| 1 | Alta Mesa Services, LP | Houston, TX 77084 | Oil & Gas Operator | Jul 2025 |
| 2 | American Operating Company | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2003 |
| 3 | Anadarko E&P Company LP | Houston, TX 77251 | Oil & Gas Operator | Aug 2014 |
| 4 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Jul 2025 |
| 5 | Arcadia Operating, LLC | Dallas, TX 75219 | Oil & Gas Operator | Jul 2025 |
| 6 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 7 | Atasca Resources Inc | Houston, TX 77219 | Oil & Gas Operator | Jul 2025 |
| 8 | Axis Energy Corporation | Roswell, NM 88202 | Oil & Gas Operator | Jul 2025 |
| 9 | B & M Operating Co., Inc. | Houston, TX 77006 | Oil & Gas Operator | Jul 2025 |
| 10 | Badger Energy, Inc. | Austin, TX 78714 | Oil & Gas Operator | Jul 2025 |
| 11 | Ballard Exploration Company,Inc. | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 12 | Beacon Petroleum MGMT.,Inc. | Dallas, TX 75244 | Oil & Gas Operator | Mar 1997 |
| 13 | Belco Energy Corp. | Dallas, TX 75231 | Oil & Gas Operator | Mar 2015 |
| 14 | Belco Operating Corp. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1998 |
| 15 | Bellwether Exploration Company | Houston, TX 77010 | Oil & Gas Operator | May 2001 |
| 16 | Bevo Production Co. | Amarillo, TX 79101 | Oil & Gas Operator | Dec 2014 |
| 17 | Black Jack Services, L.L.C. | Bastrop, TX 78602 | Oil & Gas Operator | Jul 2025 |
| 18 | Bowman, Fred Inc. | Dallas, TX 75225 | Oil & Gas Operator | Feb 2014 |
| 19 | Brown, George R. Partnership,The | Houston, TX 77002 | Oil & Gas Operator | May 2006 |
| 20 | Brown, H. L., Jr. | Midland, TX 79702 | Oil & Gas Operator | May 2002 |
| 21 | Brown, H.L. Operating, L.L.C. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 22 | Burnett Oil Co Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2025 |
| 23 | Cameron, Paul E., Jr., Inc. | Montgomery, TX 77356 | Oil & Gas Operator | May 2015 |
| 24 | Century Royalty 2000 GP, LLC | Conroe, TX 77301 | Oil & Gas Operator | Jun 2020 |
| 25 | Chase Energy, Inc. | Austin, TX 78763 | Oil & Gas Operator | Oct 2001 |
| 26 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2025 |
| 27 | Chisos, LTD | Houston, TX 77098 | Oil & Gas Operator | Jul 2025 |
| 28 | Clay Exploration, Inc. | Spring, TX 77387 | Oil & Gas Operator | Jun 2019 |
| 29 | CMS Nomeco Oil & Gas Co. | Jackson, MI 49201 | Oil & Gas Operator | Jan 2015 |
| 30 | Cochise Energy Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 31 | Coda Energy, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1998 |
| 32 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | May 2025 |
| 33 | Comet Oil & Gas, Inc. | Conroe, TX 77305 | Oil & Gas Operator | Jul 2025 |
| 34 | Comet Production | Conroe, TX 77305 | Oil Operator | Jul 2025 |
| 35 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 36 | Corda Corporation | Wichita Falls, TX 76302 | Oil & Gas Operator | Jul 2025 |
| 37 | Cummins & Walker Oil Co., Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2021 |
| 38 | Cxy Energy, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Nov 2000 |
| 39 | Daniels Corporation, The | Seabrook, TX 77586 | Oil & Gas Operator | Jul 2025 |
| 40 | Daubert Operating, L.L.C. | San Antonio, TX 78209 | Oil Operator | Jul 2025 |
| 41 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Jul 2025 |
| 42 | Deanlake Operator, L.L.C. | Houston, TX 77010 | Oil & Gas Operator | Sep 2011 |
| 43 | Dearing, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2021 |
| 44 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Jul 2025 |
| 45 | Devon Energy Operating Co., L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2009 |
| 46 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 47 | Diasu Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 48 | Drill Partners Management, LLC | Houston, TX 77056 | Oil & Gas Operator | Nov 2010 |
| 49 | Durango Resources Corp. | Houston, TX 77043 | Oil & Gas Operator | Jul 2025 |
| 50 | East Texas Production MGT. Inc | Athens, TX 75751 | Oil & Gas Operator | Jul 2025 |
| 51 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 52 | Elliott Oil & Gas Operating Co. | Magnolia, TX 77354 | Oil & Gas Operator | Jul 2025 |
| 53 | Energy Acquisitions, Inc. | Spring, TX 77379 | Oil & Gas Operator | Apr 1996 |
| 54 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | Mar 2025 |
| 55 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Apr 2025 |
| 56 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 57 | Enpower Resources Inc. | Sugar Land, TX 77479 | Oil & Gas Operator | Jul 2025 |
| 58 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 59 | Eros Operating LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jul 2025 |
| 60 | Eurovest Oil & Gas, Inc. | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 61 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 62 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Jul 2025 |
| 63 | F.I.G. Energy, LLC | Livingston, TX 77399 | Oil & Gas Operator | Jul 2025 |
| 64 | Famcor Oil, Inc. | Scottsdale, AZ 85260 | Oil & Gas Operator | Sep 2020 |
| 65 | Faulconer Vernon E Inc | Tyler, TX 75711 | Oil & Gas Operator | May 2025 |
| 66 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 67 | Five-Jab, Inc. | Tomball, TX 77377 | Oil & Gas Operator | Jul 2025 |
| 68 | Forney & McCombs | Houston, TX 77056 | Oil & Gas Operator | Jan 1998 |
| 69 | Gaither Petroleum Corporation | Katy, TX 77493 | Oil & Gas Operator | Jul 2025 |
| 70 | Galloway Energy Co. | Tomball, TX 77377 | Oil & Gas Operator | Jul 2025 |
| 71 | Galloway Lone Star, L.L.C. | Tomball, TX 77377 | Oil & Gas Operator | Jul 2025 |
| 72 | Gardner Energy Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 1999 |
| 73 | Gec Operating, Inc. | Houston, TX 77024 | Oil & Gas Operator | Jul 2025 |
| 74 | Geosouthern Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Jul 2025 |
| 75 | Goldking Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 76 | Gordy Oil Company | Houston, TX 77007 | Oil & Gas Operator | Jul 2025 |
| 77 | Gould Oil Inc. | Wichita, KS 67278 | Oil & Gas Operator | Oct 2019 |
| 78 | Great Western Drilling Co | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 79 | Halbouty, Michel T. | Houston, TX 77056 | Oil & Gas Operator | Aug 1997 |
| 80 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 81 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Jul 2025 |
| 82 | Hampton Resources Corporation | Houston, TX 77010 | Oil & Gas Operator | Mar 1996 |
| 83 | Hanson Minerals Co. | Houston, TX 77042 | Oil & Gas Operator | Oct 1993 |
| 84 | Hanson Production Company | Cuero, TX 77954 | Oil & Gas Operator | Jul 2009 |
| 85 | Hardwick Oil Company | Sugar Land, TX 77478 | Oil & Gas Operator | Nov 2014 |
| 86 | Hardy Oil & Gas USA Inc. | Houston, TX 77079 | Oil & Gas Operator | Jun 1996 |
| 87 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 88 | Heisey Ventures, Inc. | Houston, TX 77019 | Oil & Gas Operator | Jul 2025 |
| 89 | Heritage Expl. & Prod. Co., Inc. | Stafford, TX 77497 | Oil & Gas Operator | Dec 2000 |
| 90 | Heritage Operating Co., Inc. The | Stafford, TX 77497 | Oil & Gas Operator | May 1997 |
| 91 | Highmark Energy Operating, LLC | Dallas, TX 75222 | Oil & Gas Operator | Jul 2025 |
| 92 | Hill Production Co Inc-Wisconsin | Humble, TX 77347 | Oil & Gas Operator | Jun 1993 |
| 93 | HK Energy Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 94 | Hollimon Oil Corporation | Castroville, TX 78009 | Oil & Gas Operator | Nov 2016 |
| 95 | Hooper, DR. Oil & Royalty Co. | Conroe, TX 77304 | Oil & Gas Operator | Sep 1999 |
| 96 | Hopco Operating, Inc. | Stafford, TX 77497 | Oil & Gas Operator | Dec 2016 |
| 97 | Houston Hydrocarbons, Inc. (A) | Houston, TX 77042 | Oil & Gas Operator | Sep 2004 |
| 98 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Jul 2025 |
| 99 | Imperial Oil Company | Houston, TX 77073 | Oil & Gas Operator | Oct 2004 |
| 100 | Ipact | Austin, TX 78734 | Oil & Gas Operator | Jul 2025 |