| 1 | 442 Operating La, LLC | | Oil & Gas Operator | Dec 2024 |
| 2 | Ada Oil Exploration Corp | | Oil & Gas Operator | Jan 1986 |
| 3 | Amalgamated Bonanza Petr. LTD. | | Oil & Gas Operator | Apr 1980 |
| 4 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 5 | Amerada Hess-Ethyl Corporation | | Oil & Gas Operator | Sep 1990 |
| 6 | American Explorer, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Jan 1999 |
| 7 | American Petrofina Co Of Texas | | Oil & Gas Operator | Jun 1985 |
| 8 | American Quasar-Southland Roy. | | Oil & Gas Operator | Oct 1980 |
| 9 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 10 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jul 2025 |
| 11 | Anderson Exploration Co., Inc. | | Oil & Gas Operator | Sep 2023 |
| 12 | Anr Pipeline Company | | Oil & Gas Operator | Jan 2025 |
| 13 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 14 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 15 | Apd Company | | Oil & Gas Operator | Apr 1987 |
| 16 | Apollo Energy, L.L.C. | | Oil & Gas Operator | Jul 2018 |
| 17 | Arco O & G Co-Div Atl Rich Co | | Oil & Gas Operator | Feb 1994 |
| 18 | Aroc (Texas) Inc | Houston, TX 77090 | Oil & Gas Operator | Dec 2014 |
| 19 | Array Operating, LLC | | Oil & Gas Operator | Mar 2017 |
| 20 | Ashland Exploration Inc | Houston, TX 77218 | Oil & Gas Operator | Nov 2000 |
| 21 | B K L Incorporated | Morton, TX 79346 | Oil & Gas Operator | Jun 2002 |
| 22 | B. & L. Oil Company | Seguin, TX 78155 | Oil & Gas Operator | Oct 2025 |
| 23 | B. M. Hester | | Oil & Gas Operator | Mar 1993 |
| 24 | Badger Energy LLC | | Oil & Gas Operator | Dec 2024 |
| 25 | Badger Oil Corporation | Lafayette, LA 70505 | Oil & Gas Operator | Nov 2011 |
| 26 | Bargo Energy Corporation | | Oil & Gas Operator | Apr 2000 |
| 27 | Barton Oil & Gas Co., Inc. | | Oil & Gas Operator | Sep 1993 |
| 28 | Baruch-Foster Corporation | Oklahoma City, OK 73126-6770 | Oil & Gas Operator | Feb 2001 |
| 29 | Bayou Bouillon Operating LLC | | Oil & Gas Operator | Dec 2024 |
| 30 | BCF Resources, LLC | | Oil Operator | Jun 2023 |
| 31 | Biglane Operating Company | | Oil & Gas Operator | Jun 2025 |
| 32 | BKV Ventures, LLC | | Oil & Gas Operator | Nov 2020 |
| 33 | Bopco, L.P. | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 34 | Borden, Inc. | Columbus, OH 43215 | Oil & Gas Operator | May 1990 |
| 35 | BP Exploration Inc | | Oil & Gas Operator | May 1993 |
| 36 | Bridas Energy USA, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Aug 2008 |
| 37 | Bristol Resources Corporation | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2022 |
| 38 | Britlind Oil LLC | | Oil & Gas Operator | Dec 2020 |
| 39 | C & M Operating Company | Graham, TX 76450 | Oil & Gas Operator | Jun 2025 |
| 40 | C. D. Pierce | | Oil Operator | Mar 1991 |
| 41 | C.F. Braun & Company | | Oil & Gas Operator | Dec 1986 |
| 42 | Cabot Petroleum Corporation | Englewood, CO 80111-2529 | Oil & Gas Operator | Dec 2004 |
| 43 | Caddo Management, Inc | Shreveport, LA 71101 | Oil & Gas Operator | Jan 2025 |
| 44 | Cajun Minerals, Inc. | | Oil & Gas Operator | Mar 1997 |
| 45 | Callon Offshore Production, Inc. | Natchez, MS 39121 | Oil & Gas Operator | Dec 2005 |
| 46 | Callon Petroleum Company | Natchez, MS 39120 | Oil & Gas Operator | Jan 2000 |
| 47 | Callon Petroleum Operating Co | Houston, TX 77042 | Oil & Gas Operator | Jul 2024 |
| 48 | Calyx Exploration & Production | | Oil & Gas Operator | Jul 1991 |
| 49 | Campbell Energy Corp. | | Oil & Gas Operator | May 1992 |
