Abstract:
Exemplary embodiments are directed to a method and system for defining addresses for a networked switching system, controlling and enabling user control over the detonation of a plurality of explosive devices, and setting a plurality of charges located remotely down-hole beneath the earth&#39;s surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority to and benefit from U.S. Provisional Patent Application No. 61/840,457 titled “Methods And Systems For Controlling Networked Electronic Switches For Remote Detonation Of Explosive Devices” filed on Jun. 27, 2013, the entire content of which is herein expressly incorporated by reference. 
     
    
     FIELD 
       [0002]    The following disclosure generally relates to methods and systems for setting a plurality of explosive devices located remotely down-hole beneath the earth&#39;s surface using a networked switching system, and controlling the detonation of the plurality of explosive devices using network addresses corresponding to the explosive devices. 
       BACKGROUND 
       [0003]    Hydraulic fracturing, also known as “fracking,” is a process for drilling beneath the earth&#39;s surface to extract natural gas from shale rock. Once the rock formation is reached, a combination of water, sand and chemicals are inserted into the well to fracture the rock and release gas. 
         [0004]    The first step for fracking is to drill and case a well A hole is drilled down vertically and then surface casing is inserted into the hole. Cement is pumped through the casing to seal off the wellbore from fresh water in the earth. After further vertical drilling is completed, a down hole drilling motor is inserted to begin horizontal drilling. When a target distance is reached, production casing is inserted into the full length of the wellbore, and cement is pumped down the casing and out through the hole. Once this step is completed, the hole has been dug and the casing prevents hydrocarbons from seeping out as they are brought to the surface. 
         [0005]    The next step is to “perf and frack” the area. “Perfing” is accomplished via a “perforating gun,” which is lowered into the casing. Typically, a plurality of perforating guns, along with corresponding switch subs, are connected to form a gun train. The switch subs include an electronic switch that sends a signal to detonate the corresponding gun. The perf gun is loaded with extremely high explosives. The gun train is lowered by a wireline into the casing, and an electrical current is sent down the hole to set off the explosives in the perf gun. The explosives shoot small holes into the casing and cement. The perf gun explosives can develop a blast pressure on the order of 10 million PSI. The extreme pressures are necessary to overcome both the hydrostatic pressure and the yield pressure of the steel pipe of the perf gun. 
         [0006]    After the explosions, the gun train is then pulled from the well. The small holes created by the perf guns provide perforations for the “fracking” stage, which occurs after the gun train is removed. 
         [0007]    Finally, the well is “fracked” by sending water, sand and lube into the wellbore under high pressure. The holes in the walls of the well that were blown by the perf gun create channels for this “fracking fluid” to reach the surrounding shale. The extreme pressure causes the shale to fracture, creating a path that allows released gas to flow to the wellbore. Once fracking is complete, a permanent wellhead is installed and a pipeline is constructed to transport the gas. 
       SUMMARY OF THE DISCLOSURE 
       [0008]    Exemplary embodiments of the disclosure are directed to a method and system for defining addresses for a networked switching system, controlling and enabling user control over the detonation of a plurality of explosive devices, and setting a plurality of charges located remotely down-hole beneath the earth&#39;s surface. 
         [0009]    For example, an exemplary embodiment of the disclosure is directed to an addressable switch system that includes a plurality of perforating gun assemblies that are lowered into a wellbore. Each of the plurality of perforating gun assemblies includes a switch sub comprising a network communications module with a unique network address for communications over a network bus, and a perforating gun comprising explosives. The addressable switch system also includes a control panel for at least one of monitoring and controlling the plurality of perforating gun assemblies and a top sub controller that is also lowered into the wellbore. The top sub controller has a first communications module to communicate with the control panel via a wireline and a second communications module to communicate with the plurality of perforating gun assemblies via the network bus. The control panel includes an interface to select one perforating gun assembly from the plurality of perforating gun assemblies based on the unique network address of the switch sub corresponding to the selected perforating gun assembly. The control panel interface can also provide a command signal that at least one of arms and fires the perforating gun corresponding to selected perforating gun assembly. 
         [0010]    Another exemplary embodiment is directed to a method for operating an addressable switch system. The method includes providing a plurality of perforating gun assemblies, with each of the plurality of perforating gun assemblies comprising a switch sub and a perforating gun. The method further includes providing a top sub controller and a unique network address for communications over a network bus to each of the switch subs in the plurality of perforating gun assemblies. The method further includes installing explosives in each of the perforating guns of the plurality of perforating gun assemblies and monitoring and controlling the plurality of perforating gun assemblies using a control panel. The method also includes communicating between the control panel and the top sub controller via a wireline and communicating between the top sub controller and the plurality of perforating gun assemblies via the network bus. The method further includes selecting one perforating gun assembly from the plurality of perforating gun assemblies based on the unique network address of the switch sub corresponding to the selected perforating gun assembly, and providing a command signal that at least one of arms and fires the perforating gun corresponding to selected perforating gun assembly. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0011]    These and other objects, features and characteristics of the present invention will become more apparent to those skilled in the art from a study of the following detailed description in conjunction with the appended drawings, all of which form a part of this specification. In the drawings: 
           [0012]      FIG. 1  is a block diagram of a networked switching system in accordance with an embodiment of the disclosure. 
           [0013]      FIG. 2  provides an exemplary GUI for a control panel in a networked switching system in accordance with an embodiment of the disclosure. 
           [0014]      FIG. 3  illustrates a cross-sectional view of a portion of a housing for a perf gun assembly in a networked switching system in accordance with an embodiment of the disclosure. 
           [0015]      FIG. 4  illustrates a cross-section of a portion of a perf gun assembly in a networked switching system in accordance with an embodiment of the disclosure. 
           [0016]      FIG. 5  illustrates plurality of detonator electronics corresponding to a plurality of perf guns in a networked switching system in accordance with an embodiment of the disclosure. 
           [0017]      FIG. 6  is a flow diagram for an “in-shop” assembly process for a networked switching system in accordance with an embodiment of the disclosure. 
           [0018]      FIG. 7  is a flow diagram for an “in field” assembly process for a networked switching system in accordance with an embodiment of the disclosure. 
           [0019]      FIG. 8  is a flow diagram of an employment of a networked switching system in accordance with an embodiment of the disclosure. 
           [0020]      FIG. 9  is a flow diagram of a process for testing the top sub of a networked switching system for possible reuse. 
           [0021]      FIG. 10  is a flow diagram of a process for testing switch subs of a networked switching system for possible reuse. 
           [0022]      FIG. 11  illustrates an exemplary embodiment of a rotary connection assembly for use in the assembly process of a perforating gun assembly in a network switching system. 
           [0023]      FIG. 12  illustrates an exemplary embodiment of a glass-to-metal seal assembly for use in a switch sub in a network switching system. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    In conventional systems and assemblies for down-hole blasting, such as fracking, the explosives in each “perf” gun are typically actuated by standard mechanical switches. For example, in known assemblies for fracking, mechanical switches select which perf gun in the gun train is being fired and then ultimately control its firing. While this often provides an acceptable solution, there can be problems with reliability. Typically, if a switch fails to activate a perf gun in the train, perhaps due to a short, there is no way for the operators working at ground level to then select other guns in that train for firing. This can result in a plugged well, requiring operators to pull out the malfunctioning equipment and waste valuable time and expense. 
         [0025]    In accordance with certain embodiments of the disclosure, the conventional mechanical switching arrangement may be replaced with a networked architecture that enables digital communication between a controller that selects the perf gun to detonate and the switches that fire the charges in the perf gun. An electronic switch in the switch sub can include an application specific integrated circuit (“ASIC”) configured to interpret and respond to certain digital signals, e.g., signals to arm and fire the perf gun associated with the switch sub. The ASIC can be associated with a unique address so as to be separately addressable for initiation by the controller. Furthermore, each of the ASICs in the switch subs can communicate over a networked bus configured for fault tolerant operation, such that, if a short causes a perf gun to malfunction, other perf guns in the train may still maintain communications over the bus. 
         [0026]      FIG. 1  is a block diagram for a network switching assembly  100  in accordance with an embodiment of the disclosure. The arrangement includes a control panel with a graphical user interface (GUI)  10 , control panel box  30 , top sub controller  50  and a set of reusable detonator electronics  60 - 63 . 
         [0027]    In an exemplary embodiment, the control panel  10  sends and receives signals via a serial communications protocol, such as an RS232 signaling link  20 , to control panel box  30 . The signals can be communicated to switch logic  32  via a voltage translator  31 . Of course, other communications protocols may be utilized, and depending upon the protocol and the logic configuration, the voltage translator  31  may be unnecessary. In other embodiments, control panel with GUI  10  may be integrated into the control panel box  32 , such that the RS232 link  20  may also be unnecessary. In addition, the control panel  10  (or a separate device) can perform logging and reporting functions that capture the time the perforating guns are fires, the depth, the shock data from accelerometers, etc. The reports can be sent to text or spreadsheet files or over a network to other computers. 
         [0028]    In an exemplary embodiment, the control panel box  30  is above ground, at the top of the well. The control panel box  30  may be in communication with a top sub controller  50  via a wireline  40 . The top sub controller  50  is in the well, and may be hundreds or even thousands of feet below the surface. In an exemplary embodiment, the wireline  40  includes a high voltage wire, which provides the high voltage, e.g., 300 volts, needed by the detonators in each perf gun. Wireline  40  is also capable of providing communications signals over a potentially long distance, e.g., from control panel box  30  to top sub controller  50 . That is, both the communication signals and the high voltage is delivered to the top sub controller  50  using the same wire. In some embodiments, the high voltage is oscillated 8 to 12 volts, e.g., the 300 volt bus may oscillate from 288 volts to 312 volts, such that the top sub controller  50  “interprets” 288 volts as a digital “0” and 312 volts as a digital “1.” Of course, other ranges such as, e.g.,  270  volts to 300 volts can also be used. 
         [0029]    In an exemplary embodiment, the wireline  40  is fed to voltage translator  51  in top sub controller  50 . The voltage translator  51  converts the signal on wireline  40  to a low power signal to power and communicate with a field programmable gate array (FPGA)  52 . The FPGA  52  is thus configured to bi-directionally communicate with switch logic  32 . The signals communicated via switch logic  32  to FPGA  52  are then translated via Bus Driver  54  into signals that can be communicated over communication bus  56 . Bus  56  is a low power communication line that, in some embodiments, can be up to approximately 40 m in length. 
         [0030]    Bus  56  sends digital communication signals to the reusable detonator electronics  60 - 63  in each switch sub. In an exemplary embodiment, there may be up to  24  devices connected to the bus  56 . The detonator electronics  60 - 63  can be individually addressed via switch logic  32  and signaled to, e.g., “ARM” or “FIRE.” In some embodiments, the detonator electronics  60 - 63  can also receive signals to “DISARM.” Upon receiving a “FIRE” signal, the detonator electronics switches  60 - 63  send power via the 300V power line  55  to their respective detonators, which then ignite the explosives in each perf gun. As shown in  FIG. 1 , in the exemplary embodiment, power line  55  is conditioned via a 300V regulator  53 . 
         [0031]    In an exemplary embodiment, each of the reusable detonator electronics  60 - 63  may be structurally the same. The electronics  60 - 63  may include an ASIC including a bus interface (see, e.g.,  511 ,  512  in  FIG. 5 ). The ASIC can include a logic device which signals an initiator (not shown) to ARM or FIRE. The ASIC also may be connected to an external capacitor (see  513  in  FIG. 5 ), referred to as an energy fire capacitor, or ERC, for arming the initiator. 
