Abstract: An apparatus for perforating a wellbore includes a plurality of perforator units that includes a first perforator unit and a second perforator unit; and a signal transfer module connecting the first perforator unit to the second perforator unit. The signal transfer module includes an enclosure having a bore, an input end, and an output end, an initiator positioned adjacent to the first perforator unit and at least partially in the enclosure, an initiator, an igniter, a fuse, and an isolator. The initiator generates a shock wave when initiated. The igniter is positioned in the enclosure and generates a low order output upon receiving the shock wave generated by the initiator. The fuse is positioned in the enclosure and is initiated by the low order output of the igniter. The fuse outputs a high order output from the output end of the enclosure. The isolator secures the fuse body in the bore of the enclosure. The isolator includes a shock attenuator.

Abstract: An apparatus for perforating a subterranean formation comprises a first perforating gun (33b) having a box end (112) having a nose, a second perforating gun (33a) having a pin end (118) having a shoulder (124); and an alignment assembly. The alignment assembly includes internal threads formed on the box end, external threads formed on the pin end, and an alignment member (120) positioned between the box end nose and the pin end shoulder. The internal threads and the external threads are specified to form an angular alignment between the first perforating gun and the second perforating gun within a first specified angular tolerance. The alignment member has at least one characteristic selected to vary the angular alignment within the first specified angular tolerance without degrading a locking force connecting the first perforating gun to the second perforating gun.

Abstract: An apparatus for selectively firing a perforating gun having a plurality of gun assemblies may include an end plate, a portion of a signal communication circuit, an initiator assembly, and an initiating element. The end plate has a cavity formed by at least a first passage intersecting a second passage. The first passage extends from a planar end face of the end plate and the second passage extends from a circumferential surface of the end plate. The portion of a signal communication circuit is disposed in the end plate and conveys signals between the first gun and the second gun. The initiator assembly is at least partially disposed in the first passage. The initiating element is sized to pass through the second passage. The initiating element is also configured to electrically couple to the portion of the signal communication circuit and to thermally couple to the initiator assembly when at least partially seated in the first passage.

Abstract: An apparatus for selectively firing a perforating gun having a plurality of gun assemblies includes a plurality of cartridge assemblies. Each cartridge assembly is associated with a gun assembly of the plurality of gun assemblies. Each cartridge assembly includes a body having a cavity, an input contact configured to receive a signal, and a throughput contact configured to convey the signal. The perforating gun may include a carrier and at least one bulkhead.

Abstract: 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.

Abstract: 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.

Abstract: An apparatus for perforating an unconventional subterranean formation includes a charge holder having a passage along a long axis, a detonating device positioned in the passage and a plurality of shaped charges supported by the charge holder and circumferentially distributed along a same plane that is transverse to the long axis. Each shaped charge is formed of at least a charge case, an explosive material disposed in the charge case, and a liner enclosing the explosive material in the charge case. All of the shaped charges are directly energetically coupled to the detonating device.

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: A signal transfer assembly includes a signal transfer propellant assembly and a signal transfer connector tube in hydraulic communication with a signal transfer firing head. The signal transfer propellant assembly has a piston and a gas generating energetic material. The signal transfer connector tube has a bore and a first opening allowing fluid communication between a borehole fluid surrounding the connector tube and the bore. The piston generates a pressure pulse when propelled through the bore by the generated gas. The signal transfer firing head assembly includes a housing having a second opening allowing fluid communication between the housing bore and the borehole fluid. A related method includes forming a well tool by operatively connecting a signal transfer assembly as described above to a primary downhole tool and a secondary downhole tool; conveying the well tool into a wellbore using a work string; and activating the secondary downhole tool by initiating the primary downhole tool.

Abstract: A firing head assembly for a well tool includes a shaft, a piston head, a biasing member, and a housing. The shaft has a nose and a terminal end. The shaft also includes a first shoulder and a second shoulder formed between the nose and the terminal end. The piston head slides along the shaft and is positioned between the retaining element and the first shoulder. The biasing member is mounted on the shaft and positioned between the piston head and the second shoulder. The housing has a bore in which the shaft, the piston head, and biasing member are disposed. The housing includes an opening allowing fluid communication between the housing bore and the borehole fluid external to the housing.

