| 601 | Noble Energy Production Inc | Houston, TX 77067 | Oil & Gas Operator | Mar 2025 |
| 602 | Noco Investment Company Inc | Tulsa, OK 74159-0470 | Oil & Gas Operator | Mar 2005 |
| 603 | North Lake Resources LLC | Oklahoma City, OK 73132 | Oil & Gas Operator | Mar 2025 |
| 604 | Northwest Oil Company | Dallas, TX 75204 | Oil & Gas Operator | Jun 2014 |
| 605 | Nova Energy Corporation | Denver, CO 80201 | Oil & Gas Operator | Jun 2003 |
| 606 | NWM Operating Inc | Okeene, OK 73763 | Oil & Gas Operator | Jan 2025 |
| 607 | O G & E | Oklahoma City, OK 73124 | Oil & Gas Operator | Feb 2014 |
| 608 | O K Swabbing Inc | Hennessey, OK 73742 | Oil & Gas Operator | Dec 2024 |
| 609 | O'Neill Properties, LTD. | Midland, TX 79702 | Oil & Gas Operator | Mar 2025 |
| 610 | Oak Valley SWD LLC | Enid, OK 73703-4637 | Oil Operator | Aug 2022 |
| 611 | Odessa Oil Investment Co., Inc. | Odessa, TX 79762 | Oil & Gas Operator | Nov 2016 |
| 612 | Oexco, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 613 | Ofs-Tulsa Corporation | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 1997 |
| 614 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | Mar 2025 |
| 615 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2024 |
| 616 | Oklahoma & Northwestern Co. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 1997 |
| 617 | Oklahoma Energy Acquisitions LP | Houston, TX 77094-1900 | Oil & Gas Operator | Dec 2024 |
| 618 | Oklahoma Equipment & Salvage | Oklahoma City, OK 73120-5903 | Oil & Gas Operator | Mar 2015 |
| 619 | Oklahoma Natural Resources Inc | Woodward, OK 73801 | Oil & Gas Operator | Sep 1996 |
| 620 | Oklahoma Oil & Gas MGMT Inc | Edmond, OK 73083-6786 | Oil & Gas Operator | Dec 2024 |
| 621 | Oklahoma Oil Tactics Inc | Edmond, OK 73003-1351 | Oil & Gas Operator | Mar 2015 |
| 622 | Oklahoma Rig & Salvage, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2015 |
| 623 | Olympia Oil Inc | Edmond, OK 73083-7088 | Oil & Gas Operator | Jul 2020 |
| 624 | Omimex International Corp | Fort Worth, TX 76103-2300 | Oil & Gas Operator | Dec 2024 |
| 625 | Omni Oil & Gas, Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2017 |
| 626 | Oneok Exploration Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 627 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2022 |
| 628 | Oneok Gas Transportation Co | Tulsa, OK 74121-2089 | Oil & Gas Operator | Oct 2014 |
| 629 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 630 | Onyx Energy Corporation | Oklahoma City, OK 73157 | Oil & Gas Operator | May 1994 |
| 631 | Onyx Properties Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | May 2006 |
| 632 | Osage Oil & Transportation Inc | Cleveland, OK 74020 | Oil & Gas Operator | Nov 2000 |
| 633 | Osborn Heirs Co | San Antonio, TX 78217 | Oil & Gas Operator | Jan 2025 |
| 634 | Otc Petroleum Corporation | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 635 | Overflow Energy Stack LLC | Booker, TX 79005 | Oil Operator | Sep 2022 |
| 636 | Overflow Energy, LLC | Booker, TX 79005 | Oil & Gas Operator | Mar 2025 |
| 637 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Jan 2025 |
| 638 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Mar 2025 |
| 639 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Mar 2025 |
| 640 | Pacific Enterprises Royalty Co | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2002 |
| 641 | Palm Oil & Gas Company | Sedona, AZ 86340 | Oil & Gas Operator | Jan 2025 |
| 642 | Paloma Operating Co Inc | Houston, TX 77002-5220 | Oil & Gas Operator | Dec 2024 |
| 643 | Pantera Energy Company | Amarillo, TX 79101 | Oil & Gas Operator | Mar 2025 |
| 644 | Pappe Court Jr | Kingfisher, OK 73750-0688 | Oil & Gas Operator | Nov 2001 |
| 645 | Paragon Production Company | Edmond, OK 73013-5051 | Oil & Gas Operator | Feb 2021 |
| 646 | Parker & Parsley Dev Co | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 647 | Parker & Parsley Dev LP | Irving, TX 75039-3745 | Oil & Gas Operator | Mar 2015 |
| 648 | Pasco Oil Company | Oklahoma City, OK 73172-0454 | Oil & Gas Operator | Aug 2000 |
| 649 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 650 | Payne Exploration Company | Crescent, OK 73028 | Oil & Gas Operator | Dec 2024 |
