| 201 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2024 |
| 202 | Sanchez Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2025 |
| 203 | Santo Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 204 | Sasha Petroleum, Inc | | Oil Operator | Jan 1986 |
| 205 | Savant Energy Corporation | | Oil & Gas Operator | Mar 2012 |
| 206 | Scorpion Oil & Gas, LLC | Houston, TX 77036 | Oil & Gas Operator | Aug 2024 |
| 207 | Seagull Operating Co., Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jan 2025 |
| 208 | Skelly Oil Co | | Oil & Gas Operator | Mar 2005 |
| 209 | Sklar & Phillips Oil Co. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2000 |
| 210 | Skyhawk Energy, LLC | | Oil Operator | Dec 2024 |
| 211 | Smith Operating And MGMT Co. | Shreveport, LA 71161 | Oil & Gas Operator | Jun 2023 |
| 212 | Smith-Wentworth | | Oil & Gas Operator | Sep 1983 |
| 213 | Sola Operating, LLC | Trout, LA 71371 | Oil Operator | Mar 2025 |
| 214 | Son-Dad Oil & Gas | | Oil & Gas Operator | Dec 1994 |
| 215 | South Coast Oil, Inc. | | Oil & Gas Operator | Jul 1989 |
| 216 | Spooner & Marlin Expl., Inc. | | Oil & Gas Operator | Mar 1990 |
| 217 | Steaua Romana (Us) Inc. | | Oil & Gas Operator | Apr 1987 |
| 218 | Stenco | | Oil & Gas Operator | Apr 1994 |
| 219 | Steveco | | Oil Operator | Feb 1984 |
| 220 | Stratco Operating Co., Inc. | Austin, TX 78701 | Oil & Gas Operator | Mar 2025 |
| 221 | Sun Exploration-Production Co. | | Oil & Gas Operator | Jan 1990 |
| 222 | T. L. James & Co., Inc. | | Oil & Gas Operator | Oct 1992 |
| 223 | T. M. Hopkins | | Oil & Gas Operator | Aug 2007 |
| 224 | T. O. Kimbrell, LLC | | Oil & Gas Operator | Jan 2025 |
| 225 | T. West Bullock, SR. | | Oil & Gas Operator | Mar 1989 |
| 226 | Taggart Oil Co., Inc. | | Oil Operator | Oct 1992 |
| 227 | TDX Energy, LLC | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2024 |
| 228 | Tensas Delta Exploration Company, LLC | Shreveport, LA 71101-5323 | Oil & Gas Operator | Jul 2021 |
| 229 | Tensas Delta Land Company | | Oil & Gas Operator | Apr 2002 |
| 230 | Termo Co. Of Texas | | Oil & Gas Operator | Dec 1986 |
| 231 | Texaco Producing Inc. | Rock Springs, WY 82901 | Oil & Gas Operator | Dec 2000 |
| 232 | Threshold Development Company | Fort Worth, TX 76109 | Oil & Gas Operator | Aug 2016 |
| 233 | Tideway Oil Programs, Inc. | | Oil & Gas Operator | Oct 1980 |
| 234 | Titan Oil Corp. | | Oil & Gas Operator | Jan 2025 |
| 235 | TMR Exploration, Inc. | Bossier City, LA 71171 | Oil & Gas Operator | Mar 2025 |
| 236 | Tredegar Properties, Inc. | | Oil Operator | Jun 1990 |
| 237 | TWC Oil Company | | Oil Operator | Jan 2025 |
| 238 | Tyler Production, LLC | | Oil & Gas Operator | Jul 2013 |
| 239 | Vega Oil & Gas MGMT., Inc. | | Oil & Gas Operator | Aug 1981 |
| 240 | W. L. Estis | | Oil & Gas Operator | Dec 1999 |
| 241 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2025 |
| 242 | Wainoco Oil & Gas Company | Houston, TX 77024 | Oil & Gas Operator | Dec 2005 |
| 243 | Watchtower Petroleum LLC | | Oil & Gas Operator | Dec 2024 |
| 244 | Wayne J. Spears | | Oil & Gas Operator | Sep 2005 |
| 245 | Wheless DRLG Co &R.M.Bergstein | | Oil Operator | May 1986 |
| 246 | White River Operating LLC | Gilmer, TX 75644 | Oil & Gas Operator | Dec 2024 |
| 247 | Wilcox Energy Company | | Oil & Gas Operator | Dec 2024 |
| 248 | Wilcox Operating Company | | Oil Operator | Dec 1989 |
| 249 | Wilcox Operating Corporation | Shreveport, LA 71115 | Oil & Gas Operator | Mar 2025 |
| 250 | Witt Oil Production, Inc. | | Oil & Gas Operator | Nov 1984 |
| 251 | World Oil & Gas Expl., Inc. | | Oil & Gas Operator | Mar 1988 |