| 601 | Seanard Energy Company | Baton Rouge, LA 70808 | Oil & Gas Operator | Jul 2002 |
| 602 | Sem Operating Company LLC | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 603 | Seneca Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2017 |
| 604 | Sha-Jam Operating Corp. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 605 | Shell Frontier Oil & Gas Inc. | Houston, TX 77001 | Oil & Gas Operator | Feb 1997 |
| 606 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 607 | Shenandoah Petroleum Corporation | Midland, TX 79705 | Oil & Gas Operator | May 2025 |
| 608 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Feb 2025 |
| 609 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | May 2025 |
| 610 | Shifflett Operating Company | Snyder, TX 79550 | Oil & Gas Operator | May 2025 |
| 611 | Sierra Lima Oil & Gas, LLC | Abilene, TX 79604 | Oil & Gas Operator | May 2025 |
| 612 | Simray GP, LLC | Richardson, TX 75080 | Oil & Gas Operator | Dec 2015 |
| 613 | Simray Oil & Gas, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Sep 2003 |
| 614 | Simray Operating Corp. | Richardson, TX 75080 | Oil & Gas Operator | Mar 2009 |
| 615 | Slant Operating, LLC | Lafayette, LA 70503 | Oil & Gas Operator | May 2025 |
| 616 | Sledge, H. G., Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2016 |
| 617 | Sloan Petroleum Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 618 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | May 2025 |
| 619 | SMC Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 620 | Smith & Marrs Inc. | Lubbock, TX 79424 | Oil & Gas Operator | Apr 2021 |
| 621 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | May 2025 |
| 622 | Snow Oil & Gas Inc. | Andrews, TX 79714 | Oil & Gas Operator | May 2025 |
| 623 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 624 | Sogo III LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2017 |
| 625 | Southern Bay Operating, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 626 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 627 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 628 | Southwest Royalties Inc | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 629 | Sozo Natural Resources LLC | Houston, TX 77056 | Oil & Gas Operator | May 2025 |
| 630 | Special Energy Corporation | Stillwater, OK 74076 | Oil & Gas Operator | May 2025 |
| 631 | Spicewood Operating Company, LLC | Austin, TX 78746 | Oil & Gas Operator | May 2025 |
| 632 | Spindletop Drilling Co. | Dallas, TX 75230 | Oil & Gas Operator | May 2025 |
| 633 | Spiral Energy Corp. | Midland, TX 79705 | Oil & Gas Operator | Dec 2019 |
| 634 | SSC, Inc. | Lubbock, TX 79408 | Oil & Gas Operator | May 2025 |
| 635 | St. Clair Energy Corporation | Tulsa, OK 74153 | Oil & Gas Operator | Mar 2008 |
| 636 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 637 | Stallion Energy LLC | Houston, TX 77090 | Oil & Gas Operator | Oct 2009 |
| 638 | Stallion Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | Oct 2017 |
| 639 | Stanolind Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2021 |
| 640 | Stanolind Production LLC | Midland, TX 79702 | Oil & Gas Operator | Dec 2020 |
| 641 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2025 |
| 642 | Stephens, Autry C. | Midland, TX 79701 | Oil & Gas Operator | Mar 2023 |
| 643 | Stevens & Tull, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jun 2000 |
| 644 | Steward Energy II, LLC | Frisco, TX 75034 | Oil & Gas Operator | May 2025 |
| 645 | Stoltz, Deane H. | Midland, TX 79710 | Oil & Gas Operator | Oct 2000 |
| 646 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 647 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | May 2025 |
| 648 | Stronghold Energy II Oper, LLC | Midland, TX 79702 | Oil & Gas Operator | Aug 2022 |
| 649 | Summit Exploration, L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | Mar 2008 |
| 650 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | May 2025 |
| 651 | Sunray Energy, Inc. | Round Rock, TX 78683 | Oil & Gas Operator | Nov 2018 |
| 652 | Surge Operating, LLC | Houston, TX 77041 | Oil & Gas Operator | May 2025 |
| 653 | Sweet Crude Operating LLC | Brenham, TX 77834 | Oil & Gas Operator | May 2025 |
| 654 | Sweetwater Drilling Co., Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | May 2025 |
| 655 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 656 | Symba American Oil, Inc | Houston, TX 77056 | Oil Operator | May 2025 |
| 657 | T-N-T Engineering, Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | May 2025 |
| 658 | T2 Operating Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 659 | Tabula Rasa Energy, LLC | Allen, TX 75013 | Oil & Gas Operator | Dec 2020 |
| 660 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 661 | Tamer Oil & Gas | Seminole, TX 79360 | Oil & Gas Operator | May 2025 |
| 662 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 663 | Taurus Exploration U.S.A., Inc. | Midland, TX 79705 | Oil & Gas Operator | Nov 1998 |
| 664 | TC Oil And Gas, LLC | Denton, TX 76205 | Oil Operator | May 2025 |
| 665 | TCS Petroleum Co., LLC | Abilene, TX 79608 | Oil & Gas Operator | May 2025 |
| 666 | Teco Oil & Gas, Inc. | Tampa, FL 33601 | Oil & Gas Operator | Nov 1997 |
| 667 | Tejas Petroleum Resources, LLC | Aubrey, TX 76227 | Oil & Gas Operator | May 2025 |
| 668 | Tejas Trucking, Inc. | Andrews, TX 79714 | Oil & Gas Operator | May 2025 |
| 669 | Tepee Petroleum Company, Inc. | Houston, TX 77098 | Oil & Gas Operator | Feb 2014 |
| 670 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | May 2025 |
| 671 | Texakoma E & P, LLC | Plano, TX 75024 | Oil & Gas Operator | May 2025 |
| 672 | Texakoma Oil & Gas Corp | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 673 | Texas Crude Operator, Inc. | Houston, TX 77098 | Oil & Gas Operator | Aug 2017 |
| 674 | Texas Crude, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 1995 |
| 675 | Texas Mineral Group | Midland, TX 79705 | Oil & Gas Operator | Aug 2013 |
| 676 | Texland Petroleum Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2003 |
| 677 | Texland Petroleum, L.P. | Fort Worth, TX 76107 | Oil & Gas Operator | May 2025 |
| 678 | Texland Petroleum-Hobbs, L.L.C. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2025 |
| 679 | Texland-Rector & Schumacher | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2000 |
| 680 | Texzona Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Dec 1997 |
| 681 | Thompson, J. Cleo | Dallas, TX 75201 | Oil & Gas Operator | May 2024 |
| 682 | Three Rivers Operating Co II LLC | Austin, TX 78735 | Oil & Gas Operator | Mar 2017 |
| 683 | Three Rivers Operating Co LLC | Austin, TX 78735 | Oil & Gas Operator | Mar 2017 |
| 684 | Three Span Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 685 | Thresher Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | May 2025 |
| 686 | Threshold Development Company | Fort Worth, TX 76109 | Oil & Gas Operator | Aug 2016 |
| 687 | Tipperary Oil & Gas Corp | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 688 | TMBR/Sharp Drilling, Inc. | Midland, TX 79703 | Oil & Gas Operator | Feb 2004 |
| 689 | Trace Operating, LLC | Fort Worth, TX 76116 | Oil & Gas Operator | May 2025 |
| 690 | Tracer Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 691 | Transfuel Resources Co | Houston, TX 77215 | Oil & Gas Operator | Aug 2013 |
| 692 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | May 2025 |
| 693 | Trilogy Operating, Inc. | Midland, TX 79708 | Oil & Gas Operator | May 2025 |
| 694 | Trinity Bay Oil & Gas, Inc. | Lubbock, TX 79416 | Oil & Gas Operator | May 2025 |
| 695 | Trinity Eor, LLC | Midland, TX 79701 | Oil & Gas Operator | Jan 2019 |
| 696 | Triton Oil & Gas Corp. | Houston, TX 77002 | Oil & Gas Operator | Nov 2014 |
| 697 | Triumph Exploration, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 698 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 699 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 700 | Union Seaboard Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |