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.

A perforating gun system with at least one gun. Each of the perforating guns have charges disposed in a gun carrier that are angled to the longitudinal axis of the gun to achieve a predetermined proppant transport profile into clusters within a stage in a well casing. The perforation tunnels may also have burrs on each side of the casing and acts in initially aiding proppant transport during fracture treatment. A method of tuning a cluster to achieve a desired fracturing treatment based on a feedback from another cluster includes selecting a hole diameter, a hole angle for creating an angled opening, a discharge coefficient, and a proppant efficiency. Moreover, a method of improving perforation charge efficiency.

There is an igniter system for igniting an energetic material. The igniter system includes a housing having a bore; an igniter located inside the bore; a ground wire directly connected to the igniter; and a signal wire directly connected to the igniter. The ground wire and the signal wire form an electrical circuit with the igniter for igniting the energetic material.

A downhole system includes a switch sub holding a gun switch and an adapter attached to the switch sub and holding an igniter switch. The gun switch is configured to detonate a detonator, and the igniter switch is configured to ignite an igniter system.

A firing head for selectively activating an initiator of a downhole tool may include a housing, a pin, and a moveable stopper. The housing may have a bore and a radially enlarged chamber formed along the bore. The pin is disposed in the bore and has a circumferential groove formed on an outer surface of the shank. The moveable stopper is disposed in the radially enlarged chamber. The stopper is only partially disposed in the groove when the housing is in a vertical position. The stopper moves out of the groove when the housing has a predetermined minimum angular deviation from the vertical position.

A mechanical gun to gun delay for providing a desired time delay between the firing of a first gun and the firing of a second gun downhole without using a pyrotechnic fuse as the delay.

A perforating gun system with at least one gun. Each of the perforating guns have charges disposed in a gun carrier that are angled to the longitudinal axis of the gun to achieve a predetermined proppant transport profile into clusters within a stage in a well casing. The perforation tunnels may also have burrs on each side of the casing and acts in initially aiding proppant transport during fracture treatment. A method of tuning a cluster to achieve a desired fracturing treatment based on a feedback from another cluster includes selecting a hole diameter, a hole angle for creating an angled opening, a discharge coefficient, and a proppant efficiency. Moreover, a method of improving perforation charge efficiency.

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.

An ultra-short, high-density, perforating gun for use in a well casing includes a gun carrier extending along a longitudinal axis, only 2 charges located inside the gun carrier, the only 2 charges being positioned in a single plane transverse to the longitudinal axis, and a charge holder configured to carry the only 2 charges, the charge holder configured to be inserted into the gun carrier. The gun carrier ranges in length from 4 inches to 11 inches. A diameter of the gun carrier ranges from 1 to 4 inches, and wherein at least one charge of the only 2 charges has a liner that has a subtended angle from 100 to 120.

An apparatus and method for connecting a detonating cord with a shaped charge.