WO2022184654A1 - Modular perforating gun system - Google Patents

Abstract

A system for use within a gun housing of a perforating gun may include a centralizer and a detonator holder. The centralizer may include a centralizer body and a centralizer bore extending through the centralizer body. The detonator holder may be disposed within the centralizer bore and may include a first detonator holder end configured to receive a detonator and a second detonator holder end comprising a detonator holder coupling. The detonator holder may extend through the centralizer and may be mechanically coupled to the centralizer. The centralizer may be configured to engage with an inner surface of the gun housing.

Description

MODULAR PERFORATING GUN SYSTEM

[0001] This application claims the benefit of United States Provisional Patent Application 63/155,902 filed March 3, 2021, United States Provisional Patent Application 63/166,720 filed March 26, 2021, United States Provisional Patent Application 63/271,846 filed October 26, 2021, United States Provisional Patent Application 63/276,103 filed November 5, 2021, United States Provisional Patent Application 63/309,674 filed February 14, 2022, and United States Patent Application 17/677,478 filed February 22, 2022, the entire contents of each of which are incorporated herein by reference.

BACKGROUND OF THE DISCLOSURE

[0002] Hydrocarbons, such as fossil fuels (e.g. oil) and natural gas, are extracted from underground wellbores extending deeply below the surface using complex machinery and explosive devices. Once the wellbore is established by placement of casing pipes after drilling and cementing the casing pipe in place, a perforating gun assembly, or train or string of multiple perforating gun assemblies, are lowered into the wellbore, and positioned adjacent one or more hydrocarbon reservoirs in underground formations.

[0003] Assembly of a perforating gun may require assembly of multiple parts. Such parts typically include a housing or outer gun barrel containing or connected to perforating gun internal components such as: an electrical wire for relaying an electrical control signal such as a detonation signal from the surface to electrical components of the perforating gun; an electrical, mechanical, and/or explosive initiator such as a percussion initiator, an igniter, and/or a detonator; a detonating cord; one or more explosive and/or ballistic charges which are held in an inner tube, strip, or other carrying device; and other known components including, for example, a booster, a sealing element, a positioning and/or retaining structure, a circuit board, and the like. The internal components may require assembly including connecting electrical components within the housing and confirming and maintaining the connections and relationships between internal components. The assembly procedure may be difficult within the relatively small free space within the housing. Typical connections may include connecting the electrical relay wire to the detonator or the circuit board, coupling the detonator and the detonating cord and/or the booster, and positioning the detonating cord in a retainer at an initiation point of each charge. In addition, typical perforating guns may not provide components that are size-independent and therefore available for use in different perforating guns with, e.g., different gun housing inner diameters.

[0004] The housing may also be connected at each end to a respective adjacent wellbore tool or other component of the tool string such as a firing head, tandem seal adapter or other sub assembly, or the like. Connecting the housing to the adjacent component(s) typically includes screwing the housing and the adjacent component(s) together via complementary threaded portions of the housing and the adjacent components and forming a connection and seal therebetween.

[0005] Known perforating guns may further include explosive charges, typically shaped, hollow, or projectile charges, which are initiated, e.g., by the detonating cord, to perforate holes in the casing and to blast through the formation so that the hydrocarbons can flow through the casing. In other operations, the charges may be used for penetrating just the casing, e.g., during abandonment operations that require pumping concrete into the space between the wellbore and the wellbore casing, destroying connections between components, severing a component, and the like. The exemplary embodiments in this disclosure may be applicable to any operation consistent with this disclosure. For purposes of this disclosure, the term “charge” and the phrase “shaped charge” may be used interchangeably and without limitation to a particular type of explosive, charge, or wellbore operation, unless expressly indicated.

[0006] The perforating guns may be utilized in initial fracturing process or in a refracturing process. Refracturing serves to revive a previously abandoned well in order to optimize the oil and gas reserves that can be obtained from the well. In refracturing processes, a smaller diameter casing is installed and cemented in the previously perforated and accessed well. The perforating guns must fit within the interior diameter of the smaller diameter casing, and the shaped charges installed in the perforating guns must also perforate through double layers of casing and cement combinations in order to access oil and gas reserves.

[0007] The explosive charges may be arranged and secured within the housing by the carrying device which may be, e.g., a typical hollow charge carrier or other holding device that receives and/or engages the shaped charge and maintains an orientation thereof. Typically, the charges may be arranged in different phasing, such as 60°, 90°, 120°, 180°, 270°, etc. along the length of the charge carrier, so as to form, e.g., a helical pattern along the length of the charge carrier. Charge phasing generally refers to the radial distribution of charges throughout the perforating gun, or, in other words, the angular offset between respective radii along which successive charges in a charge string extend in a direction away from an axis of the charge string. An explosive end of each charge points outwardly along a corresponding radius to fire an explosive jet through the gun housing and wellbore casing, and/or into the surrounding rock formation. Phasing the charges therefore generates explosive jets in a number of different directions and patterns that may be variously desirable for particular applications. On the other hand, it may be beneficial to have each charge fire in the same radial direction. A charge string in which each charge fires in the same radial direction would have zero-degree (0°) phasing.

Still further, a gravitationally oriented shaped charge may be beneficial in certain applications. Ensuring the orientation of the shaped charges before firing may also be a critical step for ensuring accurate and effective perforating and therefore eliminating the need for multiple perforating operations for a single section of the wellbore.

[0008] Once the perforating gun(s) is properly positioned, a surface signal actuates an ignition of a fuse or detonator, which in turn initiates the detonating cord, which detonates the explosive charges to penetrate/perforate the housing and wellbore casing, and/or the surrounding rock formation to allow formation fluids to flow through the perforations thus formed and into a production string.

[0009] Typical perforating guns may suffer from shortcomings with respect to, for example, simplifying the assembly procedures for components, providing size-independent components that may be used in various gun housings having different inner diameters, and achieving the potential benefits of adaptable charge phasing including accurate orientation of shaped charges once the perforating gun is downhole (i.e., deployed within the wellbore). For example, various components of the perforating gun may require assembly and wiring on site and certain components must be specific to the perforating gun housing with the particular inner diameter that is being assembled. Metal charge tubes and other charge carriers that are not easily reconfigurable are not easily adaptable for use with different numbers of charges in different phasing and/or may not be capable of gravitational orientation. The number and phasing of charges in such rigid carriers may be limited by the number and orientation of charge holes/receivers in the particular charge carrier. Machining different charge carriers for every possible desired arrangement and number of charges in the perforating gun is not practically desirable. [0010] In addition, a charge carrier that provides a very high charge phasing (i.e., a relatively severe angle between successive charges in the charge carrier) requires that a detonating cord make relatively drastic bends, especially for charges arranged with a relatively short distance between them, as it is routed between the initiating end of successive shaped charges. The detonating cord must be precisely positioned on the initiating end, above an initiation point, of the shaped charge to ensure that the detonating cord initiates detonation of the shaped charge. The detonating cord is retained at the initiation point of the shaped charge by a variety of known detonating cord retaining components. Typically, the forces and stresses on the detonating cord, especially at the detonating cord retaining components, increases as the phasing increases and the distance decreases between successive charges. The forces and stresses may damage the detonating cord and/or cause the detonating cord to become misaligned with the initiation point either to a side of the initiation point or in a direction away from the initiation point in which the detonating cord is pulling away from the retaining component.

[0011] Accordingly, a modular perforating gun platform system and corresponding perforating gun that may address one or more of the above shortcomings would be beneficial.

BRIEF DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0012] An exemplary embodiment of a system for use within a gun housing of a perforating gun may include a centralizer and a detonator holder. The centralizer may include a centralizer body and a centralizer bore extending through the centralizer body. The detonator holder may be disposed within the centralizer bore and may include a first detonator holder end configured to receive a detonator and a second detonator holder end comprising a detonator holder coupling. The detonator holder may extend through the centralizer and may be mechanically coupled to the centralizer. The centralizer may be configured to engage with an inner surface of the gun housing.

[0013] An exemplary embodiment of perforating gun may include a gun housing, a centralizer disposed within the gun housing, a charge holder module having a first end coupled to the detonator holding coupling, and an end connector coupled to a second end of the shaped charge module opposite the first end of the shaped charge module. The centralizer may include a centralizer body and a centralizer bore extending through the centralizer body. The detonator holder may include a first detonator holder end configured to receive a detonator, a second detonator holder end comprising a detonator holder coupling, a feedthrough contact plate configured to be in electrical communication with a feedthrough terminal of the detonator, and a ground contact plate configured to be in electrical communication with a ground terminal of the detonator, the ground contact plate being in electrical communication with an inner surface of the gun housing. The end connector may include a conductive end contact. A signal relay wire may be provided in electrical communication with the feedthrough contact plate and the conductive end contact. The detonator holder may extend through the centralizer and may be mechanically coupled to the centralizer. The centralizer may be configured to engage with an inner surface of the gun housing.

[0014] An exemplary embodiment of a detonator holder for use in a perforating gun may include a detonator holder cap, a detonator holder stem extending from the detonator holder cap along a longitudinal axis, a detonator holder bore extending through the detonator holder stem, a ground plate slot formed in the detonator holder, a ground contact plate having a first portion disposed within the detonator holder cap and a second portion extending through the ground plate slot, a feedthrough plate slot formed in the detonator holder; and a feedthrough contact plate having a first portion disposed within the detonator holder cap and a second portion extending through the feedthrough plate slot.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] A more particular description will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments thereof and are not therefore to be considered to be limiting of its scope, exemplary embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0016] FIG. l is a side elevation view of an exemplary embodiment of a perforating gun in accordance with an aspect of the disclosure;

[0017] FIG. 2 is a perspective view of the perforating gun shown in FIG. 1;

[0018] FIG. 3 is a perspective view of an assembly of a centralizer and a detonator holder, shown with a detonator in accordance with an aspect of the disclosure; [0019] FIG. 4A is a perspective view of various sizes of centralizers that can be used with the detonator holder shown in FIG. 3 in accordance with an aspect of the disclosure;

[0020] FIG. 4B shows cutaways of three sizes of perforating guns using the various sizes of centralizers and detonator holder shown in FIG. 4A in accordance with an aspect of the disclosure;

[0021] FIG. 5 is an exploded assembly view of the centralizer, detonator holder, and detonator shown in FIG. 3;

[0022] FIG. 6 is a perspective view of an internal gun assembly according to an exemplary embodiment;

[0023] FIG. 7 is a perspective view of the internal gun assembly shown in FIG. 6, shown with a detonator according to an aspect of the disclosure;

[0024] FIG. 8 is another perspective view of the internal gun assembly shown in FIG. 6;

[0025] FIG. 9 is a perspective view of an internal gun assembly according to an exemplary embodiment;

[0026] FIG. 10 is a perspective view of an internal gun assembly according to an exemplary embodiment;

[0027] FIG. 11 is a cross section of an exemplary embodiment of a shaped charge holder, detonator holder, and centralizer in accordance with an aspect of the disclosure;

[0028] FIG. 12 is a perspective view of an arrangement of certain components within a detonator holder in accordance with an aspect of the disclosure;

[0029] FIG. 13 is a perspective view of a shaped charge holder and shaped charge in accordance with an aspect of the disclosure;

[0030] FIG. 14 is a perspective view of a shaped charge holder and shaped charge in accordance with an aspect of the disclosure;

[0031] FIG. 15 is a perspective view of a shaped charge holder and shaped charge in accordance with an aspect of the disclosure;

[0032] FIG. 16 is a perspective view of an assembly of a centralizer and a detonator holder according to an exemplary embodiment;

[0033] FIG. 17 is a perspective, cutaway view of an exemplary embodiment of a perforating gun in accordance with an aspect of the disclosure; [0034] FIG. 18 is a side, cutaway view of the perforating gun shown in FIG. 17;

[0035] FIG. 19 is a side view an exemplary embodiment of a bulkhead electrical feedthrough in accordance with an aspect of the disclosure;

[0036] FIG. 20 is a perspective view of an exemplary embodiment of an internal gun assembly and a bulkhead in accordance with an aspect of the disclosure;

[0037] FIG. 21 is a perspective cutaway view of an exemplary embodiment of a modular platform perforating gun system according to an aspect of the disclosure;

[0038] FIG. 22 is a perspective cutaway view of an exemplary embodiment of a modular platform perforating gun system according to an aspect of the disclosure;

[0039] FIG. 23 is a perspective cutaway view of an exemplary embodiment of a modular platform perforating gun system according to an aspect of the disclosure;

[0040] FIG. 24 is a side cutaway view of the exemplary embodiment of a modular platform perforating gun system shown in FIG. 23;

[0041] FIG. 25 shows perspective views of an exemplary embodiment of a detonator according to an aspect of the disclosure; and

[0042] FIGS. 26 and 27 are perspective views of an exemplary embodiment of an initiator head according to an aspect of the disclosure.

[0043] Various features, aspects, and advantages of the exemplary embodiments will become more apparent from the following detailed description, along with the accompanying drawings in which like numerals represent like components throughout the figures and detailed description. The various described features are not necessarily drawn to scale in the drawings but are drawn to aid in understanding the features of the exemplary embodiments.

[0044] The headings used herein are for organizational purposes only and are not meant to limit the scope of the disclosure or the claims. To facilitate understanding, reference numerals have been used, where possible, to designate like elements common to the figures.

DETAILED DESCRIPTION

[0045] Reference will now be made in detail to various exemplary embodiments. Each example is provided by way of explanation and is not meant as a limitation and does not constitute a definition of all possible embodiments. It is understood that reference to a particular “exemplary embodiment” of, e.g., a structure, assembly, component, configuration, method, etc. includes exemplary embodiments of, e.g., the associated features, subcomponents, method steps, etc. forming a part of the “exemplary embodiment”.

[0046] For purposes of this disclosure, the phrases “devices,” “systems,” and “methods” may be used either individually or in any combination referring without limitation to disclosed components, grouping, arrangements, steps, functions, or processes.

[0047] A modular perforating gun platform and system according to the exemplary embodiments discussed throughout this disclosure may generally include, without limitation, separate and variously connectable or interchangeable (i.e., modular) perforating gun components. The modular components may include size-independent components configured for use with all variants of variable components, each variable component having variants for particular applications and configured for use with the size-independent component(s).

Variants may have varying dimensions, geometries, structures, etc. However, each modular component may include standard features and structures (i.e., a platform) for, without limitation, connecting together in various configurations for particular applications.

[0048] The application incorporates by reference the following pending patent application in its entirety, to the extent not inconsistent with or incompatible with the present disclosure: U.S. Provisional Patent Application No. 63/166,720, filed March 26, 2021.

[0049] With reference now to FIG. 1 and FIG. 2, an exemplary embodiment of a perforating gun 102 and perforating gun system, as discussed throughout this disclosure, includes a housing 104 with a housing first end 106 and a housing second end 108. Each of the housing first end 106 and the housing second end 108 may include inner threads 206 for connecting to, without limitation, a tandem seal adapter 112 as shown in FIG. 1, or other wellbore tools or tandem/connector subs. In an aspect, the housing first end 106 may connect to the tandem seal adapter 112 that is configured for connecting to each of the housing first end 106 of the perforating gun 102, and a housing second end of an adjacent perforating gun, thus connecting adjacent housings/perforating guns and sealing, at least in part, each housing from an external environment and from each other.

[0050] In other embodiments, a housing may have a male connection end at a housing first end. The male connection end may have an external threaded portion corresponding to and configured for connecting to the inner (i.e., female) threads 206 of the housing second end 108. The connection between the male connection end external threads and the internal threads 206 of the housing second end 108 may connect adjacent housings/perforating guns. A tandem seal adapter may not be required or used between adjacent housings with respective male and female connecting ends, or may be an internal, baffle-style tandem seal adapter. In other embodiments, each of the housing first end 106 and the housing second end 108 may have external threads for connecting to other tandem/connector subs or adjacent wellbore tools, as applications dictate. A perforating gun housing including respective male and female connecting ends may be such as disclosed in United States Patent No. 10,920,543 issued February 16, 2021, which is commonly owned by DynaEnergetics Europe GmbH and incorporated by reference herein, to the extent not incompatible or inconsistent with this disclosure. An internal, baffle-style tandem seal adapter may be such as disclosed in United States Patent No. 10,844,697 issued November 24, 2020, which is commonly owned by DynaEnergetics Europe GmbH and incorporated by reference herein, to the extent not incompatible or inconsistent with this disclosure

[0051] With reference back to FIG. 1, one or more scallops 110 may be positioned along the exterior surface of the housing 104 and aligned with shaped charges positioned within an interior of the housing 104. Scallops 110 are well known as portions of a perforating gun housing at which the housing 104 has, e.g., a reduced thickness and/or additional machining to prevent potentially damaging burrs from forming when the shaped charge fires through the housing 104. Accordingly, perforating guns incorporating a housing with scallops 110 such as those shown in FIG. 1 must lock or otherwise ensure that an orientation of the shaped charges within the housing aligns with the scallops 110, if the scallops 110 are to be used.

[0052] With additional reference to FIG. 2, the exemplary embodiments include a detonator 202 retained in a detonator holder or sleeve 204 that is positioned within the housing 104 and at or near the housing second end 108. For purposes of this disclosure, the phrase “at or near” and other terms/phrases describing, for example, a position, proximity, dimension, geometry, configuration, relationship, or order, are used to aid in understanding the exemplary embodiments and without limitation to, e.g., particular boundaries, delineations, ranges or values, etc., unless expressly provided. Further, the phrase “housing second end" may be used interchangeably with the phrase “housing detonator end” with reference to an end of the housing 104 at which the detonator 202 is positioned or nearest in an assembled perforating gun 102, to aid in understanding, e.g., the position and relationship between components.

[0053] With additional reference to FIG. 3, FIG. 4A, FIG. 4B, FIG. 5, FIG. 6, and FIG. 7, the detonator holder 204 is retained and centralized within the housing 104 by a centralizer 302. The exemplary centralizer 302 as shown in, for example, FIGS. 3-5, has a ring 304 encircling a centralizer body such as an axially oriented center tube 320. The center tube 320 may define a centralizer bore such as a center tube passage 506 extends through the center tube 320. The center tube 320 may receive a detonator holder stem 514 of the detonator holder 204. In other words, the centralizer 302 may be slid over the detonator holder stem 514 to adjoin a cap 516 of the detonator holder 204. The detonator holder stem 514 may extend from the detonator holder cap 516 along a longitudinal axis.

[0054] With specific reference to FIG. 3 and FIG. 5, the detonator holder 204 includes a relay wire channel 318 and two locking tabs 312 extending axially along the detonator holder stem 514. A signal relay wire 816 (FIG. 8) is routed out of the detonator holder 204 via the relay wire channel 318. When the centralizer 302 is slid over the detonator holder stem 514, such that the detonator holder 204 extends through the centralizer 302, the center tube 320 covers the relay wire channel 318 to hold the signal relay wire 816 in place. The center tube 320 includes a relay signal outlet 316 for the relay wire channel 318, thereby allowing the signal relay wire 816 to pass through. The center tube 320 includes tab locking structures 314 for positively locking against the locking tabs 312, to hold the detonator holder 204 in the centralizer 302. In other words, the detonator holder 204 may be mechanically coupled to the centralizer 302.

[0055] With reference specifically to FIG. 4A and FIG. 4B, the detonator holder 204 according to the exemplary embodiments is, in an aspect, a component that is configured for use with, e.g., a variety of centralizers 302a, 302b, 302c. Each of the centralizers 302a, 302b, 303c is correspondingly configured for use with the detonator holder 204. For example, each of the centralizers 302a, 302b, 302c will assemble to the detonator holder 204, and position the detonator holder 204 within a perforating gun housing 104a, 104b, 104c, in a similar manner.

In an exemplary modular perforating gun platform and without limitation, each of the centralizers 302a, 302b, 302c may be configured, i.e., dimensioned, for use with a particular perforating gun size. The detonator holder 204 and a corresponding centralizer may be used for each of gun sizes (i.e., housing internal diameters) 3.5” (104a, 302a), 3 1/8” (104b, 302b), and 2 ¾” (104c, 302c). For example, a corresponding centralizer 302a, 302b, 302c may have an outer diameter at the ring 304 that is substantially equal to the housing internal diameter. For purposes of this disclosure, “substantially equal” is used, without limitation, to aid in the understanding of the exemplary embodiments in which, for example, the inner diameter of the housing 104 provides a barrier against the centralizer 302 to prevent the centralizer 302 from tilting or radial misalignment. In an aspect, parts configured for particular gun sizes may be color coded to enhance a production process, while using a detonator holder 204 with each size variant may improve production logistics. For example, size-independent parts such as the detonator holder 204 may be a first color such as yellow. Parts corresponding to a 3.5” gun size system (e.g., centralizer 302a) may be a second color such as cyan, parts for a 3 1/8” gun size system (e.g, centralizer 302b) may be third color such as blue, and parts for a 2 ¾” gun size system (e.g., centralizer 302c) may be a fourth color such as green.

[0056] With additional reference to FIG. 6, the ring 304, in an aspect, is connected to the center tube 320 by spokes 306, thereby forming open areas 308 that add to the free gun volume (i.e., volume not occupied by a physical component within the housing 104) when the centralizer 302 is positioned within the housing 104.