         [0032]      FIG. 2  provides an exemplary graphical user interface (GUI)  200  for control panel  10 . In a preferred embodiment, the exemplary GUI  200  can run on a laptop or on other portable electronic devices (such as a tablet). The GUI screen  200  may include soft keys or icons (e.g.,  210 ,  211 ,  212 ) to individually select a perf gun in a perf gun train to control. For example, in the illustrated example, Gun 1 is selected as shown by the bolded border around icon  210 . For each gun, a command box  220  can illustrate the options for user selection (e.g., STATUS, ARM, FIRE), and the command can be entered via a prompt at status bar  230 . In some exemplary embodiments, a command to “DISARM” may also be entered. As an example, the status bar  230  in  FIG. 2  prompts the user to select a command from the Command selections  220 . Finally, GUI  200  may include an error indicator  240 . The error indicator  240  can be configured so as to be specific to the selected perf gun (e.g.,  210 ,  211 ,  212 ) or to indicate an error anywhere in the system, e.g., along the bus  56  (as a global indicator). The GUI  200  can also display information (not shown) from sensors located in the gun train. For example, each perf gun assembly can have a temperature sensor, a pressure sensor, and/or another measurement device to provide an indication of the conditions in the perf gun assembly and/or the wellbore. In addition, the top sub, which houses top sub controller  50 , can also include sensors (such as temperature, pressure, etc.), and/or an accelerometer to provide indication of the conditions in the gun train and/or the wellbore. For example, accelerometer data from the top sub can be transmitted back to control panel  10  via communication bus  56 , wireline  40 , and the RS232 link  20  and then used to detect whether the explosives in a perf gun detonated or not. In some embodiments, in addition to the accelerometer in the top gun (or instead of the accelerometer in the top gun), each perf gun assembly can include an accelerometer. 
         [0033]    In the exemplary embodiment, when the user selects a command for a perf gun (e.g., Gun 1—FIRE), the client computer running the GUI  200 , e.g., control panel  10 , sends a signal, via, e.g., an RS232 link  20 , to control panel box  30 , which in turn, will receive and interpret the signals from the control panel  10 . For example, if Gun 1 is selected to fire, the control panel box  30  will interpret this command and determine the proper network address of the reusable electronics for Gun 1, and then send a signal with the Gun 1 fire command to top sub controller  50  via wireline  40  using the appropriate protocol. Top sub controller  50  receives and interprets the signal from control panel box  30  and relays the information, e.g., the command to file Gun 1, to the appropriate reusable electronics  60 - 63  corresponding to Gun 1 via communications bus  56 . The reusable electronics  60 - 63  that corresponds to the selected Gun 1, receives and interprets the signal from bus  56 . Because the signal from top sub controller  50  includes the network address of the reusable electronics for Gun 1, the reusable electronics  60 - 63  of the other perf guns “ignore” the signal from controller  50 . Once the reusable electronics of Gun 1, which is already in an “armed” state, detects the fire signal based on the corresponding digital address, the reusable electronics of the Gun 1 will convert the status of Gun 1 from “ARMED” to “FIRE.” 
         [0034]    In a fracking well, the casing in the horizontal section of the well can be quite narrow. Accordingly, the perf gun assembly is commonly configured as a narrow cylindrical tube that can be pushed and pulled along within the casing.  FIG. 3  illustrates a cross-sectional view of a portion of the housing for a perf gun assembly. In this exemplary embodiment, the perf gun assembly  300  includes a switch sub  310 , which contains the reusable detonator electronics  60 - 63  and, in some embodiments instrumentation such as, e.g. a temperature sensor, a pressure sensor, and /or other instrumentation, e.g., an accelerometer. The switch sub  310  is then connected, such as by a screwed (threaded) arrangement, to a tandem sub  320 . In this example, the tandem sub  320  couples the switch sub  310  to the perf gun  330 , which includes the explosives (not shown). The tandem sub  320  provides a finger hole to aid in the coupling of the gun assembly. 
