| 27001 | Southern Hills Gas Co. | | Oil Operator | Mar 2026 |
| 27002 | Southern Hydrocarbons Inc | | Oil & Gas Operator | Jul 1989 |
| 27003 | Southern Int'L Inc | Oklahoma City, OK 73107 | Oil & Gas Operator | May 2007 |
| 27004 | Southern Management Inc | Camargo, OK 73835 | Oil Operator | Jun 1992 |
| 27005 | Southern Management Services | | Oil Operator | May 2017 |
| 27006 | Southern Mineral Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2001 |
| 27007 | Southern Natural Gas Co | Houston, TX 77001 | Oil & Gas Operator | Dec 2011 |
| 27008 | Southern Natural Gas Co, LLC | | Oil & Gas Operator | Nov 2024 |
| 27009 | Southern Oil & Gas Company | | Oil & Gas Operator | Mar 2011 |
| 27010 | Southern Oil & Gas LLC | Corpus Christ, TX 78401 | Oil & Gas Operator | Jul 2026 |
| 27011 | Southern Oil Of Louisiana LLC | Madisonville, LA 70447 | Oil & Gas Operator | Jul 2026 |
| 27012 | Southern Oklahoma Production | Wilson, OK 73463-6537 | Oil & Gas Operator | May 2026 |
| 27013 | Southern Operating Corporation | Broken Arrow, OK 74014 | Oil & Gas Operator | May 2013 |
| 27014 | Southern Operating, Inc. | | Oil Operator | Dec 2000 |
| 27015 | Southern Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | Jul 2026 |
| 27016 | Southern Petroleum Company | | Oil & Gas Operator | Jan 1994 |
| 27017 | Southern Production & Expl Co. | | Oil & Gas Operator | Apr 2008 |
| 27018 | Southern Production Co Inc | Madill, OK 73446 | Oil & Gas Operator | Mar 2026 |
| 27019 | Southern Production SVC., Inc. | | Oil Operator | Mar 1997 |
| 27020 | Southern Resource Company | Corpus Christ, TX 78404 | Oil & Gas Operator | Mar 2022 |
| 27021 | Southern Resources Inc | Oklahoma City, OK 73120 | Oil & Gas Operator | May 2026 |
| 27022 | Southern Royalty Inc. | Corpus Christ, TX 78411 | Oil & Gas Operator | Feb 1997 |
| 27023 | Southern Sky Energy, LLC | | Oil Operator | Mar 2026 |
| 27024 | Southern Solutions And Services LLC | | Oil Operator | Dec 2014 |
| 27025 | Southern Star Central Gas Pipeline Inc | Owensboro, KY 42301 | Oil & Gas Operator | Mar 2026 |
| 27026 | Southern Star Operating LLC | Provo, UT 84604-7714 | Oil & Gas Operator | Jun 2017 |
| 27027 | Southern Star Operating, Inc. | | Oil & Gas Operator | Jun 2010 |
| 27028 | Southern States | | Oil & Gas Operator | Jul 1988 |
| 27029 | Southern States Gas & Oil LTD | | Oil & Gas Operator | Jul 2004 |
| 27030 | Southern States Oil Production, LLC | | Oil & Gas Operator | Oct 2013 |
| 27031 | Southern States Petroleum Corp | | Oil Operator | Jan 1984 |
| 27032 | Southern Tejas Asset Group LLC | McAllen, TX 78501 | Oil & Gas Operator | Jul 2026 |
| 27033 | Southern Triangle Oil | | Oil & Gas Operator | Dec 2000 |
| 27034 | Southern Triangle Oil Co | MT Carmel, IL 62863 | Oil & Gas Operator | Dec 2024 |
| 27035 | Southern Union Exploration | | Oil Operator | Jan 1990 |
| 27036 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 27037 | Southern Union Production Co. | | Oil Operator | Apr 1979 |
| 27038 | Southern Water Disposal, LLC | | Oil & Gas Operator | Jan 2025 |
| 27039 | Southern Wells, Inc. | | Oil Operator | Sep 2002 |
| 27040 | Southfourk Partners LLC | Blanchard, OK 73010-7209 | Oil Operator | Apr 2026 |
| 27041 | Southlake Exploration, Inc. | Southlake, TX 76092 | Oil & Gas Operator | Jul 2026 |
| 27042 | Southlake Operating LLC | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2026 |
| 27043 | Southland Energy Corporation | Houston, TX 77060 | Oil & Gas Operator | Aug 2022 |
| 27044 | Southland Royalt | | Oil & Gas Operator | Nov 1993 |
| 27045 | Southland Royalty Co.-Midland | Midland, TX 79702 | Oil & Gas Operator | Mar 1996 |
| 27046 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 27047 | Southland Royalty Company LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2021 |
| 27048 | Southport Exploration Inc | Tulsa, OK 74103-4015 | Oil & Gas Operator | Nov 1998 |
| 27049 | Southridge Homes | | Oil & Gas Operator | Dec 1999 |
| 27050 | Southridge Operating Company | San Marcos, TX 78667 | Oil & Gas Operator | Jul 2026 |
| 27051 | Southstar Energy Corporation | Ardmore, OK 73401 | Gas Operator | Aug 1990 |
