| 1 | D & B Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2003 |
| 2 | Dakota Resources, Inc. (I) | Midland, TX 79707 | Oil & Gas Operator | Dec 2024 |
| 3 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 4 | Davcro Inc. | Lubbock, TX 79401 | Oil & Gas Operator | Dec 2003 |
| 5 | Day Resources, Inc. | Midland, TX 79707 | Oil & Gas Operator | Aug 1994 |
| 6 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Sep 2024 |
| 7 | De IV Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Dec 2024 |
| 8 | De3 Operating LLC | Irving, TX 75038 | Oil & Gas Operator | Jun 2021 |
| 9 | Dean Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Nov 2019 |
| 10 | Desana Development Corporation | Midland, TX 79701 | Oil & Gas Operator | Dec 2024 |
| 11 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 12 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2024 |
| 13 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 14 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 15 | DHC, Inc. | Midland, TX 79710 | Oil & Gas Operator | Dec 1997 |
| 16 | Diamond Energy, Inc. | Sherman, TX 75091 | Oil & Gas Operator | Dec 2024 |
| 17 | Diamond S Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Dec 2024 |
| 18 | Diamondback E&P LLC | Midland, TX 79701 | Oil & Gas Operator | Dec 2024 |
| 19 | Dinero Operating Co | Midland, TX 79702 | Oil & Gas Operator | Dec 2024 |
| 20 | Discovery Operating Inc | Midland, TX 79705 | Oil & Gas Operator | Dec 2024 |
| 21 | DJ & T Services, LLC | Abilene, TX 79601 | Oil & Gas Operator | Dec 2024 |
| 22 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 23 | Dominion Operating, LLC | Midland, TX 79708 | Oil Operator | Mar 2018 |
| 24 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Dec 2014 |
| 25 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Dec 2024 |
| 26 | Draco Energy, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2024 |
| 27 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 28 | Drilmor, Inc. | Midland, TX 79701 | Oil & Gas Operator | Feb 1998 |
| 29 | Duncan Drilling Co. | Big Spring, TX 79721 | Oil & Gas Operator | Dec 2024 |
| 30 | Dune Oil And Gas, Inc. | Odessa, TX 79768 | Oil & Gas Operator | Aug 2006 |
| 31 | Durham, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2016 |
| 32 | Dyad Petroleum Company | Midland, TX 79710 | Oil & Gas Operator | Sep 2021 |