         [0035]      FIG. 4  illustrates a cross-section of a portion of a perf gun assembly. The perf gun assembly includes switch sub  430 , tandem sub  420 , and perf gun  410 . In addition, as can be seen in  FIG. 4 , the perf gun assembly  400  includes a wire for the communications bus  412  (corresponding to bus  56  in  FIG. 1 ), a high voltage power wire  411  (corresponding to the 300V wire  55  in  FIG. 1 ), and a detonator wire  422 . A detonator cord  421  is also provided. The detonator cord  421  is connected to the individual explosives (not shown) in the perf gun  410 . 
         [0036]    In the exemplary addressable switching system, switch sub  430  includes glass sealed connectors  431  and  432  at each end. These connectors are intended to protect the switch electronics  433  from heat, chemicals, gases, and other elements that are known to create a difficult environment for electronic components. In an exemplary embodiment, as seen in  FIG. 12 , a glass-to-metal seal assembly  1200  seals the internal electrical components (e.g., switch electronics  433 , including the ASIC and reusable electronics  60 - 63  (see  FIG. 1 ), and, in some embodiments, instrumentation such as accelerometers, temperature and pressure sensors, etc.) from high-pressure, high-temperature, and potentially toxic environments seen downhole. The glass-to-metal seal assembly  1200  includes a seal body  1201 , a connector section  1202 , conductors  1203 , and insulators  1204 . The conductors  1203  provide a conduction path to communicate an electrical signal in and out of the seal assembly  1200 . The conductors  1203 , which can be, e.g., high voltage bus  55  and communications bus  56 , extend from the interior of a seal body  1201 , through the seal body  1201  through glass insulating sleeves  1204  and out through the connector section  1202 . The conductors  1203  are electrically insulated from the seal body  1201  by the glass insulators  1204 . The number of conductors  1202  is not limited to two and can be one or three or more (dependent on design limitations such as space and structural stability of seal assembly  1200 ). The number of conductors  1202  will also depend on the application. For example, when the glass-to-metal seal assembly  1200  is used in the location of glass seal  432 , the glass-to-metal seal assembly  1200  will include at least two conductors—bus  56  and bus  55 , but when the glass-to-metal seal assembly  1200  is used in the location of glass seal  431 , it will include three conductors—bus  55 , bus  56 , and detonation wire  422 . 
         [0037]    In some embodiments, the glass-metal assembly and/or the switch sub  430  can be filled or coated with a thermal management material to protect the electronics in the addressable system, e.g., the ASIC and reusable electronics  60 - 63 , from high temperatures that could damage the electronics. The thermal management material has a sharp melting point and excellent heat resistance such that the thermal management material can be used around the electronics to increase the inherent thermal lag in the switch sub  430 . This means that the switch sub  430  can be exposed to temperatures beyond the limits of the electronics for an extended length of time. This is because, when the thermal management material reaches it melting point, it takes a large amount of additional heat to increase the temperature in switch sub  430  beyond the melting temperature of the thermal management material. In some exemplary embodiments, the thermal management material is a polymer or wax, e.g., a polyethylene. An example of such a material is Polywax 3000 by Baker Hughes, Inc. 
         [0038]    As discussed above, the various sections of the perf gun assembly ( 300 ,  400 ) are attached to each other by threaded connections. A threaded connection, however, makes it difficult to keep the communication bus wire  412  and the high voltage bus wire  411  from tangling as the various sections are twisted together.  FIG. 11  illustrates a rotary connection assembly  1100  that allows the various sections to be twisted together without the wires being tangled. The rotary connection assembly  1100  includes a flush connector  1110  and spring-loaded connector  1120 . The flush connector  1110  includes a metal casing  1111  with a connector section  1112 . The connector section  1112  includes a center conductor  1113  and two concentric ring connectors  1114 ,  1115 . The conductors  1113 - 1115  are housed in an insulating, heat resistant plastic, e.g., a Teflon plastic, such that the insulating material form concentric insulating sections  1116 - 1118  that are, e.g., flush with the conductors  1113 - 1115 . The flush connector  1110  may include a glass-to-metal seal. 
