| 1 | 3tec Energy Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 2 | Adco Producing Company | | Oil & Gas Operator | Mar 1989 |
| 3 | Adobe Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Aug 2002 |
| 4 | Alliance Operating Corporation | | Oil & Gas Operator | Jan 1995 |
| 5 | Alpine Expl. Companies, Inc. | | Oil & Gas Operator | Jan 2024 |
| 6 | Amax Oil & Gas Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 7 | Amax Petroleum Corporation | Houston, TX 77042 | Oil & Gas Operator | Dec 2012 |
| 8 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 9 | American Petrofina Co Of Texas | | Oil & Gas Operator | Jun 1985 |
| 10 | Americus Resources, Inc. | | Oil & Gas Operator | Feb 1993 |
| 11 | Aminoil Of Louisiana, Inc. | | Oil & Gas Operator | Dec 1981 |
| 12 | Aminoil USA Inc | | Oil & Gas Operator | Jan 1985 |
| 13 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 14 | Anadarko E&P Company LP | Houston, TX 77251 | Oil & Gas Operator | Aug 2014 |
| 15 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jul 2025 |
| 16 | Antara Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 17 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 18 | Aran Energy USA Inc. | | Oil & Gas Operator | Apr 1997 |
| 19 | Araxas Exploration, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Apr 1998 |
| 20 | Arco O & G Co-Div Atl Rich Co | | Oil & Gas Operator | Feb 1994 |
| 21 | Arkla Exploration Co. | Shreveport, LA 71151 | Oil & Gas Operator | Jan 1993 |
| 22 | Ashlawn Energy, Inc. | | Oil & Gas Operator | Jul 1995 |
| 23 | Atlas Production Services | | Oil & Gas Operator | Feb 1999 |
| 24 | Atp Oil & Gas Corporation | Houston, TX 77027 | Oil & Gas Operator | Jun 2008 |
| 25 | Aviara Energy Corporation | Dallas, TX 75201 | Oil & Gas Operator | Jun 2002 |
| 26 | Aviva America, Inc. | | Oil & Gas Operator | Nov 2013 |
| 27 | Badger Energy LLC | | Oil & Gas Operator | Dec 2024 |
| 28 | Badger Oil Corporation | Lafayette, LA 70505 | Oil & Gas Operator | Nov 2011 |
| 29 | Barnett Serio Exploration Co | | Oil & Gas Operator | Oct 1992 |
| 30 | Bass Enterprises Production Co | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2006 |
| 31 | Bay Coquille, Inc. | | Oil & Gas Operator | Jun 2023 |
| 32 | Beau Coup Oil& Gas Corporation | | Oil & Gas Operator | Feb 1986 |
| 33 | Bellwether Exploration Company | Houston, TX 77010 | Oil & Gas Operator | May 2001 |
| 34 | Bepco, L.P. | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2008 |
| 35 | Bike Oil & Gas Company, Inc. | | Oil & Gas Operator | Aug 2002 |
| 36 | Bison Energy Partners, LLC | | Oil & Gas Operator | Jan 2025 |
| 37 | Black Elk Energy Offshore Operations LLC | | Oil & Gas Operator | Jun 2016 |
| 38 | Bois D'Arc Offshore LTD. | Houston, TX 77002 | Oil & Gas Operator | Aug 2008 |
| 39 | Bois D'Arc Operating Corporation | Houston, TX 77040 | Oil & Gas Operator | Jan 2000 |
| 40 | Bopco, L.P. | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 41 | Borden, Inc. | Columbus, OH 43215 | Oil & Gas Operator | May 1990 |
| 42 | BP America Production Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2025 |
| 43 | Brammer Engineering, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 44 | Breton Sound Holdings, LLC | | Oil & Gas Operator | Dec 2024 |
| 45 | Brigham Oil & Gas, L.P. | Austin, TX 78730 | Oil & Gas Operator | Oct 2015 |
| 46 | Buckeye Petroleum Company, Inc | | Oil & Gas Operator | Apr 1983 |
| 47 | Burk Royalty Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Jan 2002 |
| 48 | Burkhart Petroleum Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2002 |
| 49 | Burlington Res Oil & Gas LP | | Oil & Gas Operator | Mar 2013 |
| 50 | C & K Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1984 |
| 51 | C & VC, Inc. | | Oil & Gas Operator | Sep 1991 |
