Patent Publication Number: US-11648513-B2

Title: Detonator positioning device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/026,431 filed Jul. 3, 2018, which is a continuation of U.S. application Ser. No. 15/117,228 filed Aug. 8, 2016 (now U.S. Pat. No. 10,188,990 issued Jan. 29, 2019), which claims priority to PCT Application No. PCT/US2015/018906 filed Mar. 5, 2015, which claims the benefit of U.S. Provisional Application No. 61/949,939 filed Mar. 7, 2014, each of which is incorporated herein by reference in its entirety. This application is a continuation-in-part of U.S. patent application Ser. No. 15/920,812 filed Mar. 14, 2018, which is a continuation of U.S. patent application Ser. No. 15/617,344 filed Jun. 8, 2017, which is a divisional patent application of U.S. patent application Ser. No. 15/287,309 filed Oct. 6, 2016 (now U.S. Pat. No. 9,702,680 issued Jul. 11, 2017), which is a divisional patent application of U.S. patent application Ser. No. 14/904,788 filed Jan. 13, 2016 (now U.S. Pat. No. 9,494,021 issued Nov. 15, 2016), which claims priority to PCT Application No. PCT/CA2014/050673 filed Jul. 16, 2014, which claims priority to Canadian Patent Application No. 2,821,506 filed Jul. 18, 2013, each of which is incorporated herein by reference in its entirety. 
    
    
     FIELD 
     A device and method for positioning a detonator within a perforating gun assembly is generally described. 
     BACKGROUND 
     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 cases after drilling, 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. The perforating gun has explosive charges, typically shaped, hollow or projectile charges, which are ignited to create holes in the casing and to blast through the formation so that the hydrocarbons can flow through the casing. Once the perforating gun(s) is properly positioned, a surface signal actuates an ignition of a fuse, which in turn initiates a detonating cord, which detonates the shaped charges to penetrate/perforate the casing and thereby allow formation fluids to flow through the perforations thus formed and into a production string. The surface signal typically travels from the surface along electrical wires that run from the surface to one or more detonators positioned within the perforating gun assembly. 
     Assembly of a perforating gun requires assembly of multiple parts, which typically include at least the following components: a housing or outer gun barrel within which is positioned an electrical wire for communicating from the surface to initiate ignition, a percussion initiator and/or a detonator, a detonating cord, one or more charges which are held in an inner tube, strip or carrying device and, where necessary, one or more boosters. Assembly typically includes threaded insertion of one component into another by screwing or twisting the components into place, optionally by use of a tandem adapter. Since the electrical wire must extend through much of the perforating gun assembly, it is easily twisted and crimped during assembly. In addition, when a wired detonator is used it must be manually connected to the electrical wire, which has lead to multiple problems. Due to the rotating assembly of parts, the wires can become torn, twisted and/or crimped/nicked, the wires may be inadvertently disconnected, or even mis-connected in error during assembly, not to mention the safety issues associated with physically and manually wiring live explosives. 
     According to the prior art and as shown in  FIG.  1   , the wired detonator  60  has typically been configured such that wires must be physically, manually connected upon configuration of the perforating gun assembly. As shown herein, the wired detonator  60  typically has three (or more or less) wires, which require manual, physical connection once the wired detonator is placed into the perforating gun assembly. For detonators with a wired integrated switch for selective perforating, the wires typically include at least a signal-in wire  61 , a signal-out wire  62  and a ground wire  63 . In a typical manual, physical connection, the wires extending along the perforating gun are matched to the wires of the detonator, and an inner metallic portion of one wire is twisted together with an inner metallic portion of the matched wire using an electrical connector cap  64  or wire nut or a scotch-lock type connector. 
     What is needed is a detonator positioning device capable of positioning a wireless detonator including a spring-contact, single wire (not two or more wires as described above) connection within a perforating gun assembly, particularly a typical perforating gun assembly that has traditionally used a fully-wired detonator. 
