Patent ID: 7461580

Claim:
A firing head for activating a perforating device capable of perforating a subterranean-earth formation through a wellbore, the perforating device comprising a plurality of gun assemblies, each gun assembly comprising a plurality of explosive charges, the firing head comprising: a body comprising a plurality of longitudinal passages there through, at least one of said longitudinal passages being a mounting passage for receipt of a tubular object; at least one gun assembly comprising at least a first charge that is configured to perforate said tubular object in said mounting passage upon detonation and a second charge that is configured to not perforate said tubular object in said mounting passage upon detonation; a plurality of donor charges, each donor charge secured within one of said longitudinal passages and positioned near a respective gun assembly; and a firing assembly for detonating the plurality of donor charges, the detonation of each donor charge creating ballistic energy that is transferred to a receiver charge in an another gun assembly for detonating the plurality of explosive charges contained therein.