| 501 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 502 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | May 2025 |
| 503 | RMS Monte Christo, LLC | Snowmass VLG., CO 81615 | Oil & Gas Operator | Mar 2023 |
| 504 | Rockford Energy Partners III,LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2012 |
| 505 | Roff Operating Company LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 506 | Rosewood Resources, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Jul 2025 |
| 507 | RTC Resources, LLP | Weatherford, OK 73096 | Oil & Gas Operator | Jul 2025 |
| 508 | Rue Johnny B | Duncan, OK 73533-2019 | Oil & Gas Operator | Jan 2025 |
| 509 | Rupe Oil Company, Inc. | Wichita, KS 67278 | Oil & Gas Operator | Mar 2025 |
| 510 | S A C Operating Inc | Woodward, OK 73802-1749 | Oil & Gas Operator | Jan 1999 |
| 511 | Sabine Oil & Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2017 |
| 512 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2025 |
| 513 | Samson Gas Producing Company | Tulsa, OK 74103 | Oil & Gas Operator | May 2001 |
| 514 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 515 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 516 | Sandlot Oil & Gas LLC | Gruver, TX 79040 | Oil & Gas Operator | Jul 2025 |
| 517 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Jul 2025 |
| 518 | Sanguine Gas Exploration, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Jul 2025 |
| 519 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |
| 520 | Schmid Properties Inc | Hico, TX 76457 | Oil & Gas Operator | Jul 2025 |
| 521 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 522 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 523 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 524 | Shattuck SWD LLC | Shattuck, OK 73858-0848 | Oil Operator | Mar 2022 |
| 525 | Shell Oil Company | Houston, TX 77210 | Oil & Gas Operator | Apr 2015 |
| 526 | Shell Western Expl & Prod Inc | Houston, TX 77251 | Oil & Gas Operator | Mar 2015 |
| 527 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Apr 2025 |
| 528 | Sidwell Oil & Gas, Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Sep 2014 |
| 529 | Singer Fleischaker Oil Op. Co. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2002 |
| 530 | Singer Oil Co LLC | Hennessey, OK 73742 | Oil & Gas Operator | May 2025 |
| 531 | Singer Oil Company | Oklahoma City, OK 73148 | Oil & Gas Operator | Apr 2025 |
| 532 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2025 |
| 533 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 534 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2025 |
| 535 | Smokey Trail LLC | Thornton, CO 80241 | Oil & Gas Operator | May 2025 |
| 536 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 537 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 538 | Sooner Exploration & Development Co Inc | Enid, OK 73702-3525 | Oil & Gas Operator | Oct 2023 |
| 539 | South Forty, The, Inc. | Laverne, OK 73848 | Oil & Gas Operator | Mar 2015 |
| 540 | Southern Resources Inc | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | May 2025 |
| 541 | Southport Exploration Inc | Tulsa, OK 74103-4015 | Oil & Gas Operator | Nov 1998 |
| 542 | Sparks Petroleum Company | Oklahoma City, OK 73128 | Oil & Gas Operator | Mar 1998 |
| 543 | Sparks Resources Inc | Bristow, OK 74010 | Oil & Gas Operator | May 2025 |
| 544 | Spartan Resources LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | May 2025 |
| 545 | Spess Oil Company Inc | Cleveland, OK 74020-4617 | Oil & Gas Operator | May 2025 |
| 546 | Spring Operating Company | Edmond, OK 73034 | Oil & Gas Operator | May 2025 |
| 547 | St Joe Petroleum U S Corp | | Oil & Gas Operator | Aug 2000 |
| 548 | Staghorn Energy, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 549 | Staghorn Resources, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2015 |
| 550 | Statoil Oil & Gas LP | Austin, TX 78730 | Oil & Gas Operator | Oct 2018 |
| 551 | Stephens Exploration, Inc. | Dallas, TX 75367 | Oil & Gas Operator | May 2025 |
| 552 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | May 2025 |
