Detonator with fused head retention features

Abstract

A detonator may include an outer hull and a first holder contact and a second holder contact at least partially disposed within the outer hull. The first holder contact and the second holder contact may be configured to electrically connect with a first fuse contact and a second fuse contact of a fuse head. The detonator may further include a retention feature configured to maintain a position of the first holder contact and the second holder contact with respect to the first fuse contact and the second fuse contact

Description

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 567,587 filed Mar. 20, 2024, the entire contents of which are incorporated herein by reference.BACKGROUND

[0002] Hydrocarbon extraction may include inserting a gun string or tool string into a wellbore for perforation operations. Perforating guns, or other tools used for hydrocarbon extraction, may be housed in tool segments, housings, or bodies, which are connected to adjacent tools, connectors, or sub assemblies, to form the tool string. Typically, perforation operations rely on an initiation capable material, such as primary explosive, deflagration material, or black powder, that is set off by an electronic detonator within the tool string. Fuse heads are the primary ignition source in an electronic detonator. The fuse head ignites the initiation capable material. The fuse heads of detonators are usually fixed to the internal electronic components by soldering.BRIEF SUMMARY

[0003] Some embodiments disclosed herein are directed to a detonator for use with a fuse head having a first fuse contact and a second fuse contact, the detonator comprising: an outer hull; a first holder contact and a second holder contact at least partially disposed within the outer hull, the first holder contact and the second holder contact configured to electrically connect with the first fuse contact and the second fuse contact of the fuse head; and a retention feature configured to maintain a position of the first holder contact and the second holder contact with respect to the first fuse contact and the second fuse contact.

[0004] Some embodiments disclosed herein are directed to a method for assembling a detonator, the method comprising: inserting a fuse head into a holder contact of the detonator via an opening in a fuse head holder of the detonator; coupling a retention cap to the fuse head holder of the detonator with the fuse head inserted into the holder contact; and disposing an outer hull over the retention cap and at least a portion of the fuse head holder.

[0005] Some embodiments disclosed herein are directed to a system comprising: a wellbore tool; and a detonator disposed in the wellbore tool, wherein the detonator includes: an outer hull; a first holder contact and a second holder contact at least partially disposed within the outer hull, the first holder contact and the second holder contact configured to electrically connect with a first fuse contact and a second fuse contact of a fuse head; a retention feature configured to maintain a position of the first holder contact and the second holder contact with respect to the first fuse contact and the second fuse contact

[0006] Embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical characteristics of the disclosed embodiments in order that the detailed description that follows may be better understood. The various characteristics and features described above, as well as others, will be readily apparent to those having ordinary skill in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated that this disclosure may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the disclosed embodiments. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the principles disclosed herein.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0007] A more particular description will be rendered by reference to exemplary embodiments that are illustrated in the accompanying figures. Understanding that these drawings depict exemplary embodiments and do not limit the scope of this disclosure, the exemplary embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0008] FIG. 1A illustrates a perspective view of a fuse head according to some embodiments.

[0009] FIG. 1B illustrates a front view of the fuse head of FIG. 1A according to some embodiments.

[0010] FIG. 1C illustrates a side view of the fuse head of FIG. 1A according to some embodiments.

[0011] FIGS. 2A-2H illustrate various aspects of a detonator with fuse head retention features according to some embodiments.

[0012] FIGS. 3A and 3B illustrate various aspects of a detonator with fuse head retention features according to some embodiments.

[0013] FIG. 4A illustrates a top cross-sectional view of a detonator according to some embodiments.

[0014] FIG. 4B illustrates a side cross-sectional view of the detonator of FIG. 4A according to some embodiments.

[0015] FIG. 5 illustrates exemplary aspects of a detonator according to some embodiments.

[0016] FIG. 6 illustrates exemplary aspects of a detonator according to some embodiments.

[0017] FIG. 7 illustrates exemplary aspects of a detonator according to some embodiments.

[0018] FIG. 8A illustrates exemplary aspects of a fuse head for a detonator according to some embodiments.

[0019] FIG. 8B illustrates a top cross-sectional view of the detonator including the fuse head of FIG. 8A according to some embodiments.

