(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2013/0126237 A1
`May 23, 2013
`(43) Pub. Date:
`Burton et al.
`
`US 2013 0126237A1
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`(54)
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`PASS-THROUGH BULKHEAD CONNECTION
`SWITCH FOR A PERFORATING GUN
`
`Inventors:
`
`Assignee:
`
`Applicant: INTERNATIONAL STRATEGIC
`ALLIANCE, LC, Woods Cross, UT
`(US)
`Robert Lane Burton, Woods Cross, UT
`(US); Brandon Lane Burton,
`Kayesville, UT (US); Thomas Robert
`Wilenski, Ogden, UT (US)
`INTERNATIONAL STRATEGIC
`ALLIANCE, LC, Woods Cross, UT
`(US)
`Appl. No.: 13/679,122
`Filed:
`Nov. 16, 2012
`Related U.S. Application Data
`Provisional application No. 61/562,844, filed on Nov.
`22, 2011.
`
`
`
`Publication Classification
`
`(2006.01)
`(2006.01)
`
`Int. C.
`E2IB 43/185.
`H02G9/00
`U.S. C.
`CPC .............. E2IB 43/1185 (2013.01); H02G9/00
`(2013.01)
`USPC ............................................. 175/2; 174/70 R
`
`ABSTRACT
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`Embodiments of the present invention relate to systems,
`methods, and apparatus for reliably communicating a deto
`nation signal and perforating oil and/or gas well casings.
`Particularly, at least one embodiment includes a pass-through
`bulkhead connection switch that can reliably withstand high
`operating temperatures and pressures. Such pass-through
`bulkhead connection Switch can be used in perforating gun
`assemblies and can eliminate or reduce incidents of failed
`detonations.
`
`GHD
`1004
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`Patent Application Publication
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`US 2013/O126237 A1
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`??????????????????????????????????????????????????????????????????????????????????????????????????????
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`FIG. 1B
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`Patent Application Publication
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`May 23, 2013 Sheet 3 of 6
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`US 2013/O 126237 A1
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`May 23, 2013
`
`PASS-THROUGH BULKHEAD CONNECTION
`SWITCH FOR A PERFORATING GUN
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`0001. The present application claims the benefit of and
`priority to U.S. Provisional Application No. 61/562,844,
`entitled “Container or Housing for the Transfer of Energy
`Within a Material Without Any Motion of the Material as a
`Whole.” filed on Nov. 22, 2011, the entirety of which is
`incorporated herein by this reference.
`
`BACKGROUND OF THE INVENTION
`0002 1. The Field of the Invention
`0003. This invention relates to systems, methods, and
`apparatus for communicating detonation and control signals
`in a perforating gun assembly.
`0004 2. Background and Relevant Art
`0005. During oil or gas extraction operations, a well cas
`ing, including the Surrounding cement layers, can be perfo
`rated to access particular areas or Zones of oil and/or gas
`deposits. Particularly, such perforations can create flow con
`duits, which can channel oil and gas from the deposit areas
`into the well. In some instances, a hydraulic fluid can be
`pumped into the well and through the perforations to produce
`fracking (or hydraulic fracturing) in the Surrounding rock
`layers, which can facilitate increased flow of oil and/or gas
`into the well.
`0006 Commonly, the perforations are made with a perfo
`rating gun (or a perforating gun assembly) that is loaded with
`explosive charges (e.g., shape charges). Such perforating gun
`can have multiple charges positioned about the circumference
`thereof. Accordingly, as the perforating gun fires or detonates
`the charges, resulting blasts can create perforations at mul
`tiple locations about the circumference of the well casing.
`0007. A perforating string incorporating a single or mul
`tiple perforating guns can be lowered into the well and the
`perforating guns can be positioned at desired depths. Subse
`quently, a detonation signal from a detonation controller
`(typically located at ground level) can be sent to the perforat
`ing gun, detonating the charges in a desired sequence. For
`instance, the perforating string may contain two perforating
`guns, and the lower perforating gun may be fired first, while
`the upper perforating gun can be fired thereafter.
