jewellery

1. (oil industry, informal) Any tools, instruments, devices, etc., placed within a drill pipe.Examples: "The rig simply retrieves the old pipe and runs a new pipe back in the hole (the completion string). Any special items on the string other than the pipe itself are referred to as "jewellery". These can be any number of things, from down-hole motors to mandrels and radioactive sources for survey purposes."informaluncountableusually