| 401 | Phoenix Hydrocarbons Operating | Midland, TX 79702 | Oil & Gas Operator | Jun 2024 |
| 402 | Pierce Junction Petroleum Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2010 |
| 403 | Pioneer Natural Res. (GPC), Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 1998 |
| 404 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | Sep 2026 |
| 405 | Placid Oil Company | Houston, TX 77227 | Oil & Gas Operator | Mar 2008 |
| 406 | Plains Production Inc | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 1995 |
| 407 | PNG Operating Company | Oklahoma City, OK 73172 | Oil & Gas Operator | Sep 2026 |
| 408 | Poco Oil Co. | Houston, TX 77069 | Oil & Gas Operator | Mar 1997 |
| 409 | Poynor Corporation | Beaumont, TX 77706 | Oil & Gas Operator | Sep 2026 |
| 410 | Preferred Pipeline Corp. | Victoria, TX 77902 | Oil & Gas Operator | Jul 2026 |
| 411 | Presidio Exploration, Inc. | Englewood, CO 80155 | Oil & Gas Operator | May 1999 |
| 412 | Prime Operating Company | Midland, TX 79705 | Oil & Gas Operator | Sep 2026 |
| 413 | Pringle Resources, Inc. | Houston, TX 77019 | Oil & Gas Operator | Sep 2026 |
| 414 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 415 | Progas Properties, Inc. | New Braunfels, TX 78132 | Oil & Gas Operator | Sep 2026 |
| 416 | Proline Energy Resources Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Sep 2026 |
| 417 | Pyramid Exploration | Houston, TX 77241 | Oil & Gas Operator | Sep 1995 |
| 418 | Quail Creek Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Sep 2026 |
| 419 | Quisto Energy Corp. | Kerrville, TX 78029 | Oil & Gas Operator | Jan 1998 |
| 420 | R & S Investments | Tulsa, OK 74146-4743 | Oil Operator | Aug 2013 |
| 421 | Radley Electric, Inc. | Sourlake, TX 77659 | Oil & Gas Operator | Oct 2001 |
| 422 | Radley, Terry R., Operator | Sourlake, TX 77659 | Oil & Gas Operator | Apr 2006 |
| 423 | Raptor Resources, Inc. | Austin, TX 78701 | Oil & Gas Operator | Sep 2026 |
| 424 | Ratts, Robert V. Inc. | Bedford, TX 76021 | Oil & Gas Operator | Aug 2003 |
| 425 | Redwood Operating, Inc. | Houston, TX 77058 | Oil & Gas Operator | Sep 2026 |
| 426 | Regal Petroleum Services | Euless, TX 76039 | Oil & Gas Operator | Aug 2002 |
| 427 | Remora Management, LLC | The Woodlands, TX 77382 | Oil & Gas Operator | Sep 2026 |
| 428 | Remora Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Sep 2026 |
| 429 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | Sep 2026 |
| 430 | Resaca Resources, L.L.C. | Austin, TX 78746 | Oil & Gas Operator | Sep 2026 |
| 431 | Reserve Management, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Sep 2026 |
| 432 | Richardson Operating Company | Denver, CO 80237 | Oil & Gas Operator | Jul 2026 |
| 433 | Riddle Engineering Corp. | Corpus Christ, TX 78401 | Oil & Gas Operator | Jul 2011 |
| 434 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | Sep 2026 |
| 435 | Rincon Petroleum Corporation | Corpus Chrsti, TX 78427 | Oil & Gas Operator | Sep 2026 |
| 436 | Rio O & P LLC | Pasadena, TX 77504 | Oil Operator | Sep 2026 |
| 437 | Rio Petroleum, Inc. | Amarillo, TX 79102 | Oil & Gas Operator | Sep 2026 |
| 438 | Riseden Services, Inc. | Houston, TX 77256 | Oil & Gas Operator | Sep 1997 |
| 439 | Rising Star Energy, L.L.C. | Dallas, TX 75219 | Oil & Gas Operator | Aug 2006 |
| 440 | Rockstar Resources, LLC | Sourlake, TX 77659 | Oil & Gas Operator | Sep 2026 |
| 441 | Rockwall Marketing Corporation | Benbrook, TX 76126 | Oil & Gas Operator | Dec 2007 |
| 442 | Rodeo Resources, L.L.C. | Houston, TX 77079 | Oil & Gas Operator | Dec 2024 |
| 443 | Rox Exploration Inc | Norman, OK 73069-6301 | Oil & Gas Operator | Jul 2026 |
| 444 | Roy Jackson Energy Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 445 | Royal Oil & Gas Corp. | Indiana, PA 15701 | Oil & Gas Operator | Apr 2014 |
| 446 | Royal Production Company, Inc. | Corpus Christ, TX 78401 | Oil & Gas Operator | Sep 2026 |
| 447 | Rutherford Oil Corporation | Houston, TX 77046 | Oil & Gas Operator | Jun 2019 |
| 448 | RWJ Operating LLC | Dallas, TX 75201 | Oil & Gas Operator | Sep 2026 |
| 449 | S & S Energy | Englewood, CO 80112 | Oil & Gas Operator | Mar 2015 |
