A detonator which is responsive to a shock tube event which is validated if a link is fused at a predetermined time interval after a light signal produced by the event is detected and if, at the end of a subsequent time interval, the link is still fused and the light signal is absent.

A control circuit for a detonator which includes a charger pump with an inductor which is connected to earth via a fusible link and wherein the charge pump is placed in an operative mode to produce a charging voltage for a firing capacitor if the link is fused in response to a shock tube event.

A detonator which is initiated by a shock tube event which is validated if a processor determines that a fusible link was not fused by a shock tube event at a predetermined time interval before light generated by the shock tube event is detected.

A detonator for use with perforating gun assemblies is presented. The detonator includes a shell including a main explosive load. The shell may include one or more openings. A non-mass explosive body is disposed in the shell, adjacent the main explosive load. The non-mass explosive body includes one or more channels extending therethrough. The detonator includes a plug adjacent the non-mass explosive body, and a PCB adjacent the plug to facilitate electrical communication with the detonator. The plug may include an elongated opening extending therethrough. The channels of the non-mass explosive body, in combination with at least one of the openings of the shell or the elongated openings of the plug, are configured to introduce fluids, such as wellbore fluids, into the non-mass explosive body to disable the detonator.

An electrical connector may include a connector body and a first electrical contact provided at a first end of the connector body. The first electrical contact may be biased so as to rest at a first rest position if no external force is being applied to the first electrical contact. The first electrical contact may be structured so as to move from the first rest position to a first retracted position in response to an application of external force against the first electrical contact.

A fast utility access device (FUAD) is provided that includes one or more casings, each of the one or more casings collectively defining a bore, and a core of a highly exothermic composition contained in the bore and surrounded by a thermally insulating inner liner, the highly exothermic composition ignitable to create a post-ignition temperature of between 500° C. and 4000° C. A method is also provided for breaching a target and includes contacting the inventive access device with a breaching target substrate, thermally coupling at least one reaction initiator to the highly exothermic composition, triggering the at least one reaction initiator thereby igniting the highly exothermic composition, and allowing the highly exothermic composition to achieve a post-ignition temperature sufficient to melt the breaching target substrate, forming a hole therethrough.

An end plate for a perforating gun assembly. The end plate has a first end defining a first face, and a second end opposite the first end defining a second face. A flange resides between the first face and the second face. The end plate has a first through-opening and a second through-opening. A first bulkhead resides in the first through-opening, and is configured to closely receive a signal transmission pin. A second bulkhead resides in the second through-opening and is configured to closely receive a detonator pin. The signal transmission pin transmits detonation signals through the end plate, while the detonator pin transmits detonation signals back up the wellbore and through the end plate. The end plate may also have an opening along the second face for receiving a ground pin.

A loading tube is configured to receive one or more shaped charges to form a perforating gun. The loading tube includes a tubular body extending along a longitudinal axis; a cord passage formed into the tubular body; a retention cutoff formed into the tubular body and configured to receive a detonator cord; and a holding element extending into the retention cutoff and being integrally made with a wall of the tubular body, wherein the holding element is configured to hold the detonator cord into the retention cutoff. The cord passage is configured to receive the detonator cord from a bore of the tubular body and to direct the detonator cord outside the bore of the tubular body.

A perforating gun system includes an outer housing, a charge carrier assembly slidably receivable in the outer housing, wherein the charge carrier assembly includes a charge carrier having a central axis, a first endplate coupled to a first end of the charge carrier, and a second endplate coupled to a second end of the charge carrier, and an initiator assembly including an electrical switch, wherein the electrical switch has a maximum length extending in a direction parallel the central axis that is less than a maximum width of the electrical switch extending in an orthogonal direction relative to the central axis; wherein the electrical switch is configured to detonate a detonator of the perforating gun system in response to receiving a firing signal.

Included are methods and systems for oilfield perforating. An example system includes a firing head subassembly; a gun subassembly; and 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.0.sup.5,9.0.sup.3,11]-dodecane (“TEX”). An example method includes lowering a perforating system into a casing of a wellbore, wherein the perforating system comprises TEX; detonating the TEX; and perforating the casing.