| 1 | 20TH Century Pipe & Equip.Co.Inc | Midland, TX 79702 | Oil & Gas Operator | Aug 2003 |
| 2 | 3tec Energy Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 3 | Abaco Operating, LLC | San Antonio, TX 78209 | Oil & Gas Operator | Aug 2025 |
| 4 | Abraxas Petroleum Corporation | San Antonio, TX 78259 | Oil & Gas Operator | Aug 2025 |
| 5 | Acock Engineering & Assoc., Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Jul 2002 |
| 6 | Acock Operating Limited | San Antonio, TX 78270 | Oil & Gas Operator | Aug 2025 |
| 7 | Acock/Anaqua Operating Co., LC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2004 |
| 8 | Acock/Anaqua Operating Co., LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Aug 2025 |
| 9 | Ageron Energy, LLC | San Antonio, TX 78209 | Oil & Gas Operator | Aug 2025 |
| 10 | Ageron Ironroc Energy, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Aug 2023 |
| 11 | Akers, Bill | Hebbronville, TX 78361 | Oil & Gas Operator | Aug 2003 |
| 12 | Alaron Energy, Inc. | Irving, TX 75038 | Oil & Gas Operator | Aug 2025 |
| 13 | Alco DRLG. Co. | Freer, TX 78357 | Oil & Gas Operator | Aug 2025 |
| 14 | Aldine Oil And Gas, LP | Houston, TX 77060 | Oil & Gas Operator | Aug 2025 |
| 15 | Alegre Energy Operating, LP | San Antonio, TX 78216 | Oil & Gas Operator | Sep 2005 |
| 16 | Alegre Energy, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Aug 2025 |
| 17 | Allar Co., The | Graham, TX 76450 | Oil & Gas Operator | Dec 2004 |
| 18 | Alyndson Oil & Gas Inc. | Alice, TX 78333 | Oil & Gas Operator | Jun 2000 |
| 19 | Ambrit Energy Corporation | Garland, TX 75044 | Oil & Gas Operator | Jun 2003 |
| 20 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 21 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 22 | Amplify Energy Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Aug 2025 |
| 23 | Anadarko E&P Company LP | Houston, TX 77251 | Oil & Gas Operator | Aug 2014 |
| 24 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Aug 2025 |
| 25 | Antara Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 26 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Aug 2025 |
| 27 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 28 | Arete Operating Company II, LLC | San Antonio, TX 78260 | Oil & Gas Operator | Aug 2025 |
| 29 | Arete Operating Company III, LLC | San Antonio, TX 78260 | Oil & Gas Operator | Aug 2025 |
| 30 | Arete Operating Company, LLC | San Antonio, TX 78260 | Oil & Gas Operator | Aug 2025 |
| 31 | Asher Resources | Boerne, TX 78006 | Oil & Gas Operator | May 2015 |
| 32 | Atasca Resources Inc | Houston, TX 77219 | Oil & Gas Operator | Aug 2025 |
| 33 | Atinum Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2025 |
| 34 | Austin Resources Corporation | Houston, TX 77027 | Oil & Gas Operator | Mar 2008 |
| 35 | Austin Resources Oper Company | Houston, TX 77019 | Gas Operator | Mar 1999 |
| 36 | Auten Operating Company, Inc. | Houston, TX 77242 | Oil & Gas Operator | May 1998 |
| 37 | Awp Operating Company | George West, TX 78022 | Oil & Gas Operator | Aug 2025 |
| 38 | Axio Production Company, L.P. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2006 |
| 39 | B & B Oil, Inc. | Kerrville, TX 78028 | Oil & Gas Operator | Aug 2025 |
| 40 | B & M Operating Co., Inc. | Houston, TX 77006 | Oil & Gas Operator | Aug 2025 |
| 41 | B & T Operating Co. | Dawson, TX 76639 | Oil & Gas Operator | Aug 2025 |
| 42 | Bannon Energy Inc | Houston, TX 77068 | Oil & Gas Operator | Jun 1998 |
| 43 | Barnhart Co. | Houston, TX 77056 | Oil & Gas Operator | Aug 2025 |
| 44 | Barrett Brothers Oil & Gas, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Dec 2020 |
| 45 | Barrier Resources,L.L.C. | Cedar Park, TX 78613 | Oil & Gas Operator | Aug 2003 |
| 46 | Basa Resources, Inc. | Dallas, TX 75254 | Oil & Gas Operator | Aug 2025 |
| 47 | Basic Earth Science Systems, Inc. | Austin, TX 78714 | Oil & Gas Operator | Apr 2010 |
| 48 | Battlecat Oil & Gas, LLC | Houston, TX 77082 | Oil & Gas Operator | Jul 2017 |
| 49 | Baxter, Kelly H. Oil And Gas Co. | Austin, TX 78767 | Oil & Gas Operator | Nov 2010 |
| 50 | Bay Rock Operating Company | San Antonio, TX 78212 | Oil & Gas Operator | Aug 2025 |
| 51 | Beaver Oil Company Inc | New Matamoras, OH 45767 | Oil & Gas Operator | Dec 2020 |
