| 4201 | Smith-Wentworth | | Oil & Gas Operator | Sep 1983 |
| 4202 | Smith-Wentworth & Coquina | | Oil Operator | Jun 1983 |
| 4203 | Smith-Wentworth & Hughes & New | | Oil Operator | Jun 1983 |
| 4204 | SMK-La, Inc. | | Oil & Gas Operator | Sep 1999 |
| 4205 | SMR Natural Gas Ventures Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Jan 1999 |
| 4206 | SND Operating, L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Jul 2026 |
| 4207 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 4208 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 4209 | Sohio Petr Co-Gulf Oil Corp | | Oil & Gas Operator | Dec 1979 |
| 4210 | Sohio Petroleum Co. | Casper, WY 82602 | Oil & Gas Operator | Apr 1986 |
| 4211 | Sohio Petroleum Co. Et Al | | Oil & Gas Operator | May 1979 |
| 4212 | Sola Oil Company, Inc. | | Oil & Gas Operator | Aug 1991 |
| 4213 | Sola Operating, LLC | Trout, LA 71371 | Oil Operator | Jul 2026 |
| 4214 | Solatex | | Oil & Gas Operator | Oct 1978 |
| 4215 | Solatex Resources, LTD | Houston, TX 77257 | Oil & Gas Operator | Jul 2026 |
| 4216 | Soldier Operating LLC | | Oil & Gas Operator | Dec 2024 |
| 4217 | Solid Rock Prod. | | Oil Operator | Nov 1994 |
| 4218 | Son-Dad Oil & Gas | | Oil & Gas Operator | Dec 1994 |
| 4219 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 4220 | Sonat Exploration Gom Inc. | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 4221 | Sonny King | | Oil & Gas Operator | Jan 2025 |
| 4222 | Sonny King Production | | Oil & Gas Operator | Jan 2025 |
| 4223 | Sonora Producing, Inc. | | Oil & Gas Operator | May 2006 |
| 4224 | Sonoran Energy Inc. | Addison, TX 75001 | Oil & Gas Operator | Jul 2026 |
| 4225 | Sooner Corp | | Oil & Gas Operator | Oct 1990 |
| 4226 | Sooner Resources, Inc. | | Oil & Gas Operator | Mar 1987 |
| 4227 | Sotrana-Texas Corp. | | Oil & Gas Operator | Oct 1984 |
| 4228 | Sound Resources Corporation | | Oil & Gas Operator | Dec 2003 |
| 4229 | Source Petroleum Inc. | San Antonio, TX 78265 | Oil & Gas Operator | Jul 2026 |
| 4230 | South Central Petroleum, Inc. | | Oil & Gas Operator | Dec 1988 |
| 4231 | South Coast Oil, Inc. | | Oil & Gas Operator | Jul 1989 |
| 4232 | South La. Production Co., Inc. | | Oil & Gas Operator | Jun 1982 |
| 4233 | South Leeville, LLC | Houston, TX 77069 | Oil & Gas Operator | Oct 2022 |
| 4234 | South Oak Production Company | | Oil & Gas Operator | Jun 2010 |
| 4235 | South River Operating, LLC | | Oil & Gas Operator | Dec 2016 |
| 4236 | Southampton Mineral Corp. | | Oil & Gas Operator | Aug 2005 |
| 4237 | Southco Oil And Gas Inc. | | Oil & Gas Operator | Nov 2000 |
| 4238 | Southeastern Public Service Co | | Oil & Gas Operator | Sep 1982 |
| 4239 | Southern Bay Operating, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 4240 | Southern G Holdings, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2007 |
| 4241 | Southern Management Services | | Oil Operator | May 2017 |
| 4242 | Southern Natural Gas Co | Houston, TX 77001 | Oil & Gas Operator | Dec 2011 |
| 4243 | Southern Natural Gas Co, LLC | | Oil & Gas Operator | Nov 2024 |
| 4244 | Southern Oil & Gas Company | | Oil & Gas Operator | Mar 2011 |
| 4245 | Southern Oil Of Louisiana LLC | Madisonville, LA 70447 | Oil & Gas Operator | Jul 2026 |
| 4246 | Southern Operating, Inc. | | Oil Operator | Dec 2000 |
| 4247 | Southern Petroleum Company | | Oil & Gas Operator | Jan 1994 |
| 4248 | Southern Production & Expl Co. | | Oil & Gas Operator | Apr 2008 |
| 4249 | Southern Production Co Inc | Madill, OK 73446 | Oil & Gas Operator | Mar 2026 |
| 4250 | Southern Production SVC., Inc. | | Oil Operator | Mar 1997 |
