quiver Oil & Gas Op, LLC | Flower Mound, TX 75027 | Oil & Gas Operator | Feb 2026 |
| 27 | Dynamic Production, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2026 |