[0057] With reference to FIG. 5, FIG. 6, and FIG. 7, the detonator holder 204 receives and houses the detonator 202 in a first detonator holder end. In an aspect, inserting the detonator 202 into the detonator holder 204 automatically makes various wireless electrical connections between electrical contacts on the detonator 202 and corresponding electrical contacts on the detonator holder 204, as explained further below. For purposes of this disclosure, “wireless electrical connection” means an electrical connection formed by physical contact between conductive components, without any wires electrically connecting the conductive components. “Electrical contact” means either a conductive component for making a wireless electrical connection, or a state of physical, conductive contact between conductive components, as the context makes clear.

[0058] In an aspect and as illustrated in FIG. 5 and FIG. 6, the detonator holder 204 includes a feedthrough contact plate 502 positioned and exposed within the detonator holder cap 516. The feedthrough contact plate 502 includes one or more feedthrough contact pins 604 for establishing electrical communication with a feedthrough terminal of the detonator. The multiple feedthrough contact pins 604 may provide redundancy to insure a stable connection to the feedthrough terminal of the detonator. The feedthrough contact plate may include a first portion disposed within the detonator holder cap 516 and a second portion extending through the feedthrough plate slot 510.

[0059] A ground contact plate 504 is also positioned within the detonator holder cap 516 and includes one or more ground contact pins 602 for establishing electrical communication with a ground terminal of the detonator. The ground contact plate 504 may include a first portion disposed within the detonator holder cap 516 and a second portion extending through the ground plate slot 512. The second portion of the ground contact plate 504 may be configured to provide an electrical path to ground, and may be in electrical communication with an inner surface of the gun housing 104.

[0060] Sliding the centralizer 302 over the detonator holder stem 514 secures each of the feedthrough contact plate 502 and the ground contact plate 504 in position within a respective feedthrough plate slot 510 and ground contact ground plate slot 512 formed in the detonator holder 204. The feedthrough contact plate 502 and the ground contact plate 504 are secured by corresponding contact plate securing structures 508 on the centralizer 302. The contact plate securing structures 508 are configured, i.e., positioned and dimensioned, to cover the feedthrough plate slot 510 and the ground contact ground plate slot 512 when the centralizer 302 adjoins the detonator holder cap 516. In an aspect, the feedthrough contact plate 502 is completely covered by the contact plate securing structure 508, and not exposed to another outside surface or body above the feedthrough plate slot 510. Accordingly, the need for a protective shield component for isolating the feedthrough contact plate 502 may be eliminated. In another aspect and as illustrated in FIG. 7, the ground contact plate 504 extends out of the detonator holder 204 through a gap 702 between the contact plate securing structures 508, and is configured for making grounding contact with the housing 104 when the centralizer 302 and detonator holder 204 are received within the housing 104. The feedthrough contact plate 502 and ground contact plate 504 are not limited to the “plate” configuration of the exemplary embodiments and may respectively take any form, configuration, shape, etc. consistent with this disclosure. With specific reference to FIG. 3, FIG. 6, and FIG. 7, the detonator 202 according to the exemplary embodiments includes a detonator alignment key 310 for properly orienting the detonator 202 within the detonator holder 204. The detonator alignment key 310 is positionable within a key slot 606 in the detonator holder 204, to orient the detonator 202 within the detonator holder 204. The centralizer 302 includes a centralizer alignment key 704 for orienting the detonator holder 204 and the detonator 202 within the housing 104. In an aspect, the detonator 202 includes an orientation sensor. Thus, the orientation of the detonator 202 within the housing 104 must be properly established as a reference for the orientation sensor to correctly determine whether the perforating gun 102 is in a desired orientation within the wellbore. [0061] In various aspects, the detonator 202, detonator holder 204, and centralizer 302 may individually and via their interaction provide a relatively short assembly for positioning the detonator 202 within the housing 104, as discussed further below. Thus, the overall length of the perforating gun 102 may be reduced, and more perforating guns connected as part of a tool string and deployed during one perforation run into the wellbore, because, e.g., perforating gun tool string length may be limited by the cable strength, and rig-up height at the well surface. [0062] With reference to FIG. 8, FIG. 9, and FIG. 10, an exemplary internal gun assembly 802 that is positioned within the housing 104 of the perforating gun 102 includes shaped charges 804 respectively received and retained in corresponding shaped charge holders 806 that are connected together in a chain 812. For the sake of this disclosure, a charge holder module may be considered to be either a single shaped charge holder 806 or the chain 812 of multiple shaped charge holders. The charge holder module may be coupled to the detonator holder coupling at a first end of the charge holder module. Each shaped charge 804 may be configured to form a perforation tunnel in a well, and may include a shaped charge case that forms a hollow cavity. Each shaped charge 804 typically includes an explosive load, for example positioned in the cavity of the shaped charge case. In some embodiments, the explosive load is disposed within the hollow cavity of the shaped charge case, and a liner is disposed adjacent to the explosive load (for example with the explosive load disposed between the liner and the shaped charge case). The liner may be configured to retain the explosive load in the hollow cavity of the shaped charge case. Some shaped charge 804 embodiments may also include a shaped charge inlay, which may be disposed on top of at least a portion of the liner (e.g. such that at least a portion of the liner is between the inlay and the explosive load). Each shaped charge 804 is typically configured to form a perforating jet for creating perforation holes in a target (e.g. the casing and/or rock formation of the well). Further details regarding shaped charges 804 are described in U.S. Application Serial No. 17/383,816. Filed July 23, 2021, and U.S. Patent No. 11,053,782, issued July 6, 2021, which are hereby incorporated by reference in their entirety to the extent not inconsistent or incompatible with this disclosure.

[0063] The detonator holder 204 is connected via the detonator holder stem 514 to a shaped charge holder 806 at a first end of the shaped charge chain 812. To aid in understanding the exemplary embodiments, this disclosure may refer to the detonator holder 204 and the centralizer 302 together, without limitation, as a detonator end assembly 810 of the internal gun assembly 802. In an aspect, the centralizer 302 includes one or more fins 818 extending radially outwardly from an exterior of the center tube 320, for contacting and pressing against an inner surface 1702 (FIG. 17) of the housing 104 to prevent axial movement of the centralizer 302 and thereby the internal gun assembly 802 within the housing 104. A conductive end connector 808 is connected to a shaped charge holder 806 at a second end of the shaped charge chain 812, opposite the first end.

[0064] In an aspect, the detonator end assembly 810 is configured for connecting to a component of the internal gun assembly 802 and being housed, as part of the internal gun assembly 802, within the housing 104. According to the exemplary embodiments, the detonator end assembly 810 is configured for connecting to the shaped charge holder 806 at the first end of the shaped charge chain 812. In other embodiments, the detonator end assembly 810 may connect to another component of the internal gun assembly 802, such as a spacer (not shown) configured for, e.g., connecting to components of the internal gun assembly 802 according to the exemplary embodiments.

[0065] A detonating cord 814 extends from the detonator holder 204 within which it is positioned and held in sufficiently close proximity (i.e., “ballistic proximity”) to the detonator 202, or a ballistic transfer such as a booster in ballistic proximity to each of the detonator 202 and the detonating cord 814, such that the detonating cord 814 will initiate in response to the detonator 202 initiating. The detonating cord 814 exits the detonator holder 204 via a detonating cord channel 1004 which extends into the detonator holder 204 in a configuration that provides the ballistic proximity between a portion of the detonating cord 814 that is within the detonating cord channel 1004 within the detonator holder 204. In the exemplary embodiments, without limitation, the detonating cord channel 1004 is adjacent to a detonator bore 1106 (FIG. 11) within which the detonator 202 is housed as explained further below.

