| 4201 | Sklar &Phillips-Great Southern | | Oil & Gas Operator | Aug 1980 |
| 4202 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | Sep 2025 |
| 4203 | Skrivanos Engineering, Inc. | Shreveport, LA 71164 | Oil & Gas Operator | Dec 2011 |
| 4204 | Skyhawk Energy, LLC | | Oil Operator | Dec 2024 |
| 4205 | Skyline Oil Company | Salt Lake City, UT 84111 | Oil & Gas Operator | Jan 1987 |
| 4206 | SKZ Inc. | | Oil Operator | Mar 1988 |
| 4207 | Slam Resources, Inc. | | Oil & Gas Operator | Apr 1994 |
| 4208 | Slapco - Emerald Exploration | | Gas Operator | Sep 1979 |
| 4209 | Sleeth And Brooks Oil Co. | | Oil Operator | Jul 1989 |
| 4210 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Sep 2025 |
| 4211 | Smackover Drilling Company Inc | Shreveport, LA 71104 | Oil & Gas Operator | Jan 2025 |
| 4212 | Smal Energy Corp | Tyler, TX 75710 | Oil & Gas Operator | Oct 1995 |
| 4213 | SMC Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | Sep 2025 |
| 4214 | Smith Oil & Gas Co., Inc. | Wichita Falls, TX 76310 | Oil Operator | Dec 2010 |
| 4215 | Smith Operating And MGMT Co. | Shreveport, LA 71161 | Oil & Gas Operator | Jun 2023 |
| 4216 | Smith Operating-Germany Oil | | Oil & Gas Operator | Dec 1995 |
| 4217 | Smith Petroleum Company | Spring, TX 77389 | Oil & Gas Operator | Sep 2025 |
| 4218 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Sep 2025 |
| 4219 | Smith-Wentworth | | Oil & Gas Operator | Sep 1983 |
| 4220 | Smith-Wentworth & Coquina | | Oil Operator | Jun 1983 |
| 4221 | Smith-Wentworth & Hughes & New | | Oil Operator | Jun 1983 |
| 4222 | SMK-La, Inc. | | Oil & Gas Operator | Sep 1999 |
| 4223 | SMR Natural Gas Ventures Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Jan 1999 |
| 4224 | SND Operating, L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2025 |
| 4225 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 4226 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 4227 | Sohio Petr Co-Gulf Oil Corp | | Oil & Gas Operator | Dec 1979 |
| 4228 | Sohio Petroleum Co. | Casper, WY 82602 | Oil & Gas Operator | Apr 1986 |
| 4229 | Sohio Petroleum Co. Et Al | | Oil & Gas Operator | May 1979 |
| 4230 | Sola Oil Company, Inc. | | Oil & Gas Operator | Aug 1991 |
| 4231 | Sola Operating, LLC | Trout, LA 71371 | Oil Operator | Sep 2025 |
| 4232 | Solatex | | Oil & Gas Operator | Oct 1978 |
| 4233 | Solatex Resources, LTD | Houston, TX 77257 | Oil & Gas Operator | Sep 2025 |
| 4234 | Soldier Operating LLC | | Oil & Gas Operator | Dec 2024 |
| 4235 | Solid Rock Prod. | | Oil Operator | Nov 1994 |
| 4236 | Son-Dad Oil & Gas | | Oil & Gas Operator | Dec 1994 |
| 4237 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 4238 | Sonat Exploration Gom Inc. | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 4239 | Sonny King | | Oil & Gas Operator | Jan 2025 |
| 4240 | Sonny King Production | | Oil & Gas Operator | Jan 2025 |
| 4241 | Sonora Producing, Inc. | | Oil & Gas Operator | May 2006 |
| 4242 | Sonoran Energy Inc. | Addison, TX 75001 | Oil & Gas Operator | Sep 2025 |
| 4243 | Sooner Corporation | | Oil & Gas Operator | Oct 1990 |
| 4244 | Sooner Resources, Inc. | | Oil & Gas Operator | Mar 1987 |
| 4245 | Sotrana-Texas Corp. | | Oil & Gas Operator | Oct 1984 |
| 4246 | Sound Resources Corporation | | Oil & Gas Operator | Dec 2003 |
| 4247 | Source Petroleum Inc. | San Antonio, TX 78265 | Oil & Gas Operator | Sep 2025 |
| 4248 | South Central Petroleum, Inc. | | Oil & Gas Operator | Dec 1988 |
| 4249 | South Coast Oil, Inc. | | Oil & Gas Operator | Jul 1989 |
| 4250 | South La. Production Co., Inc. | | Oil & Gas Operator | Jun 1982 |
| 4251 | South Leeville, LLC | Houston, TX 77069 | Oil & Gas Operator | Oct 2022 |
| 4252 | South Oak Production Company | | Oil & Gas Operator | Jun 2010 |
| 4253 | South River Operating, LLC | | Oil & Gas Operator | Dec 2016 |
| 4254 | Southampton Mineral Corp. | | Oil & Gas Operator | Aug 2005 |
| 4255 | Southco Oil And Gas Inc. | | Oil & Gas Operator | Nov 2000 |
| 4256 | Southeastern Public Service Co | | Oil & Gas Operator | Sep 1982 |
| 4257 | Southern Bay Operating, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 4258 | Southern G Holdings, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2007 |
| 4259 | Southern Management Services | | Oil Operator | May 2017 |
| 4260 | Southern Natural Gas Co | Houston, TX 77001 | Oil & Gas Operator | Dec 2011 |
| 4261 | Southern Natural Gas Company LLC | | Oil & Gas Operator | Nov 2024 |
| 4262 | Southern Oil & Gas Company | | Oil & Gas Operator | Mar 2011 |
| 4263 | Southern Oil Of Louisiana LLC | Madisonville, LA 70447 | Oil & Gas Operator | Sep 2025 |
| 4264 | Southern Operating, Inc. | | Oil Operator | Dec 2000 |
| 4265 | Southern Petroleum Company | | Oil & Gas Operator | Jan 1994 |
| 4266 | Southern Production & Expl Co. | | Oil & Gas Operator | Apr 2008 |
| 4267 | Southern Production Co | Madill, OK 73446 | Oil & Gas Operator | May 2025 |
| 4268 | Southern Production SVC., Inc. | | Oil Operator | Mar 1997 |
| 4269 | Southern Solutions And Services LLC | | Oil Operator | Dec 2014 |
| 4270 | Southern Star Operating, Inc. | | Oil & Gas Operator | Jun 2010 |
| 4271 | Southern States Gas & Oil LTD | | Oil & Gas Operator | Jul 2004 |
| 4272 | Southern States Oil Production, LLC | | Oil & Gas Operator | Oct 2013 |
| 4273 | Southern States Petroleum Corp | | Oil Operator | Jan 1984 |
| 4274 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 4275 | Southern Water Disposal, LLC | | Oil & Gas Operator | Jan 2025 |
| 4276 | Southern Wells, Inc. | | Oil Operator | Sep 2002 |
| 4277 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 4278 | Southport Exploration Inc | Tulsa, OK 74103-4015 | Oil & Gas Operator | Nov 1998 |
| 4279 | Southwest Gas Producing Co Inc | | Oil & Gas Operator | Nov 1994 |
| 4280 | Southwest General Dev., Inc. | | Oil & Gas Operator | Dec 2003 |
| 4281 | Southwest Oil Properties, Inc. | | Oil & Gas Operator | Feb 1996 |
| 4282 | Southwest Operating Inc. | | Oil & Gas Operator | Dec 2024 |
| 4283 | Southwest Rig Service | | Oil & Gas Operator | Nov 1998 |
| 4284 | Southwestern Electric Power Co | Dallas, TX 75266 | Oil & Gas Operator | Dec 1989 |
| 4285 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 4286 | Southwind Oil & Gas LLC | | Oil & Gas Operator | Dec 2023 |
| 4287 | Sovereign Energy Corp. | | Oil Operator | Dec 2001 |
| 4288 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 4289 | Spartan Petroleum Corporation | Houston, TX 77079 | Oil & Gas Operator | Oct 1987 |
| 4290 | Spartan Royalties, LLC | | Oil Operator | Dec 2024 |
| 4291 | Special Energy Corporation | Stillwater, OK 74076 | Oil & Gas Operator | Sep 2025 |
| 4292 | Speco Oil Company | | Oil & Gas Operator | Feb 1980 |
| 4293 | Spectrum Opco LLC | | Oil & Gas Operator | Nov 2024 |
| 4294 | Spicy Daugx Operators Louisiana LLC | | Oil & Gas Operator | Nov 2024 |
| 4295 | Spillers Petroleum, Inc. | | Gas Operator | Mar 2010 |
| 4296 | Spindletop Drilling Co. | Dallas, TX 75230 | Oil & Gas Operator | Sep 2025 |
| 4297 | Spirit Petroleum Company | | Oil & Gas Operator | Apr 1999 |
| 4298 | Spokane Operating, LLC | | Oil & Gas Operator | Dec 2024 |
| 4299 | Spooner & Marlin Expl., Inc. | | Oil & Gas Operator | Mar 1990 |
| 4300 | Spooner Petroleum Company | | Oil & Gas Operator | Jun 2025 |