     BRIEF DESCRIPTION 
     An embodiment provides a detonator positioning device for positioning a detonator in a perforating gun assembly. In an embodiment, the detonator positioning device is formed of a multi-part cylindrical body. 
     Another embodiment provides a perforating gun assembly including the detonator positioning device for positioning a wireless detonator. 
     Another embodiment provides a method of assembling the perforating gun assembly including a detonator positioning device and a detonator. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       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 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: 
         FIG.  1    is a perspective view of a wired detonator according to the prior art; 
         FIG.  2    is a cross-sectional side view of a wireless detonator useful with a detonator positioning device, according to an embodiment; 
         FIG.  3    is a perspective view of the detonator according to  FIG.  2   ; 
         FIG.  4    is a partial semi-cross-sectional side perspective view of a perforating gun assembly including the detonator of  FIGS.  2 - 3    seated within a detonator positioning device in which the detonator positioning device includes a multi-part cylindrical body according to an embodiment; 
         FIG.  5    is a cross-sectional side view of the detonator positioning device formed as a unitary member according to an embodiment; 
         FIG.  6    is a perspective view of the detonator positioning device including a multi-part cylindrical body of  FIG.  4    according to an embodiment; 
         FIG.  7    is a perspective view of one part of the detonator positioning device of  FIG.  6    positioned within an end plate according to an embodiment; 
         FIG.  8    is a forward end perspective view of the detonator positioning device according to an embodiment; 
         FIG.  9    is another perspective view of the detonator positioning device tilted at an angle from  FIG.  8    according to an embodiment; 
         FIG.  10    is a partial cross-sectional view of another embodiment of the detonator positioning device assembly within a perforating gun assembly; and 
         FIG.  11    is a perspective view of a ground rib according an embodiment. 
     
    
    
     Various features, aspects, and advantages of the embodiments will become more apparent from the following detailed description, along with the accompanying figures in which like numerals represent like components throughout the figures and text. The various described features are not necessarily drawn to scale, but are drawn to emphasize specific features relevant to embodiments. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various 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. 
     A detonator is provided that is capable of being positioned or placed into a perforating gun assembly with minimal effort by means of placement/positioning within a detonator positioning device according to an aspect. In an embodiment, the detonator positioning device includes a detonator positioned within the detonator positioning device, wherein the detonator electrically contactably forms an electrical connection with minimal need to manually and physically connect, cut or crimp multiple wires as required in a fully wired electrical connection. Such a wireless detonator has been generally described in commonly assigned DE Application No. 102013109227.6 filed Aug. 26, 2013, which is incorporated herein by reference in its entirety. In other words, the electrical connection is made only by making electrical contact with electrically contactable components as described in greater detail hereinbelow . . . that is by merely physically touching. Thus, as used herein, the term “wireless” means that the detonator itself is not manually, physically connected within the perforating gun assembly as has been traditionally done with wired connections, but rather merely makes electrical contact through various components as described herein to form the electrical connections. Thus, the signal is not being wirelessly transmitted, but is rather being relayed through electrical cables/wiring within the perforating gun assembly through the electrical contacts. In particular, the electrical connection is made through contact between a line-in contact-initiating pin  38  and a line-in portion  20  as described in greater detail below. 
     Now referring to  FIGS.  2  and  3    such a detonator  10  incudes a detonator shell  12  and a detonator head  18  and is configured for being electrically contactably received within a perforating gun assembly  40  (see, for instance,  FIG.  4   ) without using a wired electrical connection directly to the detonator. Rather, a single line-out wire (not shown) is connected to the detonator positioning assembly as described in more detail hereinbelow. 
     Only a portion of the perforating gun assembly  40 /adjacent perforating gun assembly  40 ′ is depicted herein, including a perforating gun body or barrel or carrier or housing  42 ,  42 ′ respectively for housing the various components of the assembly. Also shown is a distal end of a typical tandem seal adapter or tandem sub  44 , in which a bulkhead assembly  46  is shown assembled within the perforating gun assembly  40 . The tandem sub/seal adapter  44  is configured to seal inner components within the perforating gun housing  42  from the outside environment using sealing means. The tandem seal adapter  44  seals adjacent perforating gun assemblies  40 ,  40 ′ ( FIG.  10   ) from each other, and houses the bulkhead assembly  46 . 
     The bulkhead assembly  46  functions to relay a line-in contact-initiating pin  38  for wirelessly electrically contacting a line-in portion  20  of the detonator head  18  as described in greater detail hereinbelow. As shown in  FIG.  4   , for instance, bulkhead wires  48  are depicted with a coating or insulating member, typically using heat shrinking, over the wires  48  for supplying current to the bulkhead assembly  46 . With reference to  FIGS.  4  and  10   , a bulkhead retaining mechanism  49  is provided to secure the bulkhead assembly  46  within the tandem sub  44 . In the embodiment of  FIG.  4   , the retaining mechanism  49  abuts the end of the bulkhead assembly  46  from which the line-in contact-initiating pin  38  extends, while in the embodiment depicted in  FIG.  10   , the retaining mechanism  49  abuts the opposite end of the bulkhead assembly  46 . 
     The detonator shell  12  of the detonator  10  useful herein is configured as a housing or casing  11 , typically a metallic housing, which houses at least a detonator head plug  14 , a fuse head  15 , an electronic circuit board  16  and explosive components  19 . The fuse head  15  could be any device capable of converting an electric signal into an explosion. As shown in  FIG.  2   , the detonator shell  12  is shaped as a hollow cylinder. The electronic circuit board  16  is connected to the fuse head  15  and is configured to allow for selective detonation of the detonator  10 . The electronic circuit board  16  is configured to wirelessly and selectively receive an ignition signal I, (typically a digital code uniquely configured for a specific detonator), to fire the perforating gun assembly  40 . By “selective” what is meant is that the detonator  10  is configured to receive one or more specific digital sequence(s), which differs from a digital sequence that might be used to arm and/or detonate another detonator in a different, adjacent perforating gun assembly, for instance, a train of perforating gun assemblies. So, detonation of the various assemblies does not necessarily have to occur in a specified sequence. Any specific assembly can be selectively detonated. In an embodiment, the detonation occurs in a bottom-up sequence. 
     The detonator head  18  extends from one end of the detonator shell  12 , and includes more than one electrical contacting component including an electrically contactable line-in portion  20  and an electrically contactable line-out portion  22 . According to one embodiment, the detonator head  18  may also include an electrically contactable ground portion  13  (not shown). In an embodiment, the detonator head  18  may be disk-shaped. In another embodiment, at least a portion of the detonator housing  11  is configured as the ground portion  13 . The line-in portion  20 , the line-out portion  22  and the ground portion  13  are configured to replace the wired connection of the prior art wired detonator  60  and to complete the electrical connection merely by contact with other electrical contacting components. In this way, the line-in portion  20  of the detonator  10  replaces the signal-in wire  61  of the wired detonator  60 , the line-out portion  22  replaces the signal-out wire  60  and the ground portion  13  replaces the ground wire  63 . Thus, when placed into a detonator positioning device  100  (see, for instance,  FIG.  4   ) as discussed in greater detail below, the line-in portion  20 , the line-out portion  22  and the ground portion  13  make an electrical connection by merely making contact with corresponding electrical contacting components (also as discussed in greater detail below). That is, the detonator  10  is wirelessly connectable only by making and maintaining electrical contact of the electrical contacting components to replace the wired electrical connection and without using a wired electrical connection. 
     The detonator head  18  also includes an insulator  24 , which is positioned between the line-in portion  20  and the line-out portion  22 . The insulator  24  functions to electrically isolate the line-in portion  20  from the line-out portion  22 . Insulation may also be positioned between other lines of the detonator head. As discussed above and in an embodiment, it is possible for all of the contacts to be configured as part of the detonator head  18  (not shown), as found, for instance, in a banana connector used in a headphone wire assembly in which the contacts are stacked longitudinally along a central axis of the connector, with the insulating portion situated between them. 
