| 201 | Noram Field Services Corp. | | Oil Operator | Apr 1999 |
| 202 | O'Brien Energy Company | Shreveport, LA 71136 | Oil & Gas Operator | Sep 2019 |
| 203 | O'Brien Operating Company | Shreveport, LA 71164 | Oil & Gas Operator | Dec 2004 |
| 204 | O. B. Mobley | | Oil & Gas Operator | Jul 1989 |
| 205 | O. O. Cummings | | Gas Operator | Jan 1999 |
| 206 | O.G.P. Operating, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Sep 2026 |
| 207 | Oak Energy, LLC | Houston, TX 77027 | Oil & Gas Operator | Sep 2026 |
| 208 | Occidental Energy Company, Inc. | Houston, TX 77282 | Oil & Gas Operator | Jul 2021 |
| 209 | Offshore Shelf LLC | | Oil & Gas Operator | Dec 2007 |
| 210 | Oliditt Corporation | | Gas Operator | Mar 2022 |
| 211 | Opal Oil Inc. | | Oil Operator | Sep 2021 |
| 212 | Ora Oil Company | | Oil & Gas Operator | May 2017 |
| 213 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 214 | P. S. & G., Incorporated | | Gas Operator | Aug 1983 |
| 215 | Pacific Atlantic Oil Co. | | Oil & Gas Operator | Dec 2003 |
| 216 | Pan-Ok Production Company | | Oil & Gas Operator | Nov 2024 |
| 217 | Panenergy La Intrastate Co | | Oil Operator | Mar 2000 |
| 218 | Paoco-Walker | | Gas Operator | Sep 2011 |
| 219 | Par Minerals Corporation | Shreveport, LA 71101 | Oil & Gas Operator | Sep 2026 |
| 220 | Pelican Producing Co. | | Gas Operator | Nov 1992 |
| 221 | Pelico Pipeline, LLC | | Oil Operator | Dec 2024 |
| 222 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 223 | Peoples Energy Prod.-TX, L.P. | Houston, TX 77002 | Oil & Gas Operator | Sep 2007 |
| 224 | Petro-Chem Operating Company, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Sep 2026 |
| 225 | Petro-Lewis Corp. | | Oil & Gas Operator | Feb 1994 |
| 226 | Petrofunds, Inc. & Herd | | Oil & Gas Operator | Mar 1984 |
| 227 | PG&E Resources Company | Houston, TX 77042 | Oil & Gas Operator | May 1995 |
| 228 | Phillips Energy, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2018 |
| 229 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 230 | Primos Production | | Oil & Gas Operator | Dec 2024 |
| 231 | Primos-Pennzoil JV | | Gas Operator | Feb 2005 |
| 232 | Pritchard Engineering | | Oil & Gas Operator | Mar 1989 |
| 233 | Prospera Energy, Inc. | | Oil & Gas Operator | Dec 2005 |
| 234 | Pruet Production Co. | Jackson, MS 39201 | Oil & Gas Operator | Jun 2026 |
| 235 | Quadrant Exploration Inc | Marietta, OH 45750 | Oil & Gas Operator | Dec 2000 |
| 236 | R & D Holdings, Inc. | | Gas Operator | Feb 1991 |
| 237 | R. W. Ellington, Jr. | | Gas Operator | May 1985 |
| 238 | Rabalais Oil And Gas, Inc. | | Oil & Gas Operator | Sep 2023 |
| 239 | Rabun Resources | | Gas Operator | Jan 2025 |
| 240 | Relco Exploration Co., Inc. | | Gas Operator | Aug 1987 |
| 241 | Reliance TR-JV | | Gas Operator | Apr 1988 |
| 242 | Reliance Trusts | Dallas, TX 75244 | Oil & Gas Operator | Nov 1995 |
| 243 | Reliance Trusts HS | | Gas Operator | Feb 1989 |
| 244 | Reliant Energy Field SVS Inc. | | Oil Operator | Sep 2002 |
| 245 | Ric Petroleum | | Gas Operator | Dec 1998 |
| 246 | Richard T. Perry | | Gas Operator | May 1993 |
| 247 | River Energy Co., Inc. | | Gas Operator | Dec 2012 |
| 248 | Riverstone Energy Operating, LLC | Houston, TX 77090 | Oil & Gas Operator | Sep 2026 |
| 249 | RLM Energy Company Inc. | Monroe, LA 71201 | Oil & Gas Operator | Mar 2008 |
| 250 | RMR Oil Company | Jacksboro, TX 76458 | Oil & Gas Operator | Sep 2005 |
