| 501 | Ram Asset Management Co | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2015 |
| 502 | Rambler Oil Co | Oklahoma City, OK 73154 | Oil & Gas Operator | Jan 1999 |
| 503 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 504 | Ramsey Nichols Operating Company LLC | Oklahoma City, OK 73120-1955 | Oil & Gas Operator | Jul 2026 |
| 505 | Ramsey Property Management LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Jan 2026 |
| 506 | Randy Inc | Hennessey, OK 73742 | Oil & Gas Operator | May 2026 |
| 507 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 508 | Range Production Company, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2026 |
| 509 | Raven Resources LLC | Oklahoma City, OK 73172 | Oil & Gas Operator | Jun 2026 |
| 510 | Raw Crude Oil & Gas, L.L.C. | Norman, OK 73069 | Oil & Gas Operator | Jun 2026 |
| 511 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 512 | Reading & Bates Petroleum Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2009 |
| 513 | Rebellion Energy LLC | Tulsa, OK 74135-6241 | Oil & Gas Operator | Jun 2022 |
| 514 | Red Eagle Oil Company | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2005 |
| 515 | Red Plains Oil & Gas LLC | Kingfisher, OK 73750 | Oil & Gas Operator | Oct 2017 |
| 516 | Red Rocks Oil & Gas Operating LLC | Oklahoma City, OK 73103 | Oil & Gas Operator | Jul 2026 |
| 517 | Red Wolf Operating LLC | Edmond, OK 73003-2179 | Oil & Gas Operator | Jul 2026 |
| 518 | Redland Development LLC | Cashion, OK 73016-9625 | Oil & Gas Operator | May 2019 |
| 519 | Redline Energy LLC | Dover, OK 73734 | Oil & Gas Operator | Jul 2026 |
| 520 | Regal Petroleum Services Inc | Euless, TX 76039-1127 | Oil & Gas Operator | May 2015 |
| 521 | Renegade Oil And Gas LLC | Helena, OK 73741-0162 | Oil & Gas Operator | Dec 2019 |
| 522 | Review Oil & Gas Inc | Edmond, OK 73034-7648 | Oil & Gas Operator | Jun 2026 |
| 523 | Reynolds J W & Associates | Sapulpa, OK 74066 | Oil & Gas Operator | Dec 2000 |
| 524 | Rhino Operating Company LLC | Brentwood, TN 37027-8760 | Oil & Gas Operator | Jun 2026 |
| 525 | Richland Resources Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Sep 2026 |
| 526 | Ricks Exploration Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 527 | Rimrock Resource Operating LLC | Tulsa, OK 74103-4462 | Oil & Gas Operator | Jun 2026 |
| 528 | Rio Blanco Operating LLC | Victoria, TX 77904 | Oil & Gas Operator | Jun 2026 |
| 529 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2026 |
| 530 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | Jul 2026 |
| 531 | RMS Monte Christo, LLC | Snowmass VLG., CO 81615 | Oil & Gas Operator | Mar 2023 |
| 532 | Roan Resources LLC | Tulsa, OK 74103-3729 | Oil & Gas Operator | May 2026 |
| 533 | Robinson Brothers Drilling Co | | Oil & Gas Operator | Jul 2002 |
| 534 | Rosewood Resources Inc | Dallas, TX 75201 | Oil & Gas Operator | Sep 2026 |
| 535 | Rougeot Oil & Gas Corp | Sperry, OK 74073 | Oil & Gas Operator | Jun 2026 |
| 536 | Rox Exploration Inc | Norman, OK 73069-6301 | Oil & Gas Operator | Jul 2026 |
| 537 | Royalty Energy Development LLC | Edmond, OK 73003 | Oil & Gas Operator | Jul 2026 |
| 538 | RTC Resources, LLP | Weatherford, OK 73096 | Oil & Gas Operator | Sep 2026 |
| 539 | Rue Johnny B | Duncan, OK 73533-2019 | Oil & Gas Operator | Oct 2025 |
| 540 | Rupe Oil Company Inc | Wichita, KS 67278 | Oil & Gas Operator | May 2026 |
| 541 | Russell D Meloy Oil & Gas Co | Enid, OK 73703-1623 | Oil & Gas Operator | Jun 2026 |
| 542 | S & S Star Operating, LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Aug 2026 |
| 543 | S N D Energy Company, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Sep 2026 |
| 544 | S/H Petroleum Corporation | Hennessey, OK 73742-0477 | Oil & Gas Operator | Feb 2016 |
| 545 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 546 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Sep 2026 |
| 547 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 548 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 549 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2026 |
| 550 | Sandlot Oil & Gas LLC | Gruver, TX 79040 | Oil & Gas Operator | Sep 2026 |
| 551 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Sep 2026 |
| 552 | Sanguine Gas Exploration, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Sep 2026 |
| 553 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |
| 554 | Santa Fe-Andover Oil Co | Tulsa, OK 74172 | Oil & Gas Operator | Sep 2000 |
| 555 | Scana Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Dec 1999 |
| 556 | Scana Petroleum Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 557 | Scana Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2005 |
| 558 | Scarth Oil & Gas Co | Amarillo, TX 79101 | Oil & Gas Operator | Feb 1999 |
| 559 | Scissortail Energy LLC | Tulsa, OK 74137-3644 | Oil & Gas Operator | Jul 2026 |
| 560 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 561 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 562 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 563 | Seals And Brown Oil Operating | Norman, OK 73072-3020 | Oil & Gas Operator | Sep 2024 |
| 564 | Search Drilling Company | Houston, TX 77010 | Oil & Gas Operator | Feb 2001 |
| 565 | Seneca Oil Company | Tulsa, OK 74121-1518 | Oil & Gas Operator | Jan 2015 |
| 566 | Sensor Oil & Gas, Inc. | Duncan, OK 73534 | Oil & Gas Operator | May 2013 |
| 567 | Seymour Oil Co Inc | Edmond, OK 73025 | Oil & Gas Operator | Jul 2011 |
| 568 | Shelly Energy Inc | Berwyn, PA 19312 | Oil & Gas Operator | Jul 2026 |
| 569 | Shoshone Oil And Gas Inc | Lindsay, OK 73052-0217 | Oil & Gas Operator | Jan 2020 |
| 570 | Siegfried R H Inc | Tulsa, OK 74104 | Oil & Gas Operator | Mar 2008 |
| 571 | Silver Creek Oil & Gas, LLC | Flower Mound, TX 75022 | Oil & Gas Operator | Sep 2026 |
| 572 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Jun 2026 |
| 573 | Singer Oil Co LLC | Hennessey, OK 73742 | Oil & Gas Operator | Jul 2026 |
| 574 | Singer Oil Company | Oklahoma City, OK 73148 | Oil & Gas Operator | Jun 2026 |
| 575 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Sep 2026 |
| 576 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2026 |
| 577 | Sloan Petroleum Service Inc | Guthrie, OK 73044 | Oil & Gas Operator | Jul 2026 |
| 578 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Sep 2026 |
| 579 | Smith Conley P Operating Co | Eglewood, CO 80112-3640 | Oil & Gas Operator | Jun 2000 |
| 580 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 581 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 582 | Snyder Partners | Cody, WY 82414 | Oil & Gas Operator | Jun 2026 |
| 583 | Sooner Oil & Gas LLC | Fairview, OK 73737-1806 | Oil & Gas Operator | Jul 2026 |
| 584 | Sooner Trend Exploration Inc | Kingfisher, OK 73750-4752 | Oil & Gas Operator | Dec 2015 |
| 585 | Southerland Marquieta Dba Keta Oil Company | Loco, OK 73442 | Oil & Gas Operator | Jun 2026 |
| 586 | Southern Resources Inc | Oklahoma City, OK 73120 | Oil & Gas Operator | Jul 2026 |
| 587 | Southwest Energy LP | Tulsa, OK 74136 | Oil & Gas Operator | Jun 2026 |
| 588 | Sparks Petroleum Company | Oklahoma City, OK 73128 | Oil & Gas Operator | Mar 1998 |
| 589 | Spess Oil Company Inc | Cleveland, OK 74020-4617 | Oil & Gas Operator | Jul 2026 |
| 590 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 591 | Staab Alan R | Tulsa, OK 74114-4213 | Oil & Gas Operator | Sep 2010 |
| 592 | Staghorn Energy, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2026 |
| 593 | Staghorn Petroleum II LLC | Tulsa, OK 74103-3500 | Oil & Gas Operator | Jul 2026 |
| 594 | Staghorn Petroleum LLC | Tulsa, OK 74103-3500 | Oil & Gas Operator | Jun 2026 |
| 595 | Staghorn Resources, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2015 |
| 596 | Stalwart Energy Co | Tulsa, OK 74103-3518 | Oil & Gas Operator | Apr 2014 |
| 597 | Star Resources LLC | Englewood, CO 80155-5185 | Oil & Gas Operator | Dec 2013 |
| 598 | Statoil Oil & Gas LP | Austin, TX 78730 | Oil & Gas Operator | Apr 2021 |
| 599 | Stephen Michael Inc | Midwest City, OK 73130-5200 | Oil & Gas Operator | Oct 2015 |
| 600 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | Jul 2026 |