| 401 | Northwest Oil Company | Dallas, TX 75204 | Oil & Gas Operator | Jun 2014 |
| 402 | O G & E | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Feb 2014 |
| 403 | O K Swabbing Inc | Hennessey, OK 73742-0835 | Oil & Gas Operator | Feb 2024 |
| 404 | Oklahoma Energy Acquisitions LP | | Oil & Gas Operator | Feb 2024 |
| 405 | Oklahoma Liquid Resources Inc | Owasso, OK 74055-0841 | Oil & Gas Operator | Feb 2024 |
| 406 | Oklahoma Oil & Gas MGMT Inc | | Oil & Gas Operator | Feb 2024 |
| 407 | Oklahoma Oil Tactics Inc | Edmond, OK 73003-1351 | Oil & Gas Operator | Mar 2015 |
| 408 | Oklahoma Petroleum Allies LLC | Ardmore, OK 73401 | Oil Operator | Oct 2023 |
| 409 | Okland Oil Company | Oklahoma City, OK 73102-9022 | Oil & Gas Operator | Mar 2024 |
| 410 | Okmar Oil Company | Marietta, OH 45750 | Oil & Gas Operator | Jun 2005 |
| 411 | Okt Petroleum Company Inc | Oklahoma City, OK 73118-7425 | Oil & Gas Operator | Oct 2013 |
| 412 | Olympic Petroleum Company | Tulsa, OK 74114 | Oil & Gas Operator | Jun 1998 |
| 413 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2022 |
| 414 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 415 | Open Range Energy LLC | Jones, OK 73049 | Oil & Gas Operator | Jan 2024 |
| 416 | Orca Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | Mar 2024 |
| 417 | Otc Petroleum Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 418 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Mar 2024 |
| 419 | Paleo, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | May 2024 |
| 420 | Panadero Oil Company | Dallas, TX 75206 | Oil & Gas Operator | Apr 2002 |
| 421 | Panenergy Services Inc | Houston, TX 77525 | Oil & Gas Operator | May 2001 |
| 422 | Panhandle Trading Company | Houston, TX 77251-1642 | Oil & Gas Operator | Jun 2003 |
| 423 | Paradigm Petroleum Corporation | Abilene, TX 79605 | Oil & Gas Operator | May 2024 |
| 424 | Paramount Petroleum Corp | Dallas, TX 75374 | Oil Operator | Dec 2000 |
| 425 | Park Avenue Exploration Corp | Oklahoma City, OK 73102-5604 | Oil & Gas Operator | Sep 2011 |
| 426 | Parkway Petroleum, Inc. | Giddings, TX 78942 | Oil & Gas Operator | Jul 1997 |
| 427 | Parsons Engineering Corporation | Tulsa, OK 74137-7505 | Oil & Gas Operator | Oct 2017 |
| 428 | Partners Oil Company | Tulsa, OK 74135 | Oil & Gas Operator | Aug 1995 |
| 429 | Parwest Land Exploration, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Feb 2024 |
| 430 | Payrock Energy LLC | | Oil & Gas Operator | Feb 2023 |
| 431 | PBT Enterprises Inc | Garber, OK 73738-0262 | Oil & Gas Operator | May 2023 |
| 432 | Penner Energy Inc | Oklahoma City, OK 73120-1930 | Oil & Gas Operator | Mar 2024 |
| 433 | Penntex Resources, L.P. | State College, PA 16803 | Oil & Gas Operator | Mar 2016 |
| 434 | Petrocorp Incorporated | Tulsa, OK 74170 | Oil & Gas Operator | Nov 2021 |
| 435 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 436 | Petroleum Reserve Corporation | Plymouth MTNG, PA 19462 | Oil & Gas Operator | May 2008 |
| 437 | Petroleum Resources Co | Wichita, KS 67206 | Oil & Gas Operator | May 2000 |
| 438 | Phillips Oil Operating Co | Enid, OK 73703-4921 | Oil & Gas Operator | May 2019 |
| 439 | Phoenix Petrocorp, Inc. | McKinney, TX 75070 | Oil & Gas Operator | Mar 2024 |
| 440 | Pices Energy Production Co. | Alva, OK 73717-9512 | Oil & Gas Operator | Apr 2014 |
| 441 | Pike Oil & Gas Inc | Pittsfield, IL 62363 | Oil & Gas Operator | Oct 2020 |
| 442 | Plains Marketing LP | Cushing, OK 74023 | Oil & Gas Operator | Dec 2022 |
| 443 | Plainsmen Energy LLC | | Oil & Gas Operator | Mar 2024 |
| 444 | Pool, Lloyd Operating | Sandia Park, NM 87047 | Gas Operator | Dec 2013 |
| 445 | Priam Operating Company | Tulsa, OK 74152-0590 | Oil & Gas Operator | Jul 2022 |
| 446 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | May 2024 |
| 447 | Primary Natural Resources Inc. | Tulsa, OK 74136-6351 | Oil & Gas Operator | Mar 2023 |
| 448 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | May 2024 |
| 449 | Primexx Operating Corporation | Dallas, TX 75206 | Oil & Gas Operator | Jan 2024 |
| 450 | Protege Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Jan 2018 |
