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 new method and apparatus for performing a drill stem test in an open (not cased) borehole are disclosed. When the borehole is initially drilled, the drilling process induces a skin damage near the external surface of the open (not cased) wellbore. It is necessary and desirable to bypass, reduce, or eliminate the skin damage in order to provide a free or natural flow of well fluid from the reservoir in the formation into the wellbore. However, in order to determine the degree of skin damage which exists near the external surface of the wellbore, reservoir parameters such as pressures, temperature and flowrates of the formation fluid flowing from the reservoir into the wellbore is first measured in the presence of the skin damage. The skin damage is then bypassed, removed, eliminated, or reduced by, for example, perforating the external surface of the wellbore.