[0020] FIG. 8C illustrates a side cross-sectional view of the detonator including the fuse head of FIG. 8A according to some embodiments.

[0021] FIG. 9A illustrates exemplary aspects of a fuse head for a detonator according to some embodiments.

[0022] FIG. 9B illustrates a top cross-sectional view of the detonator including the fuse head of FIG. 9A according to some embodiments.

[0023] FIG. 9C illustrates a side cross-sectional view of the detonator including the fuse head of FIG. 9A according to some embodiments.

[0024] 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 emphasize specific features relevant to some exemplary embodiments.

[0025] 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

[0026] 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”.

[0027] For purposes of this disclosure, relative terms including, without limitation, “top,”“bottom,”“rear,”“front,”“upper,”“lower,”“above,”“below,”“within,” and the like are used to aid the description of, e.g., configurations of features as shown in the accompanying figures, and otherwise as the disclosure makes clear. Such relative terms do not imply any particular dimension or delineation of or between features except where the disclosure makes clear.

[0028] For purposes of this disclosure, terms including, without limitation, “first,”“second,”“third,” and “fourth” are used for descriptive purposes only and without limitation with respect to, e.g., an ordering of process steps, function, or configuration.

[0029] For purposes of this disclosure, “substantially” means generally consistent with the spirit of the disclosure but without limitation to any particular measure.

[0030] For purposes of illustrating features of the embodiments, an exemplary embodiment will now be introduced and referenced throughout the disclosure. It will be understood that this example and other exemplary embodiments described in this disclosure are illustrative and not limiting and are provided for illustrating the exemplary features of a furniture accessory equipped with a power supply.

[0031] In existing detonators for tool strings, the fuse head may be soldered into the detonator. However, solder joints can be problematic because these joints are made with fluid solder material. For example, soldering tools may be required to install the fuse head, which can be difficult and impractical in the field. However, the ability to readily install the fuse head in the field can improve safety by limiting premature ignition, such as during transport. In another example, fluid nature of solder may result in a short-circuit being formed between different contacts (e.g., a short between holder contacts). Therefore, plug-in, or solder-free, connections may be used in some applications. Plug-in connections, however, can become loose, such as due to movement and vibrations in rough environments (e.g., during placement down a wellbore or during transport), which may result in axial displacement (along x-axis) of the fuse head relative to the detonator. Loose connections can prevent proper operation of the fuse head, such as by failing to ignite the inflation initiation capable material. Further, the use of shrinkable tubing around the fuse head is insufficient to maintain proper contact. Accordingly, as described in more detail below, various embodiments described hereby include various fuse head retention features configured to maintain proper contact between holder contacts and fuse contacts. In various such embodiments, the connection between the holder contacts and fuse contacts may be plug-in and / or solder-free.

[0032] FIGS. 1A-1C illustrate various views of a fuse head 102 according to some embodiments. More specifically, FIG. 1A illustrates a perspective view of the fuse head 102; FIG. 1B illustrates a front view of the fuse head 102; and FIG. 1C illustrates a side view of the fuse head 102. As shown in the illustrated embodiments, the fuse head 102 includes a first fuse contact 104, a second fuse contact 106, and an ignition end 108. In various embodiments, a voltage difference may be applied between the first fuse contact 104 and the second fuse contact 106 to ignite the ignition end 108. Embodiments are not limited in this context.

[0033] FIGS. 2A-2H illustrate various aspects of a detonator 200 according to some embodiments. Referring to FIGS. 2A and 2B, the detonator 200 may include an outer hull 202, a casing 204, and an electronics holder 210. In various embodiments described hereby, the detonator 200 may include one or more fuse head retention features to maintain proper positioning of a fuse head 244 and / or electrical contact between the fuse head 244 and / or a holder contact 226 and / or a holder contact 228 of the detonator 200 (see e.g., FIG. 2H). Thus, the fuse head 244 will not move out of place or lose electrical contact with the holder contact 226 and / or holder contact 228 due to movement and vibrations in rough environments (e.g., during placement down a wellbore or during transport). It will be appreciated that one or more aspects and / or components of detonator 200 may be the same or similar to other detonators described hereby. Embodiments are not limited in this context.

[0034] In the illustrated embodiment, the outer hull 202 may be coupled to the casing 204 via a crimp 206. In other embodiments, the outer hull 202 may be coupled to the casing 204 using other techniques. For example, the outer hull 202 may screw into the casing 204. These attachment features (e.g., crimp 206) may operate as fuse head retention features. In some embodiments, the outer hull 202 may have a cylindrical shape and be formed of a metal. The electronics holder 210 may provide a mounting base for various electrical electronic components of the detonator 200. These electronic components may be enclosed or covered by the casing 204 when the electronics holder 210 is coupled to the casing 204. Additionally, the casing 204 may include, be connected to, and / or integrally formed with one or more fuse head retention features.

[0035] The casing 204 and electronics holder 210 may include openings that expose an electrical contact 208a, an electrical contact 208b, an electrical contact 208c, and electrical contact 208d, and an electrical contact 208e (collectively referred to as electrical contacts 208). The electrical contacts 208 may provide communication, power, and / or ground connectivity between the electrical components of the detonator 200 and various other electrical components of a tool string (e.g., perforating gun). For example, the detonator 200 installed in a perforating gun that is placed down a wellbore and power and / or an initiation signal may be received via one or more of the electrical contacts 208. In some embodiments, the electrical contacts 208 may be included in, integrally formed with, coupled to, and / or sealed with the casing 204 or electronics holder 210.

[0036] Referring to FIG. 2C, the outer hull 202 may enclose an initiation capable material 214, a spacing block 212, a retention cap 216, and a fuse head holder 218 with an indentation 220. In various embodiments, the initiation capable material 410 may include a primary explosive, a deflagration material, and / or black powder. The indentation 220 may facilitate crimping of the outer hull 202 to the casing 204. In many embodiments, the fuse head holder 218 and indentation 220 may be integrally formed with the casing 204. In other embodiments, the fuse head holder 218 and indentation 220 may include a separate component that screws into the casing 204. As described in more detail below, the retention cap 216 and fuse head holder 218 may operate as fuse head retention features. Further, the retention cap 216 may be selectively coupled to the fuse head holder 218. In various embodiments, one or more of the retention features, such as retention cap 216 may form a friction fit with the fuse head holder 218 and / or the outer hull 202 of the detonator 200. In some embodiments, one or more of the retention features may be formed from a compressible or elastic material, such as rubber or foam. For example, the retention cap 216 may be formed from a flexible, compressible, and / or elastic material, such as rubber, plastic, or foam. In many embodiments, the retention features may be formed from a material capable of withstanding the heat generated by ignition.

[0037] As shown in FIG. 2D, the electronics holder 210 may provide an attachment base for electronic components 222 of the detonator 200 including a printed circuit board (PCB) 230, the holder contact 226, and / or the holder contact 228. For example, the electronic components 222 may include a printed circuit board (PCB) 230 that is attached to the electronics holder 210. Further, the holder contact 226 and the holder contact 228, as well as other electronic components, may be mounted to the PCB 230.

[0038] A holder block 224 may be coupled to the holder contact 226 and the holder contact 228. In various embodiments, the holder block 224 may include an insulative member that is disposed between and around the holder contact 226 and the holder contact 228 and maintains proper spacing between the holder contact 226 and the holder contact 228. In the illustrated embodiment, the holder contact 226 and the holder contact 228 are mounted on the PCB 230 and extend up and through the holder block 224. Further, the holder contact 226 may include a first arm 232a and a second arm 232b. Similarly, the holder contact 228 may include a first arm 234a and a second arm 234b. The corresponding arms of the holder contact 226 and the holder contact 228 may be biased towards each other such that a fuse head (e.g., fuse head 102) can be plugged into the holder contact 226 and the holder contact 228. More specifically, a first fuse contact (e.g., fuse contact 104) of the fuse head may be positioned between the first arm 232a and the second arm 234b and a second fuse contact (e.g., fuse contact 106) of the fuse head may be positioned between the first arm 234a and the second arm 234b when the fuse head is plugged into the holder contact 226 and the holder contact 228. Advantageously, the plug-in connection between the fuse contacts and the holder contacts in combination with the fuse head retention features described hereby remove the need to solder the fuse contacts and the holder contacts together.

[0039] In various embodiments, the electronic components 222 may be configured to trigger a fuse head plugged into the holder contact 226 and the holder contact 228, such as by creating a voltage difference between the holder contact 226 and the holder contact 228 and therefore the fuse contacts of a fuse head plugged into the holder contact 226 and the holder contact 228. In various such embodiments, the electronic components 222 may trigger the fuse head in response to an initiation signal, such as one received from other components of a tool string via one or more of the electrical contacts 208. In some embodiments, the electronic components 222 may determine whether the initiation signal is addressed or directed to the detonator 200 prior to triggering the fuse head 244.

[0040] As previously mentioned, the casing 204 and electronics holder 210 may couple together via a plurality of mating features. For example, the electronics holder 210 may be coupled to the casing 204 by inserting the electronics holder 210 into the bottom of the casing 204. To this end, electronics holder 210 includes a mating feature 236a, a mating feature 236b, a mating feature 236c, and / or a mating feature 236d (collectively referred to as mating features 236).

[0041] Turning to FIGS. 2E and 2F, in many embodiments, the mating features 246 of the electronics holder 210 may be received by a mating feature 238a, a mating feature 238b, a mating feature 238c, and / or a mating feature 238d (collectively referred to as mating features 238) of the casing 204. It will be appreciated that although the mating feature 238d is not visible in the illustrated embodiment, it is positioned with respect to the mating feature 238c in the same manner as the mating feature 238a is positioned with respect to the mating feature 238b. Accordingly, when the electronics holder 210 is inserted into the bottom of the casing 204, corresponding mating features of the casing 204 and electronics holder 210 (e.g., the mating feature 236a and the mating feature 238a, the mating feature 236b and the mating feature 238b, the mating feature 236c and the mating feature 238c, the mating feature 236d and the mating feature 238d) may engage each other to secure the casing 204 to the electronics holder 210.

[0042] As previously mentioned the retention cap 216 may be selectively coupled to the fuse head holder 218. To this end, the retention cap 216 may include a coupling feature 240a, a coupling feature 240b, a coupling feature 240c, and / or a coupling feature 240d (collectively referred to as coupling features 240) and the fuse head holder 218 may include a coupling feature 242a, a coupling feature 242b, a coupling feature 242c, and a coupling feature 242d (collectively referred to as coupling features 242). It will be appreciated that although the coupling features 240d, 242d are not visible in the illustrated embodiment, they are positioned with respect to the coupling feature 240a in the same manner as the coupling feature 240c is positioned with respect to the coupling feature 240b. Thus, when the retention cap 216 is placed onto the fuse head holder 218, the coupling features 240 of the retention cap 216 and the coupling features 242 of the fuse head holder 218 may engage each other to maintain a connection between the retention cap 216 and the fuse head holder 218. In some embodiments, the coupling features 242 of the fuse head holder 218 and the coupling features 240 of the retention cap 216 may form a snap-fit and / or locking profile with each other.

[0043] Referring to FIG. 2G, in many embodiments, the connection between the retention cap 216 and the fuse head holder 218 may function as a fuse head retention feature. Accordingly, when the retention cap 216 is connected to the fuse head holder 218 with the fuse head 244 plugged into the holder contact 226 and the holder contact 228, axial displacement of the fuse head 244 may be prevented. In operation, for example, when the retention cap 216 is not coupled to the fuse head holder 218, the holder contact 226 and the holder contact 228 may be exposed via an opening in the fuse head holder 218. A user may insert the fuse head 244 into the fuse head holder 218 to plug the fuse head 244 into the holder contact 226 and the holder contact 228. In many embodiments, the opening in the fuse head holder 218 may be shaped to force the fuse head 244 to be inserted in proper alignment with the holder contact 226 and the holder contact 228. Further, the shape of the opening in the fuse head holder 218 may prevent side to side and / or back and forth motion (see e.g., FIG. 2H) of the fuse head 244 when plugged into the holder contacts 226, 228. Accordingly, as shown in FIGS. 2G and 2H, the opening may have steps and / or features that mirror steps and / or features of the fuse head 244.

[0044] Once the fuse head 244 is plugged into the holder contact 226 and the holder contact 228, the retention cap 216 may be attached to the fuse head holder 218 to hold the fuse head 244 in place and main a proper electrical connection between the fuse head 244 and the holder contact 226 and the holder contact 228. Accordingly, the interior of the retention cap 216 may be shaped to be placed over the ignition end of the fuse head 244. Further, the retention cap 216 may include an opening 246 in the top to enable energy from ignition of the fuse head 244 to be channeled into the initiation capable material 214. The opening in the top of the retention cap 216 may be narrow enough to prevent axial displacement of the fuse head 244.

[0045] Turning to FIG. 2H, a cross-sectional view of the detonator 200 is shown. In operation, the electronic components 222 of the detonator 200 may create a voltage difference between the holder contact 226 and the holder contact 228, such as in response to a signal received via the electrical contact 208e. This voltage difference may cause the fuse head 244 to ignite. Energy from the from the fuse head 244 may pass through the opening 246 of retention cap 216, through a channel in the spacing block 212 and into the initiation capable material 214, thereby detonating or igniting the initiation capable material 214. Advantageously, the retention cap 216 and the fuse head holder 218 maintain the fuse head 244 in proper position and in proper electrical contact with the holder contact 226 and the holder contact 228. Accordingly, if the detonator 200 is jarred or shaken, such as during placement of the tool string in a wellbore, the fuse head 244 cannot come disconnected from the holder contact 226 and the holder contact 228.

[0046] FIGS. 3A and 3B illustrate various aspects of a detonator 300 according to some embodiments. It will be appreciated that one or more aspects and / or components of the detonator 300 may be the same or similar to other detonators described hereby. For example, the electronic components of the detonator 300 may be the same or similar to the electronic components 222 of the detonator 200. Accordingly, description of some aspects and / or components of the detonator 300 may not be repeated with reference to other detonators described hereby. Embodiments are not limited in this context.

[0047] In some embodiments, the fuse head holder 318 may have an open end at the top that allows a fuse head to be inserted and plugged into corresponding holder contacts. In other embodiments, the fuse head holder 318 may be screwed into the casing 304. For example, the fuse head may be plugged into the holder contacts and then the fuse head holder 318 may be screwed into the casing 304 to hold the fuse head in place. The outer hull 302 may then be placed over the initiation capable material 312, the spacing block 310, and the fuse head holder 318. Next, the outer hull 302 may be crimped at an indentation 314 (creating a crimp 306a) to secure the outer hull 302 to the casing 304 and the outer hull 302 may be crimped at a space 316 (creating a crimp 306b) to prevent axial movement of the fuse head. Thus, these features (e.g., the crimp 306a and / or the crimp 306b) may operate as fuse head retention features.

[0048] FIGS. 4A and 4B illustrate various views of a detonator 400. More specifically, FIG. 4A illustrates a top cross-sectional view of the detonator 400 in conjunction with x and y axes; and FIG. 4B illustrates a side cross-section view of the detonator 400 in conjunction with x and z axes. It will be appreciated that one or more aspects and / or components of detonator 400 may be the same or similar to other detonators described hereby. For example, an outer hull 408 may be the same or similar to the outer hull 202 described with respect to FIGS. 2A through 2H. Further, the x axis of detonator 400 may correspond to an axis of detonator 200 that extends along the outer hull 202 described with respect to FIGS. 2A through 2H. Accordingly, description of some aspects and / or components of the detonator 400 may not be repeated with reference to other detonators described hereby. Embodiments are not limited in this context.

[0049] In the illustrated embodiment, the detonator 400 includes a fuse head 402 with a first fuse contact404 and a second fuse contact 406, an outer hull 408, an initiation capable material 410, a holder block 412, a first holder contact 414 and a second holder contact 416, electronic components 418, a fuse head holder 420, and a spacing block 422. Many of the components of detonator 400 may be at least partially disposed within the outer hull 408. For example, the same components of the detonator 200 that are at least partially disposed within the outer hull 202 may also be disposed within the outer hull 408 of the detonator 400. Further, the electronic components 418 may be enclosed within a casing in the same or a similar manner as the electronic components 222 of the detonator 200 are enclosed within the casing 204. In some embodiments, the outer hull 408 may have a cylindrical shape and be formed of a metal.

[0050] In operation, the electronic components 418 may create a voltage difference between the holder contact 414 and the holder contact 416, which creates a voltage difference between the fuse contact 404 and the fuse contact 406. The voltage difference between the fuse contact 404 and the fuse contact 406 may cause the fuse head 402 to ignite the initiation capable material 410. More generally, the detonator 400 may be installed in a perforating gun that is placed down a wellbore. In various embodiments, the initiation capable material 410 may include a primary explosive, a deflagration material, and / or black powder.

[0051] As shown in FIG. 4B, the first holder contact 414 may include an upper arm 424a and a lower arm 424b. Similarly, although not illustrated, the second holder contact 416 may include upper and lower arms. In various embodiments, these arms may form a plug-in connection with first fuse contact 404 and the second fuse contact 406. The fuse head 402 may be installed into or plugged into the first holder contact 414 and the second holder contact 416. For example, the upper arm 424a and the lower arm 424b may be biased towards each other and the first fuse contact 404 may be installed between the upper arm 424a and the lower arm 424b. Similarly, the arms of the second holder contact 416 may be biased towards each other and the second fuse contact 406 may be installed between the arms of the second holder contact 416. The fuse head holder 420 may limit side-to-side (along y-axis) and / or up-and-down (along z-axis) movement of the fuse head 402. In some embodiments, reference to a detonator may include a detonator without one or more components. For example, reference to a detonator may include a detonator without the fuse head installed. Embodiments are not limited in this context.

[0052] As previously discussed, in existing solutions, a fuse head may be soldered into a detonator. However, solder joints can be problematic because these joints are made with fluid solder material. For example, soldering tools may be required to install the fuse head, which can be difficult and impractical in the field. The ability to readily install the fuse head in the field, however, can improve safety by limiting premature ignition, such as during transport. In another example, fluid nature of solder may result in a short-circuit being formed between different contacts (e.g., a short between holder contacts). Therefore, plug-in, or solder-free, connections may be used in some applications. Adding further complexity, plug-in connections can become loose, such as due to movement and vibrations in rough environments (e.g., during placement down a wellbore or during transport), which may result in axial displacement (along x-axis) of the fuse head relative to the detonator. Loose connections can prevent proper operation of the fuse head, such as by failing to ignite the inflation initiation capable material. Further, the use of shrinkable tubing around the fuse head is insufficient to maintain proper contact. Accordingly, fuse head retention features disclosed hereby are configured to maintain proper contact between holder contacts and fuse contacts. Further, the connection between the holder contacts and fuse contacts may be plug-in and / or solder-free.

[0053] FIG. 5 illustrates exemplary aspects of a detonator according to some embodiments. It will be appreciated that one or more aspects and / or components of a detonator 500 may be the same or similar to other detonators described hereby. For example, a fuse head holder 504 may be the same or similar to the fuse head holder 218 described above with reference to FIGS. 2A through 2H. Accordingly, description of some aspects and / or components of the detonator 500 may not be repeated with reference to other detonators described hereby. Embodiments are not limited in this context.

[0054] In the illustrated embodiment, the detonator 500 comprises a retention feature 502 including a retention cap 506, and a fuse head holder 504. In some embodiments, the fuse head holder 504 may form a portion of the retention feature 502. More generally, the retention feature 502 may include a retention cap configured to couple to the fuse head holder and prevent axial displacement of the fuse head. In some embodiments, the retention cap 506 may be the same or similar to the retention cap 216 described above with reference to FIGS. 2A through 2H. For example, the retention cap 506 may operate in a similar manner to the retention cap 216, however, the retention cap 506 may couple to the fuse head holder 504 in a different manner. Accordingly, the retention cap 506 may include a female portion 508a and the fuse head holder 504 may include a male portion 508b. The retention cap 506 may be configured to couple to the fuse head holder 504 by installing the female portion 508a over the male portion 508b. In various embodiments, there may be a locking profile 510 between the female portion 508a and the male portion 508b. The retention cap 506 may include an opening 512 that is sufficient to ignite the initiation capable material while being narrow enough to prevent axial displacement of the fuse head. During assembly the detonator hull, comprising the initiation capable material, may be moved over the fuse head holder 504 and retention cap 506 and therefore the retention cap 506 is prevented from unlocking.