`0008 Commonly, Zones that contain desirable amounts of
`oil and/or gas deposits can be relatively thin but numerous.
`Such Zones can be separated from each other by nonproduc
`tive sections. Hence, using a perforating string with multiple
`perforating guns can be a most efficient procedure for access
`ing the oil and gas deposits near the well. Moreover, to access
`the oil and/or gas deposits, the multiple perforating guns can
`be selectively fired, to perforate the well casing adjacent the
`desired Zones.
`0009. In some instances, the signal from the surface passes
`through a connection Switch and triggers a detonator. The
`detonator can then ignite a detonating cord (e.g., Primacord),
`which can, in turn, detonate the explosive charges of the
`perforating gun. Commonly, connection Switches, which
`pass the signal from the Surface to the detonator, have various
`moving, mechanical components. Such mechanical compo
`nents can increase the risk of failure of the connection Switch.
`For example, connection Switches can be subjected to high
`pressures (e.g., static pressure within the well and increased
`
`pressure from a blast wave created after detonation of the
`explosive charges) and high temperatures.
`0010. If a connection switch fails, usually the entire per
`forating string, including all of the perforating guns, is with
`drawn out of the well to remedy the failure. Because some of
`the perforating guns may contain undetonated explosive
`charges extreme precautions typically must be taken to avoid
`surface detonation. Furthermore, usually, to replace the failed
`connection Switches, the perforating guns are disassembled,
`which can be dangerous, time consuming, and expensive.
`0011. Accordingly, there are a number of disadvantages in
`devices, systems, and methods for communicating detonation
`signals in perforating gun assemblies that can be addressed.
`
`BRIEF SUMMARY OF THE INVENTION
`0012 Embodiments of the present invention provide sys
`tems, methods, and apparatus for reliably communicating a
`detonation signal or command and perforating oil and/or gas
`well casings. Particularly, at least one embodiment includes a
`pass-through bulkhead connection Switch that can reliably
`withstand high operating temperatures and pressures. Such
`pass-through bulkhead connection Switch can be used in per
`forating gun assemblies and can eliminate or reduce incidents
`of failed detonations. Accordingly, the pass-through bulk
`head connection Switch can lead to reduced accidents during
`oil and gas drilling and/or exploration costs. Furthermore,
`reduction or elimination of failed detonations also can reduce
`or eliminate the need for withdrawing the perforating gun
`assemblies from the well before completing well perfora
`tions. Consequently, the reliable pass-through bulkhead con
`nection Switch can reduce instances of Surface detonation,
`which also can improve worker safety.
`0013. One embodiment can include a pass-through bulk
`head connection Switch that has no moving parts. The pass
`through bulkhead connection Switch is configured to provide
`a reliable connection for transmitting a detonation signal
`from a detonation controller located at ground level to a
`detonation mechanism of a perforating gun assembly config
`ured to be positioned in a well and utilized for perforating a
`well casing. The pass-through bulkhead connection Switch
`can include an insulating body comprising insulating mate
`rial. Furthermore, such insulating material can be noncorro
`sive and/or acid resistant. The insulating body can be sized
`and configured to be secured within an opening of an isolation
`Subassembly of the perforating gun assembly. Furthermore,
`the insulating body can have at least one O-ring grove in an
`outer Surface thereof. The insulating body also can have an
`aperture passing therethrough. The pass-through bulkhead
`connection Switch can further include a conductive pin that
`may have a front portion, a back portion, and a center portion
`that can be larger or smaller than one or more of the front
`portion and the back portion. The center portion of the con
`ductive pin also can be secured within the aperture of the
`insulating body. Moreover, the conductive pin can be config
`ured to transmit the detonation signal to the perforating gun
`assembly located in the well.
