| 1 | 3 & 1 Operating Inc | | Oil & Gas Operator | Aug 2015 |
| 2 | 3tec Energy Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 3 | Acadiana Reserves, Inc. | | Oil & Gas Operator | Oct 1984 |
| 4 | Ada Oil Exploration Corp | | Oil & Gas Operator | Jan 1986 |
| 5 | Adobe Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Aug 2002 |
| 6 | Aegis Energy, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Sep 1998 |
| 7 | Affiliated Holdings, Inc. | | Oil Operator | Dec 2010 |
| 8 | Alinet Corporation | | Oil & Gas Operator | Aug 2013 |
| 9 | Alta Mesa Services, LP | Houston, TX 77084 | Oil & Gas Operator | Mar 2025 |
| 10 | Amarillo Oil Company | | Oil & Gas Operator | Aug 1980 |
| 11 | Amax Oil & Gas Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 12 | Amax Petroleum Corporation | Houston, TX 77042 | Oil & Gas Operator | Dec 2012 |
| 13 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 14 | Aminoil USA Inc | | Oil & Gas Operator | Jan 1985 |
| 15 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 16 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jan 2025 |
| 17 | Anderson Exploration Co., Inc. | | Oil & Gas Operator | Sep 2023 |
| 18 | Anderson Producing, Inc. | Houston, TX 77057 | Oil & Gas Operator | Sep 2013 |
| 19 | Anglo-Dutch Energy, LLC | | Oil & Gas Operator | Sep 2022 |
| 20 | Annco Pet. Co & Equipment, Inc | | Oil & Gas Operator | Sep 1982 |
| 21 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 22 | Anschutz Corporation, The | Denver, CO 80202 | Oil & Gas Operator | Sep 2016 |
| 23 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Mar 2025 |
| 24 | Apexco, Inc. | Sand Springs, OK 74063 | Oil & Gas Operator | Oct 2024 |
| 25 | Arco O & G Co-Div Atl Rich Co | | Oil & Gas Operator | Feb 1994 |
| 26 | Arnaudville Company Inc. | | Oil & Gas Operator | Apr 1995 |
| 27 | Aspect Energy, LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2025 |
| 28 | Austral Oil Company Incorporated | Sulphur, LA 70663 | Oil & Gas Operator | Mar 2008 |
| 29 | B & M Operating Co., Inc. | Houston, TX 77006 | Oil & Gas Operator | Mar 2025 |
| 30 | B M Oil, Inc. | | Oil & Gas Operator | May 2019 |
| 31 | Baca Petroleum Corp. | Denver, CO 80202 | Oil & Gas Operator | Oct 2000 |
| 32 | Balco Energy Corporation | | Oil & Gas Operator | Jul 1983 |
| 33 | Ballard Exploration Company,Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 34 | Barton Oil & Gas Co., Inc. | | Oil & Gas Operator | Sep 1993 |
| 35 | Basin Petroleum, Inc. | | Oil & Gas Operator | Jul 1995 |
| 36 | Belnorth Petroleum Corporation | Midland, TX 79701 | Oil & Gas Operator | Feb 1991 |
| 37 | BHP Petroleum (Americas) Inc | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 38 | BKV Ventures, LLC | | Oil & Gas Operator | Nov 2020 |
| 39 | Block "T" Petroleum, Inc. | Tyler, TX 75707 | Oil & Gas Operator | Mar 2025 |
| 40 | Block T Operating, LLC | Dallas, TX 75201 | Oil & Gas Operator | Nov 2024 |
| 41 | Bralorne International, Inc. | | Oil Operator | Jan 1987 |
| 42 | Brammer Engineering, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Mar 2025 |
| 43 | Brehm Exploration, Inc. | | Oil & Gas Operator | Mar 1995 |
| 44 | Brighton Energy LLC | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2015 |
| 45 | Bristol Resources Corporation | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2022 |
| 46 | Brock Exploration Corporation | New Orleans, LA 70112-1707 | Oil & Gas Operator | Jan 1999 |
| 47 | Brown & McKenzie, Inc. | | Oil & Gas Operator | May 1984 |
| 48 | Browning Oil Company, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Mar 2025 |
| 49 | Bse Production Co. | Victoria, TX 77903 | Oil & Gas Operator | Mar 2025 |
