| 30001 | TWM Production Co., A General Partnership | Chanute, KS 66720 | Oil Operator | Dec 2023 |
| 30002 | Two Bay Petroleum | | Oil & Gas Operator | Dec 2010 |
| 30003 | Two Bayous, Inc. | | Oil & Gas Operator | Jun 2024 |
| 30004 | Two Bit Operating Company LLC | Fort Worth, TX 76110 | Oil & Gas Operator | Nov 2024 |
| 30005 | Two Black Bears Oil, Inc. | Midland, TX 79710 | Oil & Gas Operator | Sep 2003 |
| 30006 | Two Gems Company | McAlester, OK 74502-1996 | Oil & Gas Operator | Jul 2024 |
| 30007 | Two Oaks Operating Company, LLC. | Flower Mound, TX 75028 | Oil & Gas Operator | Mar 2008 |
| 30008 | Two P Partners, LLC | Golden, CO 80401 | Oil & Gas Operator | Nov 2024 |
| 30009 | Two Pines | Drumright, OK 74030-5502 | Oil & Gas Operator | Feb 2012 |
| 30010 | Twojo, Inc. | Longview, TX 75601 | Oil & Gas Operator | Nov 1996 |
| 30011 | TX Heat Of The Permian Basin Inc | Odessa, TX 79768 | Oil & Gas Operator | Dec 2021 |
| 30012 | TX Lone Star Operating Co, LLC | Sulphur SPGS, TX 75483 | Oil & Gas Operator | Nov 2024 |
| 30013 | TX Petroleum Company | Corpus Chrsti, TX 78412 | Oil & Gas Operator | Apr 1996 |
| 30014 | Txco Resources Inc. | San Antonio, TX 78280 | Oil & Gas Operator | Nov 2024 |
| 30015 | Txla Energy, Inc. | Houston, TX 77018 | Oil & Gas Operator | Nov 2024 |
| 30016 | Txo Prod Corp.-Arkla Expl. Co. | | Oil & Gas Operator | Dec 1990 |
| 30017 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 30018 | Txo Production Corp/Amh O&G Co | | Oil & Gas Operator | Dec 1990 |
| 30019 | Txok Energy Resources Company | Tulsa, OK 74172-0140 | Oil & Gas Operator | Feb 2017 |
| 30020 | Txok Texas Energy Resources,L.P. | Dallas, TX 75251 | Oil & Gas Operator | Apr 2008 |
| 30021 | Txon Partners, LLC | Houston, TX 77057 | Oil & Gas Operator | Jun 2017 |
| 30022 | TXP Operating Company | | Oil & Gas Operator | Jul 1992 |
| 30023 | TXP, Incorporated | San Angelo, TX 76906 | Oil & Gas Operator | Nov 2024 |
| 30024 | Txu Fuel Company | Dallas, TX 75201 | Oil & Gas Operator | May 2004 |
| 30025 | Txu Gas Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2004 |
| 30026 | Txu Lone Star Pipeline | Dallas, TX 75201 | Oil & Gas Operator | Oct 2003 |
| 30027 | TXX Operating LLC | Shreveport, LA 71133 | Oil & Gas Operator | Nov 2024 |
| 30028 | Ty-Tex Exploration, Inc. | Tyler, TX 75711 | Oil Operator | Dec 2000 |
| 30029 | Tyco Incorporate | | Oil & Gas Operator | Oct 1995 |
| 30030 | Tyco Oil Co. | | Oil Operator | Jul 2024 |
| 30031 | Tyco Operating Co. | Throckmorton, TX 76483 | Oil & Gas Operator | Nov 2024 |
| 30032 | Tygr Operating Company, LLC | | Oil & Gas Operator | May 2024 |
| 30033 | Tyl Oil | Canon City, CO 81212 | Gas Operator | May 1994 |
| 30034 | Tyler Enterprises Inc | Bristow, OK 74010-3192 | Oil & Gas Operator | Feb 2004 |
| 30035 | Tyler Oil & Gas Inc. | Tyler, TX 75702 | Oil & Gas Operator | Sep 2004 |
| 30036 | Tyler Oil Company | Billings, MT 59104-3203 | Oil & Gas Operator | Nov 2019 |
| 30037 | Tyler Production, LLC | | Oil & Gas Operator | Jul 2013 |
| 30038 | Tyler Rockies Exploration LTD | Tyler, TX 75710-0119 | Oil & Gas Operator | Sep 2024 |
| 30039 | Tyluka Operations, LLC | Hays, KS 67601 | Oil Operator | Jun 2024 |
| 30040 | Tyner Texas Operating Company | Dallas, TX 75248 | Oil & Gas Operator | Nov 2024 |
| 30041 | Tyrex Oil Company | Casper, WY 82602 | Oil & Gas Operator | May 1997 |
| 30042 | Tyro Oil Develop | | Oil Operator | Jul 1991 |
| 30043 | Tyrok | | Oil & Gas Operator | Nov 2010 |
| 30044 | Tysco Oil And Gas Corp. | | Oil & Gas Operator | Jun 2024 |
| 30045 | Tyson Gary | Hobart, OK 73651-6413 | Oil & Gas Operator | Mar 2018 |
| 30046 | Tyson Oil Co. | | Oil Operator | Jul 2024 |
| 30047 | Tyson Olan | Hobart, OK 73651-6413 | Oil & Gas Operator | Apr 2015 |
| 30048 | Tytan Operating Company LLC | Edmond, OK 73083-3794 | Oil & Gas Operator | May 2016 |
| 30049 | U Bee Tea Production LLC | Culbertson, MT 59218 | Oil & Gas Operator | Sep 2024 |
| 30050 | U R C C | | Oil & Gas Operator | Jun 1991 |
| 30051 | U S Department Of Energy | | Oil & Gas Operator | Apr 1999 |
| 30052 | U S Drilling Company Inc | Holdenville, OK 74848-0913 | Oil & Gas Operator | Mar 2017 |
| 30053 | U S Energy Corp. Of Amer. Inc. | Ranger, TX 76470 | Oil & Gas Operator | Nov 2024 |
| 30054 | U S Exploraton Liq Trust | | Oil & Gas Operator | Oct 1994 |
| 30055 | U S Liquids Of La., L.P. | | Oil Operator | Mar 2014 |
| 30056 | U S Oil Reclaimers LLC | Drumright, OK 74030-1155 | Oil Operator | Jun 2023 |
| 30057 | U V Industries | | Oil & Gas Operator | Jan 1993 |
| 30058 | U-N-I Exploratio | | Oil & Gas Operator | Dec 1990 |
| 30059 | U-N-I Exploration & Development, Inc. | Yates Center, KS 66783 | Oil & Gas Operator | Jan 2003 |
| 30060 | U. D. Man, Inc. | San Antonio, TX 78212 | Oil & Gas Operator | Nov 2024 |
| 30061 | U. O. C., Inc. | | Oil Operator | Jun 2019 |
| 30062 | U. S. Operating, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Nov 2024 |
| 30063 | U.S. Capital Corp Of Am, Inc. | | Oil & Gas Operator | Aug 1998 |
| 30064 | U.S. Enercorp, LLC | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2004 |
| 30065 | U.S. Enercorp, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2019 |
| 30066 | U.S. Energy Development Corp | Arlington, TX 76011 | Oil & Gas Operator | Nov 2024 |
| 30067 | U.S. Energy Partners LLC | Tulsa, OK 74105 | Oil Operator | Aug 2024 |
| 30068 | U.S. Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 30069 | U.S. Sovereign Oil And Gas, Inc. | Dallas, TX 75355 | Oil & Gas Operator | Nov 2024 |
| 30070 | U.S. Steel Mining Co., Inc. | | Gas Operator | Jan 2000 |
| 30071 | U.S. Steel Mining Co., LLC | | Gas Operator | Oct 2002 |
| 30072 | U.S.A. Plugging Company | Pearsall, TX 78061 | Oil & Gas Operator | Nov 2024 |
| 30073 | U1 Ranch Oil | Houston, TX 77269 | Oil & Gas Operator | Nov 2024 |
| 30074 | Uae Investco 1 (Estill), LLC | Ravenna, KY 40472 | Oil Operator | Dec 2022 |
| 30075 | Uae Investco 2 (Lee), LLC | Ravenna, KY 40472 | Oil Operator | Dec 2021 |
| 30076 | Ubetco, Inc. | Rockdale, TX 76567 | Oil & Gas Operator | Nov 2024 |
| 30077 | Uehlin LLC | Oberlin, KS 67749 | Oil Operator | Jun 2024 |
| 30078 | Uhc New Mexico Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2007 |
| 30079 | Uhc Petroleum Corporation | Rocksprings, TX 78880 | Oil & Gas Operator | Nov 2024 |
| 30080 | Uhl Oil Co., Inc. | Bradford, PA 16701 | Oil & Gas Operator | Dec 2023 |
| 30081 | Uhl, Robert | Bradford, PA 16701 | Oil & Gas Operator | Dec 2023 |
| 30082 | Uhls, Jimmie J. | Sedan, KS 67361 | Oil Operator | Sep 2019 |
| 30083 | Uinta Oil & Gas | Roosevelt, UT 84066 | Oil & Gas Operator | Nov 1997 |
| 30084 | Uinta Wax Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Aug 2024 |
| 30085 | Uinta-Taylor Fund, LTD | Roosevelt, UT 84066 | Oil & Gas Operator | Nov 2018 |
| 30086 | Uintah Investors LLC | Vernal, UT 84078 | Oil & Gas Operator | Sep 2024 |
| 30087 | Ulatex Oil & Gas Inc. | Nocona, TX 76255 | Oil & Gas Operator | Dec 1998 |
| 30088 | Ullum Oil And Gas Development Corporation, Inc. | Grantsville, WV 26147-0000 | Oil & Gas Operator | Dec 2021 |
| 30089 | Ulrich, William J., Jr. & Connie K. | Elma, NY 14059 | Gas Operator | Dec 2023 |
| 30090 | Ultra Oil & Gas, Inc. | Centerton, AR 72719 | Oil & Gas Operator | Nov 2024 |
| 30091 | Ultra Petroleum (U.S.A.), Inc. | Granbury, TX 76048 | Oil & Gas Operator | Sep 2003 |
| 30092 | Ultra Production Company, LLC | Cedar Bluff, VA 24609 | Gas Operator | Oct 2014 |
| 30093 | Ultra Resources Inc | Houston, TX 77060 | Oil & Gas Operator | Sep 2018 |
| 30094 | Ultramar Oil & Gas LTD | Houston, TX 77060 | Oil & Gas Operator | Jul 1995 |
| 30095 | Ultramar Production Company | | Oil & Gas Operator | Dec 1991 |
| 30096 | Ulysses, City Of | Ulysses, KS 67880 | Gas Operator | Jul 2024 |
| 30097 | Umberham Oil Company Inc | Oklahoma City, OK 73151-4000 | Oil & Gas Operator | Sep 2024 |
| 30098 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 30099 | Umma Resources, LLC | Portland, TX 78374 | Gas Operator | Nov 2024 |
| 30100 | Ummel'S Tank Ser | | Oil Operator | Sep 1994 |