A perforating gun for use in a well casing, the gun having a gun carrier extending along a longitudinal axis; plural shaped charges located inside the gun carrier, in a plurality of groups, a first group being positioned in a first single plane, transverse to the longitudinal axis, and a second group being positioned in a second single plane, transverse to the longitudinal axis. The first and second groups of charges are spaced along the longitudinal axis so that a third single plane, transverse to the longitudinal axis, intersects each of the shaped charges of the first and second groups of charges.

A safety mechanism and method for downhole perforating are disclosed. In one example, a mechanical firing head includes a firing pin carried on a pin carrier within a housing. The firing pin is movable from a retracted position to a firing position for striking an explosive initiator. A retention member retains the firing pin in the retracted position with the safety member in the armed position. A safety member is biased to a safety position that additionally blocks movement of the firing pin. The safety member is moveable to an armed position that unblocks movement of the firing pin in response to an arming pressure supplied to the housing bore. The retention member releases the firing pin in response to a firing pressure supplied to the housing in excess of the firing pressure.

A tandem seal adapter (TSA) for use with a wellbore tool may include a TSA body including a first end and a second end opposite the first end in an axial direction, a bore extending through the TSA body from the first end to the second end, an electrical contact assembly provided within the bore, the electrical contact assembly being configured to provide electrical connectivity through the bore. The electrical contact assembly may include a bulkhead provided within the bore. An axial position of a maximum outer diameter of the TSA body may overlap with the bulkhead in the axial direction. A portion of the bore overlapping in the axial direction with an entirety of the TSA body having an outer diameter equal to the maximum outer diameter may have a constant bore diameter.

A gun to gun transfer delay fuse that includes a delay housing, a first cylindrical cavity housing a firing pin and igniter, and a second cylindrical cavity housing a delay fuse with a centralizer feature.

A perforating gun may include a gun carrier extending in an axial direction and a tandem seal adapter (TSA). The gun carrier having a maximum outer carrier diameter. The TSA may include a first TSA region having a first TSA outer diameter, a second TSA region having a second TSA outer diameter, and a shoulder surface formed between an outer surface of the first TSA region and an outer surface of the second TSA region. The second TSA outer diameter may be larger than the first TSA outer diameter and smaller than the maximum outer carrier diameter. A portion of the gun carrier may abut with the shoulder surface.

Components for a perforation gun system are provided including combinations of components including a self-centralizing charge holder system and a bottom connector that can double as a spacer. Any number of spacers can be used with any number of holders for any desired specific metric or imperial shot density, phase and length gun system.

A perforating gun assembly may include a first housing extending along a longitudinal axis and a tandem seal adapter (TSA). The first housing may include a coupling provided at a first end of the first housing. The TSA may include a TSA body and a seal element provided on an outer surface of the TSA body. At least part of the TSA may be positioned inside the first housing such that the seal element and the coupling intersect with a common plane that is perpendicular to the longitudinal axis.

An interchangeable module is configured to be used in an integrated perforating gun and setting tool system. The interchangeable module includes a body having first external threads; an addressable switch located inside the body; and a connection unit located inside the body and configured to electrically connect to an initiating device. The interchangeable module is configured to be used (1) between a first gun cluster and a second gun cluster and (2) between a distal gun cluster and a setting tool.

A perforation gun assembly may include a single shaped charge holder, the shaped charge holder having a charge receiving structure and at least one projection extending from the charge receiving structure. A detonation cord and a detonator may be connected to the shaped charge holder. A top connector may be configured for connecting to a first base of the shaped charge holder and a bottom connector may be configured for connecting to a second based of the shaped charge holder. The perforation gun assembly may be positioned within an outer gun carrier of a perforation gun, and a tandem seal adapter may be positioned at least in part within the outer gun carrier.

A wellbore perforating apparatus and method according to which a perforating gun and a sensor sub are run into a wellbore toward a downhole location at which the wellbore is to be perforated. Detonable components of the perforating gun are energized to perforate the wellbore at the downhole location. An acceleration of the perforating gun and a pressure and a temperature of the wellbore are detected using the sensor sub during a time interval encompassing the energization of the detonable components. The detected acceleration, pressure, and temperature are compared to benchmark energetic responses for both detonation and deflagration events. Based on this comparison, a decision can be made as to whether an incubation period is needed to allow a reaction of the detonable components to weaken before retrieving the perforating gun from the wellbore.