| 1 | Acadiana Gas Systems, Inc. | | Oil & Gas Operator | Jan 1999 |
| 2 | Acadienergy, Inc. | | Oil & Gas Operator | Jun 1988 |
| 3 | Addison Resources Inc. | | Oil & Gas Operator | Jul 1998 |
| 4 | Alliance Resources (USA), Inc. | | Oil & Gas Operator | Oct 2002 |
| 5 | Alta Mesa Services, LP | Houston, TX 77084 | Oil & Gas Operator | Oct 2025 |
| 6 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 7 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 8 | American Exploration Oper. Co. | | Oil & Gas Operator | May 1990 |
| 9 | American National Petroleum Co. | Houston, TX 77057 | Oil & Gas Operator | Aug 1995 |
| 10 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 11 | An-Son Corporation | Oklahoma City, OK 73124 | Oil & Gas Operator | Jan 2006 |
| 12 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 13 | Aquila Energy Resources Corp. | Houston, TX 77042 | Oil & Gas Operator | Nov 2013 |
| 14 | Argos Properties, Inc. | | Oil & Gas Operator | Apr 1992 |
| 15 | Aroc (Texas) Inc | Houston, TX 77090 | Oil & Gas Operator | Dec 2014 |
| 16 | Ashland Exploration Inc | Houston, TX 77218 | Oil & Gas Operator | Nov 2000 |
| 17 | Ashland Oil, Inc | | Oil & Gas Operator | Dec 2023 |
| 18 | Aspen Exploration, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2012 |
| 19 | Badger Energy LLC | | Oil & Gas Operator | Dec 2024 |
| 20 | Badger Oil Corporation | Lafayette, LA 70505 | Oil & Gas Operator | Nov 2011 |
| 21 | Badger Oil/Clovelly Oil | | Oil & Gas Operator | Oct 2004 |
| 22 | Bandera Oil & Gas Inc | Fulshear, TX 77441 | Oil & Gas Operator | Oct 2025 |
| 23 | BCF Resources, LLC | | Oil Operator | Jun 2023 |
| 24 | Bean Energy, Inc. | | Oil & Gas Operator | Dec 1986 |
| 25 | Bean Resources, Inc. | | Oil & Gas Operator | Aug 2006 |
| 26 | Beta Operating, Inc | | Oil & Gas Operator | May 2001 |
| 27 | BHP Petroleum (Americas) Inc | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 28 | Bintliff Props. LTD. PRTNRSHP. | | Oil & Gas Operator | Dec 1987 |
| 29 | Bois D'Arc Operating Corporation | Houston, TX 77040 | Oil & Gas Operator | Jan 2000 |
| 30 | Brammer Engineering, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 31 | Brigham Oil & Gas, L.P. | Austin, TX 78730 | Oil & Gas Operator | Oct 2015 |
| 32 | Brock Energy Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 1986 |
| 33 | Brock Petroleum Corporation | | Oil & Gas Operator | Sep 1984 |
| 34 | Burk Royalty Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Jan 2002 |
| 35 | C & K Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1984 |
| 36 | Cajun Minerals, Inc. | | Oil & Gas Operator | Mar 1997 |
| 37 | Cajun Operating, Inc. | | Oil & Gas Operator | Jun 2011 |
| 38 | Callon Offshore Production, Inc. | Natchez, MS 39121 | Oil & Gas Operator | Dec 2005 |
| 39 | Calyx Exploration & Production | | Oil & Gas Operator | Jul 1991 |
| 40 | Camex, Inc. | | Oil & Gas Operator | Jun 1992 |
| 41 | Carrollton Resources Corp. | | Oil & Gas Operator | Sep 2000 |
| 42 | Cashco Oil Company | Houston, TX 77024 | Oil & Gas Operator | Aug 2003 |
| 43 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 44 | Castex Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 45 | Century Exploration Houston, Inc | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2011 |
| 46 | Century Exploration Houston, LLC | Austin, TX 78702 | Oil & Gas Operator | Jan 2016 |
| 47 | Century Exploration N.O., Inc. | | Oil & Gas Operator | Sep 2011 |
| 48 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Jun 2025 |
