US Patent 8157022 Apparatus string for use in a wellbore

An apparatus string for use in a wellbore has a plurality of activation modules having first and second ends and containing devices to be activated/initiated downhole. An apparatus string also has a plurality of initiator modules where at least initiator is operatively connected to each activation module and is addressable. Each initiator module may have a safety initiator which when the initiator module is addressed initiates the firing of the shaped charges in the gun module to which it is operatively connected. A wireless transmitter is operatively connected in and integral to the apparatus string for use in transmitting signals to address any initiator module in the apparatus string.