Abstract: A switch connectable to an upper explosive device and a lower explosive device in a perforation gun train is provided. The switch comprises a circuit, a portion of the circuit being openable upon detonation of the lower explosive device, and the switch being changeable from a first position to a second position upon the opening of the portion of the circuit. In the first position, current can flow to the lower explosive device but not to the upper explosive device. In the second position, opposing current can flow to the upper explosive device but not to the lower explosive device.

Abstract: A method and apparatus for removing fluid from a container using a conventional shaped charge such as those used in well perforation; the charge being spaced from the container wall, and producing an explosive jet, the explosive jet directed by a diffuser disk to provide a vent or drain.

Abstract: A method and apparatus for removing fluid from a container using a conventional shaped charge such as those used in well perforation; the charge being spaced from the container wall, and producing an explosive jet, the explosive jet directed by a diffuser disk to provide a vent or drain.