| 52 | C.F. Braun & Company | | Oil & Gas Operator | Dec 1986 |
| 53 | Callon Offshore Production, Inc. | Natchez, MS 39121 | Oil & Gas Operator | Dec 2005 |
| 54 | Callon Petroleum Company | Natchez, MS 39120 | Oil & Gas Operator | Jan 2000 |
| 55 | Callon Petroleum Operating Co | Houston, TX 77042 | Oil & Gas Operator | Jul 2024 |
| 56 | Calpine Natural Gas Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2002 |
| 57 | Calpine Natural Gas Company L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 58 | Calpine Natural Gas L.P. | Houston, TX 77002 | Oil & Gas Operator | Jan 2006 |
| 59 | Campbell Energy Corp. | | Oil & Gas Operator | May 1992 |
| 60 | Caribe Resources, Inc. | | Oil & Gas Operator | Jan 1985 |
| 61 | Carl Oil & Gas Co. | Bakersfield, CA 93309 | Oil & Gas Operator | Dec 1995 |
| 62 | Castex Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 63 | Castlerock Oil Company, Inc. | Addison, TX 75001 | Oil & Gas Operator | Feb 2006 |
| 64 | Cayman Exploration Corp. | Tulsa, OK 74119-1323 | Oil & Gas Operator | Jun 2001 |
| 65 | Cayman Resources Corporation | Tulsa, OK 74119-1323 | Oil & Gas Operator | Jun 2001 |
| 66 | Cedyco Corporation | Houston, TX 77227 | Oil & Gas Operator | Nov 2008 |
| 67 | Cenergy Exploration Company | Dallas, TX 75231 | Oil & Gas Operator | Sep 2000 |
| 68 | Century Exploration Company | | Oil & Gas Operator | Dec 2003 |
| 69 | Century Exploration N.O. LLC | | Oil & Gas Operator | Jun 2017 |
| 70 | Century Exploration N.O., Inc. | | Oil & Gas Operator | Sep 2011 |
| 71 | Century Mineral Corporation | | Oil & Gas Operator | Dec 1990 |
| 72 | Century Offshore MGMT. Corp. | | Oil & Gas Operator | Dec 1999 |
| 73 | Chain Oil & Gas, Inc. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 74 | Cheniere Petroleum Corporation | | Oil & Gas Operator | Feb 1989 |
| 75 | Chevron Pipe Line Company | Houston, TX 77001 | Oil Operator | Feb 2015 |
| 76 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 77 | Chroma Operating, Inc. | Washington, DC 20036 | Oil & Gas Operator | Jun 2016 |
| 78 | Claron Corporation | Houston, TX 77219 | Oil & Gas Operator | Oct 2025 |
| 79 | Clayton Williams Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2017 |
| 80 | Clements Energy, Inc. | | Oil & Gas Operator | Oct 1987 |
| 81 | Cliffs Drilling Company | | Oil & Gas Operator | Dec 1984 |
| 82 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 83 | Coalinga Corporation | Houston, TX 77002 | Oil & Gas Operator | May 1999 |
| 84 | Cockrell Oil Corporation | Houston, TX 77002-7348 | Oil & Gas Operator | Feb 2001 |
| 85 | Columbia Gas Dev. Corp. | | Oil & Gas Operator | Apr 1996 |
| 86 | Columbia Minerals Corp., Inc. | | Oil & Gas Operator | May 1996 |
| 87 | Commerce Energy, Inc. | | Oil & Gas Operator | Dec 1999 |
| 88 | Comstock Offshore, LLC | | Oil & Gas Operator | Nov 2004 |
| 89 | Concord Operating Incorporated | Horseshoe Bay, TX 78657 | Oil & Gas Operator | Dec 2008 |
| 90 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 91 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 92 | Conquest Exploration Co. | | Oil & Gas Operator | Mar 1992 |
| 93 | Continental Oil & Gas Co. Inc. | | Oil & Gas Operator | Jul 1997 |
| 94 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 95 | Cox Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2014 |
| 96 | Cox Operating, L.L.C. | | Oil & Gas Operator | Jan 2024 |
| 97 | Crawford Energy Operating Co | Houston, TX 77056 | Oil & Gas Operator | Aug 2008 |
| 98 | Crawford Hughes Operating Co. | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 99 | Crest Resources & Expl. Corp. | Houston, TX 77079 | Oil & Gas Operator | Dec 1998 |
| 100 | Crystal Oil Company | Shreveport, LA 71120 | Oil & Gas Operator | Jul 1995 |