`0014) Another embodiment can include a system for mak
`ing perforations in a well casing at multiple depth locations in
`a sequential manner. In other words, multiple perforating gun
`assemblies can be selectively fired (in aparticular sequence or
`without any particular sequence). Such perforations can be
`configured to access one or more of oil and gas deposits
`disposed within a rocklayer below ground and to channel the
`same into the well. The system can include a first perforating
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`gun assembly that can have a first plurality of charges and a
`first detonation mechanism configured to detonate the first
`plurality of charges. The system also can incorporate a second
`perforating gun assembly that can have a second plurality of
`charges, an isolation Subassembly, and a second detonation
`mechanism located in the isolation Subassembly. The second
`detonation mechanism can be configured to detonate the sec
`ond plurality of charges. Additionally, the system can include
`a pass-through bulkhead connection Switch in electrical com
`munication with the first detonation mechanism and with the
`second detonation mechanism. The pass-through bulkhead
`connection Switch can be configured to communicate a deto
`nation signal to the first detonation mechanism. The pass
`through bulkhead connection Switch can be further config
`ured to prevent or reduce increase of pressure about the
`second detonation mechanism from a blast wave formed after
`the detonation of the first plurality of charges.
`0.015
`Additional embodiments can include a method of
`reliably, sequentially or non-sequentially transmitting deto
`nation signals to detonation mechanisms of multiple perfo
`rating gun assemblies and detonating explosive charges
`housed in the perforating gun assemblies. Such method can
`include isolating a first detonation mechanism in a first iso
`lation chamber of a first perforating gun assembly by sealing
`the first isolation chamber with a pass-through bulkhead con
`nection Switch. The first detonation mechanism can be in
`electrical communication with the pass-through bulkhead
`connection Switch, and the pass-through bulkhead connec
`tion switch can be in electrical communication with a second
`detonation mechanism. The method also can include detonat
`ing a second plurality of charges located in a second perfo
`rating gun assembly by sending a detonation signal through
`the pass-through bulkhead connection Switch to the second
`detonation mechanism. Furthermore, the pass-through bulk
`head connection Switch can be configured to at least partially
`block a blast wave generated by the detonation of the second
`plurality of charges.
`0016. Additional features and advantages of exemplary
`embodiments of the invention will be set forth in the descrip
`tion which follows, and in part will be obvious from the
`description, or may be learned by the practice of Such exem
`plary embodiments. The features and advantages of Such
`embodiments may be realized and obtained by means of the
`instruments and combinations particularly pointed out in the
`appended claims. These and other features will become more
`fully apparent from the following description and appended
`claims, or may be learned by the practice of Such exemplary
`embodiments as set forth hereinafter.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`0017. In order to describe the manner in which the above
`recited and other advantages and features of the invention can
`be obtained, a more particular description of the invention
`briefly described above will be rendered by reference to spe
`cific embodiments thereof which are illustrated in the
`appended drawings. For better understanding, the like ele
`ments have been designated by like reference numbers
`throughout the various accompanying figures. Understanding
`that these drawings depict only typical embodiments of the
`invention and are not therefore to be considered to be limiting
`of its scope, the invention will be described and explained
`with additional specificity and detail through the use of the
`accompanying drawings in which:
`
`0018 FIG. 1A illustrates a cross-sectional schematic view
`of a perforating string in a well in accordance with one
`embodiment of the present invention;
`0019 FIG. 1B illustrates a cross-sectional schematic view
`of firing of a first perforating gun assembly in a perforating
`string in accordance with one embodiment of the present
`invention;
`0020 FIG. 2 illustrates a section view of an isolation sub
`assembly in accordance with one embodiment of the present
`invention;
`0021
`FIG. 3 illustrates a cross-sectional view of a middle
`section of an isolation Subassembly in accordance with one
`embodiment of the present invention;
`0022 FIG. 4A illustrates a side view of a pass-through
`bulkhead connection Switch in accordance with one embodi
`ment of the present invention;
`0023 FIG. 4B illustrates a cross-sectional view of the
`pass-through bulkhead connection switch of FIG. 4A;
`0024 FIG. 5 illustrates a cross-sectional view of a pass
`through bulkhead connection Switch in accordance with
`another embodiment of the present invention; and
`0025 FIG. 6 illustrates a cross-sectional view of a pass
`through bulkhead connection Switch in accordance with yet
`another embodiment of the present invention.
`
`DETAILED DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`0026. Embodiments of the present invention provide sys
`tems, methods, and apparatus for reliably communicating a
`detonation signal or command and perforating oil and/or gas
`well casings. Particularly, at least one embodiment includes a
`pass-through bulkhead connection Switch that can reliably
`withstand high operating temperatures and pressures. Such
`pass-through bulkhead connection Switch can be used in per
`forating gun assemblies and can eliminate or reduce incidents
`of failed detonations. Accordingly, the pass-through bulk
`head connection Switch can lead to reduced accidents during
`oil and gas drilling and/or exploration costs. Furthermore,
`reduction or elimination of failed detonations also can reduce
`or eliminate the need for withdrawing the perforating gun
`assemblies from the well before completing well perfora
`tions. Consequently, the reliable pass-through bulkhead con
`nection Switch can reduce instances of Surface detonation,
`which also can improve worker safety.
`0027. The pass-through bulkhead connection switch also
`can provide a reliable isolation and insulation for the detona
`tion signal sent from a detonation controller located at ground
`level to the perforating gun assembly (e.g., to a detonation
`mechanism). More specifically, the pass-through bulkhead
`connection Switch can facilitate transmission of the detona
`tion signal in a harsh environment, such as a high tempera
`tures and pressures, as described below. Moreover, the pass
`through bulkhead connection Switch can reduce instances of
`short-circuited connections, such as short circuits that can
`occur between an isolation Subassembly of the perforating
`gun assembly and the pass-through bulkhead connection
`Switch. Thus, the pass-through bulkhead connection Switch
`can reduce or eliminate detonation failures associated with
`Such short circuits.
`0028. In some embodiments, the pass-through bulkhead
`connection Switch can comprise an insulating portion and an
`electrically conductive portion. The electrically conductive
`portion of the pass-through bulkhead connection Switch can
`transmit the detonation signal from the detonation controller
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`to the detonation mechanism of the perforating gun assembly.
`Furthermore, as the detonation signal is transmitted through
`the conductive portion of the pass-through bulkhead connec
`tion Switch, the insulating portion of the pass-through bulk
`head connection Switch can prevent short-circuiting the deto
`nation signal, for instance, on metallic components of the
`perforating gun assembly. Moreover, the insulating portion of
`the pass-through bulkhead connection Switch can reduce or
`prevent RF interference with the detonation signal.
`0029. In some instances, a perforating String can incorpo
`rate multiple perforating gun assemblies, which can perforate
`different sections of the well casing. Also, the perforating gun
`assemblies can fire or detonate in a predetermined detonation
`sequence. For example, the detonation sequence can start
`with the lowest perforating gun assembly and can proceed in
`an upward direction, sequentially. In some embodiments, the
`pass-through bulkhead connection Switch can isolate at least
`one chamber of the perforating gun assembly, thereby pre
`venting a rapid increase in pressure therein, which can result
`from a blast wave created after the detonation of the charges.
`Accordingly, as one perforating gun assembly fires, compo
`nents of the Subsequent perforating guns assemblies can
`remain unaffected and/or undamaged by the blast wave. In
`other words, the pass-through bulkhead connection Switch
`can prevent propagation of the blast wave from the explosion
`into isolated chambers of unfired perforating gun assemblies.
`0030 Consequently, the pass-through bulkhead connec
`tion Switch can facilitate safe and reliable sequential or non
`sequential detonation of the charges. More specifically, as
`noted above, failure to detonate can be expensive and danger
`ous, as Such failure may require the ground crew to withdraw
`the perforating string from the well and disassemble and
`reassemble the perforating string. Thus, preventing damage
`to and/or failure of various components (e.g., detonation
`mechanism) of the unfired perforating gun assemblies, which
`may result from a Sudden increase of pressure caused by the
`blast wave, can lead to safer and more reliable detonations.
`Additionally, as noted above, the pass-through bulkhead con
`nection Switch can at least partially block triggering signals
`from Surrounding RF Sources, which also can increase reli
`ability of detonations.