| 50 | Cardinal Oil & Gas, Inc. | | Oil & Gas Operator | Jun 1995 |
| 51 | Carl Oil & Gas Co. | Bakersfield, CA 93309 | Oil & Gas Operator | Dec 1995 |
| 52 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 53 | Celeron Oil & Gas Company | | Oil & Gas Operator | Dec 1987 |
| 54 | Cenergy Exploration Company | Dallas, TX 75231 | Oil & Gas Operator | Sep 2000 |
| 55 | Centura Inc | | Oil & Gas Operator | Feb 1985 |
| 56 | Chaparral Energy, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Dec 2009 |
| 57 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Oct 2025 |
| 58 | Charing Cross Properties | | Oil Operator | Aug 1995 |
| 59 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 60 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 61 | Coalinga Corporation | Houston, TX 77002 | Oil & Gas Operator | May 1999 |
| 62 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Aug 2025 |
| 63 | Columbia Gas Dev. Corp. | | Oil & Gas Operator | Apr 1996 |
| 64 | Comstock Oil & Gas -- La, Inc. | | Oil & Gas Operator | Mar 2005 |
| 65 | Condor Petroleum Corporation | | Oil & Gas Operator | Aug 2020 |
| 66 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 67 | Cox Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2014 |
| 68 | Creek Operating Company, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Sep 1998 |
| 69 | Cygnus Producing Corporation | | Oil & Gas Operator | Feb 1990 |
| 70 | Cypress Oil Company, Inc. | | Oil & Gas Operator | Aug 2003 |
| 71 | Cypress Production, Inc. | Azle, TX 76020 | Oil & Gas Operator | Oct 2025 |
| 72 | D. B. McClinton | | Oil & Gas Operator | Jun 1992 |
| 73 | D. C. Bintliff-McCormick O&G | | Oil & Gas Operator | Oct 1983 |
| 74 | Dalnor Corporation | | Oil & Gas Operator | Nov 2010 |
| 75 | Daniel Oil Company | | Oil & Gas Operator | Jan 1983 |
| 76 | Darsey Operating Corporation | | Oil & Gas Operator | Sep 1990 |
| 77 | Davis Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 1988 |
| 78 | Deblin Oil & Gas, Inc | | Oil & Gas Operator | Aug 1995 |
| 79 | Denbury Management, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Dec 1999 |
| 80 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Oct 2025 |
| 81 | Denbury Resources Inc. | Plano, TX 75024 | Oil & Gas Operator | Dec 2003 |
| 82 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 83 | Drew Cornell, Inc. | | Oil & Gas Operator | Jun 1992 |
| 84 | Drillmar Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | Nov 2014 |
| 85 | Drillmar Operating Company | Houston, TX 77019 | Oil & Gas Operator | Jun 2013 |
| 86 | Dune Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2016 |
| 87 | Dynamic Exploration PTRS, LLC | | Oil & Gas Operator | Nov 2024 |
| 88 | E & E Production Company, Inc. | | Oil & Gas Operator | Dec 2004 |
| 89 | E. & S. Drilling Company | | Oil & Gas Operator | Feb 1995 |
| 90 | Ed I. Estis | | Oil & Gas Operator | Sep 1998 |
| 91 | Edwin L. Cox | | Oil & Gas Operator | May 1986 |
| 92 | Edwin L. Cox & Berry R. Cox | | Oil & Gas Operator | Jun 1986 |
| 93 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 94 | Elad Petroleum Corporation | | Oil Operator | Jun 2005 |
| 95 | Energy Corp. Of America, Inc. | | Oil & Gas Operator | Aug 1998 |
| 96 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 97 | Energy Research & Dev. Corp. | | Oil & Gas Operator | Feb 1998 |
| 98 | Energy Sources, Inc. | | Oil & Gas Operator | Nov 1990 |
| 99 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 100 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |