| 27001 | Sitton, Ronnie Incorporated | Graford, TX 76449 | Oil & Gas Operator | Feb 2020 |
| 27002 | Situs Oil & Gas, LLC | Corpus Chrsti, TX 78414 | Oil Operator | Jun 2025 |
| 27003 | Sitwell, Inc. | | Oil Operator | May 2022 |
| 27004 | Sivad Energy No 4 | Akron, NY 14001 | Gas Operator | Dec 2023 |
| 27005 | Six "E" Trading Company | Henryetta, OK 74801 | Oil & Gas Operator | Sep 2020 |
| 27006 | Six Bar Oil LLC | Pine Haven, WY 82721 | Oil & Gas Operator | Apr 2025 |
| 27007 | Six C Oil | Bowie, TX 76230 | Oil & Gas Operator | Sep 2011 |
| 27008 | Six Oil Producers | Abilene, TX 79601 | Oil & Gas Operator | Sep 2002 |
| 27009 | Six-D Exploration, LLC | Hutchinson, KS 67502 | Oil Operator | Aug 2024 |
| 27010 | Six-S Properties, Inc. | Austin, TX 78767 | Oil & Gas Operator | Jun 2025 |
| 27011 | Sixess Energy, LLC | Midland, TX 79702 | Oil & Gas Operator | Jun 2025 |
| 27012 | Sizemore, James | Hardin, TX 77561 | Oil & Gas Operator | Jun 2003 |
| 27013 | SJ Energy, LLC | Englewood, CO 80112 | Oil & Gas Operator | Feb 2019 |
| 27014 | SJ Ok Oil Company | Dallas, TX 75206-9925 | Oil & Gas Operator | Mar 2025 |
| 27015 | SJM Inc | Tulsa, OK 74133-1757 | Gas Operator | Apr 2006 |
| 27016 | SJM Oil LLC | | Oil & Gas Operator | Dec 2009 |
| 27017 | Sju Holdings LLC | Norman, OK 73072 | Oil & Gas Operator | Mar 2025 |
| 27018 | SK Nemaha LLC | Houston, TX 77079-1222 | Oil & Gas Operator | Feb 2021 |
| 27019 | SK Opr Inc | Cabot, PA 16023-1250 | Gas Operator | Dec 2024 |
| 27020 | SK Plymouth LLC | Houston, TX 77079-1222 | Oil & Gas Operator | Mar 2025 |
| 27021 | Skaar, K. M. Oil & Gas Co. | Midland, TX 79710 | Oil & Gas Operator | Jun 2025 |
| 27022 | Skaer Properties LTD Partnership | | Oil & Gas Operator | Jun 2013 |
| 27023 | Skaggs Resources LLC | Sapulpa, OK 74066-7930 | Oil Operator | Mar 2025 |
| 27024 | Skeet Oil Production LLC | Grady, OK 73569 | Oil Operator | Apr 2025 |
| 27025 | Skeeter Oil L.L.C. | Big Spring, TX 79720 | Oil Operator | Jun 2025 |
| 27026 | Skelly Oil Co | | Oil & Gas Operator | Mar 2005 |
| 27027 | Skelton Operating Co., Inc. | | Oil & Gas Operator | Aug 1980 |
| 27028 | Skelton, D.W. | | Oil Operator | Dec 1952 |
| 27029 | Skewes Operating Company | Bluefield, VA 24605 | Oil & Gas Operator | Jun 2025 |
| 27030 | Ski Production, LLC | Muenster, TX 76252 | Oil Operator | Jun 2025 |
| 27031 | Skidgel Enterprises Inc | Rawlins, WY 82301 | Oil & Gas Operator | Sep 2018 |
| 27032 | Skidmore Energy,Inc. | Salado, TX 76571 | Oil & Gas Operator | Jun 1999 |
| 27033 | Skidmore Exploration, Inc. | Dallas, TX 75219 | Oil & Gas Operator | Jul 1997 |
| 27034 | Skidmore, James E. | Nocona, TX 76255 | Oil & Gas Operator | Nov 2008 |
| 27035 | Skinner Cattle, Inc. | Nocona, TX 76255 | Oil Operator | Jun 2025 |
| 27036 | Skinner Corporation | | Oil Operator | Apr 1985 |
| 27037 | Skinner Energy Management, Inc. | Shreveport, LA 71135 | Oil & Gas Operator | Jan 2011 |
| 27038 | Skinner Oil & Gas LLC | Gillette, WY 82717 | Oil & Gas Operator | Jan 2024 |
| 27039 | Skinner'S Resources & Expl Inc | | Oil & Gas Operator | Jun 2007 |
| 27040 | Skinner, Robert V. | Spearman, TX 79081 | Oil & Gas Operator | Aug 2008 |
| 27041 | Skinner, W. E. | Wichita Falls, TX 76301 | Oil & Gas Operator | Jun 2025 |
| 27042 | Skinnergy Co. | Spearman, TX 79081 | Oil & Gas Operator | Jun 2025 |
| 27043 | Skipworth, Joseph D | | Oil Operator | Dec 2021 |
| 27044 | SKKM Oil Company | | Oil Operator | Dec 1992 |
| 27045 | Sklar | | Oil & Gas Operator | Dec 2024 |
| 27046 | Sklar & Phillips - Harry Hurt | | Oil & Gas Operator | Jul 1986 |
| 27047 | Sklar & Phillips Oil Co. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2000 |
| 27048 | Sklar & Phillips Oil Co.-Entex | | Oil & Gas Operator | Aug 1978 |
| 27049 | Sklar &Phillips-Great Southern | | Oil & Gas Operator | Aug 1980 |
| 27050 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | Jun 2025 |
