| 701 | Demo Oil Co | | Oil Operator | Jan 2020 |
| 702 | Demoss, L. V. | Graham, TX 76450 | Oil & Gas Operator | May 2004 |
| 703 | Dempsey & Rowe | | Oil Operator | Aug 1986 |
| 704 | Dempsey, Wayne L | | Oil & Gas Operator | Mar 2011 |
| 705 | Den Cal, Inc. | Borger, TX 79007 | Oil & Gas Operator | Dec 2025 |
| 706 | Den-Kay Corp. | Plano, TX 75074 | Oil Operator | Aug 2009 |
| 707 | Denali Exploration, Inc. | Amarillo, TX 79109 | Oil & Gas Operator | Nov 2018 |
| 708 | Denali Oil & Gas Management LLC | Houston, TX 77060 | Oil & Gas Operator | Dec 2012 |
| 709 | Denali Petroleum, LLC | Arlington, TX 76006 | Oil Operator | Mar 2021 |
| 710 | Denbury Management, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Dec 1999 |
| 711 | Denbury Offshore, Inc. | | Oil & Gas Operator | Nov 2004 |
| 712 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Dec 2025 |
| 713 | Denbury Resources Inc. | Plano, TX 75024 | Oil & Gas Operator | Dec 2003 |
| 714 | Denchfield, Fred | Neal, KS 66863 | Oil Operator | Dec 1997 |
| 715 | Denex Petroleum Corp. | Buckhannon, WV 26201 | Oil & Gas Operator | Dec 2021 |
| 716 | Denex, Inc. | | Oil & Gas Operator | Jul 1983 |
| 717 | Denham Danny D | Kellyville, OK 74039 | Oil & Gas Operator | Oct 2025 |
| 718 | Denham Operating Company | Tulsa, OK 74101-3627 | Oil & Gas Operator | Aug 2022 |
| 719 | Denhart & Denhart | Brownwood, TX 76804 | Oil & Gas Operator | Dec 2001 |
| 720 | Deni Frank R | | Oil Operator | Dec 2022 |
| 721 | Denis Roberts Oil | | Oil Operator | Sep 2025 |
| 722 | Denman J M Oil C | | Oil Operator | Mar 1994 |
| 723 | Denman-Friesen Co. | Lufkin, TX 75901 | Oil & Gas Operator | Nov 2006 |
| 724 | Denmark Oil | Wichita, KS 67212 | Oil & Gas Operator | May 2000 |
| 725 | Dennett'S Inc | Enid, OK 73701-1851 | Oil & Gas Operator | Apr 2014 |
| 726 | Denney Don | Citrus Heights, CA 95611-2473 | Oil Operator | Aug 2023 |
| 727 | Dennis & Broun | Bullard, TX 75757 | Oil & Gas Operator | Sep 2003 |
| 728 | Dennis & Davis Oil Co. | Nocona, TX 76255 | Oil & Gas Operator | Dec 2025 |
| 729 | Dennis Don Oil Company | Grady, OK 73569-9998 | Oil Operator | Jan 2002 |
| 730 | Dennis Fitzpatrick Rev. Trust | Sterling, KS 67579 | Gas Operator | Sep 2025 |
| 731 | Dennis Langlitz | Carlsbad, NM 88220 | Oil Operator | Jul 2009 |
| 732 | Dennis Lloyd D | Fleming, OH 45729 | Oil & Gas Operator | Dec 2024 |
| 733 | Dennis Oil & Gas LLC | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2024 |
| 734 | Dennis, Don | Grady, OK 73545 | Oil & Gas Operator | Mar 1998 |
| 735 | Dennison George | Tulsa, OK 74112-6732 | Oil & Gas Operator | Apr 2020 |
| 736 | Denny'S Inc. | Horseshoe Bay, TX 78657 | Oil & Gas Operator | Dec 2000 |
| 737 | Denny, Arthur Gene | Independence, KS 67301 | Oil Operator | Oct 1996 |
| 738 | Denoco Inc. | Plano, TX 75086 | Oil & Gas Operator | Mar 2008 |
| 739 | Denova | | Oil Operator | Jan 1989 |
| 740 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 741 | Denpac Corporation | Colorado SPGS, CO 80922 | Oil & Gas Operator | Dec 2025 |
| 742 | Densmore, Winfield F. Densmore, Debra L. | Lakewood, NY 14750 | Gas Operator | Dec 2024 |
| 743 | Denteco Oil Company LLC | Abilene, TX 79604 | Oil & Gas Operator | Dec 2025 |
| 744 | Denton Exploration, Inc. | Dallas, TX 75219 | Oil & Gas Operator | Dec 2025 |
| 745 | Denton Oil & Gas | Argyle, TX 76226 | Oil Operator | Dec 2014 |
| 746 | Denver Energy Exploration,LLC | Canyon Lake, TX 78133 | Oil Operator | Dec 2025 |
| 747 | Denveramerican Petro LLC | | Oil & Gas Operator | May 2006 |
| 748 | Denveramerican Petroleum, A LTD Liability Co | Denver, CO 80203 | Oil & Gas Operator | Sep 1997 |
| 749 | Department Of Conservation | | Oil Operator | Dec 2005 |
| 750 | Department Of Energy | Casper, WY 82601 | Oil & Gas Operator | Jan 2015 |
