Abstract: A method and system for selecting and arming each one of a plurality of firing modules in a single-line selective perforating system is disclosed. A single firing line connects each firing module one at a time in a sequence to a control unit to receive power and control signals therefrom. Each module generates internally a module active time interval in response to being connected to the firing line power. Each time interval has a first portion during which the module generates an identification pulse to the control unit to indicate that another module has been connected to the firing line, and a second portion during which the module is enabled to receive a selection pulse from the control unit to terminate further sequencing of the modules to locate the module to be selected. The next module to receive power from the control unit is connected to the firing line by a pass-thru switch in the last connected module at the end of its active time interval if that module was not selected for firing.

Abstract: In the representative embodiment of the invention herein, delicate instruments and electronics circuitry used for obtaining downhole measurements are mounted on an elongated support or chassis which is removably disposed within a tubular housing and uniquely restrained from movement in response to shocks and vibrations which might otherwise damage or destroy the components. In this preferred arrangement, at least one set of angularly-disposed transverse rollers of a somewhat-resilient material is mounted on the chassis and respectively arranged for being slightly compressed and rollingly engaged with the internal wall of the tubular enclosure as the chassis is inserted into the enclosure.