| 501 | Scana Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Dec 1999 |
| 502 | Scana Petroleum Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 503 | Scana Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2005 |
| 504 | Scandia Energy Co Inc | Traverse City, MI 49684 | Oil & Gas Operator | Dec 1993 |
| 505 | Scanfield, LLC | Russell, PA 16345 | Gas Operator | Dec 2024 |
| 506 | Scarlett Energy Enterprises LLC | Watchung, NJ 07069 | Oil & Gas Operator | Oct 2014 |
| 507 | Scarsdale Drilling Partners III LP | Scarsdale, NE 10583 | Oil & Gas Operator | Dec 2014 |
| 508 | Scarth Oil & Gas Co | Amarillo, TX 79101 | Oil & Gas Operator | Feb 1999 |
| 509 | Scavenger Oil Company Inc | Englewood, CO 80111 | Oil & Gas Operator | Mar 2000 |
| 510 | SCD Oil Operators & Drilling Inc | Houston, TX 77069 | Oil & Gas Operator | Dec 2021 |
| 511 | Sceptre Resources Inc | | Oil & Gas Operator | Dec 2007 |
| 512 | Schaben Oil LLC | Hays, KS 67601 | Oil Operator | Feb 2026 |
| 513 | Schad Jeffrey M | Mannford, OK 74044-0995 | Oil Operator | Sep 2021 |
| 514 | Schaefer, Gary L. | Holliday, TX 76366 | Oil & Gas Operator | Mar 2017 |
| 515 | Schaffner, Cecil | Byers, TX 76357 | Oil & Gas Operator | Apr 2004 |
| 516 | Schalk Development Co | Albuquerque, NM 87125 | Oil & Gas Operator | Apr 2026 |
| 517 | Schalk Oil Company, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jun 2026 |
| 518 | Schalk, Thomas S. | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 1995 |
| 519 | Schankie & Sons, LLC | Madison, KS 66860 | Oil Operator | Feb 2026 |
| 520 | Schankie Well Se | | Oil Operator | Mar 1995 |
| 521 | Schankie Well Service, Inc. | Madison, KS 66860 | Oil Operator | Feb 2026 |
| 522 | Scheck Oil Operation | | Oil & Gas Operator | Feb 2026 |
| 523 | Schenk Oil Co. | Scotland, TX 76379 | Oil Operator | Jun 2026 |
| 524 | Scheriger Production | Graham, TX 76450 | Oil & Gas Operator | Jun 2006 |
| 525 | Schetawee, Inc. | Hamlin, TX 79520 | Oil & Gas Operator | Mar 2008 |
| 526 | Schettler William D | Fletcher, OK 73541-4117 | Oil & Gas Operator | Oct 2021 |
| 527 | Scheuneman, Lester | Ridgeway, MO 64481 | Oil Operator | May 2019 |
| 528 | Schichtel'S Nursery, Inc. | Springville, NY 14141 | Gas Operator | Dec 2024 |
| 529 | Schierling Eldon | | Oil & Gas Operator | Aug 1986 |
| 530 | Schierling, Eldon J. | Wichita, KS 67202 | Oil & Gas Operator | Feb 2026 |
| 531 | Schievelbein, Bryan O. | Seguin, TX 78155 | Oil & Gas Operator | Jun 2026 |
| 532 | Schiff & Jackson Oil Producers | Dallas, TX 75206 | Oil & Gas Operator | Feb 2026 |
| 533 | Schiff, H. G. & Co. | Dallas, TX 75206 | Oil & Gas Operator | Jul 1993 |
| 534 | Schindler Oil | | Oil Operator | Dec 2009 |
| 535 | Schindler Oil, LLC | Madison, KS 66860 | Oil Operator | Feb 2026 |
| 536 | Schindler, Joe | Madison, KS 66860 | Oil Operator | Feb 2026 |
| 537 | Schippers Oilfield Services, LLC | Hoxie, KS 67740 | Oil Operator | Feb 2026 |
| 538 | Schiralli, Bradley L. | Bolivar, NY 14715 | Oil & Gas Operator | Dec 2024 |
| 539 | Schiralli, Bradley L. And Paffie, Ronald | | Oil & Gas Operator | Dec 2024 |
| 540 | Schkade & Bullock | San Angelo, TX 76901 | Oil & Gas Operator | Aug 2003 |
| 541 | Schkade Bros. Operating Company | Abilene, TX 79604 | Oil & Gas Operator | Oct 2021 |
| 542 | Schkade Exploration | San Angelo, TX 76901 | Oil & Gas Operator | Jun 2026 |
| 543 | Schkade Production Co. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2020 |
| 544 | Schkade, Carl E. | Albany, TX 76430 | Oil & Gas Operator | Sep 2009 |
| 545 | Schkade, Harold | Albany, TX 76430 | Oil & Gas Operator | Aug 2024 |
| 546 | Schkade, Louis | Albany, TX 76430 | Oil & Gas Operator | Mar 2008 |
| 547 | Schlachter Operating Corporation | Dallas, TX 75225 | Oil & Gas Operator | Jun 2026 |
| 548 | Schlachter, David A. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2015 |
