| 501 | Ranger Systems Inc | Tulsa, OK 74145 | Oil Operator | Feb 2020 |
| 502 | Ranken Energy Corporation | Edmond, OK 73013 | Oil & Gas Operator | Nov 2025 |
| 503 | Reach Oil And Gas Company Inc | Oklahoma City, OK 73118-1100 | Oil & Gas Operator | Nov 2025 |
| 504 | Red Fork Oil Co | Lakewood, CO 80215 | Oil & Gas Operator | Aug 1993 |
| 505 | Redhen Oil Company | Oklahoma City, OK 73135 | Oil & Gas Operator | Sep 2024 |
| 506 | Reed Power Tongs Inc | Seminole, OK 74818 | Oil & Gas Operator | Sep 2025 |
| 507 | Regency Exploration Inc | Oklahoma City, OK 73102-5605 | Oil & Gas Operator | Mar 1999 |
| 508 | Regional Energy Corporation | Temple, TX 76503-1733 | Oil Operator | Mar 1996 |
| 509 | Research Oil Company Inc | Norman, OK 73070-8776 | Oil & Gas Operator | Aug 2019 |
| 510 | RF Operating And Supply Inc | | Oil & Gas Operator | Feb 2013 |
| 511 | Rhoades Oil Co | Tulsa, OK 74136-5575 | Oil & Gas Operator | Aug 2013 |
| 512 | Ric Petroleum, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Aug 2003 |
| 513 | Richard W Thompson Inc | Plano, TX 75075 | Oil & Gas Operator | Jul 2019 |
| 514 | Rickelson Oil & Gas Company | Tulsa, OK 74105 | Oil & Gas Operator | Aug 1993 |
| 515 | River Valley Oil LLC | Konawa, OK 74849 | Oil Operator | Dec 2025 |
| 516 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 517 | Rja Energy LLC | Norman, OK 73069-8224 | Oil & Gas Operator | Nov 2025 |
| 518 | RKR Exploration Inc | Seminole, OK 74868 | Oil & Gas Operator | Nov 2025 |
| 519 | Roadrunner Energy Inc | Tulsa, OK 74120 | Oil & Gas Operator | Mar 2015 |
| 520 | Roberson David A | Ada, OK 74821-0008 | Oil & Gas Operator | Jul 2010 |
| 521 | Roberson Oil Company | Houston, TX 77046 | Oil & Gas Operator | Dec 2025 |
| 522 | Robinowitz Oil Company | Tulsa, OK 74136-1429 | Oil & Gas Operator | Feb 2023 |
| 523 | Robson Petroleum Company | Tulsa, OK 74104 | Oil & Gas Operator | Jan 1995 |
| 524 | Rockwell Drilling Company | New York, NY 10013 | Oil & Gas Operator | Dec 2005 |
| 525 | Rodman Petroleum Corp. | Odessa, TX 79768 | Oil & Gas Operator | Jul 2023 |
| 526 | Romine Oil & Gas LTD | Shawnee, OK 74802-3425 | Oil & Gas Operator | Jan 2013 |
| 527 | Ronmar Engineering & Expl Inc | Ada, OK 74820-1402 | Oil Operator | Aug 2013 |
| 528 | Rox Exploration Inc | Norman, OK 73069-6301 | Oil & Gas Operator | Nov 2025 |
| 529 | Roxanna Oil Company | Oklahoma City, OK 73120-2717 | Oil Operator | Aug 2016 |
| 530 | Royal Petroleum Corp. | Dallas, TX 75229 | Oil & Gas Operator | Jan 2025 |
| 531 | Royalty Energy Development LLC | Edmond, OK 73003 | Oil & Gas Operator | Dec 2025 |
| 532 | Roye Realty & Developing Inc | Stigler, OK 74462-0148 | Gas Operator | Dec 2004 |
| 533 | Rumley Robert A & Associates | Tulsa, OK 74135-1907 | Oil Operator | Dec 2025 |
| 534 | Rust Oil Corp. | Fort Worth, TX 76121 | Oil & Gas Operator | Feb 2026 |
| 535 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 536 | S & K Oil Company | Tulsa, OK 74101 | Oil & Gas Operator | Jul 1994 |
| 537 | S & W Engine Supply | Oklahoma City, OK 73107 | Oil Operator | Jun 2003 |
| 538 | S/H Petroleum Corporation | Hennessey, OK 73742-0477 | Oil & Gas Operator | Feb 2016 |
| 539 | Salt Creek Energy Company LLC | Shawnee, OK 74802-1505 | Oil & Gas Operator | Nov 2025 |
| 540 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 541 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2025 |
| 542 | Sandy Petroleum Inc | Shawnee, OK 74801-5634 | Oil & Gas Operator | Oct 2025 |
| 543 | Sanguine Gas Exploration, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Feb 2026 |
| 544 | Sanook Inc | Oklahoma City, OK 73156-0548 | Oil & Gas Operator | Jan 2007 |
| 545 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |
| 546 | Saqus Oil Co | Oklahoma City, OK 73107 | Oil & Gas Operator | May 2001 |
| 547 | Sasakwa Operating LLC | Oklahoma City, OK 73179-1902 | Oil & Gas Operator | Nov 2025 |
| 548 | Schiff & Jackson Oil Producers | Dallas, TX 75206 | Oil & Gas Operator | Nov 2025 |
| 549 | Schlachter, David A. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2015 |
| 550 | Scissortail Energy LLC | Tulsa, OK 74137-3644 | Oil & Gas Operator | Dec 2025 |
| 551 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 552 | Seaport Inc | Oklahoma City, OK 73131 | Oil & Gas Operator | Nov 2025 |
| 553 | Sellers Jack B Estate Of | Cleveland, OK 74020 | Oil & Gas Operator | Nov 2025 |
| 554 | Seminole Company (The) | | Oil Operator | Dec 1994 |
| 555 | Seminole Tank Service | Seminole, OK 74818-1587 | Oil & Gas Operator | Nov 2025 |
| 556 | Sentinel Petroleum Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2020 |
| 557 | Shannon Petroleum Inc | Tulsa, OK 74136-4603 | Oil & Gas Operator | Oct 2016 |
| 558 | Sharber Billy Jack Operating | Konawa, OK 74849-0071 | Oil & Gas Operator | Mar 2015 |
| 559 | Sharber Don E | Okemah, OK 74859-0322 | Oil Operator | Dec 2018 |
| 560 | Sharber Production Inc | Konawa, OK 74849 | Oil & Gas Operator | Dec 2024 |
| 561 | Sharp Anthony G | Shawnee, OK 74802-1701 | Oil & Gas Operator | Jul 2003 |
| 562 | Signature Exploration Inc. | Shawnee, OK 74804-4130 | Oil & Gas Operator | Mar 2015 |
| 563 | Silver Creek Oil & Gas, LLC | Flower Mound, TX 75022 | Oil & Gas Operator | Feb 2026 |
| 564 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Nov 2025 |
| 565 | Simco Operating | Shawnee, OK 74804-2501 | Oil Operator | Jan 2013 |
| 566 | Simon Royce & Joyce | Tecumseh, OK 74873-7341 | Oil Operator | Jun 2018 |
| 567 | Singer Oil Co LLC | Hennessey, OK 73742 | Oil & Gas Operator | Dec 2025 |
| 568 | Singer Oil Company | Oklahoma City, OK 73148 | Oil & Gas Operator | Oct 2025 |
| 569 | Siosi Oil & Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Nov 2013 |
| 570 | Smith Brothers Enterprises | Ardmore, OK 73402 | Oil Operator | Jul 1998 |
| 571 | Smith Manus L MFG Inc | Oklahoma City, OK 73147 | Oil & Gas Operator | Nov 1998 |
| 572 | Smith Max Dean | Wewoka, OK 74884 | Oil & Gas Operator | Oct 2025 |
| 573 | SNR Central Oklahoma Operating LLC | Oklahoma City, OK 73116-7906 | Oil Operator | Dec 2025 |
| 574 | SNR Operating, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Feb 2026 |
| 575 | Snuffy'S Oilfield Service Inc | Hennessey, OK 73742-6511 | Oil & Gas Operator | Nov 2014 |
| 576 | Sooner Drilling Inc | Shawnee, OK 74802-0037 | Oil & Gas Operator | Jan 2005 |
| 577 | Sooner Pipe & Supply Corp | | Oil & Gas Operator | Nov 2004 |
| 578 | Southland Energy Corporation | Houston, TX 77060 | Oil & Gas Operator | Aug 2022 |
| 579 | Southwest Royalties, Inc. | Midland, TX 79710 | Oil & Gas Operator | Feb 2026 |
| 580 | Southwestern Oil Corporation | Oklahoma City, OK 73106 | Oil & Gas Operator | Dec 2025 |
| 581 | SP Energy Development Company | Seattle, WA 98101-3277 | Oil & Gas Operator | Mar 2015 |
| 582 | Special Energy Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Feb 2026 |
| 583 | Spess Oil Company Inc | Cleveland, OK 74020-4617 | Oil & Gas Operator | Dec 2025 |
| 584 | Splawn & Splawn | Saint Louis, OK 74866-0098 | Oil & Gas Operator | Mar 2025 |
| 585 | Stacy Operating LLC | Cushing, OK 74023 | Oil & Gas Operator | Nov 2025 |
| 586 | Staghorn Petroleum II LLC | Tulsa, OK 74103-3500 | Oil & Gas Operator | Dec 2025 |
| 587 | Stalnaker Oil Company | Maud, OK 74854-0295 | Oil Operator | May 2017 |
| 588 | Stark Oil Properties | Asher, OK 74826 | Oil & Gas Operator | Jan 1997 |
| 589 | Sterling Oil Of Okla Inc | Tulsa, OK 74170-2163 | Oil & Gas Operator | Nov 2006 |
| 590 | Stobaugh G B Trust | Oklahoma City, OK 73124 | Oil Operator | Aug 2025 |
| 591 | Stover Company | Tulsa, OK 74152-0786 | Oil & Gas Operator | Jan 2013 |
| 592 | STP Cherokee Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2014 |
| 593 | STP Newco Inc | Oklahoma City, OK 73102-5641 | Oil & Gas Operator | Jul 2021 |
| 594 | Strat Land Exploration Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2025 |
| 595 | Stream Energy, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Nov 2025 |
| 596 | Streamline Oil And Gas Inc | Lindsay, OK 73052 | Oil & Gas Operator | Dec 2025 |
| 597 | Striker Management Co LLC | Shawnee, OK 74801 | Oil & Gas Operator | Nov 2025 |
| 598 | Sullivan & Co. | Tulsa, OK 74114 | Oil & Gas Operator | May 2022 |
| 599 | Sullivan And Company LLC | Tulsa, OK 74119 | Oil & Gas Operator | Nov 2025 |
| 600 | Summit Resources Management LLC | Edmond, OK 73083 | Oil & Gas Operator | Nov 2025 |