| 501 | Shamrock Well Operations LLC | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | May 2025 |
| 502 | Sharber Billy Jack Operating | Konawa, OK 74849-0071 | Oil & Gas Operator | Mar 2015 |
| 503 | Shawver & Son Inc | Oklahoma City, OK 73154-0778 | Oil & Gas Operator | Oct 2024 |
| 504 | Shawver Energy Inc | Oklahoma City, OK 73154-0683 | Oil & Gas Operator | Apr 2014 |
| 505 | Shelburne Oil Company | Oklahoma City, OK 73116-7639 | Gas Operator | Feb 2020 |
| 506 | Shelly Energy Inc. | Berwyn, PA 19312 | Oil & Gas Operator | May 2025 |
| 507 | Sherman Oil & Gas Co Inc | Chandler, OK 74834-0571 | Oil & Gas Operator | Apr 2020 |
| 508 | Shields Energy Inc | Fort Smith, AR 72901-4607 | Oil & Gas Operator | Apr 2025 |
| 509 | Shields Operating, Inc | Fort Smith, AR 72901-3834 | Oil & Gas Operator | Oct 2021 |
| 510 | Shoreline Operating LLC | Oklahoma City, OK 73113 | Oil & Gas Operator | Apr 2025 |
| 511 | Singer Fleischaker Oil Op. Co. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2002 |
| 512 | Singer Joseph B Expl Co | Oklahoma City, OK 73118-7486 | Oil & Gas Operator | Mar 1993 |
| 513 | SNR Operating, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Jul 2025 |
| 514 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 515 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 516 | Sooner Drilling Inc | Shawnee, OK 74802-0037 | Oil & Gas Operator | Jan 2005 |
| 517 | Sorrels J R Dba Cheyenne Oil Properties | Ponca City, OK 74601 | Oil & Gas Operator | Jul 2022 |
| 518 | Southern Resources Inc | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | May 2025 |
| 519 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 520 | SP Energy Development Company | Seattle, WA 98101-3277 | Oil & Gas Operator | Mar 2015 |
| 521 | Sparks Mick Oil Company Inc | Jennings, OK 74038-0250 | Oil & Gas Operator | May 2025 |
| 522 | Sparks Resources Inc | Bristow, OK 74010 | Oil & Gas Operator | May 2025 |
| 523 | Special Energy Corporation | Stillwater, OK 74076 | Oil & Gas Operator | Jul 2025 |
| 524 | Speller Oil Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Apr 2025 |
| 525 | Spess Oil Company Inc | Cleveland, OK 74020-4617 | Oil & Gas Operator | May 2025 |
| 526 | Spindletop Oil & Gas Co. | Dallas, TX 75230 | Oil & Gas Operator | Jul 2025 |
| 527 | Sportsman Oil, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Nov 1998 |
| 528 | Spring Operating Company | Edmond, OK 73034 | Oil & Gas Operator | May 2025 |
| 529 | Spring Valley Oil & Gas Inc | Drummond, OK 73735 | Oil & Gas Operator | May 2025 |
| 530 | Stargas Co | Tulsa, OK 74136-5407 | Oil & Gas Operator | Aug 2013 |
| 531 | Statex Petroleum Inc | Dallas, TX 75229 | Oil & Gas Operator | Dec 2000 |
| 532 | Stauros Operating Company | Edmond, OK 73083-2707 | Oil & Gas Operator | Mar 2001 |
| 533 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Jul 2025 |
| 534 | Stream Energy, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2025 |
| 535 | Sultex Oil & Gas Inc | Houston, TX 77059-3126 | Oil & Gas Operator | Aug 2002 |
| 536 | Sundial Energy LLC | Oklahoma City, OK 73013 | Oil & Gas Operator | May 2025 |
| 537 | Sunterra Energy Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2009 |
| 538 | Superior Midstream, LLC | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2020 |
| 539 | Sutton-Munson Oil | Edmond, OK 73034 | Oil & Gas Operator | Jun 1999 |
| 540 | Sweetwater Exploration LLC | Norman, OK 73069-5636 | Oil & Gas Operator | Apr 2025 |
| 541 | Synergex Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2025 |
| 542 | Tack Operating LLC | Oklahoma City, OK 73172-1492 | Oil & Gas Operator | Aug 2021 |
| 543 | Taylor R C Companies Inc | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | May 2021 |
| 544 | Tbi Exploration Inc | Englewood, CO 801556525 | Oil & Gas Operator | Jun 2011 |
| 545 | TD Operating Inc | Hinton, OK 73047 | Oil & Gas Operator | May 2025 |
| 546 | Te-Ray Resources, LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Jul 2025 |
| 547 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Apr 2025 |
| 548 | Teocalli Exploration LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2025 |
| 549 | Territory Resources LLC | Stillwater, OK 74074-1869 | Oil & Gas Operator | Jun 2025 |
