| 401 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | May 2026 |
| 402 | Oxley Petroleum Company | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 403 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Jul 2026 |
| 404 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 405 | P.O.&G. Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Jul 2026 |
| 406 | Panhandle Oil & Gas Consultants Inc | Woodward, OK 73802-5011 | Oil & Gas Operator | Jul 2015 |
| 407 | Pantera Energy Company | Amarillo, TX 79101 | Oil & Gas Operator | Jul 2026 |
| 408 | Pardee Production Co. | Skiatook, OK 74070 | Oil & Gas Operator | Mar 2021 |
| 409 | Parker & Parsley Dev Co | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 410 | Parker & Parsley Dev LP | Irving, TX 75039-3745 | Oil & Gas Operator | Mar 2015 |
| 411 | Patron Energy LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2015 |
| 412 | Payne W C Family Trust | Oklahoma City, OK 73116-9044 | Oil & Gas Operator | Mar 2015 |
| 413 | Peak Operating Oil & Gas LLC | Wichita, KS 67226 | Oil & Gas Operator | Apr 2026 |
| 414 | Pennzoil Petroleum Company | Houston, TX 77252 | Oil & Gas Operator | Nov 1999 |
| 415 | Pet-Ex Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2026 |
| 416 | Petra Petroleum Inc | Littleton, CO 80160-0319 | Oil & Gas Operator | Jun 2005 |
| 417 | Petro Speed Inc | Norman, OK 73069-8116 | Oil & Gas Operator | Mar 2015 |
| 418 | Petroleum Development Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2026 |
| 419 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 420 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | Jul 2026 |
| 421 | Polaris Energy Dev Co | Tulsa, OK 74135 | Oil & Gas Operator | Apr 2000 |
| 422 | Powerline Energy Corporation | Arlington, TX 76015 | Oil & Gas Operator | Jul 2026 |
| 423 | Premier Resources LTD | Denver, CO 80237 | Oil & Gas Operator | Jul 2002 |
| 424 | Prentice, Napier & Green, Inc. | Oklahoma City, OK 73142 | Oil & Gas Operator | May 2026 |
| 425 | Presidio Petroleum LLC | Canadian, TX 79014 | Oil & Gas Operator | Jul 2026 |
| 426 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2026 |
| 427 | Primary Natural Resources III LLC | Tulsa, OK 74136-6351 | Oil & Gas Operator | May 2026 |
| 428 | Primary Natural Resources Inc. | Tulsa, OK 74136-6351 | Oil & Gas Operator | Mar 2023 |
| 429 | Prime Energy Corp | Charleston, WV 25301-1707 | Oil & Gas Operator | Sep 2015 |
| 430 | Prime Operating Company | Midland, TX 79705 | Oil & Gas Operator | Jul 2026 |
| 431 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 432 | Proex Energy Management, L.L.C. | Spring, TX 77386 | Oil & Gas Operator | Jul 2026 |
| 433 | Prospective Investment & Trading | Scottsdale, AZ 85261-4190 | Oil & Gas Operator | Jun 2016 |
| 434 | Protege Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Jan 2018 |
| 435 | Providence Energy Corporation | Broken Arrow, OK 74013-3783 | Oil & Gas Operator | Feb 1994 |
| 436 | Providence Oil & Gas Corp | Tulsa, OK 74135-5463 | Oil & Gas Operator | May 2005 |
| 437 | Pruitt Operating Company LLC | Ratliff City, OK 73481-5802 | Oil & Gas Operator | May 2026 |
| 438 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2026 |
| 439 | Quail Oil & Gas LC | Garden City, KS 67846 | Oil & Gas Operator | May 2026 |
| 440 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Apr 2026 |
| 441 | Questa Energy Corporation | Amarillo, TX 79159 | Oil & Gas Operator | Jul 2026 |
| 442 | Questa Oil & Gas Co. | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2015 |
| 443 | Questar Explor & Prod Co | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2017 |
| 444 | R & A Moore, Inc. | Cleburne, TX 76033 | Oil & Gas Operator | Jul 2026 |
| 445 | R C Taylor Operating Company LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2026 |
| 446 | R M S Oil & Gas | Amarillo, TX 79101-2445 | Oil & Gas Operator | Sep 1997 |
| 447 | Ra-Jac LLC | Norman, OK 73069 | Oil & Gas Operator | May 2026 |
| 448 | Raker Resources LLC | Houston, TX 77042 | Oil & Gas Operator | Jul 2026 |
