| 1 | 3tec Energy Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 2 | 7711 Corporation, The | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 3 | A. Bauer, LLC | Red Rock, TX 78662 | Oil Operator | May 2025 |
| 4 | Acock Engineering & Assoc., Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Jul 2002 |
| 5 | Acock/Anaqua Operating Co., LC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2004 |
| 6 | Activa Resources, LLC | San Antonio, TX 78205 | Oil & Gas Operator | May 2025 |
| 7 | Activa Resources, LTD. | San Antonio, TX 78205 | Oil & Gas Operator | Mar 2008 |
| 8 | Alamo Operating Company, L. C. | San Antonio, TX 78278 | Oil & Gas Operator | Aug 2023 |
| 9 | Alegre Energy Operating, LP | San Antonio, TX 78216 | Oil & Gas Operator | Sep 2005 |
| 10 | Alegre Energy, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | May 2025 |
| 11 | Alexander Energy Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 12 | Allegiant Resources, LLC | Lafayette, LA 70503 | Oil & Gas Operator | May 2025 |
| 13 | American Delta Corporation | Portland, TX 78374 | Oil & Gas Operator | Jun 2013 |
| 14 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 15 | Anadarko Austin Chalk Company | Houston, TX 77251 | Oil & Gas Operator | Feb 2006 |
| 16 | Anadarko E&P Company LP | Houston, TX 77251 | Oil & Gas Operator | Aug 2014 |
| 17 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 18 | Anchor Oil Company | Gruver, TX 79040 | Gas Operator | May 2025 |
| 19 | Anchor Operating Co. | Houston, TX 77055 | Oil & Gas Operator | May 2025 |
| 20 | Aop Operating Corporation | Dallas, TX 75313 | Oil & Gas Operator | Aug 2003 |
| 21 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 22 | Arcturus Operating Company | Addison, TX 75001 | Oil & Gas Operator | May 2025 |
| 23 | Argent Energy (Us) Holdings Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Sep 2021 |
| 24 | Arkoma Prod Co Of Texas, Inc. | Dallas, TX 75225 | Oil Operator | May 2004 |
| 25 | Arpel, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2014 |
| 26 | Arrow Exploration Company | Plano, TX 75075 | Oil & Gas Operator | Dec 2004 |
| 27 | Arrowhead Operating Inc. | Argyle, TX 76226 | Oil & Gas Operator | May 2025 |
| 28 | Asm Oil & Gas Company, Inc. | Dallas, TX 75367 | Oil & Gas Operator | May 2020 |
| 29 | Atasca Resources Inc | Houston, TX 77219 | Oil & Gas Operator | May 2025 |
| 30 | Atkinson Energy Corporation | Giddings, TX 78942 | Oil & Gas Operator | Jan 2010 |
| 31 | B & B Drilling Co. | Milano, TX 76556 | Oil & Gas Operator | Jul 2015 |
| 32 | Bagley, Roy | Magnolia, TX 77354 | Oil & Gas Operator | May 2025 |
| 33 | Bargo Energy Company | Houston, TX 77010 | Oil & Gas Operator | May 2001 |
| 34 | Bass Petroleum Inc | Austin, TX 78716 | Oil & Gas Operator | May 2025 |
| 35 | Baxter, Kelly H. | Austin, TX 78767 | Oil & Gas Operator | Mar 2008 |
| 36 | Bay Rock Operating Company | San Antonio, TX 78212 | Oil & Gas Operator | May 2025 |
| 37 | Baytex Energy USA, Inc. | Houston, TX 77084 | Oil & Gas Operator | May 2025 |
| 38 | BCL Operating, LLC | Houston, TX 77269 | Oil & Gas Operator | May 2025 |
| 39 | Beaver Oil Company Inc | New Matamoras, OH 45767 | Oil & Gas Operator | Dec 2020 |
| 40 | Belco Energy Corp. | Dallas, TX 75231 | Oil & Gas Operator | Mar 2015 |
| 41 | Belco Operating Corp. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1998 |
| 42 | Bellwether Exploration Company | Houston, TX 77010 | Oil & Gas Operator | May 2001 |
| 43 | Benson Mineral Group Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 2022 |
| 44 | Berenergy Corporation | Denver, CO 80217 | Oil & Gas Operator | Apr 2025 |
| 45 | Beta Oil Corporation | San Antonio, TX 78232 | Oil & Gas Operator | May 2025 |
| 46 | Big "6" Drilling Company | Houston, TX 77063 | Oil & Gas Operator | Mar 2019 |
| 47 | Bledsoe Petro Corporation | Dallas, TX 75201 | Oil & Gas Operator | Dec 2000 |
| 48 | Blessing Energy, Inc. | Giddings, TX 78942 | Oil & Gas Operator | May 2025 |
| 49 | Bluebonnet Land & Cattle Co. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 50 | Bommer Engineering Co. | San Antonio, TX 78260 | Oil & Gas Operator | May 2025 |
