| 201 | Oilwell Acquisition Co. | | Oil & Gas Operator | Jun 1999 |
| 202 | Okie Operating Company, LTD. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2025 |
| 203 | Oleum Operating Company, L.C. | Longview, TX 75606 | Oil & Gas Operator | Dec 2021 |
| 204 | Orb Exploration, L.L.C. | | Oil & Gas Operator | Jun 2017 |
| 205 | Orx Resources, Inc. | | Oil & Gas Operator | Dec 2009 |
| 206 | Orx Resources, L.L.C. | Houston, TX 77067 | Oil & Gas Operator | Mar 2025 |
| 207 | Osr Oil & Gas Corp | Midland, TX 79710 | Oil & Gas Operator | Dec 2024 |
| 208 | Oxy Petroleum Inc | | Oil & Gas Operator | Jan 1986 |
| 209 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Mar 2025 |
| 210 | P & A Oilfield Services, Inc. | | Oil & Gas Operator | Jan 1998 |
| 211 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 212 | Panaco Production Co | Houston, TX 77002 | Oil & Gas Operator | Dec 1999 |
| 213 | Panaco, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2024 |
| 214 | Park Exploration Inc | | Oil & Gas Operator | Nov 2012 |
| 215 | Parker & Parsley Devpt L P | | Oil & Gas Operator | Oct 1997 |
| 216 | Paxton Oil Company | | Oil & Gas Operator | Dec 2024 |
| 217 | Paxton Petroleum, LTD. | | Oil & Gas Operator | May 1989 |
| 218 | Pedernales Production, LP | Houston, TX 77057 | Oil & Gas Operator | Mar 2022 |
| 219 | Petro-Guard Company, Inc. | Houston, TX 77057 | Oil & Gas Operator | Nov 2014 |
| 220 | Petro-Hunt, L.L.C. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2025 |
| 221 | Petrodome Operating, LLC | Houston, TX 77265 | Oil & Gas Operator | Nov 2024 |
| 222 | Petroleum Corporation Of Texas | Breckenridge, TX 76024 | Oil & Gas Operator | May 2002 |
| 223 | Petroquest Energy, L.L.C. | Lafayette, LA 70505 | Oil & Gas Operator | Mar 2025 |
| 224 | Pharaoh Oil & Gas, Inc. | MC Camey, TX 79752 | Oil & Gas Operator | Mar 2025 |
| 225 | Phoenix Oil & Gas LTD., L.L.P. | Houston, TX 77010 | Oil & Gas Operator | Jun 2004 |
| 226 | Pioneer Natural Resources USA Inc | Irving, TX 75039 | Oil & Gas Operator | Nov 2024 |
| 227 | Plains Resources Inc. | Houston, TX 77002 | Oil & Gas Operator | Jul 2008 |
| 228 | Plano Corp. | | Oil & Gas Operator | Mar 2005 |
| 229 | Ponderosa Oil & Gas, LLC | Houston, TX 77008 | Oil & Gas Operator | Mar 2025 |
| 230 | Presidio Exploration, Inc. | Englewood, CO 80155 | Oil & Gas Operator | May 1999 |
| 231 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 232 | Progenies Operating LLC | Austin, TX 78746 | Oil & Gas Operator | Mar 2025 |
| 233 | Prudential Oil & Gas, Inc. | | Oil & Gas Operator | Jul 1987 |
| 234 | Prudential Petroleum Co., LTD. | | Oil & Gas Operator | Dec 1990 |
| 235 | Quality Petroleum Corp. | | Oil & Gas Operator | Apr 1990 |
| 236 | R & M Oil Co. | Fredonia, KS 66736 | Oil & Gas Operator | Aug 2002 |
| 237 | Radzewicz Operating Corp. | | Oil & Gas Operator | Oct 2017 |
| 238 | Riceland Petroleum Company | | Oil & Gas Operator | Nov 2024 |
| 239 | Rig Iron Petroleum Inc | | Oil & Gas Operator | Aug 1988 |
| 240 | Rio Bravo Expl. & Prod. Co. | Houston, TX 77055 | Oil & Gas Operator | Apr 2020 |
| 241 | Rio Bravo Oil Company | The Woodlands, TX 77381 | Oil & Gas Operator | Feb 2002 |
| 242 | River Bend Operating, Inc. | | Oil & Gas Operator | Jul 1999 |
| 243 | Roblyn Petroleum Corp. | | Oil & Gas Operator | May 1983 |
| 244 | Rozel Operating Company | | Oil & Gas Operator | Oct 2014 |
| 245 | Rvo Petroleum Co. | | Oil & Gas Operator | Feb 1982 |
| 246 | Samedan Oil Corp. Et Al | | Oil & Gas Operator | Jan 1989 |
| 247 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 248 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2024 |
| 249 | Sandefer Petroleum Co. | | Oil & Gas Operator | Apr 1994 |
| 250 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Mar 2025 |
| 251 | Sandridge Onshore, LLC | Houston, TX 77010 | Oil & Gas Operator | Jun 2014 |
| 252 | Santa Fe Braun, Inc | Dallas, TX 75240-6620 | Oil & Gas Operator | Mar 1995 |
| 253 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |
| 254 | Santana Exploration, Inc. | | Oil & Gas Operator | Dec 1985 |
| 255 | Senior G&A Operating Co Inc | | Oil & Gas Operator | Nov 1991 |
| 256 | Serio Exploration Company | | Oil Operator | Jan 1992 |
| 257 | Settco Oil & Gas | | Oil & Gas Operator | May 1994 |
| 258 | Shell Oil Company | Houston, TX 77210 | Oil & Gas Operator | Apr 2015 |
| 259 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 260 | Shield Energy Resources, LLC | | Oil Operator | Dec 2024 |
| 261 | Single Barrel Oil And Gas LLC | Granbury, TX 76048 | Oil & Gas Operator | Mar 2025 |
| 262 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Mar 2025 |
| 263 | SMK-La, Inc. | | Oil & Gas Operator | Sep 1999 |
| 264 | Sohio Petroleum Co. | Casper, WY 82602 | Oil & Gas Operator | Apr 1986 |
| 265 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 266 | Source Petroleum Inc. | San Antonio, TX 78265 | Oil & Gas Operator | Mar 2025 |
| 267 | South Oak Production Company | | Oil & Gas Operator | Jun 2010 |
| 268 | Southeastern Public Service Co | | Oil & Gas Operator | Sep 1982 |
| 269 | Southern Bay Operating, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 270 | Southern Natural Gas Co | Houston, TX 77001 | Oil & Gas Operator | Dec 2011 |
| 271 | Southern Natural Gas Co, LLC | | Oil & Gas Operator | Nov 2024 |
| 272 | Southwest Rig Service | | Oil & Gas Operator | Nov 1998 |
| 273 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 274 | Square One Corporation | Giddings, TX 78942 | Oil & Gas Operator | Dec 2012 |
| 275 | Ssi Energy LLC | | Oil & Gas Operator | Jul 2021 |
| 276 | Standard Operating Company, LLC | | Oil & Gas Operator | May 2022 |
| 277 | Sugar Bowl Industrial Gas Corp | | Oil Operator | Dec 1983 |
| 278 | Sun Exploration-Production Co. | | Oil & Gas Operator | Jan 1990 |
| 279 | Sunchase Exploration, Inc. | | Oil & Gas Operator | Oct 1997 |
| 280 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 281 | Sydson D'Oro Expl. Co. | Houston, TX 77079 | Oil & Gas Operator | Jan 1992 |
| 282 | Tellus Operating Group, LLC | | Oil & Gas Operator | Dec 2024 |
| 283 | Tesla Resources, Inc. | | Oil & Gas Operator | Aug 1996 |
| 284 | Texaco Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2017 |
| 285 | Texada Resources, Inc. | | Oil & Gas Operator | Dec 1992 |
| 286 | Texakoma Operating, L.P. | Plano, TX 75024 | Oil & Gas Operator | Jan 2025 |
| 287 | Texas Crude, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 1995 |
| 288 | Texas Gas Exploration Corp. | | Oil & Gas Operator | Nov 1986 |
| 289 | Texas Meridian Operating Co. Inc | Houston, TX 77079 | Oil & Gas Operator | Oct 1993 |
| 290 | Texas Petroleum Investment Company | Houston, TX 77057 | Oil & Gas Operator | Mar 2025 |
| 291 | Texoil Company | | Oil & Gas Operator | Dec 2000 |
| 292 | The Ballard & Cordell Corp | | Oil & Gas Operator | Feb 1982 |
| 293 | The Dow Chemical Company | | Oil & Gas Operator | Dec 1997 |
| 294 | The George R Brown Partnership | | Oil & Gas Operator | Jun 1992 |
| 295 | The Meridian Res. & Exp. LLC | | Oil & Gas Operator | Sep 2010 |
| 296 | The Meridian Resource & Exp Co | | Oil & Gas Operator | Dec 2000 |
| 297 | Tipco | Shreveport, LA 71104-3047 | Oil & Gas Operator | May 1988 |
| 298 | Tipperary Oil & Gas Corp | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 299 | TMR Exploration, Inc. | Bossier City, LA 71171 | Oil & Gas Operator | Mar 2025 |
| 300 | Toce Oil Company | | Oil & Gas Operator | Dec 2014 |