Abstract: A select fire gun assembly for jet perforating includes a plurality of shaped charges capable of being detonated by blasting caps activated by passage of current through the cap. The first electric terminal of each blasting cap of the gun assembly is grounded. A second terminal of each blasting cap is connected through an electronic switch to the output of a diode, with the input of the diode being connected to the logging cable. The polarity of the diodes are arranged in alternative sequence. The gate of the electronic switch is also connected to the diode through a large resistor and to the ground or a dart through another resistor. These electronic switches are closed when the gate is grounded. Current can flow through the blasting cap only when the gate is grounded and when the diode associated with the blasting cap is of the appropriate polarity to allow current to pass through.

Abstract: A select fire gun assembly for jet perforating includes a plurality of shaped charges capable of being detonated by blasting caps activated by passage of current through the cap. The first electric terminal of the blasting cap on the bottom of the assembly is grounded. The remaining blasting caps are electrically connected to a dart that grounds only after the charge below has been detonated. The other terminal of each blasting cap is connected to the logging cable through a first diode, and these diodes are arranged in sequentially alternating polarity. The first terminal of each cap is also connected electrically through a large resistor to the gate of an electronic switch which is closed either by positive or negative voltage, depending on the nature of the switch. The switch is open when the gate is grounded. The electronic switch is incorporated in series with the logging cable. Positive and negative gated electronic switches are connected to the blasting caps in alternative sequence.

Abstract: An improved clip for holding an explosive shaped charge in a carrier strip is provided. The improved clip holds the shaped charge by inserting fingers into an annular groove formed around the perimeter near one end of the shaped charge. The clip and charge are in turn inserted into a carrier strip and held in place by notches cut into the clip. The carrier and its shaped charges are then inserted into a perforating gun tube. The carrier strip is held in position within the tube by use of spring-loaded lock pins. The lock pins are mounted on the strip so that a spring will force the pins inwardly away from the inner wall. A separate threaded screw with a cam surface is engaged to hold the lock pins in their outward position thus firmly securing the carrier strip in place.

Abstract: A perforating gun barrel for carrying a plurality of explosive charges in a spaced apart relationship comprises a plurality of tubular sections positioned with the ends of adjacent tubular sections end-to-end, with the end of one section overlapping the end of an adjacent section. A coupling member is disposed entirely internally of said tubular sections at each coupling location. A plurality of bolts extend through the overlapping ends of the adjacent tubular sections and are secured in the coupling member to prevent separation of the adjacent tubular sections at the coupling locations. Wiring for detonating the charge carried in each tubular section is routed through a passageway provided in the coupling member.