| 49 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 50 | Cities Service Company | | Oil & Gas Operator | Mar 1983 |
| 51 | Cities Service Oil & Gas Corp | | Oil & Gas Operator | Mar 1988 |
| 52 | Cities Service Oil Co. | | Oil & Gas Operator | Dec 1986 |
| 53 | Clovelly DRLG & Dev Co Inc | | Oil & Gas Operator | Oct 1983 |
| 54 | Clovelly Oil Co., Inc. | | Oil & Gas Operator | Nov 2008 |
| 55 | Cockrell Oil Corporation | Houston, TX 77002-7348 | Oil & Gas Operator | Feb 2001 |
| 56 | Cody Energy LLC | Houston, TX 77024 | Oil & Gas Operator | Jun 2020 |
| 57 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Aug 2025 |
| 58 | Columbia Gas Dev. Corp. | | Oil & Gas Operator | Apr 1996 |
| 59 | Comstock Oil & Gas -- La, Inc. | | Oil & Gas Operator | Mar 2005 |
| 60 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 61 | Consolidated Resources Inc | | Oil & Gas Operator | May 2004 |
| 62 | Contango Operators, Inc. | Houston, TX 77098 | Oil & Gas Operator | Dec 2022 |
| 63 | Contango Operators, LLC | | Oil & Gas Operator | Nov 2024 |
| 64 | Contango Resources Company | | Oil & Gas Operator | Mar 2009 |
| 65 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Oct 2025 |
| 66 | Cotton Petroleum Corporation | Tulsa, OK 74102 | Oil & Gas Operator | Jan 2005 |
| 67 | Cox Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2014 |
| 68 | Cox Operating, L.L.C. | | Oil & Gas Operator | Jan 2024 |
| 69 | Cra International, LTD | | Oil & Gas Operator | Mar 1983 |
| 70 | Crescent DRLG & DVLPMNT, Inc. | | Oil & Gas Operator | Oct 1992 |
| 71 | Crosstex Lig, LLC | | Oil Operator | Mar 2014 |
| 72 | Cuatro Petro Corp. | Richardson, TX 75080 | Oil & Gas Operator | Oct 2025 |
| 73 | Cypress Production, Inc. | Azle, TX 76020 | Oil & Gas Operator | Oct 2025 |
| 74 | D. C. Bintliff Et Al | | Oil & Gas Operator | Feb 1987 |
| 75 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 76 | Daniel Oil Company | | Oil & Gas Operator | Jan 1983 |
| 77 | Darsey Operating Corporation | | Oil & Gas Operator | Sep 1990 |
| 78 | Denbury Management, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Dec 1999 |
| 79 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Oct 2025 |
| 80 | Denbury Resources Inc. | Plano, TX 75024 | Oil & Gas Operator | Dec 2003 |
| 81 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 82 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Oct 2025 |
| 83 | DRD Operating Company | | Oil & Gas Operator | Feb 2014 |
| 84 | Duer Wagner & Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 1998 |
| 85 | Dynamic Exploration, Inc. | | Oil & Gas Operator | Oct 2003 |
| 86 | Dynamic Offshore Resources, LLC | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 87 | Ed I. Estis | | Oil & Gas Operator | Sep 1998 |
| 88 | Ed Shea | | Oil Operator | Sep 1990 |
| 89 | Edwin L Cox-Michael Halbouty | | Oil & Gas Operator | Jun 1986 |
| 90 | Edwin L. Cox & Berry R. Cox | | Oil & Gas Operator | Jun 1986 |
| 91 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 92 | Elysium Energy, L.L.C. | Denver, CO 80202 | Oil & Gas Operator | Jun 2019 |
| 93 | Energy Corp. Of America, Inc. | | Oil & Gas Operator | Aug 1998 |
| 94 | Energy Recovery Group, LLC | | Oil & Gas Operator | Jul 2008 |
| 95 | Energy Reserves Group | Houston, TX 770563020 | Oil & Gas Operator | Apr 1996 |
| 96 | Energy Xxi Gulf Coast, Inc. | | Oil & Gas Operator | Dec 2008 |
| 97 | Energy Xxi Onshore, LLC | | Oil & Gas Operator | Dec 2023 |
| 98 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 99 | Enex Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 100 | Enlink Lig, LLC | | Oil Operator | Jan 2025 |