| 27052 | Southstar Oil And Gas Inc | Andover, KS 67002-0123 | Oil & Gas Operator | Jul 2020 |
| 27053 | Southstone Energy, LLC | Austin, TX 78735 | Oil Operator | Jul 2026 |
| 27054 | Southwell Russell C | Warren, PA 16365-3686 | Oil & Gas Operator | Dec 2022 |
| 27055 | Southwell William R | Warren, PA 16365-1259 | Oil & Gas Operator | Dec 2017 |
| 27056 | Southwest Energy Devel.,Inc. | Sugar Land, TX 77478 | Oil & Gas Operator | Jul 2007 |
| 27057 | Southwest Energy Development Inc | Bison, OK 73720 | Oil & Gas Operator | Apr 2026 |
| 27058 | Southwest Energy LP | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2026 |
| 27059 | Southwest Exploration Company | Oklahoma City, OK 73132-2230 | Oil & Gas Operator | Jun 2017 |
| 27060 | Southwest Gas Producing Co Inc | | Oil & Gas Operator | Nov 1994 |
| 27061 | Southwest Gas St | | Oil & Gas Operator | Dec 1981 |
| 27062 | Southwest Gas Storage Company | | Gas Operator | Mar 2026 |
| 27063 | Southwest Gas Systems, Inc. | Spring, TX 77379 | Oil & Gas Operator | Jul 2026 |
| 27064 | Southwest Gathering Company | Alice, TX 78332 | Oil & Gas Operator | Jul 2026 |
| 27065 | Southwest General Dev., Inc. | | Oil & Gas Operator | Dec 2003 |
| 27066 | Southwest Land & Minerals, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Aug 2003 |
| 27067 | Southwest Loop 1604, LTD. | San Antonio, TX 78209 | Oil Operator | Sep 2022 |
| 27068 | Southwest Mississippi Oil & Gas LLC. | | Oil Operator | Mar 2026 |
| 27069 | Southwest Oil & Land, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Dec 1999 |
| 27070 | Southwest Oil Properties, Inc. | | Oil & Gas Operator | Feb 1996 |
| 27071 | Southwest Operating Company | Overland Park, KS 66212 | Oil & Gas Operator | Mar 2012 |
| 27072 | Southwest Operating Inc. | | Oil & Gas Operator | Dec 2024 |
| 27073 | Southwest Operating, Inc.-Tyler | Tyler, TX 75701 | Oil & Gas Operator | Jul 2026 |
| 27074 | Southwest Petroleum | San Antonio, TX 78253 | Oil & Gas Operator | Jul 2026 |
| 27075 | Southwest Petroleum Corp | Drumright, OK 74030 | Oil & Gas Operator | Mar 2018 |
| 27076 | Southwest Petroleum Oil & Gas Explor LLC | San Bernardino, CA 92404-1010 | Oil & Gas Operator | Jun 2022 |
| 27077 | Southwest Production Co | Richardson, TX BADADDR | Oil & Gas Operator | Apr 1997 |
| 27078 | Southwest Resources, Inc. | Brenham, TX 77834 | Oil & Gas Operator | Jul 2026 |
| 27079 | Southwest Rig Service | | Oil & Gas Operator | Nov 1998 |
| 27080 | Southwest Royalties, Inc. | Midland, TX 79710 | Oil & Gas Operator | Jul 2026 |
| 27081 | Southwest-Operating | Penwell, TX 79776 | Oil & Gas Operator | Jul 2026 |
| 27082 | Southwestern Electric Power Co | Dallas, TX 75266 | Oil & Gas Operator | Dec 1989 |
| 27083 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 27084 | Southwestern Exploration Consultants Inc | Oklahoma City, OK 73118-1116 | Oil & Gas Operator | May 2026 |
| 27085 | Southwestern Inc | Hobbs, NM 88240 | Oil Operator | Oct 2009 |
| 27086 | Southwestern Oil Corporation | Oklahoma City, OK 73106 | Oil & Gas Operator | May 2026 |
| 27087 | Southwestern Production Corporation | Lakewood, CO 80228 | Oil & Gas Operator | May 2026 |
| 27088 | Southwind Consulting | Pratt, KS 67124 | Oil Operator | Oct 1997 |
| 27089 | Southwind Exploration, LLC | Venice, FL 34293 | Oil & Gas Operator | Sep 2003 |
| 27090 | Southwind Oil & Gas LLC | | Oil & Gas Operator | Dec 2023 |
| 27091 | Southwind Petroleum Corp. | Wichita, KS 67203 | Oil & Gas Operator | Jun 2022 |
| 27092 | Sovereign Eagle, LLC | Roswell, NM 88202 | Oil & Gas Operator | Jul 2018 |
| 27093 | Sovereign Energy Corp. | | Oil Operator | Dec 2001 |
| 27094 | Sovereign Operating Company, LLC | Denver, CO 80202 | Oil & Gas Operator | Apr 2016 |
| 27095 | Sovereign Petroleum Company, LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Jul 2013 |
| 27096 | Sowers William & Sara | Blue Rock, OH 43720 | Oil Operator | Dec 2022 |
| 27097 | Sowle Exploratio | | Oil Operator | Aug 1986 |
| 27098 | Sowle Explorations | | Oil Operator | Dec 2002 |
| 27099 | Sozo Natural Resources LLC | Houston, TX 77056 | Oil & Gas Operator | Jul 2026 |
| 27100 | SP Energy Development Company | Seattle, WA 98101-3277 | Oil & Gas Operator | Mar 2015 |