| 301 | Edwin L Cox & Berry R Cox-Eni | | Oil & Gas Operator | May 1986 |
| 302 | Edwin L Cox-Michael Halbouty | | Oil & Gas Operator | Jun 1986 |
| 303 | Edwin L. Cox | | Oil & Gas Operator | May 1986 |
| 304 | Edwin L. Cox & Berry R. Cox | | Oil & Gas Operator | Jun 1986 |
| 305 | Ee3 LLC | | Oil & Gas Operator | Nov 2015 |
| 306 | Eec Inc | Norman, OK 73069-6344 | Oil & Gas Operator | May 2025 |
| 307 | Eei Inc | MT Pleasant, MI 48858 | Oil & Gas Operator | Dec 1990 |
| 308 | Eei Operating Inc. | Plano, TX 75093 | Oil & Gas Operator | May 2015 |
| 309 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 310 | Eex E&P Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 311 | Eex Operating, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 312 | Ef Energy, L.L.C. | Houston, TX 77084 | Oil & Gas Operator | Jun 2015 |
| 313 | Ef Oil And Gas Invest, L.L.C. | Beaver, OK 73932 | Oil Operator | Jul 2025 |
| 314 | Efficiency Operating Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Mar 2008 |
| 315 | Efficiency Operating Service | Wichita Falls, TX 76307 | Oil & Gas Operator | Jul 2025 |
| 316 | Egan Resources Inc. | Katy, TX 77494 | Oil & Gas Operator | Oct 2016 |
| 317 | Eggleston, Garaland | Big Lake, TX 76932 | Oil & Gas Operator | Aug 2003 |
| 318 | Egh Operating, LLC | | Oil & Gas Operator | Dec 2024 |
| 319 | Egi, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Jul 2025 |
| 320 | Egl Oil And Gas Corporation | Tyler, TX 75703 | Oil & Gas Operator | Aug 2003 |
| 321 | Ego Operating LLC | Boca Raton, FL 33431 | Oil Operator | Dec 2019 |
| 322 | Egolf Operating Company | Oklahoma City, OK 73114-7899 | Oil & Gas Operator | Apr 1998 |
| 323 | Egret Operating Company | Muskogee, OK 74401 | Oil & Gas Operator | Apr 2025 |
| 324 | Ehb Oil Company | | Oil Operator | Dec 2001 |
| 325 | Ehrlich, Mitchell | Perryton, TX 79070 | Oil & Gas Operator | May 1999 |
| 326 | Ehvi Exploration LLC | Denver, CO 80202 | Oil & Gas Operator | Jul 2025 |
| 327 | Eichenber A H Co | Tulsa, OK 74105 | Oil & Gas Operator | Oct 2002 |
| 328 | Eidos Energy, Inc. | | Oil & Gas Operator | Oct 2017 |
| 329 | Eig Petroleum LLC | Asheville, NC 28803-2908 | Oil Operator | Aug 2015 |
| 330 | Eighty-Six Oil Company, Inc. | Luling, TX 78648 | Oil & Gas Operator | Jul 2025 |
| 331 | Einink, Mark B. | Clymer, NY 14724 | Gas Operator | Dec 2024 |
| 332 | Eise Oil, Inc. | San Antonio, TX 78213 | Oil Operator | Jul 2025 |
| 333 | Eishen, Rosalie; Eishen, Eric; And Pray, Leonore | | Oil & Gas Operator | Dec 2024 |
| 334 | Eitel Energy, LLC | Farlington, KS 66734 | Oil Operator | Mar 2025 |
| 335 | Ej Brumage & Ra Pultorak | Waynesburg, PA 15370-2434 | Gas Operator | Dec 2018 |
| 336 | Ekg Operating Inc | Seminole, OK 74818-1028 | Oil & Gas Operator | Nov 2015 |
| 337 | El Campo Operating, LLC | Dallas, TX 75206 | Oil & Gas Operator | Feb 2011 |
| 338 | El Chjon Gas Com | | Gas Operator | May 1988 |
| 339 | El Coqui' Oil Company | Tussy, OK 73088 | Oil & Gas Operator | Oct 2009 |
| 340 | El Dorado Exploration Co. | | Oil Operator | Dec 1999 |
| 341 | El Dorado Gas & Oil, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Jul 2025 |
| 342 | El Dorado Resources Inc. | Waco, TX 76710 | Oil & Gas Operator | Oct 2009 |
| 343 | El Indio Energy LLC | Austin, TX 78746 | Oil Operator | Mar 2025 |
| 344 | El Pache Energy Inc | Duncan, OK 73533 | Oil & Gas Operator | Aug 2017 |
| 345 | El Pamco Inc | Albuquerque, NM 87191 | Gas Operator | Mar 2020 |
| 346 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 347 | El Paso E&P Zapata, L.P. | Houston, TX 77002 | Oil & Gas Operator | Dec 2010 |
| 348 | El Paso Energy Raton LLC | | Gas Operator | Sep 2008 |
| 349 | El Paso Exploration Company | | Oil & Gas Operator | Jul 1985 |
| 350 | El Paso Field Services Company | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 351 | El Paso Gas Marketing | Unknown, NM 99999 | Oil & Gas Operator | Feb 1997 |
| 352 | El Paso Natural Gas Company | El Paso, TX 79978 | Oil & Gas Operator | Apr 2013 |
| 353 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 354 | El Paso Production Gom, Inc. | | Oil & Gas Operator | Nov 2005 |
| 355 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Jul 2025 |
| 356 | El Ran, Inc. | Lubbock, TX 79408 | Oil & Gas Operator | Jul 2025 |
| 357 | El Reno Energy, LLC | Granbury, TX 76048 | Oil & Gas Operator | Jul 2025 |
| 358 | El Segundo Oil LLC | | Oil Operator | Apr 2025 |
| 359 | El Toro Oil Co. & Flagg Resc. | | Oil & Gas Operator | May 1993 |
| 360 | El Toro Production Co., Inc. | | Oil & Gas Operator | Jan 2016 |
| 361 | El Toro Resources LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Jul 2025 |
| 362 | El Tres Exploration | Houston, TX 77098 | Oil & Gas Operator | Mar 2008 |
| 363 | El Tres Petr. Corp. | | Oil & Gas Operator | Jan 1984 |
| 364 | El-Kan Exploration | Garfield, KS 67529 | Oil Operator | Jul 1997 |
| 365 | El-Oil, LTD. | | Oil & Gas Operator | Nov 2024 |
| 366 | Elad Petroleum Corporation | | Oil Operator | Jun 2005 |
| 367 | Elahs Gas Co., Inc. | | Oil & Gas Operator | Dec 2021 |
| 368 | Elam, Jack G. | Midland, TX 79702 | Oil & Gas Operator | Dec 2002 |
| 369 | Elam, Jack G., Inc. | Midland, TX 79702 | Oil & Gas Operator | Nov 2002 |
| 370 | Elan Energy Inc | Toledo, OH 43604-1207 | Oil & Gas Operator | Dec 1990 |
| 371 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | May 2025 |
| 372 | Elb Enterprise LLC | | Oil Operator | Mar 2025 |
| 373 | Elba Oil Company LLC | Macksburg, OH 45746 | Oil Operator | Dec 2024 |
| 374 | Elco Oil & Gas | San Angelo, TX 76902 | Oil & Gas Operator | Dec 2014 |
| 375 | Elco Oil & Gas, Inc. | San Angelo, TX 76902 | Oil & Gas Operator | Jul 2025 |
| 376 | Elco Resources LLC | Owasso, OK 74055-7575 | Oil & Gas Operator | May 2025 |
| 377 | Elder & Vaughn Inc | Oklahoma City, OK 73154-0938 | Oil & Gas Operator | Mar 2008 |
| 378 | Elder Oil & Gas Co | Parker, PA 16049-6426 | Oil & Gas Operator | Dec 2024 |
| 379 | Elder Oil Co. | West Union, WV 26456 | Oil & Gas Operator | Dec 2021 |
| 380 | Eldon Oil Co. | Three Rivers, TX 78071 | Oil & Gas Operator | Jul 2025 |
| 381 | Eldon Radke | | Oil Operator | May 2001 |
| 382 | Eldorado Gas Inc. | | Oil & Gas Operator | May 1986 |
| 383 | Eldorado Oil And Gas, Inc. | Dallas, TX 75230 | Oil & Gas Operator | Nov 1995 |
| 384 | Eldorado Operating Co. | Dallas, TX 75230 | Oil & Gas Operator | Jul 2004 |
| 385 | Eldred Prod And Consulting, LLC | Nocona, TX 76255 | Oil Operator | Jul 2025 |
| 386 | Elec Materials Co | North East, PA 16428-1539 | Gas Operator | Dec 1994 |
| 387 | Electragas, Inc. | Houston, TX 77064 | Oil Operator | Jul 2025 |
| 388 | Elek Aaron III | | Oil Operator | Jul 2005 |
| 389 | Elek Aaron III Estate | | Oil Operator | Feb 2015 |
| 390 | Element Petro Operating II, LLC | Midland, TX 79701 | Oil & Gas Operator | Sep 2016 |
| 391 | Element Petroleum Op III, LLC | Midland, TX 79710 | Oil & Gas Operator | May 2024 |
| 392 | Element Petroleum Operating IV, LLC | Midland, TX 79710 | Oil Operator | Jul 2025 |
| 393 | Element Petroleum Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2015 |
| 394 | Elendil Resources LLC | Pampa, TX 79066 | Oil & Gas Operator | Jul 2025 |
| 395 | Eleon Operators, LLC | Katy, TX 77494 | Oil & Gas Operator | Jul 2025 |
| 396 | Elephant Exploration Inc. | Hartville, OH 44632 | Oil & Gas Operator | Dec 2024 |
| 397 | Elephant Oil & Gas, LLC | Dallas, TX 75204 | Oil & Gas Operator | Nov 2015 |
| 398 | Elephant Operating LLC | Dallas, TX 75204 | Oil & Gas Operator | May 2025 |
| 399 | Eleuterius Company | | Oil Operator | Jan 1983 |
| 400 | Elevate Energy LTD | Aurora, CO 80016 | Oil & Gas Operator | Mar 2025 |