| 1801 | Southeastern Producing Co | | Oil Operator | Jul 1988 |
| 1802 | Southeastern Public Service Co | | Oil & Gas Operator | Sep 1982 |
| 1803 | Southeastern Resources Corp. | Mansfield, TX 76063 | Oil & Gas Operator | Feb 2004 |
| 1804 | Southerland Jackie Dale Dba Skyden Oil | Duncan, OK 73533-5392 | Oil & Gas Operator | Nov 2025 |
| 1805 | Southerland Joe Don Dba Taylor Oil Co | Duncan, OK 73533 | Oil & Gas Operator | Nov 2025 |
| 1806 | Southerland Marquieta Dba Keta Oil Company | Loco, OK 73442 | Oil & Gas Operator | Nov 2025 |
| 1807 | Southerland, Glenn Oil & Gas Co. | Hallsville, TX 75650 | Oil & Gas Operator | Feb 2021 |
| 1808 | Southern Alliance Oil Corp. | Grapevine, TX 76099 | Oil & Gas Operator | Dec 2025 |
| 1809 | Southern Bay Operating, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 1810 | Southern California Gas Company | | Oil & Gas Operator | Nov 2025 |
| 1811 | Southern Crude, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2017 |
| 1812 | Southern Energy Operating Co Inc | | Oil Operator | Oct 2025 |
| 1813 | Southern Energy Operating, LLC | | Oil & Gas Operator | Oct 2025 |
| 1814 | Southern Exploration, Inc. | Fort Worth, TX 76137 | Oil & Gas Operator | Aug 2023 |
| 1815 | Southern G Holdings, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2007 |
| 1816 | Southern Gas Inc | | Gas Operator | Jan 1987 |
| 1817 | Southern Hills Gas Co. | | Oil Operator | May 2025 |
| 1818 | Southern Hydrocarbons Inc | | Oil & Gas Operator | Jul 1989 |
| 1819 | Southern Int'L Inc | Oklahoma City, OK 73107 | Oil & Gas Operator | May 2007 |
| 1820 | Southern Management Inc | Camargo, OK 73835 | Oil Operator | Jun 1992 |
| 1821 | Southern Management Services | | Oil Operator | May 2017 |
| 1822 | Southern Mineral Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2001 |
| 1823 | Southern Natural Gas Co | Houston, TX 77001 | Oil & Gas Operator | Dec 2011 |
| 1824 | Southern Natural Gas Company LLC | | Oil & Gas Operator | Nov 2024 |
| 1825 | Southern Oil & Gas Company | | Oil & Gas Operator | Mar 2011 |
| 1826 | Southern Oil & Gas LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2025 |
| 1827 | Southern Oil Of Louisiana LLC | Madisonville, LA 70447 | Oil & Gas Operator | Dec 2025 |
| 1828 | Southern Oklahoma Production | Wilson, OK 73463-6537 | Oil & Gas Operator | Oct 2025 |
| 1829 | Southern Operating Corporation | Broken Arrow, OK 74014 | Oil & Gas Operator | May 2013 |
| 1830 | Southern Operating, Inc. | | Oil Operator | Dec 2000 |
| 1831 | Southern Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 1832 | Southern Petroleum Company | | Oil & Gas Operator | Jan 1994 |
| 1833 | Southern Production & Expl Co. | | Oil & Gas Operator | Apr 2008 |
| 1834 | Southern Production Co Inc | Madill, OK 73446 | Oil & Gas Operator | Oct 2025 |
| 1835 | Southern Production SVC., Inc. | | Oil Operator | Mar 1997 |
| 1836 | Southern Resource Company | Corpus Chrsti, TX 78404 | Oil & Gas Operator | Mar 2022 |
| 1837 | Southern Resources Inc | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | Nov 2025 |
| 1838 | Southern Royalty Inc. | Corpus Chrsti, TX 78411 | Oil & Gas Operator | Feb 1997 |
| 1839 | Southern Solutions And Services LLC | | Oil Operator | Dec 2014 |
| 1840 | Southern Star Central Gas Pipeline Inc | Owensboro, KY 42301 | Oil & Gas Operator | Oct 2025 |
| 1841 | Southern Star Operating LLC | Provo, UT 84604-7714 | Oil & Gas Operator | Jun 2017 |
| 1842 | Southern Star Operating, Inc. | | Oil & Gas Operator | Jun 2010 |
| 1843 | Southern States | | Oil & Gas Operator | Jul 1988 |
| 1844 | Southern States Gas & Oil LTD | | Oil & Gas Operator | Jul 2004 |
| 1845 | Southern States Oil Production, LLC | | Oil & Gas Operator | Oct 2013 |
| 1846 | Southern States Petroleum Corp | | Oil Operator | Jan 1984 |
| 1847 | Southern Tejas Asset Group LLC | McAllen, TX 78501 | Oil & Gas Operator | Dec 2025 |
| 1848 | Southern Triangle Oil | | Oil & Gas Operator | Dec 2000 |
| 1849 | Southern Triangle Oil Co | MT Carmel, IL 62863 | Oil & Gas Operator | Dec 2023 |
| 1850 | Southern Union Exploration | | Oil Operator | Jan 1990 |
| 1851 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 1852 | Southern Union Production Co. | | Oil Operator | Apr 1979 |
| 1853 | Southern Water Disposal, LLC | | Oil & Gas Operator | Jan 2025 |
| 1854 | Southern Wells, Inc. | | Oil Operator | Sep 2002 |
| 1855 | Southfourk Partners LLC | Blanchard, OK 73010-7209 | Oil Operator | Oct 2025 |
| 1856 | Southlake Exploration, Inc. | Southlake, TX 76092 | Oil & Gas Operator | Dec 2025 |
| 1857 | Southlake Operating LLC | Weatherford, TX 76086 | Oil & Gas Operator | Dec 2025 |
| 1858 | Southland Energy Corporation | Houston, TX 77060 | Oil & Gas Operator | Aug 2022 |
| 1859 | Southland Royalt | | Oil & Gas Operator | Nov 1993 |
| 1860 | Southland Royalty Co.-Midland | Midland, TX 79702 | Oil & Gas Operator | Mar 1996 |
| 1861 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 1862 | Southland Royalty Company LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2021 |
| 1863 | Southport Exploration Inc | Tulsa, OK 74103-4015 | Oil & Gas Operator | Nov 1998 |
| 1864 | Southridge Homes | | Oil & Gas Operator | Dec 1999 |
| 1865 | Southridge Operating Company | San Marcos, TX 78667 | Oil & Gas Operator | Dec 2025 |
| 1866 | Southstar Energy Corporation | Ardmore, OK 73401 | Gas Operator | Aug 1990 |
| 1867 | Southstar Oil And Gas Inc | Andover, KS 67002-0123 | Oil & Gas Operator | Jul 2020 |
| 1868 | Southstone Energy, LLC | Austin, TX 78735 | Oil Operator | Dec 2025 |
| 1869 | Southwell Russell C | Warren, PA 16365-3686 | Oil & Gas Operator | Dec 2022 |
| 1870 | Southwell William R | Warren, PA 16365-1259 | Oil & Gas Operator | Dec 2017 |
| 1871 | Southwest Energy Devel.,Inc. | Sugar Land, TX 77478 | Oil & Gas Operator | Jul 2007 |
| 1872 | Southwest Energy Development Inc | Bison, OK 73720 | Oil & Gas Operator | Nov 2025 |
| 1873 | Southwest Exploration Company | Oklahoma City, OK 73132-2230 | Oil & Gas Operator | Jun 2017 |
| 1874 | Southwest Gas Producing Co Inc | | Oil & Gas Operator | Nov 1994 |
| 1875 | Southwest Gas St | | Oil & Gas Operator | Dec 1981 |
| 1876 | Southwest Gas Storage Company | | Gas Operator | Sep 2025 |
| 1877 | Southwest Gas Systems, Inc. | Spring, TX 77379 | Oil & Gas Operator | Dec 2025 |
| 1878 | Southwest Gathering Company | Alice, TX 78332 | Oil & Gas Operator | Dec 2025 |
| 1879 | Southwest General Dev., Inc. | | Oil & Gas Operator | Dec 2003 |
| 1880 | Southwest Investment Fund, Inc. | Dallas, TX 75229 | Oil & Gas Operator | Aug 2003 |
| 1881 | Southwest Land & Minerals, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Aug 2003 |
| 1882 | Southwest Loop 1604, LTD. | San Antonio, TX 78209 | Oil Operator | Sep 2022 |
| 1883 | Southwest Mississippi Oil & Gas, LLC. | | Oil Operator | Oct 2025 |
| 1884 | Southwest Oil & Land, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Dec 1999 |
| 1885 | Southwest Oil Properties, Inc. | | Oil & Gas Operator | Feb 1996 |
| 1886 | Southwest Operating Company | Overland Park, KS 66212 | Oil & Gas Operator | Mar 2012 |
| 1887 | Southwest Operating Inc. | | Oil & Gas Operator | Dec 2024 |
| 1888 | Southwest Operating, Inc.-Tyler | Tyler, TX 75701 | Oil & Gas Operator | Dec 2025 |
| 1889 | Southwest Petroleum | San Antonio, TX 78253 | Oil & Gas Operator | Dec 2025 |
| 1890 | Southwest Petroleum Corp | Drumright, OK 74030 | Oil & Gas Operator | Mar 2018 |
| 1891 | Southwest Petroleum Oil & Gas Explor LLC | San Bernardino, CA 92404-1010 | Oil & Gas Operator | Jun 2022 |
| 1892 | Southwest Production Co | Richardson, TX BADADDR | Oil & Gas Operator | Apr 1997 |
| 1893 | Southwest Resources, Inc. | Brenham, TX 77834 | Oil & Gas Operator | Dec 2025 |
| 1894 | Southwest Rig Service | | Oil & Gas Operator | Nov 1998 |
| 1895 | Southwest Royalties, Inc. | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 1896 | Southwest-Operating | Penwell, TX 79776 | Oil & Gas Operator | Dec 2025 |
| 1897 | Southwestern Electric Power Co | Dallas, TX 75266 | Oil & Gas Operator | Dec 1989 |
| 1898 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 1899 | Southwestern Exploration Consultants Inc | Oklahoma City, OK 73118-1116 | Oil & Gas Operator | Nov 2025 |
| 1900 | Southwestern Inc | Hobbs, NM 88240 | Oil Operator | Oct 2009 |