| 27051 | Sklar-Tex L.L.C. | Shreveport, LA 71101 | Oil & Gas Operator | Apr 2001 |
| 27052 | Skora, James B. | Lawtons, NY 14091 | Gas Operator | Dec 2023 |
| 27053 | Skrivanos Engineering, Inc. | Shreveport, LA 71164 | Oil & Gas Operator | Dec 2011 |
| 27054 | Skrzynski, Thomas J. | Eden, NY 14057 | Gas Operator | Dec 2023 |
| 27055 | SKS Oil | Olney, TX 76374 | Oil & Gas Operator | Jun 2025 |
| 27056 | Skubis, Daniel J. | Fredonia, NY 14063 | Gas Operator | Dec 2023 |
| 27057 | Skull Creek A LLC | Douglas, WY 82633 | Oil & Gas Operator | Apr 2025 |
| 27058 | Skull Creek Oil & Gas LLC | | Oil Operator | Feb 2025 |
| 27059 | Sky Development Corporation | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 27060 | Sky Oil, L.L.C. | St. Paul, KS 66771 | Oil Operator | Dec 2004 |
| 27061 | Sky Resources, Inc. | Graham, TX 76450 | Oil & Gas Operator | Jun 2025 |
| 27062 | Skybox, LLC | | Gas Operator | Dec 2021 |
| 27063 | Skybridge Energy LLC | Jacksboro, TX 76458 | Oil & Gas Operator | Jun 2025 |
| 27064 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 2025 |
| 27065 | Skye MS, LLC | | Oil & Gas Operator | Apr 2025 |
| 27066 | Skyhawk Energy, LLC | | Oil Operator | Dec 2024 |
| 27067 | Skyline Oil Company | Salt Lake City, UT 84111 | Oil & Gas Operator | Jan 1987 |
| 27068 | Skyline Operating Company, LLC | Alpine, UT 84004 | Oil & Gas Operator | Feb 2025 |
| 27069 | Skyliner Energy LLC | Ravenna, OH 44266 | Oil & Gas Operator | Dec 2024 |
| 27070 | Skytop Oil & Gas | Giddings, TX 78942 | Oil & Gas Operator | Jun 2025 |
| 27071 | Skyway Energy LLC | Leesburg, OH 34748 | Oil & Gas Operator | Dec 2020 |
| 27072 | SKZ Inc. | | Oil Operator | Mar 1988 |
| 27073 | Slack Oil & Gas | Refugio, TX 78377 | Oil & Gas Operator | Dec 2012 |
| 27074 | Slack, R. C. | Pecos, TX 79772 | Oil & Gas Operator | Jul 2000 |
| 27075 | Slagel, H. P. Prod. Co. | Snyder, TX 79550 | Oil & Gas Operator | Dec 2006 |
| 27076 | Slam Resources, Inc. | | Oil & Gas Operator | Apr 1994 |
| 27077 | Slant Operating, LLC | Lafayette, LA 70503 | Oil & Gas Operator | Jun 2025 |
| 27078 | Slapco - Emerald Exploration | | Gas Operator | Sep 1979 |
| 27079 | Slape Oil Company, Inc. | Houston, TX 77064 | Oil & Gas Operator | Jun 2011 |
| 27080 | Slate Holdings, Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Jun 2025 |
| 27081 | Slate River Resources LLC | Denver, CO 80293 | Oil & Gas Operator | Apr 2008 |
| 27082 | Slatex Well Service, Inc. | Batson, TX 77519 | Oil Operator | Jun 2025 |
| 27083 | Slaughter J M Oil Company | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2001 |
| 27084 | Slaughter, Norman C. | | Oil & Gas Operator | Dec 2012 |
| 27085 | Slavens II Paul R | Tulsa, OK 74131-2244 | Oil & Gas Operator | Mar 2025 |
| 27086 | Slawson Clifford Ray | Healdton, OK 73438 | Oil Operator | Jan 1995 |
| 27087 | Slawson Explorat | | Oil & Gas Operator | Dec 1996 |
| 27088 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2025 |
| 27089 | Slawson, Donald C. | Wichita, KS 67202 | Oil & Gas Operator | Oct 2024 |
| 27090 | Slayton Resources Inc | Roswell, NM 88202 | Oil & Gas Operator | Apr 2025 |
| 27091 | Sledge Bros. Oil Co. | Midland, TX 79702 | Oil & Gas Operator | Mar 2016 |
| 27092 | Sledge Olen | Duncan, OK 73533 | Oil Operator | Mar 2025 |
| 27093 | Sledge, H. G., Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2016 |
| 27094 | Sleeth And Brooks Oil Co. | | Oil Operator | Jul 1989 |
| 27095 | Slick Inc. | MC Gregor, TX 76657 | Oil Operator | Jun 2025 |
| 27096 | Slick Production Inc | Tulsa, OK 74132-1718 | Oil & Gas Operator | Apr 2020 |
| 27097 | Slick Production, LLC | Muenster, TX 76252 | Oil & Gas Operator | Jun 2025 |
| 27098 | Slik-Dril P & A Inc | | Oil & Gas Operator | Sep 1989 |
| 27099 | Slik-Dril, Inc | | Oil & Gas Operator | Nov 1998 |
| 27100 | Slim Hole Inc | Farmington, NM 87401-7725 | Oil & Gas Operator | May 2013 |