| 401 | Post Oak Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Jul 2013 |
| 402 | PPP Petroleum LP | Dallas, TX 75201-1585 | Oil & Gas Operator | Jan 2026 |
| 403 | Prentice, Napier & Green, Inc. | Oklahoma City, OK 73142 | Oil & Gas Operator | Feb 2026 |
| 404 | Presidio Petroleum LLC | Canadian, TX 79014 | Oil & Gas Operator | Apr 2026 |
| 405 | Pri Producing Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2006 |
| 406 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2026 |
| 407 | Primary Natural Resources Inc. | Tulsa, OK 74136-6351 | Oil & Gas Operator | Mar 2023 |
| 408 | Prime Operating Company | Midland, TX 79705 | Oil & Gas Operator | Apr 2026 |
| 409 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 410 | Prospective Investment & Trading | Scottsdale, AZ 85261-4190 | Oil & Gas Operator | Jun 2016 |
| 411 | Proven Reserves Management, Inc. | Dallas, TX 75370 | Oil & Gas Operator | Jan 2026 |
| 412 | Providence Oil & Gas Corp | Tulsa, OK 74135-5463 | Oil & Gas Operator | May 2005 |
| 413 | Pyramid Energy Inc | San Antonio, TX 78216 | Oil & Gas Operator | Feb 2012 |
| 414 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Jan 2026 |
| 415 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Jan 2026 |
| 416 | Quarles Drilling Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2008 |
| 417 | R L Clampitt & Associates LLC | Bartlesville, OK 74006 | Oil & Gas Operator | Feb 2026 |
| 418 | Raker Resources LLC | Houston, TX 77042 | Oil & Gas Operator | Apr 2026 |
| 419 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 420 | Ramsey Property MGMT Inc | Oklahoma City, OK 73120-1955 | Oil & Gas Operator | Mar 2019 |
| 421 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 422 | Range Production Company, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2026 |
| 423 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 424 | Reading & Bates Petroleum Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2009 |
| 425 | Red Hawk Resources Inc | Edmond, OK 73003-3207 | Oil & Gas Operator | Feb 2026 |
| 426 | Red Rocks Oil & Gas Operating LLC | Oklahoma City, OK 73103-4821 | Oil & Gas Operator | Feb 2026 |
| 427 | Redland Resources LLC | Oklahoma City, OK 73127 | Oil & Gas Operator | Feb 2026 |
| 428 | Redstone Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2020 |
| 429 | Redwine Resources Inc | Dallas, TX 75225 | Oil & Gas Operator | Feb 2015 |
| 430 | Reid Williams Operating Inc | Shreveport, LA 71106-6223 | Oil & Gas Operator | Jan 2026 |
| 431 | Remnant Energy, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Apr 2026 |
| 432 | Reserve Acquisition Group | Tulsa, OK 74153 | Oil & Gas Operator | Dec 1993 |
| 433 | Revelation Resources | Cypress, TX 77410-2578 | Oil & Gas Operator | Jan 2026 |
| 434 | Richland Resources Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Apr 2026 |
| 435 | Ricks Expl Acquisition LLC | Midland, TX 79701 | Oil & Gas Operator | Aug 2013 |
| 436 | Ricks Exploration Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 437 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 438 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | Feb 2026 |
| 439 | RMS Monte Christo, LLC | Snowmass VLG., CO 81615 | Oil & Gas Operator | Mar 2023 |
| 440 | Rockford Energy Partners III,LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2012 |
| 441 | Rockies Resources Holdings LLC | Lakewood, CO 80228 | Oil & Gas Operator | Feb 2026 |
| 442 | Rosewood Resources Inc | Dallas, TX 75201 | Oil & Gas Operator | Apr 2026 |
| 443 | Roy G Oil Company | Drumright, OK 74030-1236 | Oil & Gas Operator | Oct 1995 |
| 444 | RTC Resources, LLP | Weatherford, OK 73096 | Oil & Gas Operator | Apr 2026 |
| 445 | Rupe Oil Company Inc | Wichita, KS 67278 | Oil & Gas Operator | Dec 2025 |
| 446 | S & G Operating LLC | McLoud, OK 74851 | Oil & Gas Operator | Feb 2026 |
| 447 | S & S Star Operating, LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | Mar 2026 |
| 448 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 449 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2026 |
