| 301 | Seeker Oil Company II, Inc. | San Antonio, TX 78209 | Oil Operator | Jan 2016 |
| 302 | Seeker Oil Company, Incorporated | San Antonio, TX 78209 | Oil & Gas Operator | Feb 2026 |
| 303 | Seel-Mac Oil & Gas LLC | Richardson, TX 75080 | Oil Operator | Jul 2011 |
| 304 | Seely Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2026 |
| 305 | Seelye, William L. | Plano, TX 75024 | Oil & Gas Operator | Oct 2005 |
| 306 | Segler, Charles | Holliday, TX 76366 | Oil & Gas Operator | Mar 2008 |
| 307 | Segrest-Ward Joint Venture | Longview, TX 75606 | Oil & Gas Operator | Jun 2001 |
| 308 | Seguin Pump | Seguin, TX 78155 | Oil & Gas Operator | Sep 2017 |
| 309 | Seguro Oil And Gas, LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2024 |
| 310 | Seguro Well Service, Inc. | Gonzales, TX 78629 | Oil & Gas Operator | Feb 2026 |
| 311 | Sei Operating, LLC | Mandeville, LA 70471 | Oil & Gas Operator | Feb 2026 |
| 312 | Seidler Oil & Gas Operating, LLC | Alvarado, TX 76009 | Oil & Gas Operator | Feb 2026 |
| 313 | Seiguf Oil Company, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 314 | Seiran E & P Company, LLC | Friendswood, TX 77546 | Oil & Gas Operator | Feb 2026 |
| 315 | Seisgen Exploration, Inc | Houston, TX 77024 | Gas Operator | Aug 2005 |
| 316 | Seisma Drilling Corporation | Wichita Falls, TX 76301 | Oil Operator | Aug 2003 |
| 317 | Seismic Investment Group, Inc. | Houston, TX 77055 | Oil & Gas Operator | Jun 2008 |
| 318 | Seismic Leasing Service | Denver, CO 80216 | Oil & Gas Operator | Aug 2000 |
| 319 | Seismotech Energy, Incorporated | Plano, TX 75075 | Oil & Gas Operator | Aug 2003 |
| 320 | Seistech Development, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2007 |
| 321 | Seitz, Comegys & Seitz | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 1994 |
| 322 | Seitz, J. R. & Adam | Wichita Falls, TX 76307 | Oil & Gas Operator | Mar 2008 |
| 323 | Seitz, J. R. & Adam, LTD. | Wichita Falls, TX 76307 | Oil Operator | Feb 2026 |
| 324 | Select Water Solutions, LLC | Gainesville, TX 76240 | Oil Operator | Nov 2025 |
| 325 | Self Brothers | Montague, TX 76251 | Oil & Gas Operator | Feb 2026 |
| 326 | Self, Charles D. | Jacksboro, TX 76458 | Oil & Gas Operator | Sep 2016 |
| 327 | Self, Charles Lynn | Jacksboro, TX 76458 | Oil & Gas Operator | Feb 2026 |
| 328 | Sellers Lease Service, Inc. | Flatonia, TX 78941 | Oil & Gas Operator | Feb 2026 |
| 329 | Sellers' Lease Service | Flatonia, TX 78941 | Oil & Gas Operator | Jul 1994 |
| 330 | Selous Energy, LLC | Fort Worth, TX 76109 | Oil & Gas Operator | Jul 2015 |
| 331 | Sem Operating Company LLC | Houston, TX 77042 | Oil & Gas Operator | Feb 2026 |
| 332 | Seminole Production Co. | Silsbee, TX 77656 | Oil & Gas Operator | Oct 2002 |
| 333 | Semper Fidelis Oil & Gas, LLC | Allen, TX 75013 | Oil & Gas Operator | Apr 2013 |
| 334 | Sendero Energy Inc. | Dallas, TX 75205 | Oil & Gas Operator | Feb 2026 |
| 335 | Seneca Exploration, LLC | Wichita Falls, TX 76308 | Oil Operator | Feb 2026 |
| 336 | Seneca Oil Company | Tulsa, OK 74121-1518 | Oil & Gas Operator | Jan 2015 |
| 337 | Seneca Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2017 |
| 338 | Senkel, Wesley, Inc. | Graham, TX 76450 | Oil & Gas Operator | Apr 2007 |
| 339 | Senora Resources, Inc. | Dime Box, TX 77853 | Oil & Gas Operator | Feb 2026 |
| 340 | Sensor Oil & Gas, Inc. | Duncan, OK 73534 | Oil & Gas Operator | May 2013 |
| 341 | Sentry Exploration, Inc. | Houston, TX 77006 | Oil & Gas Operator | Feb 2026 |
| 342 | Sep, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 1994 |
| 343 | Sequoia Energy Resources | Dallas, TX 75207 | Oil & Gas Operator | Feb 2026 |
| 344 | Sequoia Fossil Fuels, Inc. | Albany, TX 76430 | Oil & Gas Operator | Feb 2026 |
| 345 | Sequoia Management, LLC | Houston, TX 77060 | Oil & Gas Operator | Nov 2009 |
| 346 | Sequoia Natural Gas, Inc. | Albany, TX 76430 | Oil & Gas Operator | Feb 2026 |
| 347 | Ser E&P, Inc. | McKinney, TX 75069 | Oil & Gas Operator | Feb 2026 |
| 348 | Serco Operating LLC | Katy, TX 77450 | Oil Operator | Feb 2026 |
| 349 | Serendipity Exploration, Inc. | Weatherford, TX 76087 | Gas Operator | May 1997 |
| 350 | Serna Inc. | Austin, TX 78733 | Oil Operator | Feb 2026 |
| 351 | Serra Energy, Inc. | Hailey, ID 83333 | Oil & Gas Operator | May 2011 |
| 352 | Service Clearing Corp | Dallas, TX 75229 | Oil & Gas Operator | Feb 2026 |
| 353 | Service Drilling Co. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 1998 |
| 354 | Service Drilling Co., L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 2003 |
| 355 | Service Production Company, Inc. | Santa Fe, TX 77510 | Oil & Gas Operator | May 1999 |
| 356 | Setex Oil And Gas Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2012 |
| 357 | Setex Oil Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jan 2000 |
| 358 | Sev Texas Operating, LLC | Long Beach, CA 90755 | Oil & Gas Operator | Feb 2026 |
| 359 | Seven Cross Operating, LLC | Santa Anna, TX 76878 | Oil & Gas Operator | Feb 2026 |
| 360 | Seven Falls Company | Dallas, TX 75201 | Oil & Gas Operator | May 2008 |
| 361 | Seven Lakes Operating LLC | Austin, TX 78746 | Oil Operator | Feb 2026 |
| 362 | Seven Wells Oil & Gas Expl. | Abilene, TX 79601 | Oil & Gas Operator | Jun 2014 |
| 363 | Sevenbar Resources, LLC | Hallettsville, TX 77964 | Oil & Gas Operator | Feb 2026 |
| 364 | Seventy Oil Co. | Freer, TX 78357 | Oil & Gas Operator | Mar 2002 |
| 365 | Sevenx, LLC | Iowa Park, TX 76367 | Oil Operator | Feb 2026 |
| 366 | SFJV Enterprises, Inc. | Berclair, TX 78107 | Gas Operator | Aug 1998 |
| 367 | SFM Holdings, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Jul 1995 |
| 368 | SG Interests, Inc. | Houston, TX 77010 | Oil & Gas Operator | Jun 2007 |
| 369 | SGB Oil LLC | Luling, TX 78648 | Oil Operator | Feb 2026 |
| 370 | SGP Operating LLC | Dallas, TX 75205 | Oil & Gas Operator | Feb 2026 |
| 371 | Sha Stephens, Incorporated | Weatherford, TX 76087 | Oil & Gas Operator | Apr 2006 |
| 372 | Sha-Jam Operating Corp. | Midland, TX 79701 | Oil & Gas Operator | Feb 2026 |
| 373 | Shack, Bill | Albany, TX 76430 | Oil & Gas Operator | Apr 2006 |
| 374 | Shackelford Oil Co | Midland, TX 79707 | Oil & Gas Operator | Dec 2025 |
| 375 | Shackelford,Frank Oil Properties | Midland, TX 79701 | Oil & Gas Operator | Aug 1997 |
| 376 | Shadawn Corporation | Wichita Falls, TX 76310 | Oil & Gas Operator | Mar 2005 |
| 377 | Shady Oil Co. | Brownwood, TX 76801 | Oil & Gas Operator | Feb 2026 |
| 378 | Shahan, Donald Allan | Abilene, TX 79602 | Oil Operator | Feb 2026 |
| 379 | Shaida, John H. | Wichita, KS 67226 | Oil & Gas Operator | Feb 2026 |
| 380 | Shakespeare Oil Co Inc | Salem, IL 62881 | Oil & Gas Operator | Dec 2025 |
| 381 | Shale Energy LLC | Jeffersonville, KY 40337 | Oil Operator | Dec 2018 |
| 382 | Shale Hunter, LLC | Irving, TX 75039 | Oil & Gas Operator | Jan 2016 |
| 383 | Shale Oil Co., Inc. | Liberty, TX 77575 | Oil & Gas Operator | Feb 2026 |
| 384 | Shale Operating Co. | Dallas, TX 75356 | Oil & Gas Operator | Feb 2026 |
| 385 | Shallow Production Oper, LLC | Austin, TX 78738 | Oil Operator | Feb 2026 |
| 386 | Shamrock Minerals Corporation | Merkel, TX 79536 | Oil & Gas Operator | Nov 1998 |
| 387 | Shamrock Oil Co. | Sugar Land, TX 77478 | Oil & Gas Operator | Mar 2008 |
| 388 | Shamrock Texas Partners L.P. | San Angelo, TX 76904 | Oil & Gas Operator | Feb 2026 |
| 389 | Shana Petroleum Company | Dallas, TX 75206 | Oil & Gas Operator | Aug 2002 |
| 390 | Shanafelt Oil Operating, LLC | Jacksboro, TX 76458 | Oil Operator | Feb 2026 |
| 391 | Shanafelt, Arthur | Jacksboro, TX 76458 | Oil & Gas Operator | May 2003 |
| 392 | Shanghai Energy Corporation | Houston, TX 77027 | Oil & Gas Operator | Apr 2003 |
| 393 | Shanks, Bob | Haskell, OK 74436 | Oil Operator | Sep 2002 |
| 394 | Shannon Energy | Liberal, KS 67901 | Oil & Gas Operator | Feb 1999 |
| 395 | Shappell Oil Company | Holliday, TX 76366 | Oil & Gas Operator | Sep 2012 |
| 396 | Shappell Oil Company, L.L.C. | Harrisonburg, LA 71340 | Oil & Gas Operator | Feb 2026 |
| 397 | Share Petroleum Corp. | Mabank, TX 75147 | Oil Operator | Feb 2026 |
| 398 | Sharoco Corporation | Fort Worth, TX 76121 | Oil & Gas Operator | Dec 1996 |
| 399 | Sharon Hunter Resources, Inc. | Houston, TX 77056 | Oil & Gas Operator | Sep 2012 |
| 400 | Sharon Resources, Inc. | Houston, TX 77056 | Oil & Gas Operator | Aug 2010 |