     In an embodiment, a capacitor  17  is positioned or otherwise assembled as part of the electronic circuit board  16 . The capacitor  17  is configured to be discharged to initiate the detonator  10  upon receipt of a digital firing sequence via the ignition signal I, the ignition signal being electrically relayed directly through the line-in portion  20  and the line-out portion  22  of the detonator head  18 . In a typical arrangement, a first digital code is transmitted down-hole to and received by the electronic circuit board. Once it is confirmed that the first digital code is the correct code for that specific detonator, an electronic gate is closed and the capacitor is charged. Then, as a safety feature, a second digital code is transmitted to and received by the electronic circuit board. The second digital code, which is also confirmed as the proper code for the particular detonator, closes a second gate, which in turn discharges the capacitor via the fuse head to initiate the detonation. 
     In an embodiment, the detonator  10  may be fluid disabled. “Fluid disabled” means that if the perforating gun has a leak and fluid enters the gun system then the detonator is disabled by the presence of the fluid and hence the explosive train is broken. This prevents a perforating gun from splitting open inside a well if it has a leak and plugging the wellbore, as the hardware would burst open. In an embodiment, the detonator  10  is a selective fluid disabled electronic (SFDE) detonator. 
     The detonator  10  according to an embodiment can be either an electric or an electronic detonator. In an electric detonator, a direct wire from the surface is electrically contactingly connected to the detonator and power is increased to directly initiate the fuse head. In an electronic detonator, circuitry of the electronic circuit board within the detonator is used to initiate the fuse head. 
     The detonator  10  may be immune to stray current or voltage and/or radiofrequency (RF) signals to avoid inadvertent firing of the perforating gun. Thus, the assembly is provided with means for ensuring immunity to stray current or voltage and/or RF signals, such that the detonator  10  is not initiated through random radio frequency signals, stray voltage or stray current. In other words, the detonator  10  is configured to avoid unintended initiation. 
     The detonator  10  is configured to be electrically contactingly received within the detonator positioning device  100 , which is seated or positioned within the perforating gun assembly  40 , without using a wired electrical connection to the detonator  10  itself, as shown in  FIGS.  4 ,  5 ,  7 - 9  and  10   . 
     In an embodiment and as shown in  FIGS.  4 ,  6  and  7   , the detonator positioning device  100  includes a cylindrical body  110 ′ depicted as a multi-part member, that is a body that is formed using a plurality of parts or sections, which may facilitate ease of assembly. With reference to the embodiment of  FIG.  5   , the cylindrical body  110  may also be provided as a unitary body, one that is formed as a whole, for instance by machining or molding processes known by those of ordinary skill in the art. As used herein, the prime symbol ′ in the various figures designates the difference between embodiments of the unitary body (no prime used) as compared to features of the multi-part body (prime used), and will not generally be used in the description. As an example, with reference to a central bore  130 , the central bore will be depicted as central bore  130 ′ in the embodiment wherein multiple parts are used to form the body  110 ′, while the central bore  130  (without the prime) will be used to depict the bore of the unitary body  100 . In an embodiment and with reference to, for instance,  FIG.  7   , one or more passages  102  are provided in the closed end of the cylindrical body  110  to accommodate passage of a detonating cord (not shown) positioned within the detonator positioning device  100 . 
     With reference again in particular to  FIGS.  4 - 9   , the cylindrical body  110  includes an open end  113 , a closed end  114 , and a central bore  130  adapted for receiving the detonator  10 . The cylindrical body  110  also includes a plurality of portions, including at least a first portion  120  and a second portion  122 , and in an embodiment a third portion  124 , which will be discussed in greater detail below. The central bore  130  extends along at least some of a length of the cylindrical body  110 , and typically includes an enlarged bore portion  132  adjacent the open end  113  of the cylindrical body  110 . The enlarged bore portion  132  is adapted to receive the head  18  portion of the detonator  10 , while the central bore  130  is adapted to receive the housing  11  portion of the detonator  10 . In an embodiment, the enlarged bore portion  132  is positioned within the first portion  120  of the cylindrical body  110  and the central bore  130  extends along a majority of the length of the cylindrical body  110 . In an embodiment, the enlarged bore portion  132  and the detonator head  18  are complementarily sized and shaped to receive and seat/be received and seated, respectively, in at least a semi-fixed position within the detonator positioning device  100 . 
     In an embodiment, a plurality of arms  150  extend toward the open end  113  of the cylindrical body  110  and at least partially enclose the enlarged bore portion  132  of the central bore  130 . In this way, each of the plurality of arms  150  is adapted to retain, hold or otherwise embrace the detonator head  18  portion of the detonator  10  when the detonator  10  is positioned within the enlarged bore portion  132  of the central bore  130 . Typically, the arms  150  are made of a flexible and resilient material that is capable of being bent or otherwise moved circumferentially outward, yet return to their original position once the movement force has been removed, (e.g. once the detonator is positioned within the detonator positioning device  100 ). Thus, the arms  150  will enclose and typically contact at least a peripheral surface of the head  18  of the detonator  10 . Although the plurality of arms  150  are depicted as having four arms, it would be understood that more or less arms may be sufficient to perform the stated function, i.e., to retain the detonator head. For instance, the plurality of arms  150  could include 2, 3, 4, 5, 6, 7, 8 or more arms. As shown in  FIGS.  4 - 9    and in an embodiment, the arms may include a retainer  152  positioned at a distal end of the arms to assist in retaining and maintaining the head  18  of the detonator  10  within the detonator positioning device  100 . As shown herein, the detonator head  18  is slidably received within the enlarged bore portion  132 , meaning the detonator head  18  is capable of sliding along at least a portion of the length of the enlarged bore portion  132  created by the arms  150 . In an embodiment, the plurality of arms  150  form at least a portion of a forward end  121  of the first portion  120  of the cylindrical body  110 . 
     Although not shown, it is possible to provide a window or opening in the cylindrical body  110  of the detonator positioning device  100  to facilitate visual verification of proper seating of the detonating cord (not shown), once the detonating cord has been connected to the assembly through the passage  102 . 
     Turning to the other end of the detonator positioning device  100 , a plurality of legs  140  are adapted to assist in positioning the device  100  within the perforating gun assembly  40 . In the embodiment shown in  FIGS.  4 - 8   , the plurality of legs  140  extend from the cylindrical body  110  toward the closed end  114  of the cylindrical body  110 . Similar to the arms  150 , the legs  140  may be made from a resilient material, and typically include protrusions  142  at the distal ends thereof adapted for positioning and holding the device  100  in place. In an embodiment, each protrusion  142  extends away from the cylindrical body  110 . 
     Although the plurality of legs  140  are depicted as having four legs, it would be understood that more or less legs may be sufficient to perform the stated function, i.e., to position the detonator positioning device within a perforating gun assembly. For instance, the plurality of legs  140  could comprise 3, 4, 5, 6, 7, 8 or more legs. Having more legs (or arms as referenced above) means each individual leg/arm is ultimately thinner than if fewer legs/arms are used. Similarly, thinner legs/arms means the individual legs/arms are less rigid, so there will ultimately be a trade-off in number of legs/arms selected between rigidity and/or flexibility of the detonator positioning device and the ability to stabilize the detonator positioning device within the perforating gun assembly and/or retain the detonator head, as the case may be. 
     Further, in an embodiment, each of the plurality of arms  150  and the plurality of legs  140  are adapted to provide a snap fit upon insertion of the detonator  10  within the central bore  130  and insertion of the cylindrical body  110  within the perforating gun assembly  40 . 
     As mentioned above, a third portion  124  may also be formed as a portion of the cylindrical body  110 . As shown in  FIGS.  4 - 9    and in an embodiment, the third portion  124  is formed integrally as part of the second portion  122 , while it is contemplated that the third portion  124  could be formed as a separate unit that is attached to the cylindrically body  110 . The third portion  124  has a forward face  125  and a rearward face  126 , and as shown in this embodiment, the plurality of legs  140  extend from the rearward face  126  of the third portion  124 . As depicted herein, the third portion  124 , extends circumferentially from an outer surface  123  of the second portion  122  and the third portion  124  is discontinuous about the outer surface  123  of the second portion  122  of the cylindrical body  110 , thus forming a plurality of sections  127 . Such an arrangement typically minimized overall weight and associated costs with fabricating the unit, while maintaining sufficient structural integrity to perform the stated functions. Further as depicted in this embodiment, the third portion  124  includes a circumferentially-extending lip  128  at a distal end  129  of the third portion  124 . In this arrangement, the distal end  129  is positioned opposite the plurality of legs  140 . The lip  128  is further adapted for positioning the detonator positioning device  100  by working in concert with the plurality of legs  140  to hold the detonator positioning device  100  in place within the perforating gun assembly  40 . 
     As stated above, the central bore  130  is adapted to receive and retain the detonator  10 , wherein the central bore  130  extends from the open end  113  to the closed end  114  of the cylindrical body  110 , and the enlarged bore portion  132  is positioned adjacent the open end  113 . Thus, when the detonator  10  is positioned within the central bore  110  of the detonator positioning device  100 , the detonator housing  11  extends along a length of the central bore  130 , while the detonator head  18  is received within the enlarged bore portion  132 . 
     In an embodiment, a line-out connector biasing member  25  is positioned or otherwise situated within the central bore  130  of the cylindrical body  110 , at a base  134  of the enlarged bore portion  132 , while a ground connector biasing member  28  is positioned or otherwise situated within the central bore  130  of the cylindrical body  110 , at a base  136  of the central bore  130 . Thus, the ground connector biasing member  28  is positioned within the central bore  130  between the detonator housing  11  of the detonator  10  and the closed end  114  of the cylindrical body  110 . In addition, a terminal  26  is typically positioned adjacent the line-out connector biasing member  25 . 
     In an embodiment, the terminal  26  is formed as a semi-round metallic material, with a slotted nipple  27  extending from an outer circumferential surface of the terminal  26 . The slotted nipple  27  is adapted for connection to the single electrical line-out wire needed to complete the electrical connection for this assembly (not shown). Although a slotted nipple  27  is depicted, it will be understood by those of ordinary skill in the art that other mechanisms may be provided to create the electrical connection between the single wire and the terminal  26 . 
     The line-out connector biasing member  25  and the ground connector biasing member  28  may be formed from a spring-like material for assisting in maintenance of physical and electrical contact between the line-in contact-initiating pin  38  extending from the bulkhead assembly  46 , and may also be formed of materials suitable to facilitate electrical connectivity. Typically, these components are also metallic, that is to say they are formed from an electrically conductive metal material. 
     Once received within the central bore  130 , therefore, the detonator  10  is electrically contactingly connected to the terminal  26  that is positioned between the line-out portion  22  of the detonating head  18  of the detonator  10  and the line-out connector biasing member  25 . Thus, once the detonator  10  is positioned within the central bore  130 , and the line-in contact-initiating pin  38  of the bulkhead assembly  46  makes contact with, and thus electrically contactably connects to the line-in portion  20  of the detonator head  18 . The line-out connector biasing member  25  will thus compress, causing the line-out portion  22  of the detonator head  18  to electrically contactably connect with the terminal  26 . The grounding connection will be discussed in more detail hereinbelow. 
     With reference to the closed end  114  of the detonator positioning device  100  and in an embodiment, a grounding strip or wire  29  is provided for completing the electrical connection and is also typically formed from an electrically conductive metal material. In an embodiment, the grounding strip  29  is embedded in the closed end  114  of the cylindrical body  110 . As shown in the embodiment of  FIGS.  4 - 7   , the grounding strip  29  extends from one side of the cylindrical body  110  through to the opposite side of the cylindrical body  110  in a way that a central portion of the grounding strip  29  is positioned adjacent one end of the ground connector biasing member  28 , opposite from the housing  11  of the detonator  10 . Thus, the ends of the grounding strip  29  extend beyond the outer surface of the cylindrical body  110 . When the detonator  10  is positioned within the central bore  130  of the detonator positioning device  100 , and the detonator  10  is compressed by the contact of the bulkhead assembly  44 , the ground connector biasing member  28  compresses and electrically contactably connects the ground portion  13  of the housing  11  with the ground connector biasing member  28  and the grounding strip  29 , which completes a ground loop via connection with the perforating gun housing  42 . As shown in  FIG.  4   , the grounding strip is deformed upon insertion of the detonator positioning device  100  into an end plate  180 , the entire assembly of which is inserted within the perforating gun body  42 , thus completing the ground loop/connection. 
     As mentioned above, and with particular reference to  FIGS.  4 ,  6  and  7   , the cylindrical body  110  may be formed as a multi-part cylindrical body  110 ′ including at least a first part  111  and a second part  112 . As shown herein, the first part  111  of the cylindrical body  110  can be removably connected, (or otherwise joined, fastened, united) to the second part  112  of the cylindrical body  110 ′ to form an assembled cylindrical body  109 . In this way, each of the first part  111  and the second part  112  include at least a first portion  120 ′ and a second portion  122 ′, the assembled cylindrical body  109  comprising an open end  113 ′, a closed end  114 ′, and a central bore  130 ′ adapted for receiving the detonator  10 , the central bore  130 ′ extending along at least some of a length of the assembled cylindrical body  109 , the central bore  130 ′ including an enlarged bore portion  132 ′ adjacent the open end  113 ′ of the assembled cylindrical body  109 . In this embodiment, a plurality of arms  150 ′ extend toward the open end  113 ′ of the assembled cylindrical body  109  and at least partially enclose the enlarged bore portion  132 ′ of the central bore  130 ′. Further, each of the plurality of arms  150 ′ include a retainer  152 ′ adapted to retain the detonator head  18  of the detonator  10  positioned within the enlarged bore portion  132 ′ of the central bore  130 ′. In an embodiment, a plurality of legs  140 ′ extend from the assembled cylindrical body  109  and toward the closed end  114 ′ of the assembled cylindrical body  109 , and each of the plurality of legs  140 ′ include a protrusion  142 ′ extending away from the assembled cylindrical body  109  and adapted for positioning the assembled cylindrical body  109  in the perforating gun assembly  40 . 
     Since the assembled cylindrical body  109  according to this embodiment requires assembly in the field, a plurality of couplers  170  are provided that are adapted for attaching the first part  111  of the assembled cylindrical body  109  to the second part  112  of the assembled cylindrical body  109 . It would be understood by one of ordinary skill in the art that it is possible to attach the first part  111  to the second part  112  by any number of fasteners  172 , including screws, bolts/nuts and the like that may be received in a socket or cavity  174  through threading, frictional fit and the like. As shown best in  FIG.  7    and in an embodiment, the fastener  172  is a protrusion including a distal nob extending from the first part  111 , which is matingly inserted into an oppositely positioned cavity  174  of the second part  112  (not shown). In an embodiment, the fastener  172  snap fits into the cavity  174 . 
     In an embodiment, the first part  111  and the second part  112  may be configured as symmetrical or non-symmetrical halves. 
     According to an aspect the perforating gun assembly  40  and a method for assembling the perforating gun assembly  40  including a wireless detonator  10  and detonator positioning device  100  as described hereinabove is provided. 