| 553 | Stephens, Autry C. | Midland, TX 79701 | Oil & Gas Operator | Mar 2023 |
| 554 | Stevenson Oil Company | Lovington, NM 88260 | Oil & Gas Operator | Mar 2025 |
| 555 | Stewart K Petroleum Corp | Edmond, OK 73013 | Oil & Gas Operator | Mar 2015 |
| 556 | Stone Oak Operating LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Apr 2025 |
| 557 | Strat Land Exploration Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 558 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | Jul 2025 |
| 559 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 560 | SWN Production LLC | Spring, TX 77389-4954 | Oil & Gas Operator | Feb 2022 |
| 561 | T C Craighead & Company LLC | Ardmore, OK 73401 | Oil & Gas Operator | Aug 2019 |
| 562 | T Investments Inc | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Mar 2011 |
| 563 | Tapstone Energy LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | May 2025 |
| 564 | Tbi Exploration Inc | Englewood, CO 801556525 | Oil & Gas Operator | Jun 2011 |
| 565 | Te-Ray Energy, Inc. | Oklahoma City, OK 73108 | Oil & Gas Operator | Apr 2025 |
| 566 | Te-Ray Resources, LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Jul 2025 |
| 567 | Technical Energy Services, Inc. | Norman, OK 73070 | Oil & Gas Operator | Apr 2025 |
| 568 | Templar Operating LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Apr 2025 |
| 569 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Apr 2025 |
| 570 | Teocalli Exploration LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2025 |
| 571 | Terra Production Company | Okemah, OK 74859-5924 | Oil & Gas Operator | Apr 2020 |
| 572 | Tessera Energy LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Apr 2025 |
| 573 | Tex-Ok Energy, Limited Partnership | Cody, WY 82414 | Oil & Gas Operator | May 2025 |
| 574 | Tex-Star Production | Dallas, TX 75206 | Oil & Gas Operator | May 2025 |
| 575 | Texaco Expl. And Prod. Inc. | Houston, TX 77236 | Oil & Gas Operator | May 2025 |
| 576 | Texaco Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2017 |
| 577 | Texakoma Exploration & Production LLC | Plano, TX 75024 | Oil & Gas Operator | May 2025 |
| 578 | Texas Moran Exploration Company | Houston, TX 77098 | Oil & Gas Operator | Jun 2023 |
| 579 | The Warren Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | Jan 2016 |
| 580 | Tide West Oil Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2021 |
| 581 | Tidemark Exploration | Tulsa, OK 74170 | Oil & Gas Operator | May 2005 |
| 582 | Tilley Oil Inc | Velma, OK 73491 | Oil & Gas Operator | May 2025 |
| 583 | Todd John C | Oklahoma City, OK 73112-8049 | Oil & Gas Operator | May 2015 |
| 584 | Tomlinson Oil Co. Inc. | Great Bend, KS 67530 | Oil & Gas Operator | Jan 2025 |
| 585 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 586 | Total Minatome Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 1998 |
| 587 | Trail Ridge Energy Partners, LLC | Grapevine, TX 76051 | Oil & Gas Operator | May 2025 |
| 588 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Jul 2025 |
| 589 | Triad Energy, Inc. | Oklahoma City, OK 73105-1401 | Oil & Gas Operator | May 2025 |
| 590 | Trigg Drilling Company Inc | Oklahoma City, OK 73105 | Oil & Gas Operator | Jan 2013 |
| 591 | Triplett Larry W | Oklahoma City, OK 73112-5325 | Oil & Gas Operator | Mar 2015 |
| 592 | Triumph Resources Inc | Oklahoma City, OK 73114 | Oil & Gas Operator | Nov 2004 |
| 593 | Trueblood Resources, Inc. | Denver, CO 80222 | Oil & Gas Operator | Jul 2025 |
| 594 | Tuthill S Keith & Bill Barbee | Amarillo, TX 79101-1427 | Oil & Gas Operator | Dec 2004 |
| 595 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 596 | Txok Energy Resources Company | Tulsa, OK 74172-0140 | Oil & Gas Operator | Feb 2017 |
| 597 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 598 | Unbridled Resources, LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 599 | Unit Drilling & Exploration Co | Tulsa, OK 74132-5300 | Oil & Gas Operator | Apr 2025 |
| 600 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2025 |