[0055] FIG. 6 illustrates exemplary aspects of a detonator 600 according to some embodiments. It will be appreciated that one or more aspects and / or components of the detonator 600 may be the same or similar to other detonators described hereby. For example, a retention feature 602 may be the same or similar to crimp 306b. Accordingly, description of some aspects and / or components of the detonator 600 may not be repeated with reference to other detonators described hereby. Embodiments are not limited in this context.

[0056] In the illustrated embodiment, the detonator 600 comprises the retention feature 602 including an indentation 606a and an indentation 606b and a fuse head holder 604 with an opening 608. In various embodiments, the indentation 606a and the indentation 606b may operate to prevent axial movement of the fuse head (e.g., towards the initiation capable material), thereby maintaining proper contact between the holder contacts and the fuse contacts. In some embodiments, the indentation 606a and the indentation 606b may comprise a continuous indentation extending around the outer hull of the detonator 600 (e.g., a crimp). The opening 608 may be narrowed by the indentation 606a and the indentation 606b. However, the opening 608 is still sufficient to ignite the initiation capable material.

[0057] In various embodiments, one or more retention features may form a friction fit with the outer hull of a detonator. In various embodiments, the retention feature may be formed from a compressible or elastic material, such as rubber or foam. In many embodiments, the retention feature may be formed from a material capable of withstanding the heat generated by ignition.

[0058] FIG. 7 illustrates exemplary aspects of a detonator 700 according to some embodiments. In the illustrated embodiments, the detonator 700 comprises a retention feature 702 including a retention block 706, and a fuse head holder 704. In some embodiments, the fuse head holder 704 may form a portion of the retention feature 702. More generally, the retention feature 702 may include a retention block 706 disposed between the fuse head holder 704 and the initiation capable material and configured to prevent axial displacement of the fuse head. In various embodiments, the fuse contact 406 may be utilized in place of a spacing block (e.g., spacing block 212). The retention block 706 may include a passage 708. The passage may be sufficient to ignite the initiation capable material while being narrow enough to prevent axial displacement of the fuse head.

[0059] FIGS. 8A-8C illustrate exemplary aspects of a detonator 800 in conjunction with a fuse head 802 according to some embodiments. More specifically, FIG. 8A illustrates exemplary aspects of the fuse head 802 for the detonator 800; FIG. 8B illustrates a top cross-sectional view of the detonator 800 including the fuse head 802; and FIG. 8C illustrates a side cross-sectional view of the detonator 800 including the fuse head 802. In the illustrated embodiment, the fuse head 802 includes a first fuse contact 804, a second fuse contact 806, an ignition end 808, and a cross member 810 extending between the first fuse contact 804 and the second fuse contact 806. In many embodiments, the cross member 810 may be formed from an electrically insulative material to prevent a short-circuit between the first fuse contact 804 and the second fuse contact 806. The detonator 800 may include a retention feature 812 comprising a hook 816 extending from the contact holder 814 (also referred to as a holder block). In various embodiments, the hook 816 operates to catch on the cross member 810 when the fuse head 802 is installed in the detonator 800. Thereby, the hook 816 can function to prevent axial displacement of the fuse head 802.

