| 1901 | Southwest Exploration Company | Oklahoma City, OK 73132-2230 | Oil & Gas Operator | Jun 2017 |
| 1902 | Southwest Gas Producing Co Inc | | Oil & Gas Operator | Nov 1994 |
| 1903 | Southwest Gas St | | Oil & Gas Operator | Dec 1981 |
| 1904 | Southwest Gas Storage Company | | Gas Operator | Dec 2024 |
| 1905 | Southwest Gas Systems, Inc. | Spring, TX 77379 | Oil & Gas Operator | Apr 2025 |
| 1906 | Southwest Gathering Company | Alice, TX 78332 | Oil & Gas Operator | Apr 2025 |
| 1907 | Southwest General Dev., Inc. | | Oil & Gas Operator | Dec 2003 |
| 1908 | Southwest Investment Fund, Inc. | Dallas, TX 75229 | Oil & Gas Operator | Aug 2003 |
| 1909 | Southwest Land & Minerals, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Aug 2003 |
| 1910 | Southwest Loop 1604, LTD. | San Antonio, TX 78209 | Oil Operator | Sep 2022 |
| 1911 | Southwest Mississippi Oil & Gas, LLC. | | Oil Operator | Feb 2025 |
| 1912 | Southwest Oil & Land, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Dec 1999 |
| 1913 | Southwest Oil Properties, Inc. | | Oil & Gas Operator | Feb 1996 |
| 1914 | Southwest Operating Company | Overland Park, KS 66212 | Oil & Gas Operator | Mar 2012 |
| 1915 | Southwest Operating Inc. | | Oil & Gas Operator | Dec 2024 |
| 1916 | Southwest Operating, Inc.-Tyler | Tyler, TX 75701 | Oil & Gas Operator | Apr 2025 |
| 1917 | Southwest Petroleum | San Antonio, TX 78253 | Oil & Gas Operator | Apr 2025 |
| 1918 | Southwest Petroleum Corp | Drumright, OK 74030 | Oil & Gas Operator | Mar 2018 |
| 1919 | Southwest Petroleum Oil & Gas Explor LLC | San Bernardino, CA 92404-1010 | Oil & Gas Operator | Jun 2022 |
| 1920 | Southwest Production Co | Richardson, TX BADADDR | Oil & Gas Operator | Apr 1997 |
| 1921 | Southwest Resources, Inc. | Brenham, TX 77834 | Oil & Gas Operator | Apr 2025 |
| 1922 | Southwest Rig Service | | Oil & Gas Operator | Nov 1998 |
| 1923 | Southwest Royalties Inc | Midland, TX 79710 | Oil & Gas Operator | Apr 2025 |
| 1924 | Southwest-Operating | Penwell, TX 79776 | Oil & Gas Operator | Apr 2025 |
| 1925 | Southwestern Electric Power Co | Dallas, TX 75266 | Oil & Gas Operator | Dec 1989 |
| 1926 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 1927 | Southwestern Exploration Consultants Inc | Oklahoma City, OK 73118-1116 | Oil & Gas Operator | Jan 2025 |
| 1928 | Southwestern Inc | Hobbs, NM 88240 | Oil Operator | Oct 2009 |
| 1929 | Southwestern Production Corporation | Lakewood, CO 80228 | Oil & Gas Operator | Feb 2025 |
| 1930 | Southwind Consulting | Pratt, KS 67124 | Oil Operator | Oct 1997 |
| 1931 | Southwind Exploration, LLC | Venice, FL 34293 | Oil & Gas Operator | Sep 2003 |
| 1932 | Southwind Oil & Gas LLC | | Oil & Gas Operator | Dec 2023 |
| 1933 | Southwind Petroleum Corp. | Wichita, KS 67203 | Oil & Gas Operator | Jun 2022 |
| 1934 | Sovereign Eagle, LLC | Roswell, NM 88202 | Oil & Gas Operator | Jul 2018 |
| 1935 | Sovereign Energy Corp. | | Oil Operator | Dec 2001 |
| 1936 | Sovereign Energy LLC | | Oil & Gas Operator | Sep 2011 |
| 1937 | Sovereign Operating Company LLC | Denver, CO 80202 | Oil & Gas Operator | Apr 2016 |
| 1938 | Sovereign Petroleum Company, LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Jul 2013 |
| 1939 | Sowers William & Sara | Blue Rock, OH 43720 | Oil Operator | Dec 2022 |
| 1940 | Sowle Exploratio | | Oil Operator | Aug 1986 |
| 1941 | Sowle Explorations | | Oil Operator | Dec 2002 |
| 1942 | Sozo Natural Resources LLC | Houston, TX 77056 | Oil & Gas Operator | Apr 2025 |
| 1943 | SP Energy Development Company | Seattle, WA 98101-3277 | Oil & Gas Operator | Mar 2015 |
| 1944 | Space Production Inc. | Monahans, TX 79756 | Oil & Gas Operator | Apr 2025 |
| 1945 | Spacht, James W. & Shelly F | Ripley, NY 14775 | Gas Operator | Dec 2023 |
| 1946 | Spade Energy L.L.C. | Wichita Falls, TX 76310 | Gas Operator | Apr 2025 |
| 1947 | Spain Oil Company | Somerset, TX 78069 | Oil & Gas Operator | Apr 2025 |
| 1948 | Spalding Energy, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 1949 | Spalsbury, Arthur L | Hays, KS 67601 | Oil Operator | Aug 2001 |