| 52 | Bellows, Dewey Oper. Co., LTD. | Refugio, TX 78377 | Oil & Gas Operator | Jul 2013 |
| 53 | Bellwether Exploration Company | Houston, TX 77010 | Oil & Gas Operator | May 2001 |
| 54 | Bison Energy Partners, Inc. | Houston, TX 77060 | Oil & Gas Operator | Sep 2001 |
| 55 | Bison Energy Partners, LTD. | Houston, TX 77060 | Oil & Gas Operator | Apr 2002 |
| 56 | Black Gold Energy LLC | Jenks, OK 74037 | Oil Operator | Jun 2024 |
| 57 | Blackbeard Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Aug 2025 |
| 58 | Blackbrush O & G, Inc. | San Antonio, TX 78258 | Oil & Gas Operator | Apr 2012 |
| 59 | Blair Exploration, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2011 |
| 60 | Blake Oil & Gas Corporation | Midland, TX 79701 | Oil & Gas Operator | May 2004 |
| 61 | Block "T" Petroleum, Inc. | Tyler, TX 75707 | Oil & Gas Operator | Aug 2025 |
| 62 | Bluestone Natural Res. II, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Dec 2019 |
| 63 | Bluestone Natural Resources, LLC | Tulsa, OK 74114 | Oil & Gas Operator | Jan 2015 |
| 64 | Bommer Engineering Co. | San Antonio, TX 78260 | Oil & Gas Operator | Aug 2025 |
| 65 | Bordas Oil & Gas Company | Harper, TX 78631 | Oil Operator | Aug 2025 |
| 66 | BP America Production Company | Denver, CO 80202 | Oil & Gas Operator | Apr 2025 |
| 67 | Brammer Engineering, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Aug 2025 |
| 68 | Brask-Dumont Ranch, Inc. | Houston, TX 77255 | Oil & Gas Operator | Aug 2025 |
| 69 | Brayton Oil Corp. | Corpus Chrsti, TX 78476 | Oil & Gas Operator | Dec 1994 |
| 70 | Breck Operating Corp. | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2025 |
| 71 | Bridge Oil Company LP | Midland, TX 79702 | Oil & Gas Operator | May 1999 |
| 72 | Bridge Oil Production Co., Inc. | Midland, TX 79702 | Oil & Gas Operator | Jun 1993 |
| 73 | Bright & Company | The Colony, TX 75056 | Oil & Gas Operator | May 2015 |
| 74 | Brinkoeter Gas & Oil | Converse, TX 78109 | Oil & Gas Operator | Aug 2004 |
| 75 | Britanco, L.L.C. | Falls City, TX 78113 | Oil & Gas Operator | Aug 2025 |
| 76 | Brown, C. Douglas, LLC | Dallas, TX 75209 | Oil & Gas Operator | Dec 2005 |
| 77 | Buck Management Co. L.L.C. | Fredericksbrg, TX 78624 | Oil & Gas Operator | Aug 2025 |
| 78 | Buck, George | Laredo, TX 78041 | Oil & Gas Operator | Aug 2003 |
| 79 | Burlington Resources Oil & Gas Company LP | Houston, TX 77252 | Oil & Gas Operator | Aug 2025 |
| 80 | Burlington Resources Oil And Gas Co. | Houston, TX 77210 | Oil & Gas Operator | Mar 2023 |
| 81 | Burnett Oil Co Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 2025 |
| 82 | BXP Operating, LLC | Houston, TX 77079 | Oil & Gas Operator | Aug 2025 |
| 83 | C And S Oil & Gas | San Antonio, TX 78217 | Oil & Gas Operator | Feb 1998 |
| 84 | C.C.O. & G. Company Inc. | Austin, TX 78765 | Oil & Gas Operator | Sep 1995 |
| 85 | C.F.O., Inc. | Liberty, TX 77575 | Oil Operator | Aug 2025 |
| 86 | Calpine Natural Gas Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2002 |
| 87 | Calpine Natural Gas Company L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 88 | Calpine Natural Gas L.P. | Houston, TX 77002 | Oil & Gas Operator | Jan 2006 |
| 89 | Cannan, Morris | San Antonio, TX 78205 | Oil & Gas Operator | Aug 2025 |
| 90 | Capps, R. Oil Corp. | Midland, TX 79704 | Oil & Gas Operator | Oct 2002 |
| 91 | Carburante Exploration Co, LTD. | Granbury, TX 76048 | Oil & Gas Operator | Aug 2025 |
| 92 | Carrizo Oil & Gas, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2025 |
| 93 | Castle Gas Corporation | San Angelo, TX 76902 | Oil & Gas Operator | Oct 2014 |
| 94 | CD Resources Company | San Antonio, TX 78217 | Oil & Gas Operator | Mar 2002 |
| 95 | Central Mineral Operating Co,Inc | San Antonio, TX 78216 | Oil & Gas Operator | Apr 1997 |
| 96 | Cet Energy Corporation | Spring, TX 77391 | Oil & Gas Operator | Nov 2003 |
| 97 | Chandler Oil & Gas, LLC | Beeville, TX 78102 | Oil & Gas Operator | Aug 2025 |
| 98 | Chaparosa Production Company,Inc | Freer, TX 78357 | Oil & Gas Operator | Aug 2025 |
| 99 | Chaparral (USA) Energy, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Sep 2002 |
| 100 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Aug 2025 |