| 1 | D & B Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2003 |
| 2 | D & G Company | Iraan, TX 79744 | Oil Operator | Apr 2006 |
| 3 | D & V Oil Co., LP | San Angelo, TX 76909 | Oil & Gas Operator | Jan 2019 |
| 4 | D And B Oil | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 5 | D G D Oil Co. | Imperial, TX 79743 | Oil & Gas Operator | Oct 2025 |
| 6 | D90 Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 7 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 8 | Dameron Petroleum Corp. | Midland, TX 79708 | Oil & Gas Operator | Oct 2025 |
| 9 | Darkens Oil & Gas Inc. | MC Camey, TX 79752 | Oil & Gas Operator | Oct 2025 |
| 10 | Davidson, Dan | Ozona, TX 76943 | Oil & Gas Operator | Oct 2025 |
| 11 | Dawson Operating Company | Midland, TX 79702 | Oil & Gas Operator | Dec 1994 |
| 12 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 13 | Delhi Gas Pipeline Corporation | Palestine, TX 75802 | Oil & Gas Operator | Feb 1998 |
| 14 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 15 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 16 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 17 | Devx Operating Company | Frisco, TX 75034 | Oil & Gas Operator | Feb 2004 |
| 18 | Diamond S Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Oct 2025 |
| 19 | Diamondback E&P LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 20 | Digital Operating Company LLC | Boerne, TX 78006 | Oil & Gas Operator | Oct 2025 |
| 21 | Dinero Operating Co | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 22 | Discovery Natural Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 23 | Dittman, D. W. | Big Lake, TX 76932 | Oil & Gas Operator | Mar 2007 |
| 24 | DJH Oil & Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 25 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Oct 2025 |
| 26 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Aug 2025 |
| 27 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 28 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 29 | DPMP Energy LLC | Prosper, TX 75078 | Oil & Gas Operator | Dec 2023 |
| 30 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 31 | Driscoll S.W.D. Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2025 |
| 32 | Dune Oil And Gas, Inc. | Odessa, TX 79768 | Oil & Gas Operator | Aug 2006 |
| 33 | Dune Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 1997 |
| 34 | Durham, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2016 |
| 35 | Dyad Petroleum Company | Midland, TX 79710 | Oil & Gas Operator | Sep 2021 |