| 451 | Proven Reserves Management, Inc. | Dallas, TX 75370 | Oil & Gas Operator | Mar 2024 |
| 452 | PXP Gulf Coast Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 453 | Pyramid Oil Of America, Inc. | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2024 |
| 454 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Feb 2024 |
| 455 | R & H LLC | Ardmore, OK 73401-6329 | Oil & Gas Operator | Mar 2015 |
| 456 | R C Taylor Operating Company LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Mar 2024 |
| 457 | R E Blaik Inc | Edmond, OK 73013-6675 | Oil & Gas Operator | Mar 2024 |
| 458 | Ram Asset Management Co | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2015 |
| 459 | Ramco Energy Corporation | FT. Lauderdale, FL 33312 | Oil & Gas Operator | Dec 2008 |
| 460 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 461 | Rampage Energy Inc | Bristow, OK 74010-6415 | Oil & Gas Operator | Apr 2020 |
| 462 | Ramsey Property MGMT Inc | Oklahoma City, OK 73120-1955 | Oil & Gas Operator | Mar 2019 |
| 463 | Raw Crude Oil & Gas LLC | Oklahoma City, OK 73104-1801 | Oil & Gas Operator | Mar 2024 |
| 464 | RDH Enterprises, Inc. | El Reno, OK 73036 | Oil & Gas Operator | May 2015 |
| 465 | Red Eagle Oil Company | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2005 |
| 466 | Red Hawk Disposal LLC | | Oil Operator | Jun 2023 |
| 467 | Red Plains Oil & Gas LLC | Kingfisher, OK 73750-0364 | Oil & Gas Operator | Oct 2017 |
| 468 | Remora Operating, LLC | Houston, TX 77056 | Oil & Gas Operator | May 2024 |
| 469 | Renco Energy Inc | Calgary, AB T2H 0H6 | Oil & Gas Operator | Feb 2024 |
| 470 | Republic Resources Corporation | Oklahoma City, OK 73102-3081 | Oil & Gas Operator | May 2021 |
| 471 | Research Oil Company Inc | Norman, OK 73070-8776 | Oil & Gas Operator | Aug 2019 |
| 472 | Ricks Exploration Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 473 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2024 |
| 474 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | Mar 2024 |
| 475 | Robson Petroleum Company | Tulsa, OK 74104 | Oil & Gas Operator | Jan 1995 |
| 476 | Rogers Jerry L | Cushing, OK 74023-0911 | Oil & Gas Operator | Mar 2017 |
| 477 | Rose Petroleum Corp | Oklahoma City, OK 73146 | Oil & Gas Operator | Feb 2015 |
| 478 | Roseland Oil & Gas Inc | Rockwall, TX 75087 | Oil & Gas Operator | Feb 2003 |
| 479 | Royal Oaks Petroleum Corp | Fort Worth, TX 76116 | Oil & Gas Operator | Dec 2001 |
| 480 | Royalty Energy Development LLC | Edmond, OK 73083 | Oil & Gas Operator | Mar 2024 |
| 481 | RR Oil Well Operations LLC | | Oil & Gas Operator | Mar 2024 |
| 482 | Russell D Meloy Oil & Gas Co | Enid, OK 73703-1623 | Oil & Gas Operator | Feb 2024 |
| 483 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2024 |
| 484 | Salty Dog Disposal LLC | | Oil Operator | Apr 2024 |
| 485 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 486 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2024 |
| 487 | Sandridge Energy, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2018 |
| 488 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2024 |
| 489 | Santa Fe Energy Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2015 |
| 490 | Santa Rita Resources Inc & Subs | | Oil & Gas Operator | Mar 2015 |
| 491 | Schmid Properties Inc | Hico, TX 76457 | Oil & Gas Operator | May 2024 |
| 492 | Schonwald Supply Company | Oklahoma City, OK 73101-1571 | Oil & Gas Operator | May 1999 |
| 493 | Scoggins Production Company | Cleo Springs, OK 73729-9732 | Oil & Gas Operator | May 2022 |
| 494 | Scoggins Production LLC | | Oil & Gas Operator | Mar 2024 |
| 495 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 496 | Seals And Brown Oil Operating | Norman, OK 73072-3020 | Oil & Gas Operator | Mar 2024 |
| 497 | Service Drilling Co. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 1998 |
| 498 | Service Drilling Co., L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 2003 |
| 499 | Seven Horses LLC | Alva, OK 73717-5004 | Oil & Gas Operator | Mar 2024 |
| 500 | Shadow-Del Oil Company | Kiefer, OK 74041-0453 | Oil & Gas Operator | Jul 2015 |