| 1301 | Duke Energy Field Services LLC | | Oil Operator | Dec 2006 |
| 1302 | Duncan Energy Company | Denver, CO 80202 | Oil & Gas Operator | Mar 2008 |
| 1303 | Duncan Oil Company | Holliday, TX 76366 | Oil Operator | Mar 2008 |
| 1304 | Duncan Oil Inc | Denver, CO 80210 | Oil & Gas Operator | Jun 2016 |
| 1305 | Dundee Petroleum, Inc. | Buffalo Gap, TX 79508 | Oil & Gas Operator | Aug 2003 |
| 1306 | Dune Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2016 |
| 1307 | Dunhill Expl. & Prod., LLC | | Oil & Gas Operator | Nov 2004 |
| 1308 | Dunhill Resources, Inc. | | Oil & Gas Operator | Nov 2005 |
| 1309 | Dunn Exploration Company, LLC | | Oil & Gas Operator | Jan 2025 |
| 1310 | Dupont Oil Company | | Oil Operator | Feb 1998 |
| 1311 | Dupree And Dupree | | Oil Operator | Dec 1998 |
| 1312 | Dvi | | Oil Operator | Dec 2008 |
| 1313 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 1314 | Dykes Oil Co. | | Oil Operator | Dec 2001 |
| 1315 | Dynaco, Incorporated | | Oil & Gas Operator | Dec 1980 |
| 1316 | Dynamic Exploration PTRS, LLC | | Oil & Gas Operator | Nov 2024 |
| 1317 | Dynamic Exploration, Inc. | | Oil & Gas Operator | Oct 2003 |
| 1318 | Dynamic Offshore Resources, LLC | Houston, TX 77042 | Oil & Gas Operator | Sep 2026 |
| 1319 | Dzurik Interests, Inc. | | Oil & Gas Operator | Dec 2024 |
| 1320 | E & B Equipment | Liberty, TX 77575 | Oil & Gas Operator | Feb 2010 |
| 1321 | E & E Production Company, Inc. | | Oil & Gas Operator | Dec 2004 |
| 1322 | E D Markham | | Gas Operator | Nov 1978 |
| 1323 | E Lee Mills | | Oil Operator | Aug 1987 |
| 1324 | E Texas Production MGMT Co Inc | | Oil & Gas Operator | Oct 1996 |
| 1325 | E-Z Mart Stores, Inc. | | Oil Operator | Jul 2004 |
| 1326 | E. & H. Oil Company | Woodson, TX 76491 | Oil & Gas Operator | May 1998 |
| 1327 | E. & S. Drilling Company | | Oil & Gas Operator | Feb 1995 |
| 1328 | E. A. Courtney | | Oil & Gas Operator | Oct 1978 |
| 1329 | E. Conway Butts, Inc. | | Oil & Gas Operator | Apr 1991 |
| 1330 | E. G. Williamson, Jr. | | Oil Operator | Jan 1993 |
| 1331 | E. L. Cox And Stanrich Oil Co. | | Oil & Gas Operator | Jul 1981 |
| 1332 | E. L. Larry | | Oil & Gas Operator | Mar 1989 |
| 1333 | E. M. Self | | Oil Operator | Feb 1981 |
| 1334 | E. P. Alexander | | Oil Operator | Jan 1984 |
| 1335 | E. P. Alexander, Et Al | | Oil Operator | Jan 1984 |
| 1336 | E2 Operating LLC | Tulsa, OK 74135 | Oil & Gas Operator | Sep 2026 |
| 1337 | Eads Operating Company | | Oil & Gas Operator | Mar 1991 |
| 1338 | Eagle Energy Development Co | La Porte, TX 77571 | Oil & Gas Operator | Dec 2024 |
| 1339 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Sep 2026 |
| 1340 | Eagle Oil & Gas, Inc. | | Oil & Gas Operator | Nov 1984 |
| 1341 | Eagle Oil Management Co., LLC | | Oil & Gas Operator | Jan 2023 |
| 1342 | Earl Dyess | | Oil & Gas Operator | Jul 1990 |
| 1343 | Earl Markham Et Al | | Gas Operator | Jun 1979 |
| 1344 | Earl W Todd | | Oil Operator | Jan 2008 |
| 1345 | Easom-Middleton Operating, Inc | | Oil & Gas Operator | Sep 1992 |
| 1346 | Eason Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2012 |
| 1347 | Eason Petroleum Company | | Oil & Gas Operator | Jul 2016 |
| 1348 | East Texas Exploration, LLC | Edmond, OK 73003 | Oil & Gas Operator | Sep 2019 |
| 1349 | Eastern Oil Corporation | Houston, TX 77070 | Oil & Gas Operator | Sep 2026 |
| 1350 | Eclipse Petroleum Corporation | La Grange, TX 78945 | Oil & Gas Operator | Aug 2003 |