| 1950 | Spark'S Energy Inc | Perry, OK 73077 | Oil & Gas Operator | Nov 2014 |
| 1951 | Sparkman Energy, LLC | Fort Worth, TX 76147 | Oil & Gas Operator | Apr 2025 |
| 1952 | Sparkman Rodger E | Jenks, OK 74037-0267 | Oil Operator | Sep 2018 |
| 1953 | Sparks Daniel M | Chickasha, OK 73023-1435 | Oil & Gas Operator | Apr 2014 |
| 1954 | Sparks Greg | Afton, OK 74331 | Oil & Gas Operator | Jan 2025 |
| 1955 | Sparks Harold | Radnor, OH 43066 | Oil & Gas Operator | Dec 1987 |
| 1956 | Sparks Mick Oil Company Inc | Jennings, OK 74038-0250 | Oil & Gas Operator | Feb 2025 |
| 1957 | Sparks Petroleum Company | Oklahoma City, OK 73128 | Oil & Gas Operator | Mar 1998 |
| 1958 | Sparks Resources Inc | Bristow, OK 74010 | Oil & Gas Operator | Feb 2025 |
| 1959 | Sparks, Pearlman E | Mazie, KY 41160 | Oil Operator | Dec 2015 |
| 1960 | Sparks, Sidney A., Trustee | Alice, TX 78332 | Oil & Gas Operator | Jun 1996 |
| 1961 | Sparlin J L | Oklahoma City, OK 73156-1446 | Oil Operator | Feb 2025 |
| 1962 | Sparrow Oil & Gas LLC | | Oil & Gas Operator | Mar 2025 |
| 1963 | Sparrow Operating LLC | Comanche, OK 73529-9747 | Oil Operator | Feb 2025 |
| 1964 | Sparta Energy Corp | Oak Brook, IL 60521 | Oil & Gas Operator | Dec 1985 |
| 1965 | Sparta Energy LLC | Edmond, OK 73083-8158 | Oil & Gas Operator | May 2020 |
| 1966 | Sparta Exploration LLC | Houston, TX 77279 | Oil & Gas Operator | Apr 2025 |
| 1967 | Spartagus Corporation | Grand Saline, TX 75140 | Oil & Gas Operator | Sep 2004 |
| 1968 | Spartan Oil Corporation | Abilene, TX 79601 | Oil & Gas Operator | Aug 2003 |
| 1969 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 1970 | Spartan Petroleum Corporation | Houston, TX 77079 | Oil & Gas Operator | Oct 1987 |
| 1971 | Spartan Resource MGMT Corp | Rural Valley, PA 16249-0326 | Gas Operator | Dec 2024 |
| 1972 | Spartan Resources LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2025 |
| 1973 | Spartan Royalties, LLC | | Oil Operator | Dec 2024 |
| 1974 | SPC Resources, LLC | Midland, TX 79701 | Oil & Gas Operator | Feb 2024 |
| 1975 | Spear Production Company, Inc. | Shreveport, LA 71161 | Oil Operator | Apr 2025 |
| 1976 | Spearco Oil | Electra, TX 76360 | Oil & Gas Operator | Aug 2003 |
| 1977 | Spearpoint Energy LLC | Seminole, OK 74818-1247 | Oil Operator | Jun 2015 |
| 1978 | Spears Terry | Osage, OK 74054 | Oil Operator | Oct 2024 |
| 1979 | Speartex Grain Company | Gruver, TX 79040 | Oil & Gas Operator | Apr 2025 |
| 1980 | Specht Farms | Piqua, KS 66761 | Oil Operator | Nov 2009 |
| 1981 | Specht Oil | Iola, KS 66749 | Oil Operator | Mar 1998 |
| 1982 | Special Energy Corporation | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2025 |
| 1983 | Special JHR Corp | Bridgeville, PA 15017 | Oil & Gas Operator | Apr 2025 |
| 1984 | Specialized Technological Threading, Inc., | | Oil & Gas Operator | Oct 2019 |
| 1985 | Speco Oil Company | | Oil & Gas Operator | Feb 1980 |
| 1986 | Spectral Oil & Gas Corporation | Humble, TX 77338 | Oil Operator | Apr 2025 |
| 1987 | Spectrum Energy Inc | Scottsdale, AZ 85257 | Oil & Gas Operator | Oct 2003 |
| 1988 | Spectrum Field Services Inc | Tulsa, OK 74136-3400 | Oil & Gas Operator | Jan 2004 |
| 1989 | Spectrum Oil Company | Irving, TX 75063 | Oil & Gas Operator | May 2013 |
| 1990 | Spectrum Oil Corporation | Marietta, OH 45750 | Oil & Gas Operator | Dec 1993 |
| 1991 | Spectrum Opco LLC | | Oil & Gas Operator | Nov 2024 |
| 1992 | Speed James F | Ada, OK 74821-1221 | Oil & Gas Operator | Nov 2009 |
| 1993 | Speed, F. Michael, Trustee | Corpus Chrsti, TX 78473 | Oil & Gas Operator | Aug 1998 |
| 1994 | Speedy Well Service | | Oil & Gas Operator | Sep 2024 |
| 1995 | Speegle Oil And Gas Company | Longview, TX 75605 | Oil & Gas Operator | Apr 2025 |
| 1996 | Speer Kenneth G | Seminole, OK 74818-1202 | Oil & Gas Operator | Dec 2001 |
| 1997 | Speir R M Operating Company | Walters, OK 73572-3933 | Oil Operator | Jan 2025 |
| 1998 | Spellbound Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2025 |
| 1999 | Speller Oil Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Jan 2025 |
| 2000 | Spence Energy Company | Dallas, TX 75360 | Oil & Gas Operator | Apr 2025 |