[0066] The detonating cord 814 extends along the shaped charge chain 812 and connects to each shaped charge holder 806 at a cord clip 820 that holds the detonating cord 814 in position for initiating the shaped charge 804. The detonating cord 814 is ultimately held by a terminal cord retainer 902 that serves to hold the detonating cord 814 at or near an end of the detonating cord 814 and to keep the detonating cord 814 from interfering with the assembly, or insertion into the housing 104, of the internal gun assembly 802. In the exemplary embodiment, the terminal cord retainer 902 is a blind cylindrical container on the conductive end connector 808, but may take any form consistent with this disclosure. [0067] The signal relay wire 816 extends via the relay wire channel 318 out of the detonator holder 204, within which it is positioned and held in electrical contact with the feedthrough contact plate 502 or an electrical relay in electrical contact with each of the feedthrough contact plate 502 and the signal relay wire 816. In an exemplary embodiment, the signal relay wire 816 may be in electrical communication with the second portion of the feedthrough contact plate 502. The signal relay wire 816 extends along the shaped charge chain 812 and is routed through cord slots 822 on each shaped charge holder 806. The signal relay wire 816 extends to the conductive end connector 808 and relays and electrical signal between the feedthrough contact plate 502 and the conductive end connector 808. The signal relay wire 816 is inserted, via a relay wire slot 1002, into the conductive end connector 808, and positioned in electrical contact with a conductive end contact 1006 that is also positioned within the conductive end connector 808.

[0068] With reference to FIG. 11, a cross-section of the detonator holder 204, among other things, is shown. The signal relay wire 816 is positioned in the relay wire channel 318 that extends to the feedthrough plate slot 510, and a feedthrough contact plate leg 1102 of the feedthrough contact plate 502 extends into or adjacent to the relay wire channel 318. In an aspect, the signal relay wire 816 may be welded to the feedthrough contact plate leg 1102. The detonating cord 814 enters the detonator holder 204 via the detonating cord channel 1004 which extends into the detonator holder 204 in a position that puts the detonating cord 814 in ballistic proximity to an explosive portion 1104 of the detonator 202.

[0069] FIG. 12 shows an arrangement of certain components within the detonator holder 204, in isolation. The detonator explosive portion 1104 is in ballistic proximity to the detonating cord 814, and the signal relay wire 816 is connected to the feedthrough contact plate leg 1102. [0070] With reference to FIG. 13, FIG. 14, and FIG. 15, an exemplary shaped charge holder 806 for use with the modular perforating gun platform is shown. Like the detonator holder 204 and the centralizer 302, the shaped charge holder 806 may be color coded according to the gun size with which it is used. The shaped charge holder 806 may include a shaped charge holder body 1314 defining a shaped charge holder receptacle 1316 in which the shaped charge 804 is inserted. One or more alignment posts 1320 may guide and orient the shaped charge 804 in the shaped charge holder receptacle 1316. One or more retention clips 1304 may extend from the shaped charge holder body 1314, in a direction that is away from the shaped charge holder receptacle 1316, and may be resilient to move out of the way when the shaped charge 804 is inserted. The retention clip(s) 1304 may be configured to move back into place once the shaped charge 804 is inserted and may be configured, i.e., positioned and dimensioned, to extend above a height of the shaped charge 804 positioned within the shaped charge holder receptacle 1316. The one or more retention clips 1304 may each include a retention tab 1318 that snaps into a depression or divot formed in the external surface of a case 1306 of the shaped charge 804, to retain the shaped charge 804 within the shaped charge holder receptacle 1316.

[0071] The shaped charge holder 806 may have a male connecting side 1302 for connecting to e.g., an adjacent shaped charge holder 806, the detonator holder 204, or an additional component, such as a spacer, of the internal gun assembly 802. The connections may be standardized between different components. The male connecting side 1302 may include a knob connector 1308 that may be a cylindrical extension and include an area of increased diameter at its top, and a slit 1310 extending along its length. The area of increased diameter and the slit 1310 provide a structure and resiliency for the knob connector 1308 to engage and positively lock against a corresponding structure formed within, e.g., a central bore 1404 of a female connecting side 1402 opposite the male connecting side 1302. The male connecting side 1302 may include phasing protrusions 1312 that may fit within phasing holes 1406 arranged around the female connecting side 1402, such that adjacent shaped charge holders 806 (or other components) may be oriented at a desired phasing relative to one another by “clocking” (i.e., rotating) adjacent shaped charge holders through the different positions, such as numbers arranged around a clock face, corresponding respectively to different phasing.

[0072] As shown in FIG. 16, the detonator holder 204 may also include a central bore 1404 and two or more phasing holes 1406 for connecting to the male connecting side 1302 of a shaped charge holder 806. In other words, the phasing holes 1406 provided in the detonator holder 204 may be a detonator holder coupling provided at a second end of the detonator holder 204. The central bore 1404 may serve as a detonator holder bore extending through the detonator holder stem and configured to receive at least a portion of the detonator.

[0073] The cord clip 820 for holding the detonating cord 814 in position for initiating the shaped charge 804 may include oppositely disposed retention arms 1506 that form a detonating cord receptacle 1508 contoured for retaining the detonating cord 814 in a manner to increase the locking force on the detonating cord 814 as the phasing between adjacent charge holders increases. For example, each oppositely disposed retention arm 1506 includes a shaped sidewall portion 1510 and a corresponding flange 1512 extending transversely from a top section of the retention arm 1506.

