Abstract: An apparatus for activating a wellbore tool includes a cylinder, a shaft, and a pressure dissipater. The cylinder has a first inner surface defining a smooth bore section and a second inner surface adjacent to the first inner surface. The shaft has a piston section that includes at least one seal forming a fluid seal with the first inner surface when the seal is at a nominal diameter. The pressure dissipater is formed along the second inner surface of the cylinder, the pressure dissipater contacts and physically destabilizes the at least one seal after the at least one seal exits the smooth bore section.

Abstract: A perforating gun has shaped charges that can generate a high-pressure gas. A valve sub connects to the perforating gun and a reservoir sub connects to the valve sub. The valve sub has an enclosure with a port. A mandrel in the enclosure has a piston head and a fluid path extending at least partially through the mandrel. A sleeve is slidably mounted on the mandrel and selectively blocks fluid flow through the port. A pressure chamber in the sleeve receives the generated high-pressure gas via the fluid path. The sleeve slides toward the perforating gun after a predetermined pressure is created by the generated high-pressure gas in the pressure chamber. The reservoir sub may have at least one chamber in fluid communication with the interior of the valve sub.

Abstract: A switch includes a casing having a bore, a piston assembly having a first end and an exposed end, a plurality of flanges formed at the first end; an insulating sleeve enclosing the first end, a contact assembly disposed in the casing bore; a pin disposed in the bore; a predetermined quantity of lubricant deposited in the bore; and a spring urging the pin into engagement with the piston assembly. The insulating sleeve and the plurality of flanges are at least partially disposed in the casing bore. The pin has: (i) a first position wherein the pin electrically contacts the piston assembly and is electrically isolated from the contact assembly; and (ii) a second position wherein the pin is electrically isolated from the piston assembly and electrically engages the contact assembly. The predetermined quantity of lubricant may be approximately 0.3 grams.

Abstract: An apparatus for selectively isolating a firing head associated with a perforating gun may include an igniter coupled to a firing head, a time delay module coupled to the igniter and generating a pressure pulse after being activated by the igniter, a metering module, and a second firing head. The metering module may be coupled to the time delay module and including a housing having a bore and at least one opening exposed to a wellbore annulus. A piston disposed in the housing bore may have at least one passage. The piston is axially displaced from a first position to a second position by the generated pressure pulse. The second firing head is coupled to the metering module and is in fluid communication with the housing bore. The piston blocks fluid communication from the at least one opening of the housing and the second firing head in a first position and allows fluid communication from the at least one opening of the housing to the second firing head in the second position.

Abstract: A perforating gun includes a charge tube having shaped charges affixed thereto. Each shaped charge includes a radially outward pointing post adapted to receive a detonator cord. A retention member installed on the post provides a compressive force that energetically couples the detonator cord to the post. The radially outermost portion of the retention member is radially flush with or radially recessed relative to the radially outermost portion of each post. In one embodiment, the retention member has a rounded medial portion, a central opening and a pair of locking tabs that point radially inward to the central opening. Each post may include a slot for receiving the detonator cord and a circumferential groove that is adapted to receive the locking tabs.

Abstract: A perforating gun has shaped charges that can generate a high-pressure gas. A valve sub connects to the perforating gun and a reservoir sub connects to the valve sub. The valve sub has an enclosure with a port. A mandrel in the enclosure has a piston head and a fluid path extending at least partially through the mandrel. A sleeve is slidably mounted on the mandrel and selectively blocks fluid flow through the port. A pressure chamber in the sleeve receives the generated high-pressure gas via the fluid path. The sleeve slides toward the perforating gun after a predetermined pressure is created by the generated high-pressure gas in the pressure chamber. The reservoir sub may have at least one chamber in fluid communication with the interior of the valve sub.

Abstract: An apparatus for detonating an explosive body associated with a downhole tool includes a plurality of firing heads, each firing head including an initiating explosive body generating a high-order input when detonated; and a funnel configured to detonate the explosive body associated with the downhole tool by using a single high-order output. The funnel has a body that includes: a plurality of input openings, each input opening positioned next to an associated initiating explosive body to receive the generated high-order input, a single output opening, and a flow path connecting the plurality of input openings with the single output opening.