| 449 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 450 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 451 | Rasmussen, Hal J. Operating, Inc | Midland, TX 79701 | Oil & Gas Operator | Apr 2009 |
| 452 | Raydon Exploration, Inc. | Oklahoma City, OK 73118 | Oil & Gas Operator | Jul 2026 |
| 453 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 454 | Reading & Bates Petroleum Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2009 |
| 455 | Red Rock Resources, L.L.C. | Wichita Falls, TX 76310 | Oil & Gas Operator | Apr 2026 |
| 456 | Redland Resources LLC | Oklahoma City, OK 73127 | Oil & Gas Operator | May 2026 |
| 457 | Redline Energy LLC | Dover, OK 73734 | Oil & Gas Operator | May 2026 |
| 458 | Redstone Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2020 |
| 459 | Regency Exploration Inc | Oklahoma City, OK 73102-5605 | Oil & Gas Operator | Mar 1999 |
| 460 | Resources Investment Corp | Denver, CO 80202 | Oil & Gas Operator | Sep 2018 |
| 461 | Revelation Resources | Cypress, TX 77410-2578 | Oil & Gas Operator | Apr 2026 |
| 462 | Richard W Thompson Inc | Plano, TX 75075 | Oil & Gas Operator | Jul 2019 |
| 463 | Richardson WM S | Duncan, OK 73533 | Oil Operator | Jun 2013 |
| 464 | Ricks Exploration Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 465 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 466 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | May 2026 |
| 467 | RL&B Energy LLC | Wichita Falls, TX 76230 | Oil & Gas Operator | Apr 2026 |
| 468 | Roberts & Murphy, Inc. | Shreveport, LA 71137 | Oil & Gas Operator | Apr 2016 |
| 469 | Rosewood Resources Inc | Dallas, TX 75201 | Oil & Gas Operator | Jul 2026 |
| 470 | Royalty Energy Development LLC | Edmond, OK 73003 | Oil & Gas Operator | May 2026 |
| 471 | RTC Resources, LLP | Weatherford, OK 73096 | Oil & Gas Operator | Jul 2026 |
| 472 | Russell D Meloy Oil & Gas Co | Enid, OK 73703-1623 | Oil & Gas Operator | Apr 2026 |
| 473 | Ryan Petroleum Corp | Oklahoma City, OK 73102-9024 | Oil & Gas Operator | Aug 1994 |
| 474 | S A C Operating Inc | Woodward, OK 73802-1749 | Oil & Gas Operator | Jan 1999 |
| 475 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2026 |
| 476 | Samson Exploration LLC | Tulsa, OK 74101 | Oil & Gas Operator | May 2026 |
| 477 | Samson Gas Producing Company | Tulsa, OK 74103 | Oil & Gas Operator | May 2001 |
| 478 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 479 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2026 |
| 480 | Sandridge Energy, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2018 |
| 481 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Jul 2026 |
| 482 | Savoy Energy LP | Traverse City, MI 49685-1560 | Oil & Gas Operator | May 2026 |
| 483 | Schmid Properties, Inc. | Hico, TX 76457 | Oil & Gas Operator | Jul 2026 |
| 484 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 485 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 486 | Seaport Inc | Oklahoma City, OK 73131 | Oil & Gas Operator | Apr 2026 |
| 487 | Sec Production Inc | Edmond, OK 73013-3709 | Oil & Gas Operator | May 2026 |
| 488 | Senax Inc | Tulsa, OK 74105-2206 | Oil & Gas Operator | Apr 2026 |
| 489 | Shar Alan Oil Company | | Oil & Gas Operator | Oct 2005 |
| 490 | Shell Oil Company | Houston, TX 77210 | Oil & Gas Operator | Apr 2015 |
| 491 | Shell Western Expl & Prod Inc | Houston, TX 77251 | Oil & Gas Operator | Mar 2015 |
| 492 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Apr 2026 |
| 493 | Sho-Bar Energy Inc | Harper, KS 67058 | Oil & Gas Operator | Apr 2026 |
| 494 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Apr 2026 |
| 495 | Singer Oil Co LLC | Hennessey, OK 73742 | Oil & Gas Operator | May 2026 |
| 496 | Singer-Fleischaker Oil Op Co | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2002 |
| 497 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Jul 2026 |
| 498 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2026 |
| 499 | Sloan Petroleum Service Inc | Guthrie, OK 73044 | Oil & Gas Operator | May 2026 |
| 500 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Jul 2026 |