[0074] The shaped charge holder 806 may have a cage structure in which portions of the shaped charge holder 806 are configured with cage bars 1502 with cage voids 1504 between the cage bars 1502, rather than fully solid pieces. For example, the shaped charge holder 806 may be configured without solid wall elements, to increase free gun volume. The cage structure may impart a high mechanical strength while increasing the amount of free volume (without limitation, by up to 30% or more) within the housing 104 and decreasing the amount of material required to form the shaped charge holder 806. Injection molding processes may run more efficiently, and the final product given increased mechanical strength, when a single part is broken up into separate parts with their own thickness. In addition, smaller portions may have a decreased cool-down time, which may benefit injection molding production capacity. [0075] The shaped charge holder 806 may further include one or more relay wire clips 1514 (e.g. also termed cord slots 822, in FIG. 8) extending transversely from the detonating cord receptacle 1508. The relay wire clip 1514 may be configured to hold the signal relay wire 816 as it is routed across the shaped charge holders 806. The internal gun assembly 802 may therefore provide additional flexibility in assembling the internal gun assembly 802 because each of the detonating cord 814 and the signal relay wire 816 may be connected to the shaped charge holders 806 after the detonator end assembly 810, shaped charge holders 806, and conductive end connector 808 are assembled together. For example, the detonator end assembly 810 may be provided assembled with the signal relay wire connected to the feedthrough contact plate 502 and extending out of the detonator end assembly 810, and the shaped charges 804 connected to the detonator end assembly 810, each other, and the conductive end connector 808. The signal relay wire 816 and the detonating cord 814 may then be connected to each shaped charge holder 806 as discussed above (the detonating cord 814 may first be inserted into the detonating cord channel 1004), and then inserted respectively into the relay wire slot 1002 and terminal cord retainer 902, because each connection (except for the signal relay wire connection to the feedthrough contact plate 502) is exposed for connections. Increased mechanical strength of the shaped charge holders 806 may also eliminate the need to place the shaped charges 804 in the shaped charge holders 806 before the detonating cord 814 and signal relay wire 816 are connected. [0076] With reference to FIG. 17, FIG. 18, FIG. 19, and FIG. 20, and the exemplary embodiments shown therein, the internal gun assembly 802 is received within the gun housing 104. According to an aspect, the internal gun assembly 802 is housed within the housing 104. The centralizer 302 and the detonator holder 204 (i.e., the detonator end assembly 810) is positioned nearest the housing second end 108 (i.e., the housing detonator end 108). The tandem seal adapter 112 is connected to the housing first end 106. Fins 818 on the centralizer 302 may contact and press against the housing inner surface 1702 to lock the internal gun assembly 802 in position within the housing 104. In an aspect, the fins 818 contact a portion of the housing inner surface 1702 that is not machined and therefore has a relatively rough texture. The rough texture may aid in, e.g., preventing axial movement of the fins 818 and thereby the internal gun assembly 802. In an aspect, the ground contact plate 504 may extend to make grounding contact with the housing inner surface 1702 at a machined portion of the surface, which may be required for effective grounding contact. In an aspect, the internal gun assembly 802 may be assembled as discussed above and inserted into the housing 104 as a modular piece, locked in position by the fins 818, and therefore able to be delivered assembled and wired, to, e.g., a wellbore site, where the detonator 202 is inserted into the detonator holder 204 and electrical connections made by connecting the housing second end 108 to, without limitation, a tandem seal adapter connected to an adjacent perforating gun, as discussed further below. The centralizer alignment key 704 may be received by a centralizer key slot 1704 formed in the housing inner surface 1702, to orient the internal gun assembly 802 within the housing 104. In other words, the centralizer 302 may be engaged with the inner surface of the gun housing 104 via the centralizer alignment key 704. Alternatively, the centralizer 302 may be engaged with the inner surface of the gun housing 104 via contact between the centralizer ring 304 and the inner surface of the gun body 104.

[0077] In the exemplary embodiments, the tandem seal adapter 112 includes a tandem seal adapter bore 1802 extending through the tandem seal adapter 112. A bulkhead 1804 is sealingly received within the tandem seal adapter bore 1802. The bulkhead 1804 includes a bulkhead body 1806 that may be in contact with an inner circumferential surface bounding the tandem seal adapter bore 1802 within the tandem seal adapter 112. The bulkhead 1804 may further include one or more sealing assemblies 1808 positioned on the bulkhead body 1806 and in contact with the inner circumferential surface and forming a seal between the bulkhead body 1806 and the inner circumferential surface. For example, as shown in the exemplary embodiment, the sealing assembly 1808 may include one or more sealing mechanisms, such as elastomeric o-rings, respectively positioned in corresponding recesses on the bulkhead body 1806 and compressed against the inner circumferential surface. The sealing assembly 1808 may alone, or in combination with the bulkhead body 1806, seal the tandem seal adapter bore 1802, to isolate the interior of the housing 104 from, e.g., pressure or fluid from an interior of an adjacent, connected perforating gun housing. In addition, sealing assemblies 1808 on the tandem seal adapter 112 may create a seal against the housing inner surface 1702 at the housing first end 106, to seal the interior of the housing 104 from, e.g., wellbore fluid or other materials in the environment outside of the housing 104.

[0078] The bulkhead body 1806 houses at least a portion of a bulkhead electrical feedthrough 1904 for relaying electrical signals, such as an addressable detonation signal, a diagnostic signal, and the like, between respective electrical connections in adjacent perforating guns. The bulkhead electrical feedthrough 1904 may include, for example and as illustrated in FIG. 19, a first pin connector 1902 and a second pin connector 1906. The first pin connector 1902 may be positioned and dimensioned (i.e., configured) such that when the tandem seal adapter 112 is connected to the housing 104, the first pin connector 1902 is automatically placed in electrical contact with the conductive end contact 1006, at an end of the first pin connector 1902. The conductive end contact 1006 and/or the first pin connector 1902 may be in electrical contact with the signal relay wire 816 which may be inserted into a connecting hole 1908 on the conductive end contact 1006 or otherwise in electrical contact therewith, by known techniques. The second pin connector 1906 may be in electrical contact with an electrical connector in an adjacent perforating gun 102, as described below, at an end of the second pin connector.

[0079] FIG. 19 shows an interior of the bulkhead body 1806. The bulkhead electrical feedthrough 1904 may further include a first spring connector 1910 biasing the first pin connector 1902 towards the conductive end contact 1006. The first spring connector 1910 may be conductive and relay a signal from the first pin connector 1902 to a first intermediate conductive body 1914 within the bulkhead body 1806, and the first intermediate conductive body 1914 may be electrically connected to, or integrally formed with, a second intermediate conductive body 1916. Positioned adjacent to and in contact with the first intermediate conductive body 1916, and within the second intermediate conductive body 1916, may be a second spring connector 1912 biasing the second pin connector 1906 in a direction opposite the first pin connector 1902. The second spring connector 1912 is similarly conductive such that the first pin connector 1902 and the second pin connector 1906 are in electrical communication. In other embodiments, a solid piece of conductive metal may connect the first pin connector 1902 and the second pin connector 1906. In still other embodiments, the second intermediate conductive body 1916 may provide the electrical connection between the first pin connector 1902 and the second pin connector 1906. In embodiments in which the bulkhead electrical feedthrough 1904 includes a solid piece of conductive metal forming the first pin connector 1902, the second pin connector 1906, and an intermediate body, electrical contacts with which the pin connectors 1902, 1906 are in electrical contact within the perforating gun housings may be spring loaded.

[0080] In an aspect, the tandem seal adapter 112, bulkhead 1804, detonator holder 204, and detonator 202 are collectively configured and positioned such that when the tandem seal adapter 112 is connected to a housing detonator end 108 of an adjacent housing, the second pin connector 1906 of the bulkhead electrical feedthrough 1904 automatically makes wireless electrical contact with a line-in contact of the detonator 202. The detonator line-in contact receives the electrical signal that is relayed from the conductive end connector 808, through the bulkhead electrical feedthrough 1904.

[0081] Features and functions of the tandem seal adapter 112 and the bulkhead 1804 may be according to those disclosed in United States Patent No. 10,844,697 issued November 24, 2020, which is commonly owned by DynaEnergetics Europe GmbH and incorporated by reference herein, to the extent not incompatible or inconsistent with this disclosure.

[0082] FIG. 21 shows a modular platform perforating gun system according to the exemplary embodiments, in this case implemented with an alignment sub 2102 that functions according to the general principles of the exemplary tandem seal adapter 112 discussed above but also allows for adjacent housings to be oriented with respect to one another. In the exemplary embodiment shown in FIG. 21, each of the shaped charges 804 of the internal gun assembly 802 is pointing in the same direction, representing a zero-degree phasing.