| 549 | Schlachter, David A., Estate Of | Dallas, TX 75225 | Oil & Gas Operator | Jan 2000 |
| 550 | Schlagal, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2016 |
| 551 | Schlaikjer A L | | Oil Operator | Feb 1997 |
| 552 | Schlittler, Willard | Bryson, TX 76427 | Oil & Gas Operator | Jun 2026 |
| 553 | Schlobohm Starr | | Oil Operator | Dec 1996 |
| 554 | Schlobohm, Starr F. | Wolfeboro, NH 03894 | Oil Operator | Jul 2004 |
| 555 | Schlotterbeck Ir | | Oil Operator | Nov 1990 |
| 556 | Schmeid Ranch, LLC | Hays, KS 67601 | Oil Operator | Jun 2024 |
| 557 | Schmelzer Mark | Rushville, OH 43150 | Oil & Gas Operator | Dec 2007 |
| 558 | Schmelzer Maurice | Bremen, OH 43107 | Oil & Gas Operator | Dec 2025 |
| 559 | Schmelzer Plugging LLC | Bremen, OH 43107 | Oil & Gas Operator | Dec 2025 |
| 560 | Schmid Properties, Inc. | Hico, TX 76457 | Oil & Gas Operator | Jun 2026 |
| 561 | Schmidt Construction Services LLC | | Oil Operator | Feb 2026 |
| 562 | Schmidt Kermit O | | Oil & Gas Operator | Sep 1995 |
| 563 | Schmidt Production | Rocky Comfort, MT 64861 | Oil Operator | Sep 2015 |
| 564 | Schmidt, John T., Jr. | Dunkirk, NY 14048 | Gas Operator | Dec 2024 |
| 565 | Schmidt, Kermit | | Oil & Gas Operator | Dec 2009 |
| 566 | Schmidt, Terry D. | McPherson, KS 67460 | Oil Operator | Dec 2019 |
| 567 | Schmidt, Tracy | McPherson, KS 67460 | Oil Operator | Feb 2026 |
| 568 | Schmitt Carmen I | | Oil Operator | Dec 1996 |
| 569 | Schmude And Pangborn Associates | | Oil & Gas Operator | Apr 1993 |
| 570 | Schmude Oil Co | | Oil & Gas Operator | Mar 2014 |
| 571 | Schmude Oil Inc | | Oil & Gas Operator | Mar 2026 |
| 572 | Schneider Energy Services Inc | | Oil & Gas Operator | Feb 2026 |
| 573 | Schneider Oil Co | | Oil Operator | Oct 1988 |
| 574 | Schneider Oil Corporation | Broomfield, CO 80020 | Oil & Gas Operator | Aug 2009 |
| 575 | Schneider, Ernest | Rockdale, TX 76567 | Oil & Gas Operator | Dec 2014 |
| 576 | Schnell Louis L | | Oil Operator | Dec 2018 |
| 577 | Schneltz Oil Com | | Oil Operator | May 1992 |
| 578 | Schonfield Harold Gene | Bristow, OK 74010 | Oil Operator | Mar 2015 |
| 579 | Schonwald Supply Company | Oklahoma City, OK 73101-1571 | Oil & Gas Operator | May 1999 |
| 580 | School Creek Corporation | Winfield, KS 67156 | Oil Operator | Jan 2000 |
| 581 | Schooley Keith A | Enid, OK 73702-0767 | Oil Operator | May 2006 |
| 582 | Schrader Lawayne | Fort Worth, TX 76135 | Oil Operator | Mar 2019 |
| 583 | Schrader Willard C | Tionesta, PA 16353-8114 | Oil & Gas Operator | Dec 2025 |
| 584 | Schrecengost Fred M | Sligo, PA 16255-0216 | Oil & Gas Operator | Dec 2016 |
| 585 | Schreiber Oil Co. | | Oil Operator | Dec 2009 |
| 586 | Schreiber, Donald And Marilyn | Eden, NY 14057 | Gas Operator | Dec 2024 |
| 587 | Schreiber, Lloyd | Scotland, TX 76379 | Oil & Gas Operator | Dec 2000 |
| 588 | Schreider & Company, Inc | | Oil & Gas Operator | Jun 2023 |
| 589 | Schreiner Oil & Gas Inc | Prescott, AZ 86303 | Oil & Gas Operator | Dec 2023 |
| 590 | Schrimsher Oil & Gas Expl | Orlando, FL 32803 | Oil & Gas Operator | Dec 1992 |
| 591 | Schroeder Oil Properties | Graham, TX 76450 | Oil & Gas Operator | Jul 2022 |
| 592 | Schroeder, Donald C | | Oil & Gas Operator | Feb 2026 |
| 593 | Schuetz, Edna, Ed & Ronald(Deceased) | Coffeyville, KS 67337 | Oil Operator | Nov 2011 |
| 594 | Schulein Company LLC | Denver, CO 80246 | Oil & Gas Operator | Feb 2026 |
| 595 | Schulein Robert | | Oil & Gas Operator | Dec 1995 |
| 596 | Schuler Jr Chris C | Cleveland, OK 74020 | Oil Operator | Aug 2013 |
| 597 | Schuler Oil Properties LLC | Cleveland, OK 74020 | Oil Operator | Feb 2026 |
| 598 | Schulte Oil | Garnett, KS 66032 | Oil Operator | Mar 2022 |
| 599 | Schulte Oil - C | | Oil Operator | Dec 1989 |
| 600 | Schultheis Oil & Gas | Whipple, OH 45780 | Oil & Gas Operator | Dec 2023 |