| 601 | Delgado, Emil A | San Antonio, TX 78223 | Oil & Gas Operator | Sep 2016 |
| 602 | Delhi Gas Pipeli | | Gas Operator | Aug 1998 |
| 603 | Delhi Gas Pipeline Corporation | Palestine, TX 75802 | Oil & Gas Operator | Feb 1998 |
| 604 | Delhi Pipeline | | Oil & Gas Operator | Sep 1999 |
| 605 | Delhi-Taylor Oil Corp | | Oil & Gas Operator | Dec 1974 |
| 606 | Delhi-Trading LLC | Durango, CO 81301 | Oil & Gas Operator | Dec 2023 |
| 607 | Dell Charles E | Cleveland, OK 74020-0090 | Oil & Gas Operator | Feb 2015 |
| 608 | Dell-Ray Investments, Inc. | Nickerson, KS 67561 | Oil Operator | Dec 2019 |
| 609 | Delmar Operating, Inc. | Houston, TX 77010 | Oil & Gas Operator | Oct 1996 |
| 610 | Delone, M S | El Dorado, AR 71730 | Oil & Gas Operator | Jan 2024 |
| 611 | Delong Oil & Gas Serv Inc | Drumright, OK 74030-0591 | Oil & Gas Operator | Nov 2023 |
| 612 | Delong Ralph J | Sapulpa, OK 74066 | Oil & Gas Operator | Nov 2005 |
| 613 | Delong, Ralph S | | Oil & Gas Operator | Jul 2023 |
| 614 | Delozier, Orval & Stevens, Floyd, A General Partnership | Dewey, OK 74029 | Oil Operator | Nov 2009 |
| 615 | Delphi International, Inc. | Tulsa, OK 74104 | Oil Operator | Dec 2023 |
| 616 | Delphi Oil And Gas LLC | | Oil Operator | Dec 2023 |
| 617 | Delphi Oil, Inc. | Delphi, IN 46923 | Oil & Gas Operator | Nov 2023 |
| 618 | Delray Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Apr 2024 |
| 619 | Delta C02, LLC | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2021 |
| 620 | Delta D Operations | Wilson, OK 73463 | Oil & Gas Operator | Jul 2014 |
| 621 | Delta D Operations Inc | Ardmore, OK 73401-8678 | Oil & Gas Operator | Apr 2014 |
| 622 | Delta Development Co. Inc. | | Oil & Gas Operator | Dec 1988 |
| 623 | Delta Energy Resources, Inc. | | Oil & Gas Operator | Jun 1990 |
| 624 | Delta Expl.& Development Corp. | | Oil & Gas Operator | Dec 2023 |
| 625 | Delta Exploration Company Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 2024 |
| 626 | Delta Exploration, LLC | Fredericksbrg, TX 78624 | Oil Operator | Apr 2024 |
| 627 | Delta Oil | Holliday, TX 76366 | Oil & Gas Operator | Sep 2005 |
| 628 | Delta Oil & Gas Company | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2003 |
| 629 | Delta Oil & Gas LTD. | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2024 |
| 630 | Delta Oil Co Inc | | Oil & Gas Operator | Oct 2023 |
| 631 | Delta Operating Company | | Oil Operator | Mar 1987 |
| 632 | Delta Operating Corporation | | Oil & Gas Operator | Dec 2023 |
| 633 | Delta Petro Corp Of Colorado | Houston, TX 77010-3089 | Gas Operator | Dec 2003 |
| 634 | Delta Petroleum Company | Houston, TX 77267 | Oil Operator | Aug 1996 |
| 635 | Delta Petroleum Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 636 | Delta Petroleum Corp Of Co | | Oil & Gas Operator | Oct 2010 |
| 637 | Delta Petroleum Inc | Houston, TX 77269-1007 | Oil & Gas Operator | May 2009 |
| 638 | Delta Production Services, LLC | | Oil & Gas Operator | Sep 2002 |
| 639 | Delta Royalties LLC | | Oil & Gas Operator | Dec 2023 |
| 640 | Delta Sierra Oil & Gas LLC | | Gas Operator | Jan 2018 |
| 641 | Deltaus Corporation | | Oil & Gas Operator | Oct 1985 |
| 642 | Deltex Minerals Inc. | Peachtree Cty, GA 30269 | Oil & Gas Operator | Apr 2024 |
| 643 | Deltex Petroleum | | Oil Operator | Nov 1994 |
| 644 | Delwintex Oil & Gas Prop., Inc. | Lubbock, TX 79423 | Oil & Gas Operator | Aug 2003 |
| 645 | Dem Operations Inc | Lamont, OK 74643-5010 | Oil & Gas Operator | Jan 2024 |
| 646 | Demambro, Gene Brian | Mayville, NY 14757 | Gas Operator | Dec 2022 |
| 647 | Demand Energy, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Jul 1999 |
| 648 | Demco Oil & Gas Company | Blackwell, OK 74631-4203 | Oil & Gas Operator | Dec 2023 |
| 649 | Demers - Fleming | Wichita Falls, TX 76305 | Oil & Gas Operator | Mar 2008 |
