Abstract: In a tubing conveyed perforating gun assembly having shaped charges to perforate a well, an improved pressure sequence shaped charge detonator is included. The preferred form of device is appended to the bottom of the assembly to function as a backup detonator. First and second piston and cylinder assemblies in an elongate body provide pressure initiated arming and subsequent pressure initiated firing pin movement to achieve primer cord detonation for perforation of the well. The pressure sequence is controllable, selectively to a specified pressure to arm and thereafter to fire.

Abstract: In a tubing conveyed perforating gun assembly having shaped charges to perforate a well, an improved pressure sequence shaped charge detonator is included. The preferred form of device is appended to the bottom of the assembly to function as a backup detonator. First and second piston and cylinder assemblies in an elongate body provide pressure initiated arming and subsequent pressure initiated firing pin movement to achieve primer cord detonation for perforation of the well. The pressure sequence is controllable, selectively to a specified pressure to arm and thereafter to fire.

Abstract: For use with a tubing conveyed perforating gun assembly, a wireline manipulated electrically actuated detonator assembly traversing the interior of the tubing is described. In the preferred and illustrated embodiment, a wireline connected with a sinker bar supports the detonator assembly having a sinker bar sub terminating in a taper adjacent to a set of deflectable collet fingers comprising a latch assembly. The collet fingers are deflected outwardly by the tapered surface and are forced into an undercut located above a booster and detonating cord affixed to the tubing conveyed perforating gun assembly for firing the perforating guns.

Abstract: A laser system for inscribing permanent identification markings on or below the surface of a diamond. A shallow penetration depth and narrow line width is achieved by using a harmonic conversion device to produce an output frequency which is the second harmonic of the fundamental laser frequency in combination with a lens system having a short focal length to provide a high density pinpoint spot of laser energy. The energy intensity can be further regulated by a polarization attenuator. In operation, the diamond is mounted on a movable support structure which insures proper relationship to the laser beam. The process is activated by a computer which supplies positional commands to the movable support and is interfaced with the laser for generating programmed alpha-numeric sequences.