| 8401 | Ducote Oil Co. | | Oil & Gas Operator | Sep 1997 |
| 8402 | Duderstadt, A. R. | Boling, TX 77420 | Oil & Gas Operator | May 2026 |
| 8403 | Dudley Oil Co. | Crane, TX 79731 | Oil & Gas Operator | Jan 2006 |
| 8404 | Dudrey Carl | | Oil & Gas Operator | Feb 1993 |
| 8405 | Duer Wagner & Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 1998 |
| 8406 | Duerfeldt | | Oil Operator | Dec 2024 |
| 8407 | Duff Oil Co | | Oil & Gas Operator | Aug 2000 |
| 8408 | Duffer William R | Edmond, OK 73034-6761 | Oil & Gas Operator | Aug 2018 |
| 8409 | Dugan Evan | Martinsburg, OH 43037 | Oil & Gas Operator | Dec 2024 |
| 8410 | Dugan Guy E | Walhonding, OH 43843 | Oil & Gas Operator | Dec 2015 |
| 8411 | Dugan Harry Oil Co | Newark, OH 43055 | Oil & Gas Operator | Dec 1993 |
| 8412 | Dugan Oil And Gas LLC | Walhonding, OH 43843-9612 | Oil & Gas Operator | Dec 2025 |
| 8413 | Dugan Production Corp | Farmington, NM 87499 | Oil & Gas Operator | Feb 2026 |
| 8414 | Duggan Stephen F | Boston, MA 2131 | Oil & Gas Operator | Jun 2010 |
| 8415 | Dugger, Glenn | Alice, TX 78332 | Oil & Gas Operator | Nov 2013 |
| 8416 | Duggins Equipment Inc | Woodward, OK 73802-1213 | Gas Operator | Feb 2026 |
| 8417 | Duhring Resource Co | Sheffield, PA 16347-2642 | Oil & Gas Operator | Dec 2012 |
| 8418 | Duink, Darryl | Hamburg, NY 14075 | Gas Operator | Dec 2024 |
| 8419 | Duke Drilling Co | Wichita, KS 67202 | Oil & Gas Operator | Feb 2006 |
| 8420 | Duke Energy Field Services Inc | | Oil Operator | Mar 2000 |
| 8421 | Duke Energy Field Services LLC | | Oil Operator | Dec 2006 |
| 8422 | Duke Gas Company LLC | | Oil & Gas Operator | Jan 2026 |
| 8423 | Duke Oil & Gas Company, LLC | Wellsville, KS 66092 | Oil Operator | Dec 2025 |
| 8424 | Duke Oil & Gas Inc | Colorado City, TX 79512 | Oil & Gas Operator | May 2003 |
| 8425 | Duke Oil LLC | Garnett, KS 66032 | Oil Operator | Dec 2025 |
| 8426 | Duke Operating Company | Graham, TX 76450 | Oil Operator | May 2026 |
| 8427 | Duke, M. L. | Snyder, TX 79549 | Oil & Gas Operator | Mar 2008 |
| 8428 | Duke, M.A. "Andy", Jr. | Montague, TX 76251 | Oil & Gas Operator | Jun 2023 |
| 8429 | Dukes T F | | Oil & Gas Operator | Apr 2007 |
| 8430 | Dula Production, LLC | Stockdale, TX 78160 | Oil Operator | May 2026 |
| 8431 | Dunamis Energy Operating LLC | | Oil & Gas Operator | Dec 2025 |
| 8432 | Dunbar & Son Oil | | Oil & Gas Operator | Oct 1988 |
| 8433 | Dunbar, Ron, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jan 2012 |
| 8434 | Duncan Drilling Co. | Big Spring, TX 79721 | Oil & Gas Operator | May 2026 |
| 8435 | Duncan Energy Company | Denver, CO 80202 | Oil & Gas Operator | Mar 2008 |
| 8436 | Duncan Energy Companyuncan Energy Company | Denver, CO 80210 | Oil & Gas Operator | Jun 1995 |
| 8437 | Duncan Energy LLC | Dallas, TX 75231 | Oil & Gas Operator | May 2026 |
| 8438 | Duncan Jr J Walter | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2016 |
| 8439 | Duncan Land & Exploration, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2026 |
| 8440 | Duncan Oil & Gas Inc | Norman, OK 73072 | Oil & Gas Operator | Sep 2020 |
| 8441 | Duncan Oil Company | Holliday, TX 76366 | Oil Operator | Mar 2008 |
| 8442 | Duncan Oil Inc | Denver, CO 80210 | Oil & Gas Operator | Jun 2016 |
| 8443 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2026 |
| 8444 | Duncan Ronald R | Okemah, OK 74859-9603 | Oil & Gas Operator | Aug 2023 |
| 8445 | Duncan, Gene L Dba Duncan Oil Co | Salem, IL 62881 | Oil Operator | Dec 2018 |
| 8446 | Duncan, Raymond T | Denver, CO 80210 | Oil & Gas Operator | Feb 1996 |
| 8447 | Duncan-Taylor & Schumacher | | Oil & Gas Operator | Nov 1987 |
| 8448 | Dundee Oil & Supply Inc | Tulsa, OK 74101 | Oil & Gas Operator | Apr 2001 |
| 8449 | Dundee Petroleum, Inc. | Buffalo Gap, TX 79508 | Oil & Gas Operator | Aug 2003 |
| 8450 | Dune Oil And Gas, Inc. | Odessa, TX 79768 | Oil & Gas Operator | Aug 2006 |
| 8451 | Dune Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2016 |
| 8452 | Dune Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 1997 |
| 8453 | Dune Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | Jan 1993 |
| 8454 | Dunham'S Oil, LLC | Eureka, KS 67045 | Oil Operator | Dec 2025 |
| 8455 | Dunhill Expl. & Prod., LLC | | Oil & Gas Operator | Nov 2004 |
| 8456 | Dunhill Resources, Inc. | | Oil & Gas Operator | Nov 2005 |
| 8457 | Dunigan Operating Company, Inc. | Austin, TX 78755 | Oil & Gas Operator | May 2026 |
| 8458 | Dunigan Petroleum, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Aug 2003 |
| 8459 | Dunkin Oil And Gas LLC | Wynewood, OK 73098-9196 | Oil Operator | Nov 2025 |
| 8460 | Dunkirk City School District | Dunkirk, NY 14048 | Gas Operator | Dec 2024 |
| 8461 | Dunlap Drilling And Producing, Inc | Glenpool, OK 74033-4206 | Oil & Gas Operator | Dec 2025 |
| 8462 | Dunlap Exploration, Inc. | Fort Worth, TX 76101 | Oil & Gas Operator | Nov 2016 |
| 8463 | Dunlap Oil Company | Bristow, OK 74010 | Oil & Gas Operator | Feb 2026 |
| 8464 | Dunlap Well Service Inc | Haskell, OK 74436 | Oil & Gas Operator | Sep 1993 |
| 8465 | Dunlap, Rodge | Olney, TX 76374 | Oil & Gas Operator | Aug 2002 |
| 8466 | Dunn Energy LLC | Skiatook, OK 74070-4046 | Oil Operator | Sep 2022 |
| 8467 | Dunn Exploration Company, LLC | | Oil & Gas Operator | Jan 2025 |
| 8468 | Dunn Joseph L | Washington, PA 15301-6404 | Oil & Gas Operator | Dec 2025 |
| 8469 | Dunn Resources, LLC | Shreveport, LA 71115 | Oil & Gas Operator | Mar 2023 |
| 8470 | Dunn'S Oil And Gas Lease Management LLC | Ardmore, OK 73401 | Oil & Gas Operator | Jan 2026 |
| 8471 | Dunne Equities I | | Oil & Gas Operator | Dec 1995 |
| 8472 | Dunne Equities Operating, Inc. | Houston, TX 77057 | Oil & Gas Operator | Aug 2022 |
| 8473 | Dunne Equities, Inc. | Wichita, KS 67226 | Oil & Gas Operator | Apr 2014 |
| 8474 | Dunne Investments Operating, Inc. | Wichita, KS 67226 | Oil Operator | Mar 2002 |
| 8475 | Dunne Oil Co. | Wichita, KS 67202 | Oil Operator | Apr 1999 |
| 8476 | Dunne-Gardner Pe | | Oil & Gas Operator | Nov 1992 |
| 8477 | Dunne-Gardner Petroleum, Inc. | Wichita, KS 67202 | Gas Operator | Jun 2022 |
| 8478 | Dunnewold Farms LLC | Clymer, NY 14724 | Gas Operator | Dec 2024 |
| 8479 | Dunsmoor, David E. | Grand Junction, CO 81504 | Oil Operator | Jul 1998 |
| 8480 | Dupke Roger Oil Co Inc | Reno, OH 45773 | Oil & Gas Operator | Dec 2004 |
| 8481 | Duplantis Energy, LLC | Pleasanton, TX 78064 | Oil Operator | May 2026 |
| 8482 | Dupont Oil Company | | Oil Operator | Feb 1998 |
| 8483 | Dupree And Dupree | | Oil Operator | Dec 1998 |
| 8484 | Durango Energy Inc | Chickasha, OK 73023 | Oil Operator | Dec 1999 |
| 8485 | Durango Exploration LLC | Oklahoma City, OK 73120-5309 | Oil & Gas Operator | Feb 2026 |
| 8486 | Durango Operating Co., Inc. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2002 |
| 8487 | Durango Operating LLC | Madison, MS 39110 | Oil & Gas Operator | Feb 2026 |
| 8488 | Durango Resources Corp. | Houston, TX 77043 | Oil & Gas Operator | May 2026 |
| 8489 | Durbin, Ronald R. | Moline, KS 67353 | Oil Operator | Dec 1988 |
| 8490 | Durham, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2016 |
| 8491 | Duroc Exploration LLC | Bixby, OK 74008 | Oil & Gas Operator | Jan 2026 |
| 8492 | Durossette Bill D | Haskell, OK 74436-1350 | Oil & Gas Operator | Jul 2004 |
| 8493 | Durossette Floyd R | Warner, OK 74469-0548 | Oil & Gas Operator | Apr 2011 |
| 8494 | Durossette Jr Jess | Haskell, OK 74436 | Oil Operator | Mar 2007 |
| 8495 | Durst Oil & Gas, Inc. | Point Pleasant, WV 25550 | Oil & Gas Operator | Dec 2021 |
| 8496 | Durst Oil Company | Corpus Chrsti, TX 78477 | Oil & Gas Operator | Sep 2000 |
| 8497 | Dust Bowl Oil Company, Inc. | Spencerport, NY 14559 | Oil Operator | Dec 2024 |
| 8498 | Duster Production, Inc. | Refugio, TX 78377 | Oil & Gas Operator | Oct 2011 |
| 8499 | Dustin Energy Inc | Warren, OH 44481 | Oil & Gas Operator | Dec 2025 |
| 8500 | Dustin Enterprise | Olathe, KS 66062 | Oil Operator | Feb 1998 |