| 301 | O Hill Enterprises, Inc. | La Grange, TX 78945 | Oil & Gas Operator | Jan 2014 |
| 302 | O'Benco, Inc. | Shreveport, LA 71136 | Oil & Gas Operator | Sep 2025 |
| 303 | O'Ryan Oil And Gas | Odessa, TX 79768 | Oil & Gas Operator | Sep 2025 |
| 304 | Oak Resources Inc | Tulsa, OK 74153 | Oil & Gas Operator | Aug 2013 |
| 305 | Odyssey Petroleum Company | Houston, TX 77010 | Oil & Gas Operator | Apr 1995 |
| 306 | Ohlhausen Oil Company | Abilene, TX 79608 | Oil & Gas Operator | Sep 2025 |
| 307 | Oil & Gas Operations | Midland, TX 79706 | Oil & Gas Operator | Sep 2025 |
| 308 | Oil Rock Resources, LLC | Weatherford, TX 76088 | Oil & Gas Operator | Jan 2024 |
| 309 | Ok Arena Operating Company | Oklahoma City, OK 73101 | Oil & Gas Operator | Sep 2025 |
| 310 | Omar Operating Company | Midland, TX 79702 | Oil & Gas Operator | Sep 2013 |
| 311 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 312 | Pace Petroleum Company | Dallas, TX 75206 | Oil & Gas Operator | Sep 2025 |
| 313 | Pantera Energy Company | Amarillo, TX 79101 | Oil & Gas Operator | Sep 2025 |
| 314 | Par Producing Company | Snyder, TX 79550 | Oil & Gas Operator | Jun 2017 |
| 315 | Paragon Corporation | Abilene, TX 79604 | Oil & Gas Operator | Sep 2025 |
| 316 | Parallel Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Jan 2010 |
| 317 | Patrick Pet. Corp. Of Michigan | Houston, TX 77227 | Oil & Gas Operator | Aug 1995 |
| 318 | Patterson Petroleum LP | Snyder, TX 79550 | Oil & Gas Operator | Mar 2008 |
| 319 | Patterson Petroleum, Inc. | Snyder, TX 79550 | Oil & Gas Operator | Feb 2000 |
| 320 | Patton Exploration, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Sep 2025 |
| 321 | Payne Petroleum | Abilene, TX 79604 | Oil & Gas Operator | Sep 2025 |
| 322 | Ped Oil Corporation | Midland, TX 79702 | Oil & Gas Operator | Sep 2025 |
| 323 | Peregrine Petroleum PRTNR, LTD. | Dallas, TX 75201 | Oil & Gas Operator | Sep 2025 |
| 324 | Permian Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 325 | Petex | Breckenridge, TX 76424 | Oil & Gas Operator | Sep 2025 |
| 326 | Petra Oleum Corp. | Midland, TX 79702 | Oil & Gas Operator | Sep 2025 |
| 327 | Petroleum Technical Services Co. | Midland, TX 79707 | Oil & Gas Operator | Dec 2004 |
| 328 | Petrosource Energy Corporation | Fort Worth, TX 76112 | Oil & Gas Operator | Sep 2025 |
| 329 | Petrotex, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Aug 2003 |
| 330 | Pgi Operating, LLC | Sweetwater, TX 79556 | Oil Operator | Sep 2025 |
| 331 | Phillips, Bob | Weatherford, TX 76086 | Oil & Gas Operator | Nov 2019 |
| 332 | Phoenix Petrocorp, Inc. | McKinney, TX 75070 | Oil & Gas Operator | Jul 2025 |
| 333 | Pittencrieff America, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Feb 2003 |
| 334 | Plains Exploration & Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Jul 2013 |
| 335 | Plains Petroleum Operating Co. | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 336 | Plantation Operating, LLC | Houston, TX 77041 | Oil & Gas Operator | Nov 2011 |
| 337 | Powell, A. Brandt | Coleman, TX 76834 | Oil & Gas Operator | Mar 1999 |
| 338 | Powell, A. Brandt Co. | Hawley, TX 79525 | Oil & Gas Operator | Sep 2025 |
| 339 | Prairie Petroleum, Inc | Plano, TX 75093 | Oil & Gas Operator | May 1999 |
| 340 | Presley Prod Investments, LLC | Abilene, TX 79604 | Oil Operator | Sep 2025 |
| 341 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Sep 2025 |
| 342 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 343 | Probe Exploration Company | Abilene, TX 79605 | Oil & Gas Operator | Sep 2025 |
| 344 | Proco Operating Co., Inc. | Graford, TX 76449 | Oil & Gas Operator | Sep 2025 |
| 345 | Production Operators Of TX, LLC | Abilene, TX 79605 | Oil & Gas Operator | Sep 2025 |
| 346 | Proline Energy Resources Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Sep 2025 |
| 347 | Purvis, J. H. | Midland, TX 79702 | Oil & Gas Operator | Dec 1994 |
| 348 | Quail Operating, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Sep 2025 |
| 349 | Quail Well Service, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Sep 2025 |
| 350 | R & R Well Service, Inc. | Arlington, TX 76012 | Oil & Gas Operator | Sep 2025 |
