| 501 | Production Management Associates | Plano, TX 75075 | Oil & Gas Operator | Apr 2025 |
| 502 | Production Operators Of TX, LLC | Abilene, TX 79605 | Oil & Gas Operator | Apr 2025 |
| 503 | Pryor Petroleum Corporation | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2025 |
| 504 | Putnam Oil Production | Abilene, TX 79603 | Oil & Gas Operator | Jun 2002 |
| 505 | PV Oil Services, LLC | Abilene, TX 79601 | Oil & Gas Operator | Apr 2025 |
| 506 | Quail Well Service, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 507 | Quantum Investments | Lubbock, TX 79424 | Oil Operator | Apr 2025 |
| 508 | Quatro Oil And Gas, Inc. | Joshua, TX 76058 | Oil & Gas Operator | Apr 2025 |
| 509 | Quest Petroleum, Inc. | Abilene, TX 79603 | Oil & Gas Operator | Apr 2025 |
| 510 | R & P Operating | Tuscola, TX 79562 | Oil & Gas Operator | Jun 1997 |
| 511 | Rainey, Wayne | Sweetwater, TX 79556 | Oil & Gas Operator | Feb 2019 |
| 512 | Ranger Operating Co. | Graham, TX 76450 | Oil & Gas Operator | Apr 2025 |
| 513 | Ratex Energy Inc. | Manchaca, TX 78652 | Oil & Gas Operator | Sep 2002 |
| 514 | Rayco Operating, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 515 | Raymond, WM. C. | Rockdale, TX 76567 | Oil & Gas Operator | Apr 2025 |
| 516 | RBD-Shelby Agency | Dallas, TX 75283 | Oil & Gas Operator | Dec 1993 |
| 517 | Rci, L.L.C. | Abilene, TX 79606 | Oil & Gas Operator | Apr 2025 |
| 518 | Red Rock Resources, L.L.C. | Wichita Falls, TX 76310 | Oil & Gas Operator | Jan 2025 |
| 519 | Red-Tex Petroleum, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Aug 2003 |
| 520 | Reef Exploration, Inc. (A-1) | Richardson, TX 75080 | Oil & Gas Operator | Oct 2006 |
| 521 | Reilly, K. L. | Huntsville, TX 77342 | Oil Operator | Dec 2004 |
| 522 | Reliance Oil And Gas, Inc. | Austin, TX 78748 | Oil Operator | Jun 2012 |
| 523 | Renegade Operating Company, LLC | Abilene, TX 79608 | Oil Operator | Oct 2006 |
| 524 | Revard Petroleum, L.L.C. | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2025 |
| 525 | Rexcom, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Apr 2025 |
| 526 | RHB Exploration & Production,LLC | Grapevine, TX 76099 | Oil & Gas Operator | Apr 2025 |
| 527 | Rhodes Drilling Company | Abilene, TX 79608 | Oil & Gas Operator | Sep 2000 |
| 528 | Rhonda Operating Company | Midland, TX 79710 | Oil & Gas Operator | Aug 2017 |
| 529 | Richey, Ray Management Co., Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Apr 2025 |
| 530 | Rister, Dewey | Avoca, TX 79503 | Oil & Gas Operator | Apr 2025 |
| 531 | RMB Operating LLC | Lubbock, TX 79493 | Oil & Gas Operator | Apr 2025 |
| 532 | Ro-Jo, Inc. | Highland VLG, TX 75077 | Oil & Gas Operator | Aug 2003 |
| 533 | Robertson Resources, Inc. | Midland, TX 79708 | Oil & Gas Operator | Apr 2025 |
| 534 | Robertson, French M. Oil Co. | Abilene, TX 79608 | Oil & Gas Operator | Mar 1995 |
| 535 | Robinson Operating Company | Abilene, TX 79604 | Oil & Gas Operator | Aug 2012 |
| 536 | Rockwood Resources Inc | Coleman, TX 76834 | Oil & Gas Operator | Apr 2025 |
| 537 | Roco Petroleum, Incorporated | Abilene, TX 79605 | Oil & Gas Operator | Apr 2025 |
| 538 | Romac Oil Company, Inc. | Throckmorton, TX 76483 | Oil & Gas Operator | Apr 2025 |
| 539 | Ross Engineering, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Apr 2025 |
| 540 | Rover Petroleum Operating, LLC | Plano, TX 75075 | Oil & Gas Operator | Apr 2025 |
| 541 | Royal Oil & Gas Corp. | Indiana, PA 15701 | Oil & Gas Operator | Apr 2014 |
| 542 | Royal Texan Energy Co. | Irvine, CA 92618 | Oil & Gas Operator | Apr 2025 |
| 543 | Royal Texan Resources Co. | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2025 |
| 544 | Royal Texas Petroleum | Lago VIsta, TX 78645 | Oil & Gas Operator | Apr 2025 |
| 545 | Rush Creek Operating LLC | McKinney, TX 75070 | Oil & Gas Operator | Apr 2025 |
| 546 | Russell, T. Operating Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Aug 2005 |
| 547 | Rust Oil Corp. | Fort Worth, TX 76108 | Oil & Gas Operator | Apr 2025 |
| 548 | RVR Operating Co. | Bedford, TX 76021 | Oil & Gas Operator | Jan 2017 |
| 549 | RWJ Operating LLC | Dallas, TX 75201 | Oil & Gas Operator | Apr 2025 |
| 550 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 551 | S & P Energy | Benbrook, TX 76126 | Oil & Gas Operator | Oct 1994 |
| 552 | S & R Operating | Merkel, TX 79536 | Oil & Gas Operator | Mar 2008 |
| 553 | S.B. Street Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Apr 2025 |
| 554 | S.U.E. Company | Abilene, TX 79604 | Oil Operator | Jan 1998 |
| 555 | Sabio Oil & Gas Inc. | Dallas, TX 75206 | Oil & Gas Operator | Jan 1998 |
| 556 | Sabre Oil And Gas Corp. | Houston, TX 77063 | Oil & Gas Operator | Apr 2025 |
| 557 | Safari Resources, LLC | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2025 |
| 558 | Saling Oil Co. | Abilene, TX 79604 | Oil & Gas Operator | Dec 2002 |
| 559 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 560 | Sanders Energy LLC | Aledo, TX 76008 | Oil & Gas Operator | Apr 2025 |
| 561 | Sandstone Services, LLC | Graham, TX 76450 | Oil & Gas Operator | Apr 2025 |
| 562 | Santa Fe Energy Oper. Part., LP | Houston, TX 77057 | Oil & Gas Operator | Dec 1994 |
| 563 | Saxon Oil Company | Dallas, TX 75204 | Oil & Gas Operator | Oct 2009 |
| 564 | Schalk, Thomas S. | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 1995 |
| 565 | Schkade Bros. Operating Company | Abilene, TX 79604 | Oil & Gas Operator | Oct 2021 |
| 566 | Schkade Production Co. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2020 |
| 567 | Schkade, Carl E. | Albany, TX 76430 | Oil & Gas Operator | Sep 2009 |
| 568 | Schkade, Louis | Albany, TX 76430 | Oil & Gas Operator | Mar 2008 |
| 569 | Scott Operating, Inc. | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 570 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Apr 2025 |
| 571 | Scranton Exploration | Eastland, TX 76448 | Oil & Gas Operator | Apr 2025 |
| 572 | Seago Operating Co., L.L.C. | Abilene, TX 79608 | Oil & Gas Operator | Oct 2011 |
| 573 | Sedona Oil & Gas Corporation | Austin, TX 78746 | Oil & Gas Operator | Apr 2025 |
| 574 | Seely Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2025 |
| 575 | Seismotech Energy, Incorporated | Plano, TX 75075 | Oil & Gas Operator | Aug 2003 |
| 576 | Semper Fidelis Oil & Gas, LLC | Allen, TX 75013 | Oil & Gas Operator | Apr 2013 |
| 577 | Sequoia Energy Resources | Dallas, TX 75207 | Oil & Gas Operator | Apr 2025 |
| 578 | Sequoia Fossil Fuels, Inc. | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 579 | Sequoia Natural Gas, Inc. | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 580 | Seven Wells Oil & Gas Expl. | Abilene, TX 79601 | Oil & Gas Operator | Jun 2014 |
| 581 | Shamrock Minerals Corporation | Merkel, TX 79536 | Oil & Gas Operator | Nov 1998 |
| 582 | Sharp Image Energy, Inc. | Big Spring, TX 79721 | Oil & Gas Operator | Apr 2025 |
| 583 | Shelby, Michael H. | Shreveport, LA 71101 | Oil & Gas Operator | Apr 2025 |
| 584 | Sherman, L. B. | Early, TX 76803 | Oil & Gas Operator | Jun 1998 |
| 585 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Apr 2025 |
| 586 | Signal Oil And Gas Company | Colleyville, TX 76034 | Oil & Gas Operator | Apr 2025 |
| 587 | Silver Creek Oil | Merkel, TX 79536 | Oil & Gas Operator | Aug 2003 |
| 588 | Sinclair Exploration Company | Abilene, TX 79604 | Oil & Gas Operator | Nov 1998 |
| 589 | Sissom Oil | Holliday, TX 76366 | Oil & Gas Operator | Mar 2008 |
| 590 | Sky Development Corporation | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 591 | Sky Resources, Inc. | Graham, TX 76450 | Oil & Gas Operator | Apr 2025 |
| 592 | Smail, James R. | Big Prairie, OH 44611 | Oil & Gas Operator | Dec 1998 |
| 593 | Smalley, Bill | Albany, TX 76430 | Oil & Gas Operator | Jul 2001 |
| 594 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | Apr 2025 |
| 595 | Smith, Joe T., Inc. | Hawley, TX 79525 | Oil & Gas Operator | Apr 2025 |
| 596 | Snyder Drilling Corp. | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 597 | Sojourner Drilling Corporation | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 598 | Southern Crude, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2017 |
| 599 | Southern Exploration, Inc. | Fort Worth, TX 76137 | Oil & Gas Operator | Aug 2023 |
| 600 | Southern Mineral Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2001 |