| 501 | R K Petroleum Corp. | Midland, TX 79708 | Oil & Gas Operator | May 2024 |
| 502 | Rand Oil & Gas Corp. | Houston, TX 77040 | Oil & Gas Operator | Sep 2026 |
| 503 | Ranger 40 Petroleum, LLC | Fairfield, CT 06824 | Oil & Gas Operator | Sep 2026 |
| 504 | Rattler Midstream Operating LLC | Midland, TX 79701 | Oil Operator | Sep 2026 |
| 505 | Raw Production | Kermit, TX 79745 | Oil & Gas Operator | Sep 2026 |
| 506 | Ray Oil Company | Dallas, TX 75370 | Oil Operator | Dec 1989 |
| 507 | Rayden | Southlake, TX 76092 | Oil & Gas Operator | Sep 2026 |
| 508 | RBJ & Associates, LP | Midland, TX 79707 | Oil Operator | Jan 2020 |
| 509 | RCS Drilling Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 1994 |
| 510 | Re-Op Corp. | Houston, TX 77274 | Oil & Gas Operator | Sep 2026 |
| 511 | Reatta Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |
| 512 | Recovery Operating LP | San Angelo, TX 76904 | Oil & Gas Operator | Sep 2026 |
| 513 | Red Stone Resources LLC | Edmond, OK 73013 | Oil Operator | Jun 2023 |
| 514 | Red Willow Production Company | Ignacio, CO 81137 | Oil & Gas Operator | May 2026 |
| 515 | Red Willow Production, LLC | Ignacio, CO 81137 | Oil & Gas Operator | Oct 2015 |
| 516 | Reef Exploration, L.P. | Richardson, TX 75080 | Oil & Gas Operator | Sep 2026 |
| 517 | Reeves County Systems, Inc. | Odessa, TX 79760 | Oil & Gas Operator | Aug 2019 |
| 518 | Rein Pusher Operating LLC | Brenham, TX 77834 | Oil & Gas Operator | Sep 2026 |
| 519 | Remnant Oil Operating, LLC | Midland, TX 79704 | Oil & Gas Operator | Jul 2024 |
| 520 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | Sep 2026 |
| 521 | Resolute Natural Res. Co., LLC | Midland, TX 79706 | Oil & Gas Operator | Sep 2026 |
| 522 | Resolute Natural Resources Co., LLC | Denver, CO 80203 | Oil & Gas Operator | Feb 2017 |
| 523 | Rhonda Operating Company | Midland, TX 79710 | Oil & Gas Operator | Aug 2017 |
| 524 | Riata Energy, Inc. | Oklahoma City, OK 73101 | Oil & Gas Operator | Nov 2006 |
| 525 | Richardson, Bud II | Graham, TX 76450 | Oil & Gas Operator | Sep 2026 |
| 526 | Ring Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |
| 527 | Rio Oil And Gas (Permian) II,LLC | The Woodlands, TX 77382 | Oil & Gas Operator | Nov 2024 |
| 528 | Rio Petroleum, Inc. | Amarillo, TX 79102 | Oil & Gas Operator | Sep 2026 |
| 529 | Rio-Tex, Inc. | San Antonio, TX 78258 | Oil & Gas Operator | Sep 2026 |
| 530 | Rittenhouse Oil & Gas Co. | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |
| 531 | Rki Exploration & Production LLC | Tulsa, OK 74172 | Oil & Gas Operator | Sep 2026 |
| 532 | Roanoke Corporation | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 1995 |
| 533 | Robertson Resources, Inc. | Horseshoe Bay, TX 78657 | Oil & Gas Operator | Sep 2026 |
| 534 | Roca Resource Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 535 | Rockport Energy Solutions LLC | Austin, TX 78730 | Oil & Gas Operator | Sep 2026 |
| 536 | Roosth Production Co. | Tyler, TX 75711 | Oil & Gas Operator | Sep 2026 |
| 537 | Rosetta Resources Operating LP | San Antonio, TX 78216 | Oil & Gas Operator | Sep 2026 |
| 538 | Rosewood Resources Inc | Dallas, TX 75201 | Oil & Gas Operator | Sep 2026 |
| 539 | Rover Petroleum Operating, LLC | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2026 |
| 540 | Royalty Operating, Inc. | Richardson, TX 75081 | Oil & Gas Operator | Nov 2007 |
| 541 | Rubicon Oil & Gas, LLC | Midland, TX 79701 | Oil & Gas Operator | Sep 2026 |
| 542 | Ruwco Oil And Gas Corp. | Austin, TX 78701 | Oil & Gas Operator | Aug 2021 |
| 543 | S & P Energy | Benbrook, TX 76126 | Oil & Gas Operator | Oct 1994 |
| 544 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 545 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Sep 2026 |
| 546 | Saga Pet. LTD Liability Co Of Co | Midland, TX 79701 | Oil & Gas Operator | Apr 2004 |
| 547 | Saga Petroleum LLC Of Colorado | Norman, OK 73072 | Oil & Gas Operator | Sep 2026 |
| 548 | Sage Energy Company | San Antonio, TX 78215 | Oil & Gas Operator | Sep 2026 |
| 549 | Saguaro Petroleum, LLC | Eastland, TX 76448 | Oil & Gas Operator | Sep 2026 |