Abstract: A well tool (60) includes a perforating gun (108), a sealing element (130), at least one pressure sensor (150), a detector (132), a controller (152), and an anchor (134). The perforating gun (108) perforates the wellbore tubular in response to a firing signal. The sealing element (130) is connected to the perforating gun (108) and generates a pressure differential thereacross. The at least one pressure sensor (150) is associated with the sealing element (130) and detects a surface transmitted pressure signal. The detector (132) detects at least one marker (70) positioned along the wellbore (12) and which includes a perforating marker (70) associated with a perforating depth.

Abstract: A firing head assembly for a well tool includes a shaft, a piston head, a biasing member, and a housing. The shaft has a nose and a terminal end. The shaft also includes a first shoulder and a second shoulder formed between the nose and the terminal end. The piston head slides along the shaft and is positioned between the retaining element and the first shoulder. The biasing member is mounted on the shaft and positioned between the piston head and the second shoulder. The housing has a bore in which the shaft, the piston head, and biasing member are disposed. The housing includes an opening allowing fluid communication between the housing bore and the borehole fluid external to the housing.

Abstract: A signal transfer assembly includes a signal transfer propellant assembly and a signal transfer connector tube in hydraulic communication with a signal transfer firing head. The signal transfer propellant assembly has a piston and a gas generating energetic material. The signal transfer connector tube has a bore and a first opening allowing fluid communication between a borehole fluid surrounding the connector tube and the bore. The piston generates a pressure pulse when propelled through the bore by the generated gas. The signal transfer firing head assembly includes a housing having a second opening allowing fluid communication between the housing bore and the borehole fluid. A related method includes forming a well tool by operatively connecting a signal transfer assembly as described above to a primary downhole tool and a secondary downhole tool; conveying the well tool into a wellbore using a work string; and activating the secondary downhole tool by initiating the primary downhole tool.

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: 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: A well tool (60) includes a perforating gun (108), a sealing element (130), at least one pressure sensor (150), a detector (132), a controller (152), and an anchor (134). The perforating gun (108) perforates the wellbore tubular in response to a firing signal. The sealing element (130) is connected to the perforating gun (108) and generates a pressure differential thereacross. The at least one pressure sensor (150) is associated with the sealing element (130) and detects a surface transmitted pressure signal. The detector (132) detects at least one marker (70) positioned along the wellbore (12) and which includes a perforating marker (70) associated with a perforating depth.

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 tool includes an encapsulated shaped charge that has a bulkhead with a reduced wall thickness section, a plate having a shallow recess, and a detonating cord having an energetic core. The energetic core forms the plate into an explosively formed perforator when detonated. The plate is positioned to direct the explosively formed perforator into the reduced wall thickness section.

Abstract: A perforating tool includes a charge holder connected to a work string and a perforator fixed in a charge holder disposed along the work string. The perforator includes a cylindrical case, an explosive material, a metal cap, and a detonating cord. The case has a bulkhead at a first end, an open mouth at a second end, and an interior volume. The first end includes a post having a slot. The explosive material is disposed in the interior volume. The metal cap covers the open mouth of the case and has a disk section defined by a separator ring. The separator ring has a structurally weakened zone that encircles the disk section. The detonating cord is received in the slot of the post.

Abstract: An initiation block for connecting a detonator with a detonating cord has a body that includes opposing first and second faces and a first and a second chamber extending between the opposing faces. The first chamber is formed by a first bore serially arranged with a second bore, which is shaped to seat the detonator adjacent to the second face. The second chamber is parallel with the first chamber and shaped complementary to the detonating cord. A passage provides communication between the first chamber and the second chamber. A booster is positioned in the first bore, proximate to the first face, and along the passage. The body further has an opening that provides communication between an exterior of the body and a portion of the chamber between the booster and the detonator.