| 4251 | Southern Solutions And Services LLC | | Oil Operator | Dec 2014 |
| 4252 | Southern Star Operating, Inc. | | Oil & Gas Operator | Jun 2010 |
| 4253 | Southern States Gas & Oil LTD | | Oil & Gas Operator | Jul 2004 |
| 4254 | Southern States Oil Production, LLC | | Oil & Gas Operator | Oct 2013 |
| 4255 | Southern States Petroleum Corp | | Oil Operator | Jan 1984 |
| 4256 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 4257 | Southern Water Disposal, LLC | | Oil & Gas Operator | Jan 2025 |
| 4258 | Southern Wells, Inc. | | Oil Operator | Sep 2002 |
| 4259 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 4260 | Southport Exploration Inc | Tulsa, OK 74103-4015 | Oil & Gas Operator | Nov 1998 |
| 4261 | Southwest Gas Producing Co Inc | | Oil & Gas Operator | Nov 1994 |
| 4262 | Southwest General Dev., Inc. | | Oil & Gas Operator | Dec 2003 |
| 4263 | Southwest Oil Properties, Inc. | | Oil & Gas Operator | Feb 1996 |
| 4264 | Southwest Operating Inc. | | Oil & Gas Operator | Dec 2024 |
| 4265 | Southwest Rig Service | | Oil & Gas Operator | Nov 1998 |
| 4266 | Southwestern Electric Power Co | Dallas, TX 75266 | Oil & Gas Operator | Dec 1989 |
| 4267 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 4268 | Southwind Oil & Gas LLC | | Oil & Gas Operator | Dec 2023 |
| 4269 | Sovereign Energy Corp. | | Oil Operator | Dec 2001 |
| 4270 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 4271 | Spartan Petroleum Corporation | Houston, TX 77079 | Oil & Gas Operator | Oct 1987 |
| 4272 | Spartan Royalties, LLC | | Oil Operator | Dec 2024 |
| 4273 | Special Energy Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Jul 2026 |
| 4274 | Speco Oil Company | | Oil & Gas Operator | Feb 1980 |
| 4275 | Spectrum Opco LLC | | Oil & Gas Operator | Nov 2024 |
| 4276 | Spicy Daugx Operators Louisiana LLC | | Oil & Gas Operator | Nov 2024 |
| 4277 | Spillers Petroleum, Inc. | | Gas Operator | Mar 2010 |
| 4278 | Spindletop Drilling Co. | Dallas, TX 75230 | Oil & Gas Operator | Jul 2026 |
| 4279 | Spirit Petroleum Company | | Oil & Gas Operator | Apr 1999 |
| 4280 | Spokane Operating, LLC | | Oil & Gas Operator | Dec 2024 |
| 4281 | Spooner & Marlin Expl., Inc. | | Oil & Gas Operator | Mar 1990 |
| 4282 | Spooner Petroleum Company | | Oil & Gas Operator | May 2026 |
| 4283 | Spyglass Oil & Gas LLC | | Oil & Gas Operator | Dec 2024 |
| 4284 | Square Mile Energy, L.L.C. | Houston, TX 77057 | Oil & Gas Operator | Jul 2026 |
| 4285 | Square One Corporation | Giddings, TX 78942 | Oil & Gas Operator | Dec 2012 |
| 4286 | SRP Production Corp. | | Oil & Gas Operator | Nov 1997 |
| 4287 | Ssi Energy LLC | | Oil & Gas Operator | Jul 2021 |
| 4288 | SSM Partnership-PV79 | | Oil Operator | Jun 1989 |
| 4289 | St Johns Operating #1 LP | Houston, TX 77060 | Oil & Gas Operator | Aug 2023 |
| 4290 | St. Croix Corporation | | Oil & Gas Operator | Apr 1990 |
| 4291 | St. Mary Energy Company | Houston, TX 77079 | Oil & Gas Operator | Aug 2008 |
| 4292 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 4293 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 4294 | St. Paul Oil And Gas Corp. | | Oil & Gas Operator | Aug 1991 |
| 4295 | Stallion Oil Corporation | | Oil & Gas Operator | Nov 1987 |
| 4296 | Stanco Petroleum Inc | Kimball, NE 69145 | Oil & Gas Operator | Jul 1999 |
| 4297 | Standard Operating Company, LLC | | Oil & Gas Operator | May 2022 |
| 4298 | Standard Production | | Oil Operator | Oct 1997 |
| 4299 | Star Energy Inc | Dayton, PA 16222-4325 | Oil & Gas Operator | Dec 2025 |
| 4300 | Star Falcon Oil Co. | | Oil Operator | Feb 1986 |