`0031
`Referring now to the Figures, FIG. 1A illustrates a
`perforating string 100 lowered into a well 10, for creating
`perforations in a well casing 12. The perforating string 100
`can have a single or multiple perforatinggunassemblies. Such
`as perforating gun assemblies 110a, 110b. The perforating
`gun assembly 110a can be the same as or similar to the
`perforating gun assembly 110b. Thus, references to and
`description of the perforating gun assembly 110a and/or any
`components thereof is equally applicable to the perforating
`gun assembly 110b, and vice versa.
`0032. As noted above, the perforating gun assembly 110a
`can be located along the length of the perforating string 100.
`Particularly, as the perforating string 100 is lowered into the
`well 10, the perforating gun assemblies 110a, 110b can be
`positioned at locations of gas and/or oil deposits, such that
`perforations through the well casing can allow the gas and/or
`oil to flow into the well.
`0033. In some embodiments, the perforating gun assem
`blies 110a, 110b can include respective charge carriers 120a,
`120b and isolation subassemblies 130a, 130b. The charge
`carriers 120a, 120b can hold multiple charges 140a, 140b
`(e.g., shape charges) that, after detonation, can perforate the
`well casing 12 and a surrounding cement layer 14. In light of
`
`this disclosure, those skilled in the art should appreciate that
`the charges 140a, 140b can have any suitable arrangement on
`or in the charge carriers 120a, 120b, which can vary from one
`embodiment to the next.
`0034. As described below in greater detail, the isolation
`subassemblies 130a, 130b can house various components,
`including the detonation mechanism, which can trigger deto
`nation of the charges 140a, 140b. For instance, the detonation
`mechanisms of the isolation subassemblies 130a, 130b can
`ignite detonating cords 150a, 150b, which can trigger the
`detonation of the charges 140a, 140b. Furthermore, the deto
`nation mechanism of the perforating gun assembly 110a can
`be in electrical communication with the perforating gun
`assembly 110b, which can be located at a lower position along
`the perforating string 100. Hence, the detonation signal can
`be sent first to the perforating gun assembly 110b and can,
`Subsequently, proceed from the perforating gun assembly
`110b to the perforating gun assembly 110a. In other words,
`the perforating gun assembly 110b can fire first, and the
`perforating gun assembly 110a can fire thereafter.
`0035) To fire the perforating gun assemblies 110a and/or
`110b, the perforating string 100 can be connected to a deto
`nation controller 160. For instance, a cable 170 can connect
`the perforating gun assemblies 110a, 100b to the detonation
`controller 160. The detonation controller 160 can send the
`detonation signal down the cable 170 to the perforating gun
`assemblies 110a, 110b (i.e., to the detonation mechanisms
`thereof). In some instance, the detonation signal can be a
`pulse or series of pulses of alternating or direct current having
`predetermined frequency (or frequencies and addresses). For
`example, the perforating gun assembly 110b can be triggered
`by a first pulse (having a first frequency) and the perforating
`gun assembly 110a can be triggered by a second pulse (hav
`ing a second frequency). Hence, the detonation controller 160
`can stagger and sequence firings of the perforation gun
`assemblies 110a, 110b in a predetermined manner.
`0036 Furthermore, the isolation subassemblies 130a,
`130b can at least partially isolate (or insulate) various com
`ponents of the respective perforating gun assemblies 110a,
`110b from a blast wave created during the firing of the other
`perforating gun assembly. For example, as illustrated in FIG.
`1B, the second perforating gun assembly 110b can detonate
`the charges 140b located in the charge carrier 120b. Particu
`larly, the detonation mechanism located in the isolation Sub
`assembly 130b can ignite the detonating cord 150b, which
`can detonate the charges 140b.
`0037. Such detonation of the charges 140b can perforate
`the well casing 12 and the Surrounding cement layer 14 of the
`well 10. In addition to or in lieu of perforating the well casing
`12, detonation of the charges 140b can create a blast wave 16
`(i.e., a pressure wave), which can propagate within the per
`forating string 100. The localized pressure created by the
`blast wave 16 can be up to 30,000 psi per second or 20 Terapsi
`per nanosecond. Furthermore, the blast wave 16 also can
`create an increase in temperature of the Surrounding air (and/
`or other gases), which can travel together with the blast wave
`16.