| 651 | Payne W C Family Trust | Oklahoma City, OK 73116-9044 | Oil & Gas Operator | Mar 2015 |
| 652 | Payrock Energy LLC | Oklahoma City, OK 73134-2612 | Oil & Gas Operator | Feb 2023 |
| 653 | PCX Corporation | | Oil & Gas Operator | Feb 1994 |
| 654 | Pearl Oil Company | Nichols Hills, OK 73120-1408 | Oil & Gas Operator | Nov 2023 |
| 655 | Pedestal Oil Company Inc | Oklahoma City, OK 73101-1522 | Oil & Gas Operator | May 2019 |
| 656 | Pegasus Energy Corporation | Oklahoma City, OK 73162 | Oil & Gas Operator | Mar 2015 |
| 657 | Penn VIrginia MC Operating Co LLC | Houston, TX 77084-7213 | Oil & Gas Operator | Dec 2024 |
| 658 | Penner Energy Inc | Oklahoma City, OK 73120-1930 | Oil & Gas Operator | Jan 2025 |
| 659 | Pennmark Resources Company | Edmond, OK 73013 | Oil & Gas Operator | Dec 2024 |
| 660 | Pet-Ex, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Nov 2024 |
| 661 | Petro Speed Inc | Norman, OK 73069-8116 | Oil & Gas Operator | Mar 2015 |
| 662 | Petro-Management Assoc., Inc. | Edmond, OK 73083-2346 | Oil & Gas Operator | Jun 2007 |
| 663 | Petrodudes | Crescent, OK 73028-8706 | Oil & Gas Operator | Aug 2024 |
| 664 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 665 | Petroleum Investment Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Nov 1998 |
| 666 | Petroleum Management Prof Inc | Oklahoma City, OK 73120-1848 | Oil & Gas Operator | Apr 2009 |
| 667 | Petroleum Production MGMT., Inc. | Kansas City, MO 64112 | Oil & Gas Operator | Mar 2025 |
| 668 | Petroleum Properties MGMT. Co. | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2014 |
| 669 | Petroleum Reserve Corporation | Plymouth MTNG, PA 19462 | Oil & Gas Operator | May 2008 |
| 670 | Petrolia Drilling Corporation | | Oil & Gas Operator | Jul 2003 |
| 671 | Petromark Exploration Company | | Oil & Gas Operator | Nov 2001 |
| 672 | Phillips Oil Operating Co | Enid, OK 73703-4921 | Oil & Gas Operator | May 2019 |
| 673 | Pioneer Natural Res. USA, Inc. | Irving, TX 75038 | Oil & Gas Operator | Mar 2025 |
| 674 | Pioneer Trucking LLC | Oklahoma City, OK 73162 | Oil Operator | Jan 2025 |
| 675 | Plains Marketing, LP | Cushing, OK 74023 | Oil & Gas Operator | Dec 2022 |
| 676 | Plainsmen Energy LLC | Enid, OK 73703-5747 | Oil & Gas Operator | Jan 2025 |
| 677 | Plotner Ralph Oil & Gas Inv Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Nov 2021 |
| 678 | Polaris Energy Dev Co | Tulsa, OK 74135 | Oil & Gas Operator | Apr 2000 |
| 679 | Post Oak Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Jul 2013 |
| 680 | Potter J And D Oil LLC | Kingfisher, OK 73750-3832 | Oil & Gas Operator | Mar 2015 |
| 681 | Powerline Energy Corporation | Arlington, TX 76015 | Oil & Gas Operator | Mar 2025 |
| 682 | Prentice Napier & Green Inc | Oklahoma City, OK 73142 | Oil & Gas Operator | Jan 2025 |
| 683 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2025 |
| 684 | Primary Natural Resources Inc. | Tulsa, OK 74136-6351 | Oil & Gas Operator | Mar 2023 |
| 685 | Prime Energy Corp | Charleston, WV 25301-1707-1707 | Oil & Gas Operator | Sep 2015 |
| 686 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Mar 2025 |
| 687 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 688 | Proex Energy Management, L.L.C. | Spring, TX 77386 | Oil & Gas Operator | Mar 2025 |
| 689 | Protege Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Jan 2018 |
| 690 | PT II LTD | | Oil & Gas Operator | Oct 2004 |
| 691 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2024 |
| 692 | Quad J Oil & Gas LLC | Crescent, OK 73028 | Oil & Gas Operator | Jan 2025 |
| 693 | Quail Creek Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2025 |
| 694 | Quail Creek Petro MGMT Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Aug 2013 |
| 695 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Dec 2024 |
| 696 | Quest Property Inc | Yukon, OK 73099 | Oil & Gas Operator | Dec 2024 |
| 697 | Questar Energy Trading | Salt Lake City, UT 84145-0601 | Oil & Gas Operator | Mar 2020 |
| 698 | Questar Explor & Prod Co | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2017 |
| 699 | R & A Moore, Inc. | Cleburne, TX 76033 | Oil & Gas Operator | Mar 2025 |
| 700 | R & B Trucking | Crescent, OK 73028-0775 | Oil & Gas Operator | Nov 2021 |