| 401 | Quatros Operating Company | Kilgore, TX 75663 | Oil Operator | May 2024 |
| 402 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 403 | R & C Petroleum, Inc. | Flint, TX 75762 | Oil & Gas Operator | May 2024 |
| 404 | R2Q Operating LLC | Iowa Park, TX 76367 | Oil & Gas Operator | May 2024 |
| 405 | Ranger Investments, Inc. | Longview, TX 75605 | Oil & Gas Operator | Nov 2006 |
| 406 | Redwood Oil & Gas | McKinney, TX 75070 | Oil & Gas Operator | Apr 2013 |
| 407 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | May 2024 |
| 408 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | May 2024 |
| 409 | Reostar Operating Incorporated | Fort Worth, TX 76107 | Oil & Gas Operator | Sep 2012 |
| 410 | Reserve Management, Inc. | Tyler, TX 75711 | Oil & Gas Operator | May 2024 |
| 411 | Reserve Production, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Mar 2008 |
| 412 | Reynolds Drilling Co., Inc. | Shreveport, LA 71105 | Oil & Gas Operator | May 2024 |
| 413 | Rheata Resources, LLC | Kilgore, TX 75663 | Oil & Gas Operator | May 2024 |
| 414 | Richter Operating Company | San Antonio, TX 78217 | Oil & Gas Operator | Dec 2007 |
| 415 | Rig Runner Express Inc Of Texas | Kilgore, TX 75663 | Oil & Gas Operator | May 2014 |
| 416 | Rig Runner Express, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Mar 2008 |
| 417 | Riverine, L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Nov 2021 |
| 418 | RLM Energy Company Inc. | Monroe, LA 71201 | Oil & Gas Operator | Mar 2008 |
| 419 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 420 | Rmor Production | Kilgore, TX 75662 | Oil Operator | May 2024 |
| 421 | Roach, R. Byron Trustee | Judson, TX 75660 | Oil & Gas Operator | Mar 1999 |
| 422 | Robbins Petroleum Corp. | Longview, TX 75606 | Oil & Gas Operator | Sep 1994 |
| 423 | Robertson Resources, Inc. | Midland, TX 79708 | Oil & Gas Operator | May 2024 |
| 424 | Robertson-Bryce Management, LLC | Tyler, TX 75701 | Oil & Gas Operator | May 2024 |
| 425 | Robinett Resources Inc. | Longview, TX 75601 | Oil & Gas Operator | Dec 1999 |
| 426 | Rockcliff Energy Operating LLC | Houston, TX 77002 | Oil & Gas Operator | May 2024 |
| 427 | Rojo Burro Petroleo & Gas | Kilgore, TX 75662 | Oil & Gas Operator | Aug 2007 |
| 428 | Roosth & Genecov Production Co. | Tyler, TX 75710 | Oil & Gas Operator | Aug 2003 |
| 429 | Roosth Production Co. | Tyler, TX 75711 | Oil & Gas Operator | May 2024 |
| 430 | Royal Petroleum Corp. | Dallas, TX 75229 | Oil & Gas Operator | Jan 2024 |
| 431 | RS & LS Management, L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2023 |
| 432 | Rusk Co. Well Service Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | May 2024 |
| 433 | Rusk County Well Service, Inc | Kilgore, TX 75662 | Gas Operator | Dec 2023 |
| 434 | Russell - FT. Trinidad Op., LLC | Tyler, TX 75710 | Oil & Gas Operator | May 2024 |
| 435 | RWS Operating Co. LLC | Kilgore, TX 75663 | Oil Operator | May 2024 |
| 436 | S N D Energy Company, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | May 2024 |
| 437 | S.E.D.I. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2015 |
| 438 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | May 2024 |
| 439 | Sabine Oil & Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2017 |
| 440 | Sabine Pipe & Supply Co. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2004 |
| 441 | Sabine Pipe, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | May 2024 |
| 442 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 443 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 444 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 445 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2024 |
| 446 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2024 |
| 447 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2024 |
| 448 | Schlachter Operating Corporation | Dallas, TX 75225 | Oil & Gas Operator | May 2024 |
| 449 | Schlachter, David A. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2015 |
| 450 | Schlachter, David A., Estate Of | Dallas, TX 75225 | Oil & Gas Operator | Jan 2000 |
| 451 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | May 2024 |
| 452 | SDG Operating Company, Inc | Tyler, TX 75701 | Oil & Gas Operator | May 2024 |
| 453 | Segrest-Ward Joint Venture | Longview, TX 75606 | Oil & Gas Operator | Jun 2001 |
| 454 | Sei Operating, LLC | Mandeville, LA 70471 | Oil & Gas Operator | May 2024 |
| 455 | Setex Oil And Gas Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2012 |
| 456 | Sheer Energy, LLC | Kilgore, TX 75663 | Oil & Gas Operator | May 2024 |
| 457 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 458 | Shoco Production LLC | Kilgore, TX 75663 | Oil & Gas Operator | May 2024 |
| 459 | Shoco Production, L.P. | Kilgore, TX 75663 | Oil & Gas Operator | May 2020 |
| 460 | SHS Operating Company | Shreveport, LA 71149 | Oil & Gas Operator | Dec 2023 |
| 461 | Sigmon Construction Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | May 2024 |
| 462 | Sigmon Production Company, Inc. | Longview, TX 75608 | Oil & Gas Operator | Dec 2013 |
| 463 | Signal Oil Company, LLC | Kilgore, TX 75663 | Oil & Gas Operator | May 2024 |
| 464 | Silver Oak Operating, Inc. | Longview, TX 75601 | Oil & Gas Operator | Dec 2009 |
| 465 | Silver Oak Operating, LLC | Longview, TX 75604 | Oil & Gas Operator | May 2024 |
| 466 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Feb 2024 |
| 467 | Sinclair Exploration Company | Abilene, TX 79604 | Oil & Gas Operator | Nov 1998 |
| 468 | Siroco Operating Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2010 |
| 469 | Sklar & Phillips Oil Co. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2000 |
| 470 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | May 2024 |
| 471 | Smal Energy Corp | Tyler, TX 75710 | Oil & Gas Operator | Oct 1995 |
| 472 | Smith & Marrs Inc. | Lubbock, TX 79424 | Oil & Gas Operator | Apr 2021 |
| 473 | Smith Oil Company | Smackover, AR 71762 | Oil Operator | Mar 2024 |
| 474 | Smith Operating & Management Co. | Shreveport, LA 71161 | Oil & Gas Operator | Dec 2022 |
| 475 | Smith Resources, Inc. | Marshall, TX 75671 | Oil & Gas Operator | May 2024 |
| 476 | Smith Resources, L.L.C. | Marshall, TX 75671 | Oil & Gas Operator | May 2024 |
| 477 | Smith, E.N. III Energy Corp. | Marshall, TX 75671 | Oil & Gas Operator | Sep 2006 |
| 478 | Smith, R. E. Interests, Inc. | Houston, TX 77027 | Oil & Gas Operator | Mar 1998 |
| 479 | SND Operating, L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | May 2024 |
| 480 | Sonat Exploration Company -Tyler | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 481 | Sonat Exploration Company-MCR | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 482 | Southern Bay Operating, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 483 | Southlake Operating LLC | Weatherford, TX 76086 | Oil & Gas Operator | May 2024 |
| 484 | Southwest Operating, Inc.-Tyler | Tyler, TX 75701 | Oil & Gas Operator | May 2024 |
| 485 | Southwestern Electric Power Co | Dallas, TX 75266 | Oil & Gas Operator | Dec 1989 |
| 486 | SSC, Inc. | Lubbock, TX 79408 | Oil & Gas Operator | May 2024 |
| 487 | Stephens, Glynn | Overton, TX 75684 | Oil & Gas Operator | Oct 2001 |
| 488 | Stetson Petroleum Corp. | Rollins, MT 59931 | Oil & Gas Operator | May 2024 |
| 489 | Stoneburner Exploration, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Oct 1997 |
| 490 | Stroube Energy Corporation | Dallas, TX 75248 | Oil & Gas Operator | Jan 2012 |
| 491 | Stroud Petroleum, Inc. | Shreveport, LA 71162 | Oil & Gas Operator | May 2024 |
| 492 | Sulphur River Exploration, Inc. | Dallas, TX 75244 | Oil & Gas Operator | May 2024 |
| 493 | Sydri Operating, LLC | Dallas, TX 75231 | Oil & Gas Operator | May 2024 |
| 494 | T & G Oil, Inc. | White Oak, TX 75693 | Oil & Gas Operator | Dec 2010 |
| 495 | T & J Oil Production, L.L.C. | Lone Grove, OK 73443 | Oil & Gas Operator | Feb 2024 |
| 496 | T M Hopkins Operating Co | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2002 |
| 497 | T. J. Oil And Gas, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2002 |
| 498 | T.O.I. | Midland, TX 79710 | Oil & Gas Operator | Mar 2001 |
| 499 | Tanos Exploration II, LLC | Tyler, TX 75701 | Oil & Gas Operator | Sep 2023 |
| 500 | Tanos Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Oct 2018 |