Abstract: In aspects, the present disclosure provides a perforating gun that includes a carrier tube, and a charge tube assembly. The carrier tube includes a bore and a groove formed along an inner surface. The charge tube assembly is disposed in the bore of the carrier tube and includes a charge tube, an alignment end plate, an insertion end plate, a retention member, shaped charges, and a detonating cord. The charge tube has a plurality of shaped charge openings, a plurality of post openings, a first end, and a second end. The alignment end plate is connected to the first end of the charge tube. The insertion end plate is connected to the second end of the charge tube. The shaped charges are disposed in each of the shaped charge openings. Each shaped charge has a post projecting out of one post opening. The detonating cord is connected to each of the projecting posts.

Abstract: An interrupter for use with a wellbore tool may include a housing having an interior and a fusible body disposed in the housing interior. The fusible body may be solid below a specified temperature and liquid above the specified temperature. The fusible body communicates a first high-order detonation to a detonator only when liquid. The communicated the first high-order detonation is at a magnitude sufficient to cause the detonator to produce a second high-order detonation.

Abstract: A switch includes a casing having a bore, a piston assembly having a first end and an exposed end, a plurality of flanges formed at the first end; an insulating sleeve enclosing the first end, a contact assembly disposed in the casing bore; a pin disposed in the bore; a predetermined quantity of lubricant deposited in the bore; and a spring urging the pin into engagement with the piston assembly. The insulating sleeve and the plurality of flanges are at least partially disposed in the casing bore. The pin has: (i) a first position wherein the pin electrically contacts the piston assembly and is electrically isolated from the contact assembly; and (ii) a second position wherein the pin is electrically isolated from the piston assembly and electrically engages the contact assembly. The predetermined quantity of lubricant may be approximately 0.3 grams.

Abstract: An apparatus for activating a wellbore tool includes a cylinder, a shaft, and a pressure dissipater. The cylinder has a first inner surface defining a smooth bore section and a second inner surface adjacent to the first inner surface. The shaft has a piston section that includes at least one seal forming a fluid seal with the first inner surface when the seal is at a nominal diameter. The pressure dissipater is formed along the second inner surface of the cylinder, the pressure dissipater contacts and physically destabilizes the at least one seal after the at least one seal exits the smooth bore section.

Abstract: An apparatus for detonating an explosive body associated with a downhole tool includes a plurality of firing heads, each firing head including an initiating explosive body generating a high-order input when detonated; and a funnel configured to detonate the explosive body associated with the downhole tool by using a single high-order output. The funnel has a body that includes: a plurality of input openings, each input opening positioned next to an associated initiating explosive body to receive the generated high-order input, a single output opening, and a flow path connecting the plurality of input openings with the single output opening.

Abstract: A perforating gun includes an orienting device retained in a carrier and a charge tube rotatably connected to the orienting device. The orienting device misaligns a center axis of the charge tube with a different second axis such that gravity can cause the charge tube to rotate about the different second axis. The charge tube does not rotate about the center axis of the charge tube while the charge tube rotates about the different second axis.

Abstract: An interrupter for use with a wellbore tool may include a housing having an interior and a fusible body disposed in the housing interior. The fusible body may be solid below a specified temperature and liquid above the specified temperature. The fusible body communicates a first high-order detonation to a detonator only when liquid. The communicated the first high-order detonation is at a magnitude sufficient to cause the detonator to produce a second high-order detonation.

Abstract: An apparatus for selectively isolating a firing head associated with a perforating gun may include an igniter coupled to a firing head, a time delay module coupled to the igniter and generating a pressure pulse after being activated by the igniter, a metering module, and a second firing head. The metering module may be coupled to the time delay module and including a housing having a bore and at least one opening exposed to a wellbore annulus. A piston disposed in the housing bore may have at least one passage. The piston is axially displaced from a first position to a second position by the generated pressure pulse. The second firing head is coupled to the metering module and is in fluid communication with the housing bore. The piston blocks fluid communication from the at least one opening of the housing and the second firing head in a first position and allows fluid communication from the at least one opening of the housing to the second firing head in the second position.