Abstract: An implosion shaped charge device for jet perforating. In its overall concept, the implosion shaped charge perforator comprises a liner of implosive geometry, a primary explosive contiguous to the liner for providing implosion impulse to such and means for detonating the primary explosive. In a first embodiment the detonating means is an explosively actuated impact detonator. In a second embodiment the detonating means is a laser initiated explosive detonator. Both embodiments may be utilized in a perforating gun for perforating subsurface earth formations. In the operation of the embodiments the primary explosive is detonated with the resulting detonation wave approximately constantly accelerating the liner to radially converge to a small volume, from which a jet is propagated in the direction of the maximum pressure gradient.

Abstract: An explosive safe/arm system for use in a perforating gun includes a selectively rotatable member mounted intermediate a detonator and a length of detonator cord. The rotatable member includes a transversely oriented bore which is selectively rotatable into and out of axial alignment with the detonator and the detonator cord. Mounted within the bore is an explosive element for transferring an explosive detonation wave from the detonator to the detonator cord when the bore is in axial alignment.