[0083] FIG. 22 shows a modular perforating gun platform system according to the exemplary embodiments applied to a perforating gun having single shaped charge holder 806 positioned within a housing 104 including a housing detonator end 108 with internal threads 206 and a housing male end 2208 including external threads 2204 for connecting to an alignment sub 2206. The centralizer 302 and shaped charge holder 806 are green to indicate that the housing is a 2 ¾” housing 104c. In the exemplary embodiment shown in FIG. 22, a shortened bulkhead 2202 is used. The shortened bulkhead 2202 may be shorter in an axial direction but otherwise similar in form and function to the bulkhead 1804 discussed above. The shortened bulkhead 2202 includes a bulkhead electrical feedthrough including, among other things, second pin connector 1906. The shortened bulkhead 2202 may be used where, e.g., the perforating gun design including a tandem seal adapter or sub is dimensioned for a bulkhead with a shorter axial length than the exemplary bulkhead 1804 discussed with respect to, e.g., FIG. 17 and FIG. 18.

[0084] In an aspect, the shaped charge holder 806 includes two retention tabs 1318 for retaining a shaped charge in the shaped charge holder 806.

[0085] FIG. 22 further shows how, in an aspect, conductive end connector 808 includes a knob connector 1308 for connecting the conductive end connector 808 to the central bore 1404 of the shaped charge holder female connecting side 1402, and thereby the shaped charge holder 806.

[0086] With reference to FIG. 23 and FIG. 24, the exemplary modular perforating gun platform system is shown applied to a perforating gun having a two-piece tandem seal adapter 2302. In an aspect, the exemplary embodiment of FIG. 23 and FIG. 24 also includes the shortened bulkhead 2202 with bulkhead electrical feedthrough including second pin connector 1906.

[0087] With reference to FIG. 25, FIG. 26, and FIG. 27, an exemplary embodiment of a detonator 202, such as an orienting detonator, for use with the exemplary modular platform perforating gun system is shown. FIG. 25 and FIG. 26 show, among other things, an exemplary embodiment of an initiator head 2502. The initiator head may include an initiator head housing 2602, a circuit board 2604, a line-in terminal 2504, a feedthrough (or, “line-out”) terminal 2506, a ground terminal 2508, an initiator stem 2606, and a fuse 2608.

[0088] The initiator head housing 2602 may be formed of an insulating material, by, e.g., molding, 3D-printing, additive manufacturing, subtractive manufacturing, or any other suitable method. The initiator head housing 2602 may include a first housing piece 2510 and a second housing piece 2512 engaged together by a latch 2514. The initiator head housing 2602 may define an interior space within the first housing piece 2510 and the second housing piece 2512 within which the circuit board 2604 is positioned. Alternatively, the initiator head housing 2602 may be an integral or monolithic piece molded or additively manufactured around the circuit board 2604.

[0089] A through hole 2516 in the first housing piece 2510 may be structured to expose the line-in terminal 2504 to an exterior of the initiator head housing 2502. The second housing piece 2512 may include contact through holes 2518 structured to expose the feedthrough terminals 2506 and the ground terminals 2508 to an exterior of the initiator head housing 2502. The line-in terminal 2504, the feedthrough terminals 2506, the ground terminals 2508, and the fuse 2608 may be in electrical communication with the circuit board 2604. The line-in terminal 2504 may be provided on an opposite side of the circuit board 2604 from the feedthrough terminals 2506 and the ground terminals 2508. The circuit board 2604 may further include surface mounted components such as a temperature sensor, an orientation sensor, a safety circuit, a capacitor, and the like. Readings from one of these components may be used by a microprocessor on the circuit board 2604 to determine when it is appropriate to activate the fuse 2608 to detonate the detonator 202.

[0090] The fuse 2608 may be positioned within a hollow interior of the initiator stem 2606. The initiator stem 2606 may be received within a hollow initiator shell 2520 and crimped therein. The detonator explosive portion 1104 may be an explosive load positioned within the hollow initiator shell 2520 and configured for initiation by the fuse 2608. With reference back to FIG. 11, the hollow initiator shell 2520 is received within the detonator bore 1106, when the detonator 202 is inserted into the detonator holder 204. The detonator bore 1106, hollow initiator shell 2520, initiator head housing 2602, and detonator holder cap 516 are together configured for the initiator head housing 2602 to be received in the detonator holder cap 516 when the detonator 202 is inserted into the detonator holder 204, including when the hollow initiator shell 2520 is pushed into the detonator bore 1106. Upon inserting the detonator 202 into the detonator holder 204, feedthrough terminals 2506 and ground terminals 2508 are respectively positioned for automatically making wireless electrical contact with the feedthrough contact pins 604 and the ground contact pins 602.

[0091] Accordingly, as discussed above, when, e.g., a pin connector such as second pin connector 1906 from a bulkhead electrical feedthrough 1904 makes wireless electrical contact with the line-in terminal 2504, an electrical signal from the bulkhead electrical feedthrough 1904 may be relayed to the circuit board 2604 which may, e.g., detonate the detonator 202 and/or relay the signal, via the feedthrough terminal(s) 2506, feedthrough contact plate 502, signal relay wire 816, and conductive end contact 1006, to a next bulkhead or electrical feedthrough assembly.

[0092] This disclosure, in various embodiments, configurations and aspects, includes components, methods, processes, systems, and/or apparatuses as depicted and described herein, including various embodiments, sub-combinations, and subsets thereof. This disclosure contemplates, in various embodiments, configurations and aspects, the actual or optional use or inclusion of, e.g., components or processes as may be well-known or understood in the art and consistent with this disclosure though not depicted and/or described herein.

[0093] The phrases "at least one", "one or more", and "and/or" are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions "at least one of A, B and C", "at least one of A, B, or C", "one or more of A, B, and C", "one or more of A, B, or C" and "A, B, and/or C" means A alone, B alone, C alone, A and B together,

A and C together, B and C together, or A, B and C together.

[0094] In this specification and the claims that follow, reference will be made to a number of terms that have the following meanings. The terms "a" (or "an") and "the" refer to one or more of that entity, thereby including plural referents unless the context clearly dictates otherwise.

As such, the terms "a" (or "an"), "one or more" and "at least one" can be used interchangeably herein. Furthermore, references to "one embodiment", "some embodiments", "an embodiment" and the like are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as "about" is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Terms such as "first," "second," "upper," "lower" etc. are used to identify one element from another, and unless otherwise specified are not meant to refer to a particular order or number of elements.

[0095] As used herein, the terms "may" and "may be" indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and/or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of "may" and "may be" indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while taking into account that in some circumstances the modified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances an event or capacity can be expected, while in other circumstances the event or capacity cannot occur - this distinction is captured by the terms "may" and "may be."

[0096] As used in the claims, the word "comprises" and its grammatical variants logically also subtend and include phrases of varying and differing extent such as for example, but not limited thereto, "consisting essentially of and "consisting of." Where necessary, ranges have been supplied, and those ranges are inclusive of all sub-ranges therebetween. It is to be expected that the appended claims should cover variations in the ranges except where this disclosure makes clear the use of a particular range in certain embodiments.

[0097] The terms "determine", "calculate" and "compute," and variations thereof, as used herein, are used interchangeably and include any type of methodology, process, mathematical operation or technique.

[0098] Reference to a “detonator holder and/or detonator” herein refers to at least one of a detonator holder and a detonator, and may be termed a detonation-related element for more convenient reference.

[0099] This disclosure is presented for purposes of illustration and description. This disclosure is not limited to the form or forms disclosed herein. In the Detailed Description of this disclosure, for example, various features of some exemplary embodiments are grouped together to representatively describe those and other contemplated embodiments, configurations, and aspects, to the extent that including in this disclosure a description of every potential embodiment, variant, and combination of features is not feasible. Thus, the features of the disclosed embodiments, configurations, and aspects may be combined in alternate embodiments, configurations, and aspects not expressly discussed above. For example, the features recited in the following claims lie in less than all features of a single disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this disclosure.

[0100] Advances in science and technology may provide variations that are not necessarily express in the terminology of this disclosure although the claims would not necessarily exclude these variations.

Claims

CLAIMS What is claimed is:

1. A system for use within a gun housing of a perforating gun, the system comprising: a centralizer comprising: a centralizer body; and a centralizer bore extending through the centralizer body; a detonator holder disposed within the centralizer bore, the detonator holder comprising: a first detonator holder end configured to receive a detonator; and a second detonator holder end comprising a detonator holder coupling; wherein the detonator holder extends through the centralizer and is mechanically coupled to the centralizer; and the centralizer is configured to engage with an inner surface of the gun housing.

2. The system of claim 1, wherein the detonator holder comprises: a detonator holder cap provided at the first detonator holder end; and a detonator holder stem extending from the detonator holder cap along a longitudinal axis; and a detonator holder bore extending through the detonator holder stem, the detonator holder bore being configured to receive at least a portion of the detonator; wherein the second detonator holder end is provided at an end of the detonator holder stem opposite the detonator holder cap.

3. The system of claim 2, further comprising: a ground plate slot formed in the detonator holder; and a ground contact plate having a first portion disposed within the detonator holder cap and a second portion extending through the ground plate slot; wherein the first portion of the ground contact plate is configured to be in electrical communication with a ground terminal of the detonator.

4. The system of claim 3, wherein the second portion of the ground contact plate is in electrical contact with the inner surface of the gun housing.

5. The system of any one of claims 2 to 4, further comprising: a feedthrough plate slot formed in the detonator holder; and a feedthrough contact plate having a first portion disposed within the detonator holder cap and a second portion extending through the feedthrough plate slot; wherein the first portion of the feedthrough contact plate is configured to be in electrical communication with a feedthrough terminal of the detonator.

6. The system of claim 5, further comprising a signal relay wire having a first end in electrical communication with the second portion of the feedthrough contact plate.

7. The system of any one of claims 2 to 6, wherein the detonator holder further comprises a locking tab protruding from the detonator holder cap, the locking tab being configured to couple with the centralizer body.

8. The system of any one of claims 1 to 7, further comprising a charge holder module coupled to the detonator holder coupling at a first end of the charge holder module, the charge holder module being configured to receive a shaped charge.

9. The system of claim 8, wherein the charge holder module comprises a shaped charge holder comprising: a first shaped charge holder coupling provided at a first end of the shaped charge holder; a second shaped charge holder coupling provided at a second end of the shaped charge holder; and a receptacle for receiving the shaped charge; wherein the first shaped charge holder coupling is configured to couple with the detonator holder coupling.

10. The system of claim 8, wherein the charge holder module comprises a plurality of shaped charge holders, each shaped charge holder of the plurality of shaped charge holders comprising: a first shaped charge holder coupling provided at a first end of the shaped charge holder; a second shaped charge holder coupling provided at a second end of the shaped charge holder; and a receptacle for receiving a first shaped charge; wherein the first shaped charge holder coupling of a first shaped charge holder of the plurality of shaped charge holders is coupled with the detonator holder coupling, and the first shaped charge holder coupling of a second shaped charge holder adjacent to the first shaped charge holder is coupled with the second shaped charge holder coupling of the first shaped charge holder.

11. The system of claim 10, wherein the first shaped charge holder coupling and the second shaped charge holder coupling are configured such that a phasing between the first shaped charge holder and the second shaped charge holder is selectable by a user.

12. The system of claim 11, wherein: the first shaped charge holder coupling comprises a protrusion; the second shaped charge holder coupling comprises a plurality of holes arranged circumferentially around a longitudinal axis; and each hole of the plurality of holes is dimensioned to receive the protrusion.

13. The system of any one of claims 8 to 12, further comprising an end connector coupled to a second end of the shaped charge module opposite the first end of the shaped charge module, the end connector comprising a conductive end contact.

14. The system of claim 13, wherein: the detonator holder further comprises a feedthrough contact plate configured to be in electrical communication with a feedthrough terminal of the detonator; and a signal relay wire is connected between the feedthrough contact plate and the conductive end contact.

15. The system of any one of claims 1 to 14, wherein: the centralizer is one of set of a plurality of centralizers; each centralizer of the plurality of centralizers has a different outer diameter configured to fit different sizes of perforating gun housings; and each centralizer of the plurality of centralizers is configured to receive the detonator holder.

16. The system of any one of claims 1 to 15, wherein the centralizer further comprises: an outer centralizer ring; and a plurality of spokes extending from the centralizer body to the outer centralizer ring; wherein the outer centralizing ring is configured to engage with the inner surface of the gun housing.

17. A perforating gun comprising: a gun housing: a centralizer disposed within the gun housing, the centralizer comprising: a centralizer body; a centralizer bore extending through the centralizer body; a detonator holder disposed within the centralizer bore, the detonator holder comprising: a first detonator holder end configured to receive a detonator; a second detonator holder end comprising a detonator holder coupling; a feedthrough contact plate configured to be in electrical communication with a feedthrough terminal of the detonator; and a ground contact plate configured to be in electrical communication with a ground terminal of the detonator, the ground contact plate being in electrical communication with an inner surface of the gun housing; a charge holder module having a first end coupled to the detonator holding coupling; an end connector coupled to a second end of the shaped charge module opposite the first end of the shaped charge module, the end connector comprising a conductive end contact; and a signal relay wire in electrical communication with the feedthrough contact plate and the conductive end contact; wherein the detonator holder extends through the centralizer and is mechanically coupled to the centralizer; and the centralizer is configured to engage with an inner surface of the gun housing.

18. The perforating gun of claim 17, wherein the centralizer further comprises: an outer centralizer ring; and a plurality of spokes extending from the centralizer body to the outer centralizer ring; wherein the outer centralizing ring is configured to engage with the inner surface of the gun housing.

19. A detonator holder for use in a perforating gun, the detonator holder comprising: a detonator holder cap; a detonator holder stem extending from the detonator holder cap along a longitudinal axis; a detonator holder bore extending through the detonator holder stem; a ground plate slot formed in the detonator holder; a ground contact plate having a first portion disposed within the detonator holder cap and a second portion extending through the ground plate slot; a feedthrough plate slot formed in the detonator holder; and a feedthrough contact plate having a first portion disposed within the detonator holder cap and a second portion extending through the feedthrough plate slot.

20. The detonator holder of claim 19, further comprising a locking tab extending from the detonator cap along the longitudinal direction, the locking tab being configured to couple with a centralizer.