`0038. In some embodiments, the detonation mechanisms
`can be located in respective upper portions 180a, 180b of the
`isolation subassemblies 130a, 130b. The detonation mecha
`nism housed in the isolation subassembly 130a can be dam
`aged by the increased pressure caused by the blast wave 16
`and/or by increased temperature that may be caused by heated
`air and gases traveling with the blast wave 16. As noted above,
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`damage to the detonation mechanism of the perforating gun
`assembly 110a can lead to unintended firing outside of the
`intended pay Zones or to the failure of the perforating gun
`assembly 110a to fire.
`0039. In some instances, the blast wave 16 can enter a
`lower portion 190a of the isolation subassembly 130a. To
`prevent or minimize damage to the detonation mechanism
`located in the upper portion 180a of the isolation subassem
`bly 130a, the isolation subassembly 130a can block or
`impede propagation of the blast wave 16 from the lower
`portion 190a to the upper portion 180a thereof, as described
`below in greater detail. Consequently, blocking or impeding
`propagation of the blast wave 16 can reduce or eliminate
`increase in pressure and/or temperature in the environment
`Surrounding the detonation mechanism, which can lead to
`reduction or elimination of detonation failures caused by
`damage to the components (e.g., detonation mechanism) of
`the unfired perforating gun assembly 110a.
`0040 FIG. 2 illustrates an exemplary embodiment of an
`isolation subassembly 130, which can block or impede propa
`gation of the blast wave from a lower portion 190 to an upper
`portion 180 thereof. Particularly, the upper portion 180 can
`comprise a cap 200 that can couple to a main sub body 210.
`Opposite to the upper portion 180, the lower portion 190 can
`comprise a lower gun assembly 220. The lower gun assembly
`220 can couple to a first end of a middle section 230. On a
`second end (opposite to the first end), the middle section 230
`can couple to the main body 210. In at least one embodiment,
`the various components of the isolation subassembly 130 can
`couple have threaded connections.
`0041. A detonating cord 150 can exit the cap 200 and can
`connect to the charges (as illustrated in FIGS. 1A-1B). Addi
`tionally, a first wire 240 can pass through the cap 200 and can
`connect to the detonation mechanism, such as a Switch/deto
`nator 250. For instance, the Switch/detonator 250 can be a
`combination of a Switching device (e.g., a Selectronic Switch
`from DYNAenergetics) and a detonator. Hence, the switch/
`detonator 250 can receive the detonation signal from the
`detonation controller and can cause the detonator to ignite the
`detonating cord 150. As mentioned above (and further
`described below), the switch/detonator 250 can be located in
`the upper portion 180 of the isolation subassembly 130. It
`should be noted that those skilled in the art should appreciate
`that the wires in the perforating gun assemblies can have a
`conductive portion or core, which can be surrounded by or
`encased in insulating material.
`0042. The detonation signal can be sent from the detona
`tion controller over the first wire 240. As described above,
`multiple perforating gun assemblies can be controlled and
`fired in a single deployment. In some instance, the detonation
`signal can be transmitted from the switch/detonator 250
`through a second wire 260, which can be in electrical com
`munication with the detonation mechanism of the Subsequent
`perforating gun assembly. Furthermore, the Switch/detonator
`250 can be configured to fire any perforating gun assembly or
`multiple perforating gun assemblies in any desired sequence.
`0043. In one or more embodiments, the second wire 260
`can be connected to a pass-through bulkhead connection
`switch 270. The pass-through bulkhead connection switch
`270 can be located in the middle section 230. Specifically, the
`pass-through bulkhead connection switch 270 can be secured
`within an opening in the middle section 230. The pass
`through bulkhead connection switch 270 can connect the
`Second wire 260 to a third wire 280. The third wire 280 can be
`
`connected to the detonation mechanism of the Subsequent
`perforating gun assembly. Accordingly, the detonation signal
`can proceed from the switch/detonator 250 down the second
`wire 260, through the pass-through bulkhead connection
`switch 270, and down the third wire 280 to the detonation
`mechanism of the Subsequent perforating gun assembly.