| 650 | Demier Oil Company | Tulsa, OK 74105-2128 | Oil & Gas Operator | Nov 2008 |
| 651 | Deminex U.S. Oil Company | | Oil & Gas Operator | Jan 1998 |
| 652 | Demiran Production, Inc. | | Oil Operator | Mar 2008 |
| 653 | Demo Oil Co | | Oil Operator | Jan 2020 |
| 654 | Demoss, L. V. | Graham, TX 76450 | Oil & Gas Operator | May 2004 |
| 655 | Dempsey & Rowe | | Oil Operator | Aug 1986 |
| 656 | Dempsey, Wayne L | | Oil & Gas Operator | Mar 2011 |
| 657 | Den Cal, Inc. | Borger, TX 79007 | Oil & Gas Operator | Apr 2024 |
| 658 | Den-Kay Corp. | Plano, TX 75074 | Oil Operator | Aug 2009 |
| 659 | Denali Exploration, Inc. | Amarillo, TX 79109 | Oil & Gas Operator | Nov 2018 |
| 660 | Denali Oil & Gas Management, LLC | Houston, TX 77060 | Oil & Gas Operator | Dec 2012 |
| 661 | Denali Petroleum, LLC | Arlington, TX 76006 | Oil Operator | Mar 2021 |
| 662 | Denbury Management, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Dec 1999 |
| 663 | Denbury Offshore, Inc. | | Oil & Gas Operator | Nov 2004 |
| 664 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Apr 2024 |
| 665 | Denbury Resources Inc. | Plano, TX 75024 | Oil & Gas Operator | Dec 2003 |
| 666 | Denchfield, Fred | Neal, KS 66863 | Oil Operator | Dec 1997 |
| 667 | Denell Oil Corporation | Yukon, OK 73085 | Oil & Gas Operator | Jul 1994 |
| 668 | Denex Petroleum Corp. | Buckhannon, WV 26201 | Oil & Gas Operator | Dec 2021 |
| 669 | Denham Danny D | Kellyville, OK 74039-0638 | Oil & Gas Operator | Dec 2023 |
| 670 | Denham Operating Company | Tulsa, OK 74101-3627 | Oil & Gas Operator | Aug 2022 |
| 671 | Denhart & Denhart | Brownwood, TX 76804 | Oil & Gas Operator | Dec 2001 |
| 672 | Deni Frank R | | Oil Operator | Dec 2022 |
| 673 | Denis Roberts Oil | | Oil Operator | Dec 2023 |
| 674 | Denman J M Oil C | | Oil Operator | Mar 1994 |
| 675 | Denman-Friesen Co. | Lufkin, TX 75901 | Oil & Gas Operator | Nov 2006 |
| 676 | Denmark Oil | Wichita, KS 67212 | Oil & Gas Operator | May 2000 |
| 677 | Dennett'S Inc | Enid, OK 73701-1851 | Oil & Gas Operator | Apr 2014 |
| 678 | Denney Don | Citrus Heights, CA 95611-2473 | Oil Operator | Aug 2023 |
| 679 | Dennis & Broun | Bullard, TX 75757 | Oil & Gas Operator | Sep 2003 |
| 680 | Dennis & Davis Oil Co | Nocona, TX 76255 | Oil & Gas Operator | Apr 2024 |
| 681 | Dennis & Eckhardt Management, LLC | Oklahoma City, OK 73118 | Gas Operator | Jan 2024 |
| 682 | Dennis Don Oil Company | Grady, OK 73569-9998 | Oil Operator | Jan 2002 |
| 683 | Dennis Fitzpatrick Rev. Trust | Sterling, KS 67579 | Gas Operator | Dec 2023 |
| 684 | Dennis Langlitz | Carlsbad, NM 88220 | Oil Operator | Jul 2009 |
| 685 | Dennis Lloyd D | Fleming, OH 45729 | Oil & Gas Operator | Dec 2023 |
| 686 | Dennis Oil & Gas LLC | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2022 |
| 687 | Dennis, Don | Grady, OK 73545 | Oil & Gas Operator | Mar 1998 |
| 688 | Dennison George | Tulsa, OK 74112-6732 | Oil & Gas Operator | Apr 2020 |
| 689 | Denny'S Inc. | Horseshoe Bay, TX 78657 | Oil & Gas Operator | Dec 2000 |
| 690 | Denny, Arthur Gene | Independence, KS 67301 | Oil Operator | Oct 1996 |
| 691 | Denoco Inc. | Plano, TX 75086 | Oil & Gas Operator | Mar 2008 |
| 692 | Denova | | Oil Operator | Jan 1989 |
| 693 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 694 | Denpac Corporation | Colorado SPGS, CO 80922 | Oil & Gas Operator | Apr 2024 |
| 695 | Densmore, Winfield F. Densmore, Debra L. | Lakewood, NY 14750 | Gas Operator | Dec 2022 |
| 696 | Denteco Oil Company LLC | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 697 | Denton Exploration, Inc. | Dallas, TX 75219 | Oil & Gas Operator | Apr 2024 |
| 698 | Denton Oil & Gas | Argyle, TX 76226 | Oil Operator | Dec 2014 |
| 699 | Denver Energy Exploration,LLC | Canyon Lake, TX 78133 | Oil Operator | Apr 2024 |
| 700 | Denveramerican Petro LLC | | Oil & Gas Operator | May 2006 |