| 1 | 3tec Energy Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 2 | Acadian Gas Pipeline System | | Oil Operator | Jan 2025 |
| 3 | Ada Oil Exploration Corp | | Oil & Gas Operator | Jan 1986 |
| 4 | Adams Resources Expl. Corp. | Houston, TX 77001 | Oil & Gas Operator | Apr 2020 |
| 5 | Addison Resources Inc. | | Oil & Gas Operator | Jul 1998 |
| 6 | Alfred C. Glassell, Jr. | | Oil & Gas Operator | Apr 2007 |
| 7 | Alliance Exploration Corp. | | Oil & Gas Operator | Mar 1983 |
| 8 | Alliance Resources (USA), Inc. | | Oil & Gas Operator | Oct 2002 |
| 9 | Alpine Expl. Companies, Inc. | | Oil & Gas Operator | Jan 2024 |
| 10 | Amax Oil & Gas Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 11 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 12 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 13 | American Exploration Oper. Co. | | Oil & Gas Operator | May 1990 |
| 14 | American Explorer, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Jan 1999 |
| 15 | American Petrofina Co Of Texas | | Oil & Gas Operator | Jun 1985 |
| 16 | Americus Resources, Inc. | | Oil & Gas Operator | Feb 1993 |
| 17 | Aminoil Of Louisiana, Inc. | | Oil & Gas Operator | Dec 1981 |
| 18 | Aminoil USA Inc | | Oil & Gas Operator | Jan 1985 |
| 19 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 20 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 21 | Araxas Exploration, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Apr 1998 |
| 22 | Arco O & G Co-Div Atl Rich Co | | Oil & Gas Operator | Feb 1994 |
| 23 | Aroc (Texas) Inc | Houston, TX 77090 | Oil & Gas Operator | Dec 2014 |
| 24 | Arrowhead Energy Expl, LLC | | Oil & Gas Operator | May 2013 |
| 25 | Arrowhead Enterprises, Inc. | Baton Rouge, LA 70816 | Oil & Gas Operator | Apr 2001 |
| 26 | Ascent Energy, Inc | McKinney, TX 75069 | Oil & Gas Operator | Nov 2008 |
| 27 | Ashlawn Corporation | | Oil & Gas Operator | Dec 2008 |
| 28 | Aspect Energy, LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 29 | Aspen Exploration | | Oil & Gas Operator | Jan 1983 |
| 30 | Atc Realty Eight, Inc. | | Oil & Gas Operator | Nov 1988 |
| 31 | Atinum Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 32 | Azimuth Energy, LLC | Denver, CO 80203 | Oil & Gas Operator | Sep 2006 |
| 33 | Aztec Oil & Gas Company | | Oil & Gas Operator | Mar 1978 |
| 34 | Baby Oil, Inc. | | Oil & Gas Operator | Oct 2017 |
| 35 | Badger Energy LLC | | Oil & Gas Operator | Dec 2024 |
| 36 | Badger Oil Corporation | Lafayette, LA 70505 | Oil & Gas Operator | Nov 2011 |
| 37 | Ballard Exploration Company,Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 38 | Bargo Energy Company | Houston, TX 77010 | Oil & Gas Operator | May 2001 |
| 39 | Bass Enterprises Production Co | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2006 |
| 40 | Bay Coquille, Inc. | | Oil & Gas Operator | Jun 2023 |
| 41 | Bean Energy, Inc. | | Oil & Gas Operator | Dec 1986 |
| 42 | Bean Resources, Inc. | | Oil & Gas Operator | Aug 2006 |
| 43 | Bechtel Energy PTNR LTD PRTNRS | | Oil & Gas Operator | Jan 1996 |
| 44 | Bechtel Energy Resources Corp. | Houston, TX 77210 | Oil & Gas Operator | Jun 1996 |
| 45 | Beem Oil & Gas Company | | Oil & Gas Operator | Dec 1994 |
| 46 | Bellwether Exploration Company | Houston, TX 77010 | Oil & Gas Operator | May 2001 |
| 47 | Black Diamond Energy, LLC | | Oil & Gas Operator | Oct 2008 |
| 48 | Block "T" Petroleum, Inc. | Tyler, TX 75707 | Oil & Gas Operator | Oct 2025 |
| 49 | Bois D'Arc Offshore LTD. | Houston, TX 77002 | Oil & Gas Operator | Aug 2008 |
| 50 | Bon Oil Company, Inc. | | Oil & Gas Operator | Nov 1993 |
| 51 | Borden, Inc. | Columbus, OH 43215 | Oil & Gas Operator | May 1990 |
| 52 | Bradco Oil & Gas Company | | Oil & Gas Operator | Dec 1980 |
| 53 | Brammer Engineering, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 54 | Brechtel Energy Corporation | | Oil & Gas Operator | Sep 2008 |
| 55 | Bridge Oil Company LP | Midland, TX 79702 | Oil & Gas Operator | May 1999 |
| 56 | Bridwell Oil Management, LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 2025 |
| 57 | Bridwell Oil MGMT Of Al, LLC | | Oil & Gas Operator | Apr 2006 |
| 58 | Bristol Resources Corporation | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2022 |
| 59 | Brock Exploration Corporation | New Orleans, LA 70112-1707 | Oil & Gas Operator | Jan 1999 |
| 60 | Brock Oil & Gas Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2019 |
| 61 | Brooklyn Union Expl. Co., Inc. | | Oil & Gas Operator | Jul 1994 |
| 62 | Browning Oil Company, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Oct 2025 |
| 63 | Bta Oil Producers | Midland, TX 79701 | Oil & Gas Operator | Sep 2009 |
| 64 | Burlington Res Offshore Inc | | Oil & Gas Operator | Oct 2002 |
| 65 | Burlington Res Oil & Gas Co | | Oil & Gas Operator | Dec 2000 |
| 66 | Burlington Res Oil & Gas LP | | Oil & Gas Operator | Mar 2013 |
| 67 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Jun 2025 |
| 68 | Campbell Wells Corporation | | Oil Operator | Dec 1995 |
| 69 | Canada Crown Inv Corporation | | Oil & Gas Operator | Apr 1998 |
| 70 | Canlan Oil Company | | Oil & Gas Operator | Mar 1992 |
| 71 | Cantium, LLC | | Oil & Gas Operator | Dec 2024 |
| 72 | Carl Oil & Gas Co. | Bakersfield, CA 93309 | Oil & Gas Operator | Dec 1995 |
| 73 | Carrizo Oil & Gas, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 74 | Castex Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 75 | Castlerock Oil Company, Inc. | Addison, TX 75001 | Oil & Gas Operator | Feb 2006 |
| 76 | Cedyco Corporation | Houston, TX 77227 | Oil & Gas Operator | Nov 2008 |
| 77 | Century Mineral Corporation | | Oil & Gas Operator | Dec 1990 |
| 78 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Oct 2025 |
| 79 | Charles A. O'Niell, Jr. | | Oil & Gas Operator | Apr 2001 |
| 80 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Oct 2025 |
| 81 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Jun 2025 |
| 82 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 83 | Christeve Oil Company, Inc. | Houston, TX 77068 | Oil & Gas Operator | Dec 2022 |
| 84 | Chroma Operating, Inc. | Washington, DC 20036 | Oil & Gas Operator | Jun 2016 |
| 85 | Clayton Williams Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2017 |
| 86 | Clovelly Oil Co., Inc. | | Oil & Gas Operator | Nov 2008 |
| 87 | CMS Nomeco Oil & Gas Co. | Jackson, MI 49201 | Oil & Gas Operator | Jan 2015 |
| 88 | CMS Oil And Gas Company | Jackson, MI 49201 | Oil & Gas Operator | Oct 2002 |
| 89 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 90 | Cockrell Oil Corporation | Houston, TX 77002-7348 | Oil & Gas Operator | Feb 2001 |
| 91 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Aug 2025 |
| 92 | Collet Oil Ventures, Inc. | Denver, CO 80217 | Oil & Gas Operator | Jun 2004 |
| 93 | Colt Production Corp. Inc. | | Oil & Gas Operator | Jul 1996 |
| 94 | Columbia Gulf Transmission Co. | | Oil Operator | Dec 2014 |
| 95 | Columbia Gulf Transmission Company, LLC | | Oil Operator | Jan 2025 |
| 96 | Comstock Oil & Gas -- La, Inc. | | Oil & Gas Operator | Mar 2005 |
| 97 | Concord Resources, LLC | | Oil & Gas Operator | Nov 2000 |
| 98 | Conquest Exploration Co. | | Oil & Gas Operator | Mar 1992 |
| 99 | Consolidated Resources Inc | | Oil & Gas Operator | May 2004 |
| 100 | Corum Production Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |