| 1 | D & D Oil Company | Dayton, TX 77535 | Oil & Gas Operator | Oct 2025 |
| 2 | D J Production | Pasadena, TX 77502 | Oil & Gas Operator | Mar 2025 |
| 3 | D-Mil Production Inc | Argyle, TX 76226 | Oil & Gas Operator | Oct 2025 |
| 4 | Dartex Energy Corporation | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 5 | Davis, Roland C. | Hardin, TX 77561 | Oil & Gas Operator | May 1997 |
| 6 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Oct 2025 |
| 7 | De-Vac Inc. | Daisetta, TX 77533 | Oil Operator | Oct 2025 |
| 8 | Delta Exploration Company Inc | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 9 | Denali Oil & Gas Management, LLC | Houston, TX 77060 | Oil & Gas Operator | Dec 2012 |
| 10 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 11 | Devon Energy Operating Co., L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2009 |
| 12 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 13 | Dewbre Petroleum Corporation | Corpus Chrsti, TX 78404 | Oil & Gas Operator | Oct 2025 |
| 14 | Diamond S Masada LLC | Magnolia, TX 77354 | Oil & Gas Operator | Oct 2025 |
| 15 | DJH Oil & Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 16 | Doggy Oil Corp | Decatur, GA 30031 | Oil & Gas Operator | Oct 2025 |
| 17 | Dogwood Operating Company, Inc. | Houston, TX 77069 | Oil & Gas Operator | Oct 2025 |
| 18 | Dominion Corporation | Houston, TX 77001 | Oil & Gas Operator | Dec 2010 |
| 19 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 20 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 21 | Dorough, Lee Operations | Orlando, FL 32801 | Oil & Gas Operator | Oct 2025 |
| 22 | Douglas Petroleum Inc. | Spring, TX 77379 | Oil & Gas Operator | Nov 2010 |
| 23 | Draco Energy, Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 24 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 25 | Drum Oil & Gas, Inc. | Houston, TX 77082 | Oil & Gas Operator | Oct 2025 |
| 26 | Drum, Delton | Liberty, TX 77575 | Oil & Gas Operator | Jul 2005 |
| 27 | DSTJ Corporation | Montgomery, TX 77316 | Oil & Gas Operator | Mar 2001 |
| 28 | DSW Production Corp. | Houston, TX 77265 | Oil & Gas Operator | Oct 2025 |
| 29 | Duncan Energy LLC | Dallas, TX 75231 | Oil & Gas Operator | Oct 2025 |
| 30 | Dynamic Production, Inc. | Fort Worth, TX 76106 | Oil & Gas Operator | Oct 2025 |