| 1 | Daesung Energy Resources Inc. | Dallas, TX 75206 | Oil & Gas Operator | Apr 2024 |
| 2 | Dakota Resources, Inc. (I) | Midland, TX 79707 | Oil & Gas Operator | Apr 2024 |
| 3 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 4 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Dec 2023 |
| 5 | Delray Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Apr 2024 |
| 6 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 7 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2024 |
| 8 | Diamond S Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Apr 2024 |
| 9 | Diasu Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 10 | Discovery Operating Inc | Midland, TX 79705 | Oil & Gas Operator | Apr 2024 |
| 11 | Dittman, D. W. | Big Lake, TX 76932 | Oil & Gas Operator | Mar 2007 |
| 12 | Diversified Operating Corporation | Golden, CO 80401 | Oil & Gas Operator | Oct 2012 |
| 13 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 14 | DPMP Energy LLC | Prosper, TX 75078 | Oil & Gas Operator | Dec 2023 |
| 15 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |