| 501 | Rampart Petroleum, Incorporated | Buffalo Gap, TX 79508 | Oil & Gas Operator | Jan 2009 |
| 502 | Ramtex Energy LLC | Tulsa, OK 74114 | Oil & Gas Operator | Dec 2025 |
| 503 | Ranger 40 Petroleum, LLC | Fairfield, CT 06824 | Oil & Gas Operator | Dec 2025 |
| 504 | Rasmussen, Tom | San Angelo, TX 76904 | Oil & Gas Operator | Dec 2025 |
| 505 | Rattler Midstream Operating LLC | Midland, TX 79701 | Oil Operator | Dec 2025 |
| 506 | Ratts, Robert V. Inc. | Bedford, TX 76021 | Oil & Gas Operator | Aug 2003 |
| 507 | Raw Oil & Gas, Inc. | Lubbock, TX 79401 | Oil & Gas Operator | Dec 2025 |
| 508 | Raw Production | Kermit, TX 79745 | Oil & Gas Operator | Dec 2025 |
| 509 | Rayden | Midland, TX 79711 | Oil & Gas Operator | Dec 2025 |
| 510 | RBD-Shelby Agency | Dallas, TX 75283 | Oil & Gas Operator | Dec 1993 |
| 511 | Reata Resources | Kermit, TX 79745 | Oil & Gas Operator | Sep 2007 |
| 512 | Red Willow Production, LLC | Ignacio, CO 81137 | Oil & Gas Operator | Oct 2015 |
| 513 | Rein Pusher Operating LLC | Brenham, TX 77834 | Oil & Gas Operator | Dec 2025 |
| 514 | Remnant Oil Operating, LLC | Midland, TX 79704 | Oil & Gas Operator | Jul 2024 |
| 515 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | Dec 2025 |
| 516 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | Dec 2025 |
| 517 | Resaca Operating Company | Houston, TX 77010 | Oil & Gas Operator | Sep 2013 |
| 518 | Resource Operating Company | Abilene, TX 79601 | Oil & Gas Operator | Jul 1997 |
| 519 | Restore Operating LLC | Andrews, TX 79714 | Oil & Gas Operator | Dec 2025 |
| 520 | Rhombus Operating Co., LTD | Littleton, CO 80160 | Oil & Gas Operator | Oct 2025 |
| 521 | Rhonda Operating Company | Midland, TX 79710 | Oil & Gas Operator | Aug 2017 |
| 522 | Riata Energy, Inc. | Oklahoma City, OK 73101 | Oil & Gas Operator | Nov 2006 |
| 523 | Richardson, Bud II | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 524 | Ridge Petroleum Inc. | Tyler, TX 75701 | Oil & Gas Operator | Dec 2025 |
| 525 | Ring Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 526 | Rki Exploration & Production LLC | Tulsa, OK 74172 | Oil & Gas Operator | Dec 2025 |
| 527 | Robertson Resources, Inc. | Horseshoe Bay, TX 78657 | Oil & Gas Operator | Dec 2025 |
| 528 | Roc Operating, Inc. | Plano, TX 75093 | Oil & Gas Operator | Oct 2008 |
| 529 | Roca Operating, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 530 | Rockland Oil Company | Addison, TX 75001 | Oil & Gas Operator | Oct 2025 |
| 531 | Rodan, Inc. | Wink, TX 79789 | Oil & Gas Operator | Dec 2025 |
| 532 | Roden Oil Company | Midland, TX 79702 | Oil & Gas Operator | Feb 2008 |
| 533 | Roswell Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2019 |
| 534 | Rover Operating Inc | Richardson, TX 75080 | Oil & Gas Operator | Apr 2000 |
| 535 | Roy Jackson Energy Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 536 | Royal Oil LTD. Co. | Hobbs, NM 88241 | Oil & Gas Operator | Mar 1996 |
| 537 | RSP Permian, LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2018 |
| 538 | Ruckus Energy Operating, LLC | San Antonio, TX 78257 | Oil & Gas Operator | Dec 2025 |
| 539 | Rust Oil Corp. | Fort Worth, TX 76121 | Oil & Gas Operator | Dec 2025 |
| 540 | S & P Energy | Benbrook, TX 76126 | Oil & Gas Operator | Oct 1994 |
| 541 | Saba Energy Of Texas Inc | Houston, TX 77042 | Oil & Gas Operator | Jul 2007 |
| 542 | Saber Oil & Gas Ventures, LLC | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 543 | Sabinal Energy Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2025 |
| 544 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 545 | Saddleback Exploration, LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2024 |
| 546 | Sage Energy Company | San Antonio, TX 78215 | Oil & Gas Operator | Dec 2025 |
| 547 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 548 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2025 |
| 549 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Dec 2025 |
| 550 | Sapient Energy Corp | Oklahoma City, OK 73154 | Oil & Gas Operator | Jan 2002 |
| 551 | Saxet Oil Corporation | Midland, TX 79708 | Oil & Gas Operator | Dec 2025 |
| 552 | Schlachter Operating Corporation | Dallas, TX 75225 | Oil & Gas Operator | Dec 2025 |
| 553 | Schlachter, David A. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2015 |
| 554 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Dec 2025 |
| 555 | Scythian, LTD. | Midland, TX 79701 | Oil & Gas Operator | Dec 2020 |
| 556 | SDG Resources L.P. | Montrose, CO 81402 | Oil & Gas Operator | May 2006 |
| 557 | SDX Resources, Inc. | Midland, TX 79705 | Oil & Gas Operator | Dec 2025 |
| 558 | Sea Sand Oil Company | Fort Worth, TX 76185 | Oil & Gas Operator | Jun 1995 |
| 559 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 560 | Seanard Energy Company | Baton Rouge, LA 70808 | Oil & Gas Operator | Jul 2002 |
| 561 | Seco Production Company | Midland, TX 79708 | Oil & Gas Operator | Aug 2003 |
| 562 | Seguro Oil And Gas, LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2024 |
| 563 | Seven Falls Company | Dallas, TX 75201 | Oil & Gas Operator | May 2008 |
| 564 | Shaida, John H. | Wichita, KS 67226 | Oil & Gas Operator | Dec 2025 |
| 565 | Shelby, Michael H. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2025 |
| 566 | Shell Western E&P | Houston, TX 77001 | Oil & Gas Operator | Dec 2025 |
| 567 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 568 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 569 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Dec 2025 |
| 570 | Shifflett Operating Company | Snyder, TX 79550 | Oil & Gas Operator | Dec 2025 |
| 571 | Silver Hill Energy Partners, LLC | Dallas, TX 75219 | Oil & Gas Operator | Feb 2017 |
| 572 | Simon, W. D. Oil Co. | Kermit, TX 79745 | Oil & Gas Operator | Dec 2025 |
| 573 | Simpson Bros. Oil Co. | Odessa, TX 79760 | Oil & Gas Operator | Jan 2001 |
| 574 | Simpson Oil Company | Odessa, TX 79760 | Oil & Gas Operator | Oct 2004 |
| 575 | Slack, R. C. | Pecos, TX 79772 | Oil & Gas Operator | Jul 2000 |
| 576 | Slant Operating, LLC | Lafayette, LA 70503 | Oil & Gas Operator | Dec 2025 |
| 577 | SMC Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 578 | Smith & Marrs Inc. | Lubbock, TX 79424 | Oil & Gas Operator | Apr 2021 |
| 579 | Sogo III LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2017 |
| 580 | Southern Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 581 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 582 | Southwest Royalties, Inc. | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 583 | Special Energy Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Dec 2025 |
| 584 | Spindletop Drilling Co. | Dallas, TX 75230 | Oil & Gas Operator | Dec 2025 |
| 585 | Staley Operating Co. | Midland, TX 79702 | Oil & Gas Operator | Jan 2022 |
| 586 | Stanolind Operating Corp. | Midland, TX 79701 | Oil & Gas Operator | Apr 2008 |
| 587 | Stanolind Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2021 |
| 588 | Stanolind Production LLC | Midland, TX 79702 | Oil & Gas Operator | Dec 2020 |
| 589 | Stephens, Autry C. | Midland, TX 79701 | Oil & Gas Operator | Mar 2023 |
| 590 | Stevens & Tull, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jun 2000 |
| 591 | Stickney Oil & Gas, Inc. | Midland, TX 79704 | Oil & Gas Operator | Nov 2014 |
| 592 | Stickney, F. C., Inc. | Midland, TX 79704 | Oil & Gas Operator | Oct 1998 |
| 593 | Stonegate Operators, Inc. | Addison, TX 75001 | Oil Operator | Dec 2025 |
| 594 | Stout Energy Inc. | Midland, TX 79708 | Oil & Gas Operator | Dec 2025 |
| 595 | Strat Land Exploration Company | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2025 |
| 596 | Stronghold Energy II Oper, LLC | Midland, TX 79702 | Oil & Gas Operator | Aug 2022 |
| 597 | Summit Exploration, L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | Mar 2008 |
| 598 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | Dec 2025 |
| 599 | Synergex Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Sep 2025 |
| 600 | T & D Oil | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 2025 |