| 351 | R K Petroleum Corp. | Midland, TX 79708 | Oil & Gas Operator | May 2024 |
| 352 | Rainey, Wayne | Sweetwater, TX 79556 | Oil & Gas Operator | Feb 2019 |
| 353 | Rampart Petroleum, Incorporated | Buffalo Gap, TX 79508 | Oil & Gas Operator | Jan 2009 |
| 354 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 355 | Raymond, WM. C. | Rockdale, TX 76567 | Oil & Gas Operator | Sep 2025 |
| 356 | Redbud E & P, Inc. | Giddings, TX 78942 | Oil & Gas Operator | Sep 2025 |
| 357 | Remington Oil | South Bend, TX 76481 | Oil & Gas Operator | Mar 2008 |
| 358 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | Sep 2025 |
| 359 | RHB Exploration & Production,LLC | Grapevine, TX 76099 | Oil & Gas Operator | Sep 2025 |
| 360 | Rhodes Drilling Company | Abilene, TX 79608 | Oil & Gas Operator | Sep 2000 |
| 361 | Richardson, Bud II | Graham, TX 76450 | Oil & Gas Operator | Sep 2025 |
| 362 | Richey, Ray Management Co., Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Sep 2025 |
| 363 | Ridge Oil Company | Breckenridge, TX 76424 | Oil & Gas Operator | Sep 2025 |
| 364 | Rincon Production Co., Inc. | Farmers BRNCH, TX 75234 | Oil & Gas Operator | Apr 1997 |
| 365 | RMB Operating LLC | Lubbock, TX 79493 | Oil & Gas Operator | Sep 2025 |
| 366 | Robertson, French M. Oil Co. | Abilene, TX 79608 | Oil & Gas Operator | Mar 1995 |
| 367 | Roco Petroleum, Incorporated | Abilene, TX 79605 | Oil & Gas Operator | Sep 2025 |
| 368 | Rodessa Operating Company | Corpus Chrsti, TX 78426 | Oil & Gas Operator | Sep 2025 |
| 369 | Rosewood Resources, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Sep 2025 |
| 370 | Ross Engineering, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Sep 2025 |
| 371 | Ross, Dwight M. DRLG. Co., Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Sep 2025 |
| 372 | Rover Petroleum Operating, LLC | Plano, TX 75075 | Oil & Gas Operator | Sep 2025 |
| 373 | Rozzlle Operating Company, LLC | Blackwell, TX 79506 | Oil & Gas Operator | Sep 2025 |
| 374 | Ruby Operating Company, Inc | Clyde, TX 79510 | Oil & Gas Operator | Sep 2025 |
| 375 | Rust Oil Corp. | Fort Worth, TX 76108 | Oil & Gas Operator | Sep 2025 |
| 376 | RW Operating Corp. | Midland, TX 79702 | Oil & Gas Operator | Jul 2016 |
| 377 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 378 | S.B. Street Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Sep 2025 |
| 379 | Sabre Oil And Gas Corp. | Houston, TX 77063 | Oil & Gas Operator | Sep 2025 |
| 380 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 381 | San Antonio Gas & Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Feb 2000 |
| 382 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Sep 2025 |
| 383 | Sauder Management Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Sep 2025 |
| 384 | Savannah Ross And Company, LLC | Graham, TX 76450 | Oil & Gas Operator | Sep 2025 |
| 385 | SBJ Oil & Gas | MC Camey, TX 79752 | Oil & Gas Operator | Feb 2009 |
| 386 | Schlachter, David A. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2015 |
| 387 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Sep 2025 |
| 388 | Scythian, LTD. | Midland, TX 79701 | Oil & Gas Operator | Dec 2020 |
| 389 | Seago Operating Co., L.L.C. | Abilene, TX 79608 | Oil & Gas Operator | Oct 2011 |
| 390 | Seely Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2025 |
| 391 | Sentry Exploration, Inc. | Houston, TX 77006 | Oil & Gas Operator | Sep 2025 |
| 392 | Sequoia Natural Gas, Inc. | Albany, TX 76430 | Oil & Gas Operator | Sep 2025 |
| 393 | Seven Wells Oil & Gas Expl. | Abilene, TX 79601 | Oil & Gas Operator | Jun 2014 |
| 394 | Shamrock Minerals Corporation | Merkel, TX 79536 | Oil & Gas Operator | Nov 1998 |
| 395 | Sharp Image Energy, Inc. | Big Spring, TX 79721 | Oil & Gas Operator | Sep 2025 |
| 396 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Jun 2025 |
| 397 | Shoshone Oil Company | Dallas, TX 75244 | Oil & Gas Operator | May 1994 |
| 398 | Sinclair Oil & Gas Company | Salt Lake Cty, UT 84130 | Oil & Gas Operator | Sep 2025 |
| 399 | Sinclair Oil Corporation | Salt Lake Cty, UT 84130 | Oil & Gas Operator | Aug 2006 |
| 400 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | Sep 2025 |