| 251 | Roberson Well Service | | Gas Operator | Dec 2024 |
| 252 | Rosamond Drilling Co., Inc. | | Gas Operator | Nov 1984 |
| 253 | Rosbottom Production Corp | Shreveport, LA 71134 | Oil & Gas Operator | Dec 2017 |
| 254 | Rosestone Operating Company, LLC | | Oil & Gas Operator | Dec 2024 |
| 255 | Rowe, Inc. | | Oil & Gas Operator | Jun 1992 |
| 256 | Roy M. Teel | | Oil & Gas Operator | Nov 1983 |
| 257 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Sep 2026 |
| 258 | Samson Contour Energy E&P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2017 |
| 259 | Sand Hill, LTD. | | Gas Operator | Dec 2024 |
| 260 | Schmid Properties, Inc. | Hico, TX 76457 | Oil & Gas Operator | Sep 2026 |
| 261 | Segars Operating | | Gas Operator | Apr 2014 |
| 262 | Shadrack Production Company | | Gas Operator | Dec 1982 |
| 263 | Shiloh Creek Resources, Inc. | | Gas Operator | Nov 2024 |
| 264 | Shoreline Pipeline Corporation | | Oil Operator | Dec 2020 |
| 265 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Jun 2026 |
| 266 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | Sep 2026 |
| 267 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 268 | South Coast Oil, Inc. | | Oil & Gas Operator | Jul 1989 |
| 269 | Southern Solutions And Services LLC | | Oil Operator | Dec 2014 |
| 270 | Southern States Petroleum Corp | | Oil Operator | Jan 1984 |
| 271 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 272 | Spillers Petroleum, Inc. | | Gas Operator | Mar 2010 |
| 273 | Spirit Petroleum Company | | Oil & Gas Operator | Apr 1999 |
| 274 | Spooner Petroleum Company | | Oil & Gas Operator | Jun 2026 |
| 275 | St Johns Operating #1 LP | Houston, TX 77060 | Oil & Gas Operator | Aug 2023 |
| 276 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 277 | Stinson Gas Company, L.L.C. | | Gas Operator | Jul 2018 |
| 278 | Story Oil And Gas Inc | Magnolia, AR 71753 | Oil & Gas Operator | Jan 2025 |
| 279 | Strago Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Aug 1994 |
| 280 | Strataform, Inc. | | Gas Operator | Jun 2002 |
| 281 | Stroud Petroleum, Inc. | Shreveport, LA 71162 | Oil & Gas Operator | Sep 2026 |
| 282 | Sundance Energy Corporation | | Oil & Gas Operator | Jan 2025 |
| 283 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 284 | SWN Production Company, LLC | Spring, TX 77391 | Oil & Gas Operator | Dec 2025 |
| 285 | T. L. James & Co., Inc. | | Oil & Gas Operator | Oct 1992 |
| 286 | Tahoe Corporation | | Gas Operator | Feb 2023 |
| 287 | TBR Operating Company Inc. | | Gas Operator | Dec 2024 |
| 288 | TD & Associates, Inc. | | Oil & Gas Operator | Jun 1998 |
| 289 | Terrier Oil Company | | Oil & Gas Operator | Feb 2015 |
| 290 | Terronne Petroleum Corporation | | Oil & Gas Operator | Nov 2024 |
| 291 | Texaco Producing Inc. | Rock Springs, WY 82901 | Oil & Gas Operator | Dec 2000 |
| 292 | Texas Petroleum Investment Company | Houston, TX 77057 | Oil & Gas Operator | Sep 2026 |
| 293 | Texoma Production Co | | Oil & Gas Operator | Jun 1986 |
| 294 | The Pioneer | | Gas Operator | Feb 2008 |
| 295 | Thomas Aitken, Inc. | | Gas Operator | Dec 2024 |
| 296 | Time Energy, L.L.C. | | Oil & Gas Operator | Nov 2020 |
| 297 | TMR Exploration, Inc. | Bossier City, LA 71171 | Oil & Gas Operator | Sep 2025 |
| 298 | Tomlinson Oil Co Inc | Great Bend, KS 67530 | Oil & Gas Operator | Mar 2026 |
| 299 | Tommy Joe Jenny | | Gas Operator | Nov 2024 |
| 300 | Total Minatome Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 1998 |