     In an aspect, the method of assembling the perforating gun assembly  40  while using a semi-wired electrical connection includes at least the following steps: positioning the detonator positioning device  100  within the perforating gun assembly  40 , the detonator positioning device  100  including the central bore  130 ; positioning the ground connector biasing member  28  at the base  136  of the central bore  130 ; positioning the line-out connector biasing member  25  at the base  134  of the enlarged portion  132  of the central bore  130 ; positioning the terminal  26  for receiving the single line-out wire adjacent the line-out connector biasing member  25 ; positioning the wireless detonator  10  within the central bore  130  such that the housing  11  of the detonator  10  extends along at least a portion of the central bore  130  and the ground portion  13  of the housing  11  electrically contacts the ground connector biasing member  28 , and positioning the head  18  of the detonator  10  within the enlarged portion  132  of central bore  130  such that the line-out portion  22  of the detonator  10  electrically contacts the terminal  26 , and the line-in contact-initiating pin  38  electrically contacts the line-in portion  20  of the detonator  10 . 
     According to an aspect, the step of positioning the detonator positioning device  100  within the perforating gun assembly  40  includes positioning the detonator positioning device within a support member or end plate  180 , as seen, for instance,  FIGS.  4 ,  5  and  7 - 10   , and as discussed briefly above. As shown herein the end plate  180  has an inner cavity that is sufficiently sized to receive the closed end  114  of the cylindrical body  110 , and in particular to receive at least the second portion  122  (and/or the third portion  124 ) by interlocking and/or snap-fit action with the plurality of legs  140  at a rearward end of the endplate  180  (see  FIGS.  4 ,  5  and  7   ) and by abutting the circumferentially-extending lip against the outer surface of the end plate  180  (see in particular  FIGS.  8  and  9   ) at the opposite end of the end plate  180 . Similarly, the outer dimension or exterior surface of the end plate  180  is sufficiently sized to be received within the perforating gun barrel  42 . Although not specifically shown, it will be understood by one of ordinary skill in the art that it is possible to form various members and components described herein as integrated units. 
     Turning to the embodiment found in  FIG.  10   , a separate component is provided to facilitate the ground loop discussed hereinabove. As shown herein, a grounding rib  182  is attached to the exterior surface of the end plate  180  to complete the ground loop upon positioning of the detonator positioning device  100  within the perforating gun assembly  40 . In an embodiment, the grounding rib  182  is formed as a long, narrow, thin, semi-curved, flexible and resilient, metallic member, as seen best in  FIG.  11   . As shown herein, a securing mechanism  184  is provided for attaching the grounding rib  182  to the exterior surface of the end plate  180 . Thus, when the assembly is inserted into the perforating gun barrel  42 , the grounding rib  182  flexed circumferentially inwardly to complete the ground loop. 
     As used herein, “hold” means to enclose within bounds, to limit or hold back from movement or to keep in a certain position. The detonator positioning device  100  is positioned within the perforating gun assembly  40  and functions to receive and hold in place the detonator  10  according to an embodiment. In addition, the detonator positioning device  100  also functions to provide electrical contacting components for wirelessly-connectably electrically receiving the detonator  10 , while providing for a single wired connection to the detonator positioning device  100  itself. 
     The components and methods illustrated are not limited to the specific embodiments described herein, but rather, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the device and method include such modifications and variations. Further, steps described in the method may be utilized independently and separately from other steps described herein. 
     While the device and method have been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope contemplated. In addition, many modifications may be made to adapt a particular situation or material to the teachings found herein without departing from the essential scope thereof. 
     In this specification and the claims that follow, reference will be made to a number of terms that have the following meanings. The singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. 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. Terms such as “first,” “second,” “forward,” “rearward,” 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. 
     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.” 
     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.” 
     Advances in science and technology may make equivalents and substitutions possible that are not now contemplated by reason of the imprecision of language; these variations should be covered by the appended claims. This written description uses examples to disclose the device and method, including the best mode, and also to enable any person of ordinary skill in the art to practice the device and method, including making and using any devices or systems and performing any incorporated methods. The patentable scope thereof is defined by the claims, and may include other examples that occur to those of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.