| 450 | S & S Operating Company, Inc. | Winnie, TX 77665 | Oil & Gas Operator | Sep 2026 |
| 451 | S & V Operating | Zephyr, TX 76890 | Oil & Gas Operator | Sep 2026 |
| 452 | Sabco Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2011 |
| 453 | Sabinal Resources, Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Sep 2026 |
| 454 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 455 | Samson Exploration LLC | Tulsa, OK 74101 | Oil & Gas Operator | Jul 2026 |
| 456 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 457 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 458 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2026 |
| 459 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2026 |
| 460 | Sanchez Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Sep 2026 |
| 461 | Sanchez-O'Brien Oil & Gas Corp | Houston, TX 77057 | Oil & Gas Operator | May 1998 |
| 462 | Saratoga Energy Corporation | Sourlake, TX 77659 | Oil & Gas Operator | Dec 2004 |
| 463 | Saratoga Oil Company | Batson, TX 77519 | Oil & Gas Operator | Sep 2026 |
| 464 | Saratoga Production Company LLC | Sourlake, TX 77659 | Oil Operator | Sep 2026 |
| 465 | Sarita Energy Resources, LTD. | Houston, TX 77277 | Oil & Gas Operator | Sep 2026 |
| 466 | Sawtooth, Inc. | Houston, TX 77024 | Oil & Gas Operator | Dec 2013 |
| 467 | Saxet Exploration Ent. Co., Inc. | Austin, TX 78731 | Oil Operator | Sep 2026 |
| 468 | Seabreeze Production Co | Hungerford, TX 77448 | Oil & Gas Operator | Sep 2026 |
| 469 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 470 | Sedona Oil & Gas Corporation | Dallas, TX 75231 | Oil & Gas Operator | Sep 2026 |
| 471 | Setex Oil Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jan 2000 |
| 472 | Shale Oil Co., Inc. | Liberty, TX 77575 | Oil & Gas Operator | Sep 2026 |
| 473 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Sep 2026 |
| 474 | Sideline Oil & Gas, L.P. | Friendswood, TX 77549 | Oil Operator | Sep 2026 |
| 475 | Silverbrook Operating II LLC | Barker, TX 77413 | Oil & Gas Operator | Sep 2026 |
| 476 | Silverbrook Operating, LLC | Barker, TX 77413 | Oil & Gas Operator | Sep 2026 |
| 477 | Sisters Operating Company | Victoria, TX 77904 | Oil & Gas Operator | Nov 2010 |
| 478 | Sizemore, James | Hardin, TX 77561 | Oil & Gas Operator | Jun 2003 |
| 479 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | Sep 2026 |
| 480 | Smith Petroleum Company | Spring, TX 77389 | Oil & Gas Operator | Sep 2026 |
| 481 | Smith Production Inc. | The Woodlands, TX 77381 | Oil & Gas Operator | Sep 2026 |
| 482 | Smith, L C Production | Jacksonville, TX 75766 | Oil Operator | Sep 2026 |
| 483 | Smith, L. C. | Jacksonville, TX 75766 | Oil & Gas Operator | Sep 2026 |
| 484 | SND Operating, L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2026 |
| 485 | Solatex Resources, LTD | Houston, TX 77257 | Oil & Gas Operator | Sep 2026 |
| 486 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 487 | Sonat Exploration Co. - Houston | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 488 | Sonora Petroleum Corp. | Austin, TX 78734 | Oil & Gas Operator | Sep 2026 |
| 489 | South Texas Operating Company | San Antonio, TX 78217 | Oil & Gas Operator | Sep 2026 |
| 490 | Southeastern Pipe Line Company | Tyler, TX 75711 | Oil & Gas Operator | Dec 2020 |
| 491 | Southern G Holdings, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2007 |
| 492 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 493 | Spi Operations LLC | Midland, TX 79710 | Oil & Gas Operator | Jan 2013 |
| 494 | Spicewood Operating Company, LLC | Austin, TX 78746 | Oil & Gas Operator | Sep 2026 |
| 495 | Spindletop Drilling Co. | Dallas, TX 75230 | Oil & Gas Operator | Sep 2026 |
| 496 | Spindletop Oil & Gas Co. | Dallas, TX 75230 | Oil & Gas Operator | Sep 2026 |
| 497 | Square Mile Energy, L.L.C. | Houston, TX 77057 | Oil & Gas Operator | Sep 2026 |
| 498 | SR Production Corp. | Liberty, TX 77575 | Oil & Gas Operator | Mar 2010 |
| 499 | St Johns Operating #1 LP | Houston, TX 77060 | Oil & Gas Operator | Aug 2023 |
| 500 | Standard Resources Corp. | Houston, TX 77063 | Oil & Gas Operator | Sep 2026 |