| 50 | Buckeye Petroleum Company, Inc | | Oil & Gas Operator | Apr 1983 |
| 51 | Burlington Res Oil & Gas Co | | Oil & Gas Operator | Dec 2000 |
| 52 | Burlington Res Oil & Gas LP | Houston, TX 77079 | Oil & Gas Operator | Nov 2024 |
| 53 | Buttes Resources Company | Houston, TX 77056 | Oil & Gas Operator | May 2007 |
| 54 | C.F. Braun & Company | | Oil & Gas Operator | Dec 1986 |
| 55 | Cairn Energy Partners, LLC | | Oil & Gas Operator | Feb 2023 |
| 56 | Cajun Minerals, Inc. | | Oil & Gas Operator | Mar 1997 |
| 57 | Callon Petroleum Company | Natchez, MS 39120 | Oil & Gas Operator | Jan 2000 |
| 58 | Cambridge Energy Corporation | | Oil & Gas Operator | Jul 2003 |
| 59 | Camex Operating Company | | Oil & Gas Operator | Dec 2024 |
| 60 | Campbell Wells Corporation | | Oil Operator | Dec 1995 |
| 61 | Cardinal Oil & Gas, Inc. | | Oil & Gas Operator | Jun 1995 |
| 62 | Caribbean Oil & Gas Corp | | Oil & Gas Operator | Mar 1980 |
| 63 | Carl Oil & Gas Co. | Bakersfield, CA 93309 | Oil & Gas Operator | Dec 1995 |
| 64 | Carl Oil & Gas Co.-CNG | | Oil & Gas Operator | Dec 1995 |
| 65 | Carrollton Resources Corp. | | Oil & Gas Operator | Sep 2000 |
| 66 | Castex Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 67 | Cel Properties LLC | | Oil & Gas Operator | Jan 2025 |
| 68 | Centergate Resources LLC | | Oil & Gas Operator | Dec 2024 |
| 69 | Century Exploration Houston, Inc | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2011 |
| 70 | Chaparral Energy, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Dec 2009 |
| 71 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Mar 2025 |
| 72 | Charles Holston, Inc. | | Oil Operator | Jan 2025 |
| 73 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Mar 2025 |
| 74 | Cico Oil & Gas Company | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 75 | Clayton W. Williams, Jr. | | Oil & Gas Operator | Sep 1986 |
| 76 | Clover Energy Corp | | Oil & Gas Operator | May 1980 |
| 77 | Coda Energy, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1998 |
| 78 | Cody Energy LLC | Houston, TX 77024 | Oil & Gas Operator | Jun 2020 |
| 79 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Jan 2025 |
| 80 | Columbia Gulf Transmission Co. | | Oil Operator | Dec 2014 |
| 81 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 82 | Consolidated Resources Inc | | Oil & Gas Operator | May 2004 |
| 83 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Mar 2025 |
| 84 | Cordex Petroleums, Inc. | | Oil & Gas Operator | Jun 1996 |
| 85 | Cox Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2014 |
| 86 | Crimson Explor Operating, Inc. | | Oil & Gas Operator | Dec 2009 |
| 87 | Crown Central Petroleum Corp | Richmond, TX 77469 | Oil & Gas Operator | Dec 1999 |
| 88 | Crystal Oil And Land Company | | Oil & Gas Operator | May 1992 |
| 89 | CSX Oil & Gas Corporation | Houston, TX 77210-4326 | Oil & Gas Operator | Mar 1993 |
| 90 | CX Operating, Inc. | | Oil & Gas Operator | Oct 2023 |
| 91 | Czar Resources Inc | Houston, TX 77060 | Oil & Gas Operator | Oct 1992 |
| 92 | D-O-R Lease Service, Inc. | | Oil & Gas Operator | Mar 2009 |
| 93 | D90 Energy, LLC | Austin, TX 78746 | Oil & Gas Operator | Mar 2025 |
| 94 | Daniel Oil Company | | Oil & Gas Operator | Jan 1983 |
| 95 | Dantex Oil & Gas, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Aug 2003 |
| 96 | Darsey Operating Corporation | | Oil & Gas Operator | Sep 1990 |
| 97 | Davis Oil Company | Pawhuska, OK 74056 | Oil & Gas Operator | Jun 2018 |
| 98 | Davis Petroleum Corp. | Houston, TX 77027 | Oil & Gas Operator | Mar 2025 |
| 99 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Mar 2025 |
| 100 | DBL DRLG.&Prod. Services, Inc. | | Oil & Gas Operator | Jul 1997 |