`0044 Particularly, the second wire 260 can be connected
`to a conductive pin 275 of the pass-through bulkhead connec
`tion switch 270, as further described below. The third wire
`280 can be connected to a second conductive pin 285. When
`the middle section 230 is coupled to the lower gun assembly
`220, the conductive pin 275 can be in contact with the second
`conductive pin 285, thereby connecting the second wire 260
`to the third wire 280. In other words, the pass-through bulk
`head connection switch 270 can be in electrical connection
`with the second conductive pin 285, which together, can
`connect the second wire 260 to the third wire 280. Thus, the
`detonation signal can travel along the second wire 260 to the
`third wire 280.
`0045. As can be seen, the isolation subassembly 130 can
`have two isolation chambers: a first isolation chamber 290
`and a second isolation chamber 300. In one or more embodi
`ments, the pass-through bulkhead connection switch 270 can
`seal the first isolation chamber 290 from the second isolation
`chamber 300, such that the pressure produced within the first
`isolation chamber 290 cannot be communicated to the second
`isolation chamber 300 and vice versa. Additionally, to seal
`and isolate the first isolation chamber 290 and second isola
`tion chamber 300 from each other, the isolation subassembly
`130 can incorporate O-rings 340a, 340b. Particularly, the
`O-rings 340a, 340b can create a pressure seal between the
`second end of the middle section 230 and the main sub body
`210 and between a first end of the middle section 230 and the
`lower gun assembly 220. Hence, the second end of the middle
`section 230 and the main sub body 210 can define the first
`isolation chamber 290, which can be sealed and isolated from
`the second isolation chamber 300 by the O-rings 34.0a and by
`the pass-through bulkhead connection switch 270.
`0046. In light of this disclosure, those skilled in the art
`should appreciate that the first and second isolation chambers
`290, 300 can be sealed (e.g., via O-rings 340a) from gases,
`liquids, slurries, and the like. For example, in Some instances,
`liquid (e.g., mud) can be pumped into the well, which can
`create hydrostatic pressure of about 15,000 psi at the location
`of the perforating gun assembly. Hence, in at least one
`embodiment, the first and second isolation chambers 290,300
`can be sealed from liquid leaks, which may otherwise result
`from the pressurized liquid Surrounding the perforating gun
`assembly and the isolation subassembly 130.
`0047. As noted above, the switch/detonator 250 can be
`isolated (or insulated) from the blast wave and, thus, pro
`tected from localized pressure and/or temperature increases,
`which can damage or destroy the switch/detonator 250. More
`specifically, the switch/detonator 250 can be located in the
`second isolation chamber 300. Accordingly, the switch/deto
`nator 250 can be at least partially insulated from the pressure
`and temperature increases that can occur within the first iso
`lation chamber 290.
`0048. In some instances, there may be an imperfect seal
`between the first isolation chamber 290 and second isolation
`chamber 300. Thus, over time, the pressure across the first
`isolation chamber 290 and second isolation chamber 300 may
`equalize. However, a Sudden and Substantial increase in pres
`sure within one of the first isolation chamber 290 may not
`
`Page 11 of 16 (PGR2021-00078)
`G&H DIVERSIFIED MANUFACTURING, LP v. DYNAENERGETICS EUROPE GMBH
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`US 2013/O 126237 A1
`
`May 23, 2013
`
`produce an equally Sudden and Substantial increase within the
`second isolation chamber 300, and vice versa.
`0049. For example, the blast wave can create a sudden and
`Substantial increase in pressure in the first isolation chamber
`290. The pass-through bulkhead connection switch 270, how
`ever, can prevent the blast wave from propagating from the
`first isolation chamber 290 into the second isolation chamber
`300. Furthermore, as noted above, the pass-through bulkhead
`connection switch 270 can provide elect