| 51 | Bowman, Fred Inc. | Dallas, TX 75225 | Oil & Gas Operator | Feb 2014 |
| 52 | BP America Production Company | Denver, CO 80202 | Oil & Gas Operator | Feb 2025 |
| 53 | Brammer Supply Inc | Gainesville, TX 76240 | Oil & Gas Operator | Nov 2014 |
| 54 | Brazos Resources, Inc. | College Sta, TX 77840 | Oil & Gas Operator | Dec 1998 |
| 55 | BRG Petroleum Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2020 |
| 56 | Bridge Oil Company LP | Midland, TX 79702 | Oil & Gas Operator | May 1999 |
| 57 | Brittany Drilling Co. | Abilene, TX 79604 | Oil & Gas Operator | Dec 2000 |
| 58 | Browning Oil Company, Inc. | Dallas, TX 75251 | Oil & Gas Operator | May 2025 |
| 59 | Bull Operating, LLC | Houston, TX 77010 | Oil & Gas Operator | May 2025 |
| 60 | Burro Bluff Corporation | Houston, TX 77024 | Oil & Gas Operator | May 2025 |
| 61 | BXP Operating, LLC | Houston, TX 77079 | Oil & Gas Operator | May 2025 |
| 62 | Byng Energy Group Inc | Enid, OK 73703 | Oil & Gas Operator | May 2025 |
| 63 | C&P Resources Operating Co,LLC | Houston, TX 77056 | Oil & Gas Operator | May 2025 |
| 64 | Cabeza Oil And Gas, LLC | Austin, CO 81410 | Oil & Gas Operator | Mar 2022 |
| 65 | Cag Petroleum Corp. | Dallas, TX 75382 | Oil & Gas Operator | May 2025 |
| 66 | Cago, Inc. | College Sta, TX 77845 | Oil & Gas Operator | May 2025 |
| 67 | Central Plains Oil&Gas Corp. (A) | Bryan, TX 77802 | Oil & Gas Operator | Mar 2003 |
| 68 | Champlin Exploration, Inc. | Enid, OK 73702 | Oil & Gas Operator | Mar 2025 |
| 69 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | May 2025 |
| 70 | Chapman Oil Company | Midland, TX 79702 | Oil & Gas Operator | Mar 2025 |
| 71 | Chemily Management Company | Cypress, TX 77429 | Oil & Gas Operator | Apr 2023 |
| 72 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | May 2025 |
| 73 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Jan 2025 |
| 74 | Chisos, LTD | Houston, TX 77098 | Oil & Gas Operator | May 2025 |
| 75 | Christensen & Matthews | Houston, TX 77040 | Oil & Gas Operator | May 2025 |
| 76 | Cibolo Energy Operating, Inc. | Bulverde, TX 78163 | Oil & Gas Operator | May 2025 |
| 77 | Cico Oil & Gas Company | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 78 | Cimarron Engineering, LLC | Kingsville, TX 78364 | Oil & Gas Operator | May 2025 |
| 79 | Cinco Natural Resources Corp | La Grange, TX 78945 | Oil & Gas Operator | May 2025 |
| 80 | Cirrus Production Company | Enid, OK 73702 | Oil & Gas Operator | Feb 2025 |
| 81 | Clayton Williams Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2017 |
| 82 | CML Exploration, LLC | Austin, TX 78746 | Oil & Gas Operator | May 2025 |
| 83 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 84 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2025 |
| 85 | Coda Energy, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1998 |
| 86 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Mar 2025 |
| 87 | Cole, Frank W Engineering | Dallas, TX 75254 | Oil & Gas Operator | Mar 2006 |
| 88 | Columbia Gas Development Corp. | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 89 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 90 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 91 | Costilla Energy Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 92 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 93 | County Management, Inc. | Houston, TX 77055 | Oil & Gas Operator | Apr 1993 |
| 94 | Cox & Perkins Exploration, Inc. | Houston, TX 77057 | Oil & Gas Operator | May 2025 |
| 95 | Crawford Energy, Incorporated | Houston, TX 77056 | Oil & Gas Operator | Mar 2008 |
| 96 | Crawford Hughes Operating Co. | The Woodlands, TX 77380 | Oil & Gas Operator | May 2025 |
| 97 | Creative Oil & Gas Operating,LLC | Giddings, TX 78942 | Oil & Gas Operator | May 2024 |
| 98 | Credo Petroleum Corporation | Denver, CO 80202 | Oil & Gas Operator | Jan 2013 |
| 99 | Crimson Energy Company, LC | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2004 |
| 100 | Crimson Exploration Oper., Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |