| 1 | O & G Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Oct 1996 |
| 2 | O & O Operators, LLC. | Fate, TX 75132 | Oil & Gas Operator | Sep 2025 |
| 3 | O Hill Enterprises, Inc. | La Grange, TX 78945 | Oil & Gas Operator | Jan 2014 |
| 4 | O S & S Oil Company | Electra, TX 76360 | Oil & Gas Operator | Jan 2018 |
| 5 | O&G Investments Inc. | Runge, TX 78151 | Oil & Gas Operator | Feb 2003 |
| 6 | O'Bar Operating Co., Inc. | Longview, TX 75604 | Oil & Gas Operator | Sep 2025 |
| 7 | O'Benco, Inc. | Shreveport, LA 71136 | Oil & Gas Operator | Sep 2025 |
| 8 | O'Blue Corp. | Kerrville, TX 78028 | Oil & Gas Operator | Mar 1998 |
| 9 | O'Brien Energy Company | Shreveport, LA 71136 | Oil & Gas Operator | Sep 2019 |
| 10 | O'Brien Energy Resources Corp | Portsmouth, NH 03801 | Oil & Gas Operator | Sep 2025 |
| 11 | O'Brien Operating Company | Shreveport, LA 71164 | Oil & Gas Operator | Dec 2004 |
| 12 | O'Brien Resources LLC | Shreveport, LA 71136 | Oil Operator | Nov 2017 |
| 13 | O'Brien, George H. Jr. | Midland, TX 79701 | Oil & Gas Operator | Jun 1994 |
| 14 | O'Connor & Hewitt, LTD. | Victoria, TX 77901 | Oil & Gas Operator | Jun 1998 |
| 15 | O'Connor Energy Management, LLC | Victoria, TX 77902 | Oil Operator | Sep 2025 |
| 16 | O'Dell, Mitchell | Cross Plains, TX 76443 | Oil & Gas Operator | Sep 2025 |
| 17 | O'Donohoe, Jack | Wichita Falls, TX 76301 | Oil & Gas Operator | May 2002 |
| 18 | O'Leary'S Oil & Gas Inc. | Arcadia, FL 34266 | Oil & Gas Operator | May 2008 |
| 19 | O'Neal Cattle Co. | Pampa, TX 79066 | Gas Operator | Sep 2025 |
| 20 | O'Neal Oil & Gas Co | Fort Worth, TX 76107-1479 | Oil & Gas Operator | Jun 2025 |
| 21 | O'Neal Oil Company | Nocona, TX 76255 | Oil & Gas Operator | Sep 2025 |
| 22 | O'Neal Operating Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 1999 |
| 23 | O'Neal, Lindell | Nocona, TX 76255 | Oil & Gas Operator | May 2025 |
| 24 | O'Neil, Pat | Wichita Falls, TX 76308 | Oil & Gas Operator | Nov 2005 |
| 25 | O'Neill Properties, LTD. | Midland, TX 79702 | Oil & Gas Operator | Sep 2025 |
| 26 | O'Ryan Oil And Gas | Odessa, TX 79768 | Oil & Gas Operator | Sep 2025 |
| 27 | O'Sand Production, Inc. | Tomball, TX 77377 | Oil & Gas Operator | Aug 2003 |
| 28 | O'Sullivan Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2000 |
| 29 | O'Tool Oil & Gas, LLC | Dallas, TX 75219 | Oil & Gas Operator | Sep 2025 |
| 30 | O. H. B. Inc. | San Angelo, TX 76902 | Oil & Gas Operator | Sep 2019 |
| 31 | O. H. M. Operating | Pampa, TX 79065 | Oil & Gas Operator | Sep 2025 |
| 32 | O.G.O. Refining | Luling, TX 78648 | Oil & Gas Operator | Jun 2013 |
| 33 | O.G.P. Operating, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Sep 2025 |
| 34 | O.T. Oil | Kilgore, TX 75663 | Oil Operator | Sep 2025 |
| 35 | Oahe Oil Company | Texline, TX 79087 | Oil & Gas Operator | May 2004 |
| 36 | Oak Energy, LLC | Houston, TX 77027 | Oil & Gas Operator | Sep 2025 |
| 37 | Oak Hills Drilling & Oper., LLC | Holdenville, OK 74848 | Oil & Gas Operator | May 2013 |
| 38 | Oak Prairie Operations, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Sep 2025 |
| 39 | Oak Resources Inc | Tulsa, OK 74153 | Oil & Gas Operator | Aug 2013 |
| 40 | Oak Valley Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2015 |
| 41 | Oakland Petroleum Oper Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2025 |
| 42 | Oakmont Oil And Gas | Graham, TX 76450 | Oil & Gas Operator | Sep 2025 |
| 43 | Oakridge Energy, Inc. | Wichita Falls, TX 76302 | Oil & Gas Operator | Sep 2025 |
| 44 | Oakridge Oil And Gas, LP | Jacksboro, TX 76458 | Oil & Gas Operator | Sep 2025 |
| 45 | Oaktree Oil Company | Albany, TX 76430 | Oil & Gas Operator | Sep 2025 |
| 46 | Oakwood Energy, Inc. | Jourdanton, TX 78026 | Oil & Gas Operator | Mar 2023 |
| 47 | Oasis Operating, Inc. | Lubbock, TX 79404 | Oil & Gas Operator | Nov 2020 |
| 48 | Oasis Petroleum Permian LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2025 |
| 49 | Oates, John Co., Inc. | Stinnett, TX 79083 | Oil & Gas Operator | Sep 2025 |
| 50 | Obax Oil And Gas LLC | Saint Louis, MO 63131 | Oil Operator | Sep 2025 |
| 51 | Oblaen Resources LLC | Wallis, TX 77485 | Oil & Gas Operator | Sep 2025 |
| 52 | Occam Petroleum E&P, LLC | Meeker, OK 74855 | Oil Operator | Sep 2025 |
| 53 | Occidental Energy Company, Inc. | Houston, TX 77282 | Oil & Gas Operator | Jul 2021 |
| 54 | Occidental Energy Marketing, Inc. | Houston, TX 77227 | Gas Operator | Sep 2015 |
| 55 | Occidental Permian LTD. | Houston, TX 77046 | Oil & Gas Operator | Sep 2025 |
| 56 | Occidental W TX Overthrust, Inc. | Houston, TX 77210 | Oil & Gas Operator | Dec 2021 |
| 57 | Ocean Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 58 | Ocotillo Energy Resources, LLC | Odessa, TX 79765 | Oil Operator | Sep 2025 |
| 59 | Octane Energy Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Sep 2025 |
| 60 | Odegard Energy, Inc. | Houston, TX 77024 | Oil & Gas Operator | Jul 2020 |
| 61 | Oden, Robin H., Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 1994 |
| 62 | Odessa Exploration, Inc. | Midland, TX 79702 | Oil & Gas Operator | Sep 2025 |
| 63 | Odessa Oil Investment Co., Inc. | Odessa, TX 79762 | Oil & Gas Operator | Nov 2016 |
| 64 | Odom, R. H. | Snyder, TX 79550 | Oil & Gas Operator | Jun 1996 |
| 65 | Odum Oil & Gas Co. | Harper, TX 78631 | Oil & Gas Operator | Sep 2025 |
| 66 | Odyssey Operating Company | Shreveport, LA 71106 | Oil & Gas Operator | Sep 2020 |
| 67 | Odyssey Petroleum Company | Houston, TX 77010 | Oil & Gas Operator | Apr 1995 |
| 68 | Oexco, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 69 | Offset Oil & Gas | Big Spring, TX 79720 | Oil & Gas Operator | Aug 2003 |
| 70 | Offshore Group, Inc. The | Houston, TX 77024 | Oil & Gas Operator | Sep 2025 |
| 71 | Offshore Oil & Gas Inc | Houston, TX 77063 | Oil & Gas Operator | Sep 1994 |
| 72 | Oft Inc. | Houston, TX 77079 | Oil & Gas Operator | Sep 2025 |
| 73 | Og Co., Inc. | Houston, TX 77057 | Oil & Gas Operator | Sep 2025 |
| 74 | Oga Operating L.L.C. | Midland, TX 79702 | Oil & Gas Operator | Jan 2000 |
| 75 | Ogden Resources Corporation | Bryan, TX 77802 | Oil & Gas Operator | Sep 2025 |
| 76 | Ogden Resources, LTD. | Bryan, TX 77802 | Oil & Gas Operator | Feb 2009 |
| 77 | Ogog Operating, LLC | Dallas, TX 75367 | Oil & Gas Operator | Sep 2025 |
| 78 | Ogris Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | Sep 2025 |
| 79 | Ogs Operating Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2008 |
| 80 | Ogx Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Sep 2025 |
| 81 | Ogx Resources LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2011 |
| 82 | Ohlhausen Oil Company | Abilene, TX 79608 | Oil & Gas Operator | Sep 2025 |
| 83 | Oil & Gas Acquisition Group Inc | Austin, TX 78716 | Oil & Gas Operator | May 2003 |
| 84 | Oil & Gas Operations | Midland, TX 79706 | Oil & Gas Operator | Sep 2025 |
| 85 | Oil & Gas Properties | Midland, TX 79704 | Oil & Gas Operator | Sep 2025 |
| 86 | Oil & Gas Property MGMT., Inc. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1996 |
| 87 | Oil Coast Corp. | S Houston, TX 77587 | Oil & Gas Operator | Sep 2025 |
| 88 | Oil Lease Operating Co. | Coldspring, TX 77331 | Oil & Gas Operator | Aug 2003 |
| 89 | Oil Management Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2022 |
| 90 | Oil Patch Operators Co., L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2025 |
| 91 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | Sep 2025 |
| 92 | Oil Projects, LLC | Houston, TX 77027 | Oil & Gas Operator | Sep 2025 |
| 93 | Oil Rock Resources, LLC | Weatherford, TX 76088 | Oil & Gas Operator | Jan 2024 |
| 94 | Oil Well Buyers Corp. | Houston, TX 77056 | Oil & Gas Operator | Dec 2024 |
| 95 | Oil, Gas, Etc. LLC | Katy, TX 77449 | Oil & Gas Operator | Sep 2025 |
| 96 | Oil-X Corp., The | FT Stockton, TX 79735 | Oil & Gas Operator | Sep 2025 |
| 97 | Oilex Int'L Investments, Inc. | Luling, TX 78648 | Oil & Gas Operator | Sep 2025 |
| 98 | Oilfield Management, Inc. (A) | Midland, TX 79702 | Oil & Gas Operator | Sep 2025 |
| 99 | Oilrox Resources LLC | San Antonio, TX 78258 | Oil & Gas Operator | Jun 2025 |
| 100 | Oilton Resources, Inc. | Laredo, TX 78041 | Oil & Gas Operator | Sep 2025 |