| 1351 | Eclipse Services, Inc. * | La Grange, TX 78945 | Oil & Gas Operator | Jul 2003 |
| 1352 | Ed I. Estis | | Oil & Gas Operator | Sep 1998 |
| 1353 | Ed Shea | | Oil Operator | Sep 1990 |
| 1354 | Eddie Mayo | | Oil Operator | Jun 2006 |
| 1355 | Eddy Enterprises, Inc. | | Oil & Gas Operator | Sep 2023 |
| 1356 | Edge Petroleum Oper. Co., Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 1357 | Edgewater Oil Co. Inc. | | Oil & Gas Operator | Jul 1995 |
| 1358 | Edgewood Exploration Inc. | | Oil & Gas Operator | Mar 1993 |
| 1359 | Edisto Resources Corporation | Houston, TX 77057 | Oil & Gas Operator | Oct 1999 |
| 1360 | Edward Oil Company | Youngsville, PA 16371 | Oil & Gas Operator | Nov 2024 |
| 1361 | Edwards & Leach Oil Company | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2005 |
| 1362 | Edwin L Cox & Berry R Cox-Eni | | Oil & Gas Operator | May 1986 |
| 1363 | Edwin L Cox-Michael Halbouty | | Oil & Gas Operator | Jun 1986 |
| 1364 | Edwin L. Cox | | Oil & Gas Operator | May 1986 |
| 1365 | Edwin L. Cox & Berry R. Cox | | Oil & Gas Operator | Jun 1986 |
| 1366 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 1367 | Eex E&P Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 1368 | Egh Operating, LLC | | Oil & Gas Operator | Dec 2024 |
| 1369 | Eidos Energy, Inc. | | Oil & Gas Operator | Oct 2017 |
| 1370 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 1371 | El Paso Exploration Company | | Oil & Gas Operator | Jul 1985 |
| 1372 | El Paso Field Services Company | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 1373 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 1374 | El Paso Production Gom, Inc. | | Oil & Gas Operator | Nov 2005 |
| 1375 | El Toro Production Co Inc | | Oil & Gas Operator | Jan 2016 |
| 1376 | El Tres Petr. Corp. | | Oil & Gas Operator | Jan 1984 |
| 1377 | El-Oil, LTD. | | Oil & Gas Operator | Nov 2024 |
| 1378 | Elad Petroleum Corporation | | Oil Operator | Jun 2005 |
| 1379 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Jul 2026 |
| 1380 | Eldon Radke | | Oil Operator | May 2001 |
| 1381 | Eldorado Gas Inc. | | Oil & Gas Operator | May 1986 |
| 1382 | Eleuterius Company | | Oil Operator | Jan 1983 |
| 1383 | Elf Aquitaine Inc | Houston, TX 77002 | Oil & Gas Operator | May 1991 |
| 1384 | Elf Aquitaine Operating, Inc. | | Oil & Gas Operator | Jan 1992 |
| 1385 | Elfco, Inc. | College Sta, TX 77845 | Oil & Gas Operator | Jun 1996 |
| 1386 | Elgie Company, Inc. | | Oil & Gas Operator | Aug 1993 |
| 1387 | Elgin Energy Corp. | | Oil Operator | May 1995 |
| 1388 | Eli Rebich | | Oil & Gas Operator | Dec 1986 |
| 1389 | Elizabeth Oil Company | | Oil Operator | Oct 1999 |
| 1390 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 1391 | Ellis M. Moore, Et Al | | Oil Operator | Mar 1986 |
| 1392 | Ellora Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Sep 2026 |
| 1393 | Ellora Operating, L.P. | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2011 |
| 1394 | Elmwood Operating LLC | | Oil & Gas Operator | Jun 2024 |
| 1395 | Elsbury & Acker | | Oil & Gas Operator | Feb 2003 |
| 1396 | Elsbury & McGrew | | Oil & Gas Operator | Nov 1986 |
| 1397 | Elysium Energy, L.L.C | Denver, CO 80202 | Oil & Gas Operator | Jun 2019 |
| 1398 | Elysium Jennings, LLC | | Oil & Gas Operator | Dec 2024 |
| 1399 | Emerald Oil Co. | | Oil & Gas Operator | Apr 1980 |
| 1400 | Emerald Oil Company LLC | E. Rochester, NY 14445 | Oil & Gas Operator | Jan 2025 |