Abstract: The present invention provides systems, methods and devices for selectively firing a gun train formed of a plurality of guns. Conventionally, the guns each include a detonator assembly that detonates upon receiving a firing signal transmitted by a surface source. In one embodiment of the present invention, an operator provided in the gun train selectively couples one or more of the guns to the signal transmission medium. The operator has an safe state wherein the operator isolates the gun from the firing signal and an armed state wherein the operator enable the transmission of the firing signal to the gun. A control signal is used to move operator between the safe state and the armed state. In some embodiments, two or more guns are each provided with a separate operator. In other embodiments, one operator can selectively engage two or more guns.

Abstract: An improved downhole explosive charge carrier is disclosed. The invention uses a unique staggered charge pattern and a mounting configuration which allows the use of a straight, axially-located detonator in order to achieve a greater number of shots per unit length over conventional carriers. The invention also reduces the interference caused by the detonator and the closeness of the shots and thereby increases the performance of the individual charges, allowing smaller charges to be used to achieve the same perforation size.

Abstract: A charge assembly for use in a cutter for splitting couplings used in joining together lengths of buried pipe is provided that allows several explosive charge segments to be used instead of a single explosive charge. The smaller explosive charge segments utilize less explosive material which complies with applicable shipping regulations. The charge assembly has an elongate charge housing with an open interior. At least two linear charge segments are longitudinally aligned in an abutting relationship with the other within the housing interior. The linear charge segments may be formed from an explosive core encased within a metal sheath. A pair of longitudinally spaced charge abutment members may be mounted within the housing interior, with the abutment members engaging the aligned charge segments at opposite ends. One of the abutment members includes a housing end closure.