| 450 | Safe Earth Management Inc | | Oil Operator | Nov 2021 |
| 451 | Safe Earth Management LLC | Hammon, OK 73650 | Oil Operator | Nov 2025 |
| 452 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 453 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 454 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2026 |
| 455 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Apr 2026 |
| 456 | Sanguine Gas Exploration, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2026 |
| 457 | Santa Fe Energy Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2015 |
| 458 | Santa Fe Energy Operating Partner LP | Midland, TX 79701 | Oil & Gas Operator | Sep 2004 |
| 459 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |
| 460 | Sarkeys Inc | | Oil & Gas Operator | Dec 1998 |
| 461 | Scoggins Production LLC | Enid, OK 73703-3002 | Oil & Gas Operator | Feb 2026 |
| 462 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 463 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 464 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 465 | Search Drilling Company | Houston, TX 77010 | Oil & Gas Operator | Feb 2001 |
| 466 | Sensor Oil & Gas, Inc. | Duncan, OK 73534 | Oil & Gas Operator | May 2013 |
| 467 | Shannon Energy | Liberal, KS 67901 | Oil & Gas Operator | Feb 1999 |
| 468 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Jan 2026 |
| 469 | Shoreline Operating LLC | Oklahoma City, OK 73113 | Oil & Gas Operator | Feb 2026 |
| 470 | Sierra Resources, Inc. | Oklahoma City, OK 73142 | Oil & Gas Operator | Dec 2025 |
| 471 | Simmons Donald M | Muskogee, OK 74401 | Oil & Gas Operator | May 2013 |
| 472 | Singer Oil Co LLC | Hennessey, OK 73742 | Oil & Gas Operator | Feb 2026 |
| 473 | Singer Oil Company | Oklahoma City, OK 73148 | Oil & Gas Operator | Jan 2026 |
| 474 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2026 |
| 475 | Slawson Donald C | Wichita, KS 67202 | Oil & Gas Operator | Oct 2025 |
| 476 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2026 |
| 477 | Sloan Petroleum Service Inc | Guthrie, OK 73044 | Oil & Gas Operator | Feb 2026 |
| 478 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Apr 2026 |
| 479 | Smith Edward F | Avant, OK 74001-0024 | Oil & Gas Operator | Nov 2014 |
| 480 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 481 | Sooner Exploration & Development Co Inc | Enid, OK 73702-3525 | Oil & Gas Operator | Oct 2023 |
| 482 | Sooner Oil & Gas LLC | Fairview, OK 73737-1806 | Oil & Gas Operator | Feb 2026 |
| 483 | Sorrels J R Dba Cheyenne Oil Properties | Ponca City, OK 74601 | Oil & Gas Operator | Jul 2022 |
| 484 | Southern Management Inc | Camargo, OK 73835 | Oil Operator | Jun 1992 |
| 485 | Southwest Energy LP | Tulsa, OK 74136 | Oil & Gas Operator | Dec 2025 |
| 486 | SP Energy Development Company | Seattle, WA 98101-3277 | Oil & Gas Operator | Mar 2015 |
| 487 | Sparks Resources Inc | Bristow, OK 74010 | Oil & Gas Operator | Feb 2026 |
| 488 | Special Energy Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2026 |
| 489 | Spess Oil Company Inc | Cleveland, OK 74020-4617 | Oil & Gas Operator | Feb 2026 |
| 490 | Spring Operating Company | Edmond, OK 73034 | Oil & Gas Operator | Feb 2026 |
| 491 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 492 | Stalwart Energy Co | Tulsa, OK 74103-3518 | Oil & Gas Operator | Apr 2014 |
| 493 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | Feb 2026 |
| 494 | Stewart K Petroleum Corp | Edmond, OK 73013 | Oil & Gas Operator | Mar 2015 |
| 495 | Stoneriver Energy, LLC | Lubbock, TX 79424 | Oil & Gas Operator | Apr 2026 |
| 496 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | Apr 2026 |
| 497 | Sundown Energy, Inc. | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 498 | Sweetwater Exploration LLC | Norman, OK 73069-5636 | Oil & Gas Operator | Jan 2026 |
| 499 | SWN Production LLC | Spring, TX 77389-4954 | Oil & Gas Operator | Feb 2022 |
| 500 | T-K Exploration Company | Oklahoma City, OK 73102-7029 | Oil & Gas Operator | Mar 2015 |