| 1 | 442 Operating La, LLC | | Oil & Gas Operator | Dec 2024 |
| 2 | Agip Petroleum Co., Inc. | | Oil & Gas Operator | Jan 2003 |
| 3 | Aldine Oil And Gas, LP | Houston, TX 77060 | Oil & Gas Operator | Oct 2025 |
| 4 | Alegre Energy, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Oct 2025 |
| 5 | Alliance Operating Corporation | | Oil & Gas Operator | Jan 1995 |
| 6 | Alltex Exploration, Inc. | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 7 | Alpine Energy, Inc. | | Oil & Gas Operator | Dec 1999 |
| 8 | Alpine Expl. Companies, Inc. | | Oil & Gas Operator | Jan 2024 |
| 9 | Amax Petroleum Corporation | Houston, TX 77042 | Oil & Gas Operator | Dec 2012 |
| 10 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 11 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 12 | American Petrofina Co Of Texas | | Oil & Gas Operator | Jun 1985 |
| 13 | American Quasar Petroleum Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2014 |
| 14 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 15 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jul 2025 |
| 16 | Anderson Exploration Co., Inc. | | Oil & Gas Operator | Sep 2023 |
| 17 | Anderson Producing, Inc. | Houston, TX 77057 | Oil & Gas Operator | Sep 2013 |
| 18 | Anglo Production Company | | Oil & Gas Operator | Nov 1983 |
| 19 | Anr Pipeline Company | | Oil & Gas Operator | Jan 2025 |
| 20 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 21 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 22 | Apache Shelf, Inc. | Houston, TX 77056 | Oil & Gas Operator | Jan 2014 |
| 23 | Apexco-McCormick-Coastal | | Oil & Gas Operator | Dec 1977 |
| 24 | Apollo Energy Operating Co, LP | Lake Charles, LA 70601 | Oil & Gas Operator | Dec 2024 |
| 25 | Apollo Energy Operating, LP | | Oil & Gas Operator | Mar 2011 |
| 26 | Araxas Exploration, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Apr 1998 |
| 27 | Arco O & G Co-Div Atl Rich Co | | Oil & Gas Operator | Feb 1994 |
| 28 | Ashland Exploration Inc | Houston, TX 77218 | Oil & Gas Operator | Nov 2000 |
| 29 | Aspect Energy, LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 30 | Atlantic & Gulf Petroleum Co. | Houston, TX 77002 | Gas Operator | Mar 1991 |
| 31 | Auro USA, Inc. | | Oil Operator | Dec 2024 |
| 32 | Auster Oil And Gas, Inc. | | Oil & Gas Operator | Mar 1989 |
| 33 | Austral Oil Company Incorporated | Sulphur, LA 70663 | Oil & Gas Operator | Mar 2008 |
| 34 | Azimuth Energy, LLC | Denver, CO 80203 | Oil & Gas Operator | Sep 2006 |
| 35 | Badger Oil Corporation | Lafayette, LA 70505 | Oil & Gas Operator | Nov 2011 |
| 36 | Ballard Exploration Company,Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 37 | Basf Corporation | Houston, TX 77027 | Oil & Gas Operator | Nov 1992 |
| 38 | Bean Resources, Inc. | | Oil & Gas Operator | Aug 2006 |
| 39 | Beem Oil & Gas Company | | Oil & Gas Operator | Dec 1994 |
| 40 | Bel Oil Corporation | Jenks, OK 74037 | Oil & Gas Operator | Jun 2005 |
| 41 | Bellwether Exploration Company | Houston, TX 77010 | Oil & Gas Operator | May 2001 |
| 42 | BHP Billiton Petro (KCS Resources), LLC | | Oil & Gas Operator | Jul 2019 |
| 43 | BHP Petroleum (Americas) Inc | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 44 | Black Diamond Production Co. | | Oil & Gas Operator | Mar 2021 |
| 45 | Blakely Land & Exploration Co. | | Oil & Gas Operator | Apr 1991 |
| 46 | Boca Production Inc | | Oil & Gas Operator | Jun 2002 |
| 47 | Borden, Inc. | Columbus, OH 43215 | Oil & Gas Operator | May 1990 |
| 48 | BP America Production Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2025 |
| 49 | BP Exploration Inc | | Oil & Gas Operator | May 1993 |
| 50 | BPX (KCS Resources), LLC | | Oil & Gas Operator | Feb 2022 |
| 51 | BPX Operating Company | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 52 | Brammer Engineering, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 53 | Breakthrough Ventures, LLC | | Oil Operator | Jan 2025 |
| 54 | Brechtel Energy Corporation | | Oil & Gas Operator | Sep 2008 |
| 55 | Breton Sound Holdings, LLC | | Oil & Gas Operator | Dec 2024 |
| 56 | Bristol Resources Corporation | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2022 |
| 57 | British-Borneo Exploration Inc | | Oil & Gas Operator | Dec 1999 |
| 58 | Burlington Res Offshore Inc | | Oil & Gas Operator | Oct 2002 |
| 59 | Burlington Res Oil & Gas Co | | Oil & Gas Operator | Dec 2000 |
| 60 | Burlington Res Oil & Gas LP | | Oil & Gas Operator | Mar 2013 |
| 61 | Burton-Sutton Oil Co., Inc. | | Oil & Gas Operator | Apr 1988 |
| 62 | C & F Petroleum | | Oil & Gas Operator | Apr 1991 |
| 63 | C & K Offshore Company | | Oil & Gas Operator | Oct 1980 |
| 64 | C & K Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1984 |
| 65 | C.F. Braun & Company | | Oil & Gas Operator | Dec 1986 |
| 66 | Callon Petroleum Company | Natchez, MS 39120 | Oil & Gas Operator | Jan 2000 |
| 67 | Callon Petroleum Operating Co | Houston, TX 77042 | Oil & Gas Operator | Jul 2024 |
| 68 | Cameron Development Co., Inc. | | Oil & Gas Operator | Mar 1988 |
| 69 | Cameron LNG, LLC | | Oil Operator | Jan 2025 |
| 70 | Camex Operating Company | | Oil & Gas Operator | Dec 2024 |
| 71 | Camex, Inc. | | Oil & Gas Operator | Jun 1992 |
| 72 | Campbell Energy Corp. | | Oil & Gas Operator | May 1992 |
| 73 | Cardinal Oil & Gas, Inc. | | Oil & Gas Operator | Jun 1995 |
| 74 | Caroline Hunt Schoellkopf | | Oil & Gas Operator | Aug 1987 |
| 75 | Carter-Langham, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Oct 2025 |
| 76 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 77 | Castex Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 78 | Catlett & Ferguson-Carl O & G | | Oil & Gas Operator | Jun 1978 |
| 79 | Cenco, Inc. | | Oil & Gas Operator | Mar 2022 |
| 80 | Central Crude, Inc. | | Oil & Gas Operator | Jul 2014 |
| 81 | Central Resources Inc | Denver, CO 80203 | Oil & Gas Operator | Dec 2019 |
| 82 | Centurion Exploration Company | Houston, TX 77042 | Oil & Gas Operator | May 2009 |
| 83 | Chaparral Energy, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Dec 2009 |
| 84 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Oct 2025 |
| 85 | Charles F. Word & Associates | | Oil Operator | Dec 1978 |
| 86 | Charleston Oil & Gas, Inc. | | Oil & Gas Operator | Mar 1997 |
| 87 | Chevron Pipe Line Company | Houston, TX 77001 | Oil Operator | Feb 2015 |
| 88 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 89 | Christeve Oil Company, Inc. | Houston, TX 77068 | Oil & Gas Operator | Dec 2022 |
| 90 | Chroma Operating, Inc. | Washington, DC 20036 | Oil & Gas Operator | Jun 2016 |
| 91 | Clayton W. Williams, Jr., Inc. | | Oil & Gas Operator | May 1993 |
| 92 | Clayton Williams Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2017 |
| 93 | Cliffs Oil And Gas Company | | Oil & Gas Operator | Oct 1997 |
| 94 | Cliffwood Production Co. | Houston, TX 77090 | Oil & Gas Operator | Aug 2013 |
| 95 | CMS Nomeco Oil & Gas Co. | Jackson, MI 49201 | Oil & Gas Operator | Jan 2015 |
| 96 | Coastal Minerals, Inc. | | Oil Operator | Aug 1991 |
| 97 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 98 | Coastal States Gas Prod. Co. | | Oil & Gas Operator | Jun 1996 |
| 99 | Cockrell Oil Corporation | Houston, TX 77002-7348 | Oil & Gas Operator | Feb 2001 |
| 100 | Cody Energy LLC | Houston, TX 77024 | Oil & Gas Operator | Jun 2020 |