| 550 | Sahara Operating Company | Midland, TX 79704 | Oil & Gas Operator | Sep 2026 |
| 551 | Samson Exploration LLC | Tulsa, OK 74101 | Oil & Gas Operator | Jul 2026 |
| 552 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 553 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 554 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2026 |
| 555 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | May 2026 |
| 556 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Sep 2026 |
| 557 | Saturn Oil And Development Corp. | Carlsbad, NM 88220 | Oil & Gas Operator | Sep 2026 |
| 558 | Savannah Ross And Company, LLC | Graham, TX 76450 | Oil & Gas Operator | Sep 2026 |
| 559 | Sbog, LLC | Granbury, TX 76048 | Oil & Gas Operator | Feb 2021 |
| 560 | Schmid Properties, Inc. | Hico, TX 76457 | Oil & Gas Operator | Sep 2026 |
| 561 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Sep 2026 |
| 562 | Scythian, LTD. | Midland, TX 79701 | Oil & Gas Operator | Dec 2020 |
| 563 | Seaboard Oil Company | Midland, TX 79710 | Oil & Gas Operator | Mar 2008 |
| 564 | Seaboard Operating Co. | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 565 | Seguro Oil And Gas, LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2024 |
| 566 | Sha-Jam Operating Corp. | Midland, TX 79701 | Oil & Gas Operator | Jul 2026 |
| 567 | Shaida, John H. | Wichita, KS 67226 | Oil & Gas Operator | Sep 2026 |
| 568 | Shale Energy LLC | Jeffersonville, KY 40337 | Oil Operator | Dec 2018 |
| 569 | Shell Western E&P | Houston, TX 77001 | Oil & Gas Operator | Sep 2026 |
| 570 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 571 | Shenandoah Petroleum Corporation | Midland, TX 79705 | Oil & Gas Operator | Sep 2026 |
| 572 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | May 2026 |
| 573 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Sep 2026 |
| 574 | Shinnery Oil Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2026 |
| 575 | Shoreham Oil & Gas Company, Inc. | Katy, TX 77492 | Oil & Gas Operator | Sep 2026 |
| 576 | Siete Oil And Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Aug 2003 |
| 577 | Siltstone Resources Op II, LLC | Wilmington, DE 19801 | Oil & Gas Operator | Sep 2026 |
| 578 | Silverback Operating, LLC | San Antonio, TX 78257 | Oil & Gas Operator | Oct 2016 |
| 579 | Simon, W. D. Oil Co. | Kermit, TX 79745 | Oil & Gas Operator | Sep 2026 |
| 580 | Single Barrel Oil And Gas LLC | Granbury, TX 76048 | Oil & Gas Operator | Sep 2026 |
| 581 | Slack, R. C. | Pecos, TX 79772 | Oil & Gas Operator | Jul 2000 |
| 582 | Sledge Bros. Oil Co. | Midland, TX 79702 | Oil & Gas Operator | Mar 2016 |
| 583 | SMC Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 584 | Snow Oil & Gas Inc. | Andrews, TX 79714 | Oil & Gas Operator | Sep 2026 |
| 585 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 586 | Solis Partners, L.L.C. | Midland, TX 79704 | Oil & Gas Operator | Jun 2026 |
| 587 | Sonat Exploration Co. - Midland | Houston, TX 77251 | Oil & Gas Operator | Mar 1999 |
| 588 | Sonat Exploration Company -Tyler | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 589 | Sonoran Energy Inc. | Addison, TX 75001 | Oil & Gas Operator | Sep 2026 |
| 590 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 591 | Southwest Energy LP | Tulsa, OK 74136 | Oil & Gas Operator | May 2026 |
| 592 | Southwest Royalties, Inc. | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 593 | Spiller Operating Co., Inc. | Round Rock, TX 78665 | Oil & Gas Operator | May 2015 |
| 594 | SSC, Inc. | Lubbock, TX 79408 | Oil & Gas Operator | Sep 2026 |
| 595 | Staley Operating Co. | Midland, TX 79702 | Oil & Gas Operator | Jan 2022 |
| 596 | Stallion Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | Oct 2017 |
| 597 | Stanolind Operating Corp. | Midland, TX 79701 | Oil & Gas Operator | Apr 2008 |
| 598 | Steward Energy, LLC | Frisco, TX 75034 | Oil & Gas Operator | Nov 2014 |
| 599 | Stickney Oil & Gas, Inc. | Midland, TX 79704 | Oil & Gas Operator | Nov 2014 |
| 600 | Stickney, F. C., Inc. | Midland, TX 79704 | Oil & Gas Operator | Oct 1998 |