| 401 | Petroleum Reserve Corporation | Plymouth MTNG, PA 19462 | Oil & Gas Operator | May 2008 |
| 402 | Petroleum Resources Co | Wichita, KS 67206 | Oil & Gas Operator | May 2000 |
| 403 | Phillips Oil Operating Co | Enid, OK 73703-4921 | Oil & Gas Operator | May 2019 |
| 404 | Phoenix Petrocorp, Inc. | McKinney, TX 75070 | Oil & Gas Operator | Mar 2026 |
| 405 | Pices Energy Production Co. | Alva, OK 73717-9512 | Oil & Gas Operator | Apr 2014 |
| 406 | Pike Oil & Gas Inc | Pittsfield, IL 62363 | Oil & Gas Operator | Oct 2020 |
| 407 | Plainsmen Energy LLC | Enid, OK 73703-5747 | Oil & Gas Operator | Mar 2026 |
| 408 | Pollok Energy LLC | Tulsa, OK 74159 | Oil & Gas Operator | Mar 2026 |
| 409 | Pool, Lloyd Operating | Sandia Park, NM 87047 | Gas Operator | Dec 2013 |
| 410 | Priam Operating Company | Tulsa, OK 74114 | Oil & Gas Operator | Jul 2022 |
| 411 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Jun 2026 |
| 412 | Primary Natural Resources Inc. | Tulsa, OK 74136-6351 | Oil & Gas Operator | Mar 2023 |
| 413 | Prime Operating Company | Midland, TX 79705 | Oil & Gas Operator | Jun 2026 |
| 414 | Primexx Operating Corporation | Dallas, TX 75206 | Oil & Gas Operator | Mar 2024 |
| 415 | Protege Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Jan 2018 |
| 416 | Proven Reserves Management, Inc. | Dallas, TX 75370 | Oil & Gas Operator | Mar 2026 |
| 417 | PXP Gulf Coast Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 418 | Pyramid Oil Of America, Inc. | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2026 |
| 419 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Mar 2026 |
| 420 | R & H LLC | Ardmore, OK 73401-6329 | Oil & Gas Operator | Mar 2015 |
| 421 | R E Blaik Inc | Edmond, OK 73013-6675 | Oil & Gas Operator | Apr 2026 |
| 422 | Ram Asset Management Co | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2015 |
| 423 | Ramco Energy Corporation | FT. Lauderdale, FL 33312 | Oil & Gas Operator | Dec 2008 |
| 424 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 425 | Rampage Energy Inc | Bristow, OK 74010-6415 | Oil & Gas Operator | Apr 2020 |
| 426 | Ramsey Property MGMT Inc | Oklahoma City, OK 73120-1955 | Oil & Gas Operator | Mar 2019 |
| 427 | Raw Crude Oil & Gas, L.L.C. | Norman, OK 73069 | Oil & Gas Operator | Mar 2026 |
| 428 | RDH Enterprises Inc | El Reno, OK 73036 | Oil & Gas Operator | May 2015 |
| 429 | Red Eagle Oil Company | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2005 |
| 430 | Red Plains Oil & Gas LLC | Kingfisher, OK 73750 | Oil & Gas Operator | Oct 2017 |
| 431 | Redland Resources LLC | Oklahoma City, OK 73127 | Oil & Gas Operator | Apr 2026 |
| 432 | Remora Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Jun 2026 |
| 433 | Renco Energy Inc | Calgary, AB T2H 0H6 | Oil & Gas Operator | Mar 2026 |
| 434 | Republic Resources Corporation | Oklahoma City, OK 73102-3081 | Oil & Gas Operator | May 2021 |
| 435 | Research Oil Company Inc | Norman, OK 73070-8776 | Oil & Gas Operator | Aug 2019 |
| 436 | Revolution Resources III, LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Mar 2026 |
| 437 | Ricks Exploration Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 438 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 439 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | Apr 2026 |
| 440 | Robson Petroleum Company | Tulsa, OK 74104 | Oil & Gas Operator | Jan 1995 |
| 441 | Rogers Jerry L | Cushing, OK 74023-0911 | Oil & Gas Operator | Mar 2017 |
| 442 | Rose Petroleum Corp | Oklahoma City, OK 73146 | Oil & Gas Operator | Feb 2015 |
| 443 | Roseland Oil & Gas Inc | Rockwall, TX 75087 | Oil & Gas Operator | Feb 2003 |
| 444 | Royalty Energy Development LLC | Edmond, OK 73003 | Oil & Gas Operator | Apr 2026 |
| 445 | RR Oil Well Operations LLC | Ringwood, OK 73768 | Oil & Gas Operator | Mar 2026 |
| 446 | Russell D Meloy Oil & Gas Co | Enid, OK 73703-1623 | Oil & Gas Operator | Mar 2026 |
| 447 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jun 2026 |
| 448 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 449 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2026 |
| 450 | Sandridge Energy, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2018 |
| 451 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Jun 2026 |
| 452 | Santa Fe Energy Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2015 |
| 453 | Santa Rita Resources Inc & Subs | | Oil & Gas Operator | Mar 2015 |
| 454 | Schmid Properties, Inc. | Hico, TX 76457 | Oil & Gas Operator | Jun 2026 |
| 455 | Schonwald Supply Company | Oklahoma City, OK 73101-1571 | Oil & Gas Operator | May 1999 |
| 456 | Scoggins Production Company | Cleo Springs, OK 73729-9732 | Oil & Gas Operator | May 2022 |
| 457 | Scoggins Production LLC | Enid, OK 73703-3002 | Oil & Gas Operator | Apr 2026 |
| 458 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 459 | Seals And Brown Oil Operating | Norman, OK 73072-3020 | Oil & Gas Operator | Sep 2024 |
| 460 | Service Drilling Co. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 1998 |
| 461 | Service Drilling Co., L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 2003 |
| 462 | Seven Horses LLC | Alva, OK 73717-5004 | Oil & Gas Operator | Mar 2026 |
| 463 | Shadow-Del Oil Company | Kiefer, OK 74041-0453 | Oil & Gas Operator | Jul 2015 |
| 464 | Shannon Petroleum Inc | Tulsa, OK 74136-4603 | Oil & Gas Operator | Oct 2016 |
| 465 | Shell Western Expl & Prod Inc | Houston, TX 77251 | Oil & Gas Operator | Mar 2015 |
| 466 | Shelly Energy Inc | Berwyn, PA 19312 | Oil & Gas Operator | Mar 2026 |
| 467 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Apr 2026 |
| 468 | Singer Oil Company | Oklahoma City, OK 73148 | Oil & Gas Operator | Feb 2026 |
| 469 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Jun 2026 |
| 470 | Sloan Petroleum Service Inc | Guthrie, OK 73044 | Oil & Gas Operator | Mar 2026 |
| 471 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Jun 2026 |
| 472 | Smiley Drilling Co | Oklahoma City, OK 73156-0773 | Oil & Gas Operator | Apr 1999 |
| 473 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 474 | Sooner Acquisition Corp | Wichita, KS 67206 | Oil & Gas Operator | Sep 1993 |
| 475 | Sooner Exploration & Development Co Inc | Enid, OK 73702-3525 | Oil & Gas Operator | Oct 2023 |
| 476 | South Forty Inc (The) | Laverne, OK 73848 | Oil & Gas Operator | Mar 2015 |
| 477 | Southwest Energy Development Inc | Bison, OK 73720 | Oil & Gas Operator | Mar 2026 |
| 478 | Southwest Energy LP | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2026 |
| 479 | Southwest Royalties, Inc. | Midland, TX 79710 | Oil & Gas Operator | Jun 2026 |
| 480 | SP Energy Development Company | Seattle, WA 98101-3277 | Oil & Gas Operator | Mar 2015 |
| 481 | Special Energy Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Jun 2026 |
| 482 | Spess Oil Company Inc | Cleveland, OK 74020-4617 | Oil & Gas Operator | Apr 2026 |
| 483 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 484 | Staghorn Energy, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2026 |
| 485 | Staghorn Petroleum II LLC | Tulsa, OK 74103-3500 | Oil & Gas Operator | Apr 2026 |
| 486 | Staghorn Petroleum LLC | Tulsa, OK 74103-3500 | Oil & Gas Operator | Mar 2026 |
| 487 | Staghorn Resources, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2015 |
| 488 | Startex Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Jun 2026 |
| 489 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | Mar 2026 |
| 490 | Stevens & Tull, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jun 2000 |
| 491 | Stewart K Petroleum Corp | Edmond, OK 73013 | Oil & Gas Operator | Mar 2015 |
| 492 | Stillwater Oil & Gas | Irving, TX 75062 | Oil & Gas Operator | Mar 2015 |
| 493 | Stoneriver Energy, LLC | Lubbock, TX 79424 | Oil & Gas Operator | Jun 2026 |
| 494 | STP Cherokee Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2014 |
| 495 | STP Newco Inc | Oklahoma City, OK 73102-5641 | Oil & Gas Operator | Jul 2021 |
| 496 | Strat Land Exploration Company | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2026 |
| 497 | Stride Energy LLC | Piedmont, OK 73078 | Oil & Gas Operator | Mar 2026 |
| 498 | Sullivan & Co. | Tulsa, OK 74114 | Oil & Gas Operator | May 2022 |
| 499 | Sullivan And Company LLC | Tulsa, OK 74119 | Oil & Gas Operator | Mar 2026 |
| 500 | Sundance Energy Oklahoma LLC Dba Seo LLC | Denver, CO 80202-3620 | Oil & Gas Operator | Nov 2021 |