Editing Wireline (cabling) (section)

====Gamma perforating tools====
A cased hole gamma perforator is used to perform mechanical services, such as shooting [[Perforation (oil well)|perforations]], setting downhole tubing/casing elements, dumping remedial cement, tracer surveys, etc.  Typically, a gamma perforator will have some sort of explosively initiated device attached to it, such as a perforating gun, a setting tool, or a dump bailor.  In certain instances, the gamma perforator is used to merely spot objects in the well, as in tubing conveyed perforating operations and tracer surveys.

Gamma perforators operate in much the same way as an open hole natural gamma ray tool.  Gamma rays given off from naturally occurring radioactive elements bombard the scintillation detector mounted on the tool.  The tool processes the gamma ray counts and sends the data uphole where it processed by a computerized acquisition system, and plotted on a log versus depth.  The information is then used to ensure that the depth shown on the log is correct.  After that, power can be applied through the tool to set off explosive charges for things like perforating, setting plugs or packers, dumping cement, etc.