| 401 | Petro-Hunt Corporation | Dallas, TX 75201 | Oil & Gas Operator | Jun 2003 |
| 402 | Petro-Hunt, L.L.C. | Dallas, TX 75201 | Oil & Gas Operator | Sep 2025 |
| 403 | Petronomics Petroleum, Inc. | Austin, TX 78734 | Oil & Gas Operator | Jan 1995 |
| 404 | Pharaoh & Associates, Inc. | Houston, TX 77252 | Oil & Gas Operator | Aug 2002 |
| 405 | Phoenix Fund, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Jun 2000 |
| 406 | Pickens Company, Inc., The | Dallas, TX 75225 | Oil & Gas Operator | Dec 2024 |
| 407 | Placer Oil Co. | Sugar Land, TX 77479 | Oil & Gas Operator | Apr 2008 |
| 408 | Placid Oil Company | Houston, TX 77227 | Oil & Gas Operator | Mar 2008 |
| 409 | Plains Marketing, LP | Cushing, OK 74023 | Oil Operator | Jan 2012 |
| 410 | Plains Petroleum Operating Co. | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 411 | Pmo | Garland, TX 75040 | Oil & Gas Operator | Feb 2018 |
| 412 | Premier Minerals, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2025 |
| 413 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Sep 2025 |
| 414 | Producers Engineering Company | Destin, FL 32541 | Oil & Gas Operator | Sep 1999 |
| 415 | Progenies Operating LLC | Austin, TX 78746 | Oil & Gas Operator | Sep 2025 |
| 416 | Property Development Group, Inc. | San Antonio, TX 78212 | Oil & Gas Operator | Sep 2025 |
| 417 | R. K. G. Engineering, Inc. | Odessa, TX 79760 | Oil & Gas Operator | Sep 2025 |
| 418 | R.C.I. Energy | Alice, TX 78333 | Oil & Gas Operator | Sep 2025 |
| 419 | Ram Operating Company, Inc. | Houston, TX 77002 | Oil & Gas Operator | Sep 2012 |
| 420 | Ram Operating Inc. | Browns, IL 62818 | Oil & Gas Operator | Aug 2008 |
| 421 | Rec Well Service, Inc. | Pleasanton, TX 78064 | Oil & Gas Operator | Jul 2008 |
| 422 | Red Arrow Energy, LLC | Houston, TX 77027 | Oil & Gas Operator | Jul 2016 |
| 423 | Regal Petroleum Services | Euless, TX 76039 | Oil & Gas Operator | Aug 2002 |
| 424 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | Sep 2025 |
| 425 | Republic Resources, LLC. | San Antonio, TX 78212 | Oil & Gas Operator | Sep 2025 |
| 426 | Reserve Management, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Sep 2025 |
| 427 | Resource Expl & Prod, Inc. | Salado, TX 76571 | Oil & Gas Operator | Sep 2025 |
| 428 | Riata Energy Inc | Oklahoma City, OK 73101 | Oil & Gas Operator | Apr 2008 |
| 429 | Richey Properties, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Sep 2025 |
| 430 | Rickaway Energy, Corp. | Pleasanton, TX 78064 | Oil & Gas Operator | Sep 2025 |
| 431 | Ricochet Energy, Inc. | San Antonio, TX 78258 | Oil & Gas Operator | Sep 2025 |
| 432 | Ridgemar Energy Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Jan 2025 |
| 433 | Riggs, Don R. | San Antonio, TX 78270 | Oil & Gas Operator | Aug 2003 |
| 434 | Riley Exploration Opg Co, LLC | La Grange, TX 78945 | Oil & Gas Operator | Sep 2025 |
| 435 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | Sep 2025 |
| 436 | Rio Bravo Royalty Co. | Bandera, TX 78003 | Oil & Gas Operator | Aug 2003 |
| 437 | Rio-Tex, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Sep 2025 |
| 438 | Ritchie, H. G. Jr. | Taft, TX 78390 | Oil & Gas Operator | Sep 2025 |
| 439 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 440 | Roc Operating, Inc. | Plano, TX 75093 | Oil & Gas Operator | Oct 2008 |
| 441 | Rock Creek Oil, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Nov 2019 |
| 442 | Rock Solid Operating, LLC | Southlake, TX 76092 | Oil Operator | Sep 2021 |
| 443 | Roma Oil And Gas, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2025 |
| 444 | Rosewood Resources, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Sep 2025 |
| 445 | Royko Oil Company | Horseshoe Bay, TX 78657 | Oil & Gas Operator | Sep 2025 |
| 446 | S & L Oil Field Services | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Jan 1999 |
| 447 | Sabinal Resources, Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Sep 2025 |
| 448 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Sep 2025 |
| 449 | Sage Energy Company | San Antonio, TX 78215 | Oil & Gas Operator | Sep 2025 |
| 450 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | May 2025 |