| 550 | Tex-Star Production | Dallas, TX 75206 | Oil & Gas Operator | May 2025 |
| 551 | Tex/Con Oil & Gas Company | Houston, TX 77074 | Oil & Gas Operator | Feb 2001 |
| 552 | TGX Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2004 |
| 553 | The Calvert Company | Oklahoma City, OK 73154-1589 | Oil & Gas Operator | Dec 2021 |
| 554 | The Quintin Little Company Inc | Ardmore, OK 73401 | Oil & Gas Operator | May 2025 |
| 555 | Thomas J L Engineering Inc | Edmond, OK 73003-0026 | Oil & Gas Operator | Jul 2016 |
| 556 | Thompson, Joe L., Inc. | Oklahoma City, OK 73132 | Oil & Gas Operator | Oct 2005 |
| 557 | Thunder Oil & Gas, LLC | Ardmore, OK 73402 | Oil & Gas Operator | Apr 2025 |
| 558 | Tide West Oil Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2021 |
| 559 | Tidemark Exploration Inc | Tulsa, OK 74120 | Oil & Gas Operator | Apr 2019 |
| 560 | TLS Operating Company | Greenwood VIlge, CO 80111 | Oil & Gas Operator | Dec 2013 |
| 561 | TNT Operating Company Inc | Blanchard, OK 73010 | Oil & Gas Operator | Sep 2024 |
| 562 | Toklan Oil And Gas Corporation | Tulsa, OK 74136 | Oil & Gas Operator | May 2025 |
| 563 | Toland & Johnston Inc | Edmond, OK 73034 | Oil & Gas Operator | May 2025 |
| 564 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 565 | Totalfinaelf E&P USA Inc | Houston, TX 77024 | Oil & Gas Operator | Jul 2007 |
| 566 | Trail Ridge Energy Partners, LLC | Grapevine, TX 76051 | Oil & Gas Operator | May 2025 |
| 567 | Trepco Production Company, Inc. | Yukon, OK 73099 | Oil & Gas Operator | Apr 2025 |
| 568 | Triad Energy, Inc. | Oklahoma City, OK 73105-1401 | Oil & Gas Operator | May 2025 |
| 569 | Trinity Bay Oil & Gas, Inc. | Lubbock, TX 79416 | Oil & Gas Operator | Jul 2025 |
| 570 | Triple L Management Co Inc | Edmond, OK 73025-2908 | Oil & Gas Operator | Apr 2018 |
| 571 | Tripower Resources LLC | Ardmore, OK 73402 | Oil & Gas Operator | Jul 2025 |
| 572 | Tripower Resources, Inc. | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2020 |
| 573 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 574 | Txok Energy Resources Company | Tulsa, OK 74172-0140 | Oil & Gas Operator | Feb 2017 |
| 575 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 576 | Underwood Oil And Gas LLC | Chandler, OK 74834-1414 | Oil & Gas Operator | May 2025 |
| 577 | Union Valley Petroleum Corporation | Enid, OK 73701 | Oil & Gas Operator | May 2025 |
| 578 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2025 |
| 579 | Uplands Resources Inc | Tulsa, OK 74103-4141 | Oil & Gas Operator | Apr 2025 |
| 580 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Jul 2025 |
| 581 | Vaquero Resources, LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2025 |
| 582 | Veenker Resources, Inc. | Oklahoma City, OK 73113 | Oil & Gas Operator | May 2025 |
| 583 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Apr 2025 |
| 584 | W C T Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2025 |
| 585 | W M Energy Corp | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2015 |
| 586 | W S Crude Oil Purchasing Inc | Oklahoma City, OK 73129-7613 | Oil & Gas Operator | May 2008 |
| 587 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2025 |
| 588 | Walker Keith F | Ardmore, OK 73401 | Oil & Gas Operator | Jan 2019 |
| 589 | Ward Petroleum Corporation | Enid, OK 73702 | Oil & Gas Operator | Apr 2025 |
| 590 | Wehlu Producers Inc | Edmond, OK 73083-5278 | Oil & Gas Operator | Sep 2002 |
| 591 | Wellco Energy Inc | Harrah, OK 73045 | Oil & Gas Operator | Apr 2025 |
| 592 | Wessely Energy Company | Dallas, TX 75206 | Oil & Gas Operator | May 2001 |
| 593 | Wheeler Richard Jr | Oklahoma City, OK 73112-8857 | Oil & Gas Operator | Mar 2005 |
| 594 | White Goat Resources LLC | Yukon, OK 73099 | Oil & Gas Operator | May 2025 |
| 595 | White Operating Company | Oklahoma City, OK 73159-7136 | Oil & Gas Operator | May 2025 |
| 596 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 597 | Whitmar Exploration Company | Denver, CO 80202 | Oil & Gas Operator | Apr 2025 |
| 598 | Whitmar Operating Company | Tulsa, OK 74103-3515 | Oil & Gas Operator | Apr 2009 |
| 599 | Wilcox Pipe & Supply Co | Oklahoma City, OK 73189 | Oil & Gas Operator | May 2006 |
| 600 | Wildhorse Operating Company | Ardmore, OK 73402 | Oil & Gas Operator | Jul 2025 |