| 751 | Depco Inc. | Denver, CO 80202 | Oil & Gas Operator | Apr 2014 |
| 752 | Depco, Inc. & Texas Pacific Oil Co. | | Oil Operator | Jul 1995 |
| 753 | Depriest, Howard Joseph & Susan M. | East Aurora, NY 14052 | Gas Operator | Dec 2024 |
| 754 | Depuy Drilling Co | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 755 | Derae Oil Company | Seminole, OK 74868-2617 | Oil & Gas Operator | Feb 1997 |
| 756 | Deran Resources, Inc. | Spencer, WV 25276 | Oil & Gas Operator | Dec 2021 |
| 757 | Derby Exploration LLC | Okc, OK 73102 | Oil & Gas Operator | Nov 2025 |
| 758 | Derby Oil & Gas Corp | Cumberland, OH 43732 | Oil & Gas Operator | Dec 1986 |
| 759 | Derby Oil Of Texas | Ventura, CA 93003 | Oil & Gas Operator | May 1996 |
| 760 | Derby Operating Corp | Wooster, OH 44691 | Oil & Gas Operator | Dec 2024 |
| 761 | Dernick Resources Inc | Dallas, TX 75204 | Oil & Gas Operator | Jan 2002 |
| 762 | Derrick Exploration, Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Jan 2003 |
| 763 | Derrick Oil & Gas, Inc. | Rosharon, TX 77583 | Oil & Gas Operator | Aug 2003 |
| 764 | Derrick Petroleu | | Oil Operator | Sep 1994 |
| 765 | Derrick Petroleum Inc | Bladensburg, OH 43005 | Oil & Gas Operator | Dec 2024 |
| 766 | Derrick Resources Inc | Henryetta, OK 74437-4249 | Oil & Gas Operator | Oct 2025 |
| 767 | Derrick-Amer Oil | | Oil Operator | Dec 1991 |
| 768 | Derwen Operating Company | Houston, TX 77098 | Gas Operator | Dec 2009 |
| 769 | Des Oil Inc/Osage Only | | Oil Operator | Nov 1998 |
| 770 | Desana Development Corporation | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 771 | Desco Corp | Columbus, OH 43085 | Oil & Gas Operator | Dec 1989 |
| 772 | Desco Oil Company | Houston, TX 77056 | Oil & Gas Operator | Feb 2017 |
| 773 | Desco-Medders | | Oil & Gas Operator | Jun 1984 |
| 774 | Desert Eagle Operating LLC | | Gas Operator | Oct 2025 |
| 775 | Desert Mountain Energy Corp. | Carson, NV 89701 | Gas Operator | Nov 2025 |
| 776 | Desert Production, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 777 | Desert States Energy, Inc. | Hobbs, NM 88240 | Oil & Gas Operator | Aug 1995 |
| 778 | Deshal Energy LLC | Oklahoma City, OK 73170 | Oil Operator | Aug 2025 |
| 779 | Deshazo Production Company | Dewey, OK 74029-2811 | Oil & Gas Operator | Nov 2005 |
| 780 | Deshields Gary | Atwood, OK 74827 | Oil Operator | Aug 2025 |
| 781 | Deshields Oil & Gas Inc | Okemah, OK 74859-9612 | Oil & Gas Operator | Sep 2014 |
| 782 | Desoto Gas Corporation | | Oil & Gas Operator | Oct 1986 |
| 783 | Desoto Gas Prod Co Inc-Zadeck | | Gas Operator | Jan 1990 |
| 784 | Desoto Gas Producing Co. Inc | | Oil & Gas Operator | Jan 1990 |
| 785 | Desoto Oil & Gas Corporation | | Oil & Gas Operator | Dec 1990 |
| 786 | Desperation Oil & Gas Co. | | Gas Operator | Jan 1989 |
| 787 | Despot Expl. Inc-Serio Expl Co | | Oil & Gas Operator | Apr 1990 |
| 788 | Despot Exploration, Inc. | | Oil & Gas Operator | Apr 1990 |
| 789 | Despot Production Company | | Oil & Gas Operator | May 1983 |
| 790 | Despot, Inc. | | Oil & Gas Operator | Mar 1983 |
| 791 | Destin Corporation | Enid, OK 73702-2403 | Oil & Gas Operator | Mar 2005 |
| 792 | Destin Operating Company, Inc. | | Oil & Gas Operator | Jan 2023 |
| 793 | Destin Resources LLC | | Gas Operator | Jul 2018 |
| 794 | Destiny Inc | Sprankle Mills, PA 15776-9705 | Gas Operator | Dec 2009 |
| 795 | Destiny Petroleum LLC | The Woodlands, TX 77381 | Oil & Gas Operator | May 2024 |
| 796 | Destiny Services LLC | Pratt, KS 67124 | Oil & Gas Operator | Jan 2024 |
| 797 | Dette Oil Corporation | Oklahoma City, OK 73162-6249 | Oil & Gas Operator | Oct 2015 |
| 798 | Deuble, Adam And Misty Pennington | Jamestown, NY 14701 | Gas Operator | Dec 2024 |
| 799 | Deuel Arch W | | Oil & Gas Operator | Aug 1995 |
| 800 | Deuel Pet. Co. Inc. | | Oil & Gas Operator | Dec 2005 |