[0060] FIGS. 9A-9C illustrate exemplary aspects of a detonator 900 in conjunction with a fuse head 902 according to some embodiments. More specifically, FIG. 9A illustrates exemplary aspects of the fuse head 902 for the detonator 900; FIG. 9B illustrates a top cross-sectional view of the detonator 900 including the fuse head 902; and FIG. 9C illustrates a side cross-sectional view of the detonator 900 including the fuse head 902. In the illustrated embodiment, the fuse head 902 includes a first fuse contact 904, and second fuse contact 906, an ignition end 908, a first hole 910 in the first fuse contact 904, and a second hole 912 in the second fuse contact 906. The detonator 900 may include a retention feature 914 comprising one or more portions of a first retaining contact 916 and a second retaining contact 918. The first retaining contact and the second retaining contact 918 may comprise holder contacts in which at least one of the upper or lower arm includes a feature configured to engage with corresponding fuse contacts and prevent the corresponding fuse contacts from moving axially away from first retaining contact 916 and the second retaining contact 918. The first retaining contact 916 and the second retaining contact 918 may be configured to catch within the first hole 910 and the second hole 912 of the first fuse contact 904 and the second fuse contact 906. For example, the retaining contact 918 may include an upper arm 920a and a lower arm 920b. The lower arm may include a feature, such as a hook, configured to catch on the second hole 912 of the fuse contact 906 when the fuse head 902 is installed in the detonator 900. In other embodiments, the upper arm 920a may additionally, or alternatively, be configured to catch on the second hole 912. Thereby, the lower arm 920b can function to prevent axial displacement of the fuse head 902. Similarly, the first retaining contact 916 may also include upper and lower arms with one or more of the arms configured to catch on the hole 910.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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 considering 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.”

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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

1. A detonator for use with a fuse head having a first fuse contact and a second fuse contact, the detonator comprising:an outer hull;a first holder contact and a second holder contact at least partially disposed within the outer hull, the first holder contact and the second holder contact configured to electrically connect with the first fuse contact and the second fuse contact of the fuse head; anda retention feature configured to maintain a position of the first holder contact and the second holder contact with respect to the first fuse contact and the second fuse contact.

2. The detonator of claim 1, wherein the retention feature is configured to maintain the position of the first and second holder contacts with respect to the first and second fuse head contacts when a solder-free connection connects the first and second holder contacts to the first and second fuse contacts.

3. The detonator of claim 1, further comprising a fuse head holder is disposed around at least a portion of the holder block and configured to surround at least a portion of the fuse head.

4. The detonator of claim 3, wherein the retention feature includes a retention cap configured to couple with the fuse head holder.

5. The detonator of claim 3, wherein the fuse head holder is integrally formed with a casing of the detonator.

6. The detonator of claim 1, wherein the retention feature comprises a retention block disposed between the fuse head holder and an ignition capable material.

7. The detonator of claim 1, comprising a casing coupled to the outer hull.

8. The detonator of claim 7, wherein the casing is coupled to the outer hull with a crimp.

9. The detonator of claim 7, further comprising one or more electronic components enclosed by the casing.

10. The detonator of claim 1, wherein the retention feature includes at least one indentation in the outer hull.

11. The detonator of claim 10, wherein the at least one indentation in the outer hull comprises a crimp.

12. The detonator of claim 1, wherein the fuse head includes a cross member extending between the first fuse contact and the second fuse contact and the retention feature includes a hook extending from the contact holder and configured to couple with the cross member.

13. The detonator of claim 1, wherein the first fuse contact and the second fuse contact include an opening and the retention feature includes a hook formed in the first holder contact or the second holder contact, wherein the hook is configured to couple with the opening.

14. A method for assembling a detonator, the method comprising:inserting a fuse head into a holder contact of the detonator via an opening in a fuse head holder of the detonator;coupling a retention cap to the fuse head holder of the detonator with the fuse head inserted into the holder contact; anddisposing an outer hull over the retention cap and at least a portion of the fuse head holder.

15. The method of claim 14, further comprising securing the outer hull to a casing of the detonator.

16. The method of claim 15, wherein securing the outer hull to the casing of the detonator includes crimping the outer hull.

17. The method of claim 14, coupling the retention cap to the fuse head holder of the detonator via one or more coupling features of the fuse head holder and one or more coupling features of the retention cap.

18. The method of claim 17, wherein the one or more coupling features of the fuse head holder form a snap-fit with the one or more coupling features of the retention cap.

19. The method of claim 14, further comprising disposing the detonator within a wellbore tool.

20. A system comprising:a wellbore tool;a detonator disposed in the wellbore tool, wherein the detonator includes:an outer hull;a first holder contact and a second holder contact at least partially disposed within the outer hull, the first holder contact and the second holder contact configured to electrically connect with a first fuse contact and a second fuse contact of a fuse head;a retention feature configured to maintain a position of the first holder contact and the second holder contact with respect to the first fuse contact and the second fuse contact.

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