| 451 | Sanchez Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Sep 2025 |
| 452 | Sanchez-O'Brien Oil & Gas Corp | Houston, TX 77057 | Oil & Gas Operator | May 1998 |
| 453 | Sandia Energy Corporation-NM | Holdenville, OK 74848 | Oil & Gas Operator | Aug 2003 |
| 454 | Sandstone Operating Company, Inc | Odessa, TX 79762 | Oil & Gas Operator | Jul 1995 |
| 455 | Santana Energy Services, LLC | Baton Rouge, LA 70809 | Oil & Gas Operator | Sep 2025 |
| 456 | Satex Energy, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Aug 2003 |
| 457 | Sbog, LLC | Granbury, TX 76048 | Oil & Gas Operator | Feb 2021 |
| 458 | Seago Petroleum, Inc. | Abilene, TX 79606 | Oil & Gas Operator | Sep 2025 |
| 459 | Seagull Operating Co., Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jan 2025 |
| 460 | Seco Production Company | Midland, TX 79708 | Oil & Gas Operator | Aug 2003 |
| 461 | Sedco Resources Inc | Kerrville, TX 78029 | Oil & Gas Operator | Sep 2025 |
| 462 | Seeker Oil Company, Incorporated | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2025 |
| 463 | Senora Resources, Inc. | Dime Box, TX 77853 | Oil & Gas Operator | Sep 2025 |
| 464 | Serra Energy, Inc. | Hailey, ID 83333 | Oil & Gas Operator | May 2011 |
| 465 | Setex Oil And Gas Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2012 |
| 466 | Shana Petroleum Company | Dallas, TX 75206 | Oil & Gas Operator | Aug 2002 |
| 467 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 468 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Sep 2025 |
| 469 | Shield Petroleum | College Sta, TX 77845 | Oil & Gas Operator | Sep 2025 |
| 470 | Showdown Energy Corporation | Dallas, TX 75230 | Oil & Gas Operator | Aug 2003 |
| 471 | Showdown Operating, Inc. | Dallas, TX 75230 | Oil & Gas Operator | May 1996 |
| 472 | Sien Operating Company, LLC | San Antonio, TX 78209 | Oil Operator | May 2023 |
| 473 | Sierra Exploration Company | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2008 |
| 474 | Silver Anchor Resources LLC | Azle, TX 76020 | Oil & Gas Operator | Sep 2025 |
| 475 | Silver Rock Energy, LLC | Terrell, TX 75160 | Oil Operator | Sep 2025 |
| 476 | Silverbow Resources Oper, LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2025 |
| 477 | Single Barrel Oil And Gas LLC | Granbury, TX 76048 | Oil & Gas Operator | Sep 2025 |
| 478 | Sisters Operating Company | Victoria, TX 77904 | Oil & Gas Operator | Nov 2010 |
| 479 | Skidmore Energy,Inc. | Salado, TX 76571 | Oil & Gas Operator | Jun 1999 |
| 480 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | Sep 2025 |
| 481 | Smal Energy Corp | Tyler, TX 75710 | Oil & Gas Operator | Oct 1995 |
| 482 | SN Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 483 | Snow Operating Co., Inc. | Haltom City, TX 76117 | Oil & Gas Operator | Feb 2024 |
| 484 | Solano Gas Processing, Inc. | Austin, TX 78759 | Oil & Gas Operator | Aug 1998 |
| 485 | Somex Energy Company | San Antonio, TX 78230 | Oil & Gas Operator | Mar 2002 |
| 486 | South Oil, Inc. | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 487 | South Texas Operating Company | San Antonio, TX 78217 | Oil & Gas Operator | Sep 2025 |
| 488 | Southwest Land & Minerals, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Aug 2003 |
| 489 | Southwest Oil & Land, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Dec 1999 |
| 490 | Spiller Operating Co., Inc. | Round Rock, TX 78665 | Oil & Gas Operator | May 2015 |
| 491 | Spur Operating Co. | Austin, TX 78701 | Oil & Gas Operator | Sep 2025 |
| 492 | Square One Corporation | Giddings, TX 78942 | Oil & Gas Operator | Dec 2012 |
| 493 | Starr Operating Company | Austin, TX 78759 | Oil & Gas Operator | Sep 2025 |
| 494 | Sto Operating Company | San Antonio, TX 78258 | Oil & Gas Operator | Sep 2025 |
| 495 | Stoneburner Exploration, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Oct 1997 |
| 496 | Stonegate Operators, Inc. | Addison, TX 75001 | Oil Operator | Sep 2025 |
| 497 | Stonegate Production Company,LLC | Houston, TX 77024 | Oil & Gas Operator | Sep 2025 |
| 498 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | Sep 2025 |
| 499 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | Sep 2025 |
| 500 | Stubbs, J. W. | Suwanee, GA 30024 | Oil & Gas Operator | Mar 2008 |