| 1 | T. A. Atkinson Opr. | | Gas Operator | Dec 1997 |
| 2 | T. E. Adams Petroleum Corp. | | Oil & Gas Operator | Dec 2025 |
| 3 | Tamarack Energy Inc | Midland, TX 79701 | Oil & Gas Operator | Dec 2015 |
| 4 | Tannehill Oil Company | | Oil & Gas Operator | Dec 1991 |
| 5 | Target Drilling | | Oil & Gas Operator | Feb 2018 |
| 6 | Tatum Petroleum Corp | Zanesville, OH 43702 | Oil & Gas Operator | Dec 2008 |
| 7 | TB Properties | | Oil & Gas Operator | Dec 2025 |
| 8 | Team Operating, L.L.C. | Pinehurst, TX 77362 | Oil & Gas Operator | Jul 2026 |
| 9 | Ted Koble Operator | | Oil & Gas Operator | Nov 2007 |
| 10 | Tej Ventures | | Oil & Gas Operator | Dec 2002 |
| 11 | Temblor Petroleum Co. LLC | | Oil & Gas Operator | Dec 2025 |
| 12 | Temescal Resources LLC | | Oil & Gas Operator | May 2026 |
| 13 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Dec 2025 |
| 14 | Tenneco West, Inc. | | Oil & Gas Operator | Dec 1983 |
| 15 | Termo Company Of Texas | | Oil & Gas Operator | Dec 1986 |
| 16 | Terra Exploration & Production Co. Inc. | | Oil & Gas Operator | Dec 2009 |
| 17 | Tetra Oil Company | | Oil & Gas Operator | Dec 2025 |
| 18 | Texaco Producing Inc. | Rock Springs, WY 82901 | Oil & Gas Operator | Dec 2000 |
| 19 | Texas Crude Energy, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 2012 |
| 20 | Texas Pacific Oil Co. | | Oil & Gas Operator | Dec 1980 |
| 21 | Texcal Energy (GP) LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2016 |
| 22 | Texinia Oil & Gas Inc | Dallas, TX 75214 | Oil & Gas Operator | Apr 2026 |
| 23 | The Arvin Company | | Oil Operator | Dec 2004 |
| 24 | The Hampton Oil Corporation | | Oil & Gas Operator | Aug 2014 |
| 25 | The Harter Family Trust Of 1995 | | Oil Operator | Dec 2003 |
| 26 | The Krik Company | | Oil Operator | Dec 2004 |
| 27 | The Lansdale Co. | | Oil & Gas Operator | May 2026 |
| 28 | The Nahabedian Exploration Group LLC | | Oil & Gas Operator | Dec 2025 |
| 29 | The Port Of Long Beach | | Oil & Gas Operator | Dec 1997 |
| 30 | The Procter And Gamble Co. | | Gas Operator | Dec 1989 |
| 31 | The Termo Company | Long Beach, CA 90801 | Oil & Gas Operator | May 2026 |
| 32 | Thomas C. King | | Oil & Gas Operator | Dec 1995 |
| 33 | Thomas Oil Company | | Oil & Gas Operator | Dec 2008 |
| 34 | Thomas Oilers | | Oil & Gas Operator | Jun 2026 |
| 35 | Thomas R. Banks | | Oil Operator | Dec 2025 |
| 36 | Thompson Energy Resources LLC | | Oil & Gas Operator | May 2026 |
| 37 | Thompson Oil Co. | Corsicana, TX 75151 | Oil & Gas Operator | Apr 2026 |
| 38 | Thriftway Company | Farmington, NM 87401 | Oil & Gas Operator | Dec 1996 |
| 39 | Thums Long Beach Co. | | Oil & Gas Operator | May 2026 |
| 40 | Thurner Energy Corporation | | Oil & Gas Operator | Dec 2001 |
| 41 | Tidelands Oil Production Co. | | Oil & Gas Operator | May 2026 |
| 42 | Tiger Oil Company | Dallas, TX 75221 | Oil & Gas Operator | May 2007 |
| 43 | Timco Oil Co. | | Oil & Gas Operator | Dec 1987 |
| 44 | Titan Energy, Inc. | Austin, TX 78703 | Oil & Gas Operator | Jul 2026 |
| 45 | TJ Ballantyne Living Trust | | Oil & Gas Operator | Dec 2019 |
| 46 | TJ Scott Family Investments LLC | | Oil & Gas Operator | May 2026 |
| 47 | Tonka Energy Inc. | | Oil & Gas Operator | Dec 2004 |
| 48 | Tonner Hills SSP LLC | | Oil & Gas Operator | Dec 2012 |
| 49 | Tooby Farms | | Gas Operator | Dec 1989 |
| 50 | Topko N. Wilmington Prtnrship. | | Oil & Gas Operator | Dec 1995 |
| 51 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 52 | Torrance Petroleum Inc. | | Oil & Gas Operator | Dec 2003 |
| 53 | Tosco Enhanced Oil Recovery Corporation | | Oil Operator | Dec 1981 |
| 54 | Towne Exploration Company LP | | Oil & Gas Operator | May 2026 |
| 55 | TPC Operating Inc. | | Oil & Gas Operator | Dec 2025 |
| 56 | Transco Oil & Gas Inc. | | Gas Operator | Dec 1992 |
| 57 | Transpac Petroleum Inc. | | Oil & Gas Operator | Dec 1995 |
| 58 | TRC Cypress Group LLC | | Oil & Gas Operator | Dec 2025 |
| 59 | TRC Operating Company Inc. | | Oil & Gas Operator | May 2026 |
| 60 | Tri-Valley Oil & Gas Co. | | Oil & Gas Operator | Dec 2025 |
| 61 | Trio Petroleum LLC | | Oil & Gas Operator | May 2026 |
| 62 | Triton Oil & Gas Corp. | Houston, TX 77002 | Oil & Gas Operator | Nov 2014 |
| 63 | TS Leasing Operations Inc. | | Oil & Gas Operator | May 2026 |
| 64 | Two Bay Petroleum | | Oil & Gas Operator | Dec 2010 |
| 65 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |