Abstract: For use in closing a cylindrical passageway through a working member in which the passageway is defined in part by a reduced diameter internal circumferential sealing surface and an internal locking groove, a completion plug having a plug body with a cylindrical external surface receivable within the cylindrical passageway of the working member and having an external circumferential sealing surface dimensioned to radially compressibly engage the working member internal circumferential sealing surface. The plug body has on its cylindrical surface an external locking groove. A locking ring is received in the working member internal locking groove and simultaneously in the plug body external locking groove and serves to lock the plug body within the working member.

Abstract: A method of plugging a pipeline includes the steps of welding onto the exterior of the pipeline (10) first (12) and second (14) spaced apart collars, each having a sealing face (26,26A) in a plane perpendicular the pipeline (10) axis. A containment housing (34,36) is affixed by welding to the collars (12,14) to fully encompass a section of the pipeline (10) between the collars (12,14). A tapping (60) machine is then removably attached to an open top of the containment housing (34). Using the tapping machine (60) a short length of the pipeline (10) is cut and removed from between the collars (12,14) leaving two open exposed pipe ends (78,80). First and second seal elements (92,94) are positioned between the collars (12,14), Each having a forward sealing face. The seal elements (92,94) are forced apart from each other into sealing engagement with the collar sealing faces thereby closing the open, exposed ends (78,80) of the pipe (10).

Abstract: A system and method of plugging a pipe including sealably securing onto the exterior of a pipe first and second spaced apart collars, each collar having a sealing face in a plane perpendicular the pipe axis, cutting and removing a length of pipe from between the collars leaving two open pipe ends, positioning first and second seal cups between the collars, each seal cup having a forwardly extending circumferential lip of internal diameter greater than the external diameter of the pipe, each seal cup having top and bottom cam followers, moving cam surfaces against the cam followers to guide the seal cups into sealing engagement with the sealing faces of the collars, and forcing a wedge between rearward surfaces of the seal cups.

Abstract: Apparatus for tapping a hole in a pipeline adapted to be attached to a support assembly having sealed communication with the exterior of a pipeline and having a tapping machine body with a boring bar rotatably supported therein with a circular cutter at the lower end thereof, a feed screw rotatably supported by the tapping machine body for axially positioning the boring bar, a hydraulically powered boring bar drive assembly within the tapping machine body driving the boring bar, a hydraulically powered feed screw drive assembly within the tapping machine body driving the feed screw and an auxiliary drive shaft affixed to rotate the feed screw drive assembly extending exteriorly of the tapping machine body and adapted to receive supplementary mechanical rotary energy for rotation of the feed screw so the boring bar can be retracted if hydraulic power is lost. A pressure compensation system permits the apparatus to be operated in a subsea environment.