Abstract: The invention is for a pipeline pigging plug which is adapted to be launched from normal instrumented pig launchers and received in comparable pig traps utilized in connection with pipeline operations. The pigging plug is arranged for pigging along the internal surface of a pipeline by the application of fluid pressure therebehind until it arrives at a selected point in the pipeline where a plug is to be effected. Upon application of pressurized fluid to the apparatus the pig is caused to become set or locked in position within the pipeline and a fluid-tight seal is created with the pipeline by the plug. Thus set, the plug is self-energized, i.e., it will remain set against high differential pressure without continued application of said pressurized fluid. When it is desired to remove the plug it can be deactuated and removed by a tether or by the application of fluid pressure thereto as with a conventional pig.