         [0039]    The spring-loaded connector  1120  includes a metal casing  1121  with a connector section  1122 . The connector section  1122  includes a spring-loaded center conductor  1123  and two spring-loaded concentric ring conductors  1124 ,  1125 . The flush connector  1110  is designed to mate with the spring-loaded connector  1120  such that the connectors  1113 - 1115  match up with and contact spring-loaded conductors  1123 - 1125 , respectively. The contacts on the spring-loaded conductors  1123 - 1125 , as the name implies have springs or other biasing mechanisms to ensure a positive contact with conductors  1113 - 1115 . The spring-loaded connector  1120  may also have a glass-to-metal seal. 
         [0040]    In some embodiments, the ends of each section in the perf gun assembly (i.e., perf gun  410 , tandem sub  420 , switch sub  430 ) will have either the flush connector  1110  or the spring-loaded connector  1120  and the corresponding end of the next section in the gun assembly will have the other mating connector  1110 ,  11120 . By using a rotary design having a center conductor and concentric ring conductors, the sections of the perf gun assembly can be threaded together without twisting the wires. As with the metal-to-glass seal assembly  1200  discussed above, the number of conductors in the rotary connector assembly  1110  can vary depending on the application. 
         [0041]    Continuing with  FIG. 4 , tandem sub  420  includes the bus wire  412 , high voltage power wire  411  and detonator wire  422  that are each connected to switch electronics  433  in the switch sub  430 . The bus wire  412  and the power wire  411  extend to the other perf guns via the glass-metal seal  1200  or rotary connector assembly  1100 . When the switch electronics  433  indicates a firing condition, a signal is sent to the detonator wire  422  (with the housing of the tandem sub  420  acting as ground). The detonator wire  422  causes the explosives (not shown) in the perf gun  410  to detonate via the detonator cord  421 . 
         [0042]    In accordance with at least one embodiment, the ASIC in the reusable detonator electronics  60 - 63  can be preprogrammed with a network address that identifies the ASIC device to other devices on the bus  56 , e.g., to sub controller  50 , control panel box  30 , control panel  10 , etc. In some embodiments, the network addresses uniquely identifies each perf gun in the system. When a user builds a gun train, the addresses of each of the ASICs in the tandem subs  420  can be placed into the control system. Software that runs the control panel  10  can be configured to prompt the user via the GUI to enter each address into the control system, such that each perf gun assembly  400  is associated with a network address. 
         [0043]    To ensure that the correct addresses are entered, in one embodiment, a tester (not shown) can be provided to confirm that, as the gun train is being assembled, the ASIC in each switch sub  420  is communicating properly and responding appropriately to its address. An “assembly checker” (not shown) can additionally include a USB port for a “memory stick” or some other storage device to store information concerning the order of each perf gun assembly  400  in a gun train, so that the information can then be transmitted to the control panel box  30 , control panel  10 , or another device as needed. In some embodiments, the information can be transmitted via a wired or wireless network. 
         [0044]    In another embodiment, two ASICs can be provided in each switch sub  420 . One ASIC controls the “firing” functions of the perf gun assembly  400  and the other ASIC controls a switch that either opens or closes the connection of the communications bus and the high voltage wire to the rest of the perf gun assemblies in the system. With this configuration, the switch logic  32  in the control panel box  30  can poll each of the perf gun assemblies  400  and turn them on/off one at a time to determine the order that they are in. In some embodiments, the poll function can be included in the control panel  10 . In this manner, the addressing for the different switch subs  420  can be detected in an automated manner after the gun train is assembled, without requiring user intervention. 
         [0045]    The automated addressing configuration is illustrated in  FIG. 5 . The plurality of detonator electronics  500  can be seen as electronics corresponding to a plurality of guns, GUN 1-GUN 4 ( 510 ,  520 ,  530 ,  540 ), where GUN 1  510  is closest to the bottom of the well, and GUN 4  540  is closest to the top of the well. The electronics for each gun includes two ASICs. For example, for GUN 4  540 , Firing ASIC  542  and Communication ASIC  541  are both connected to the high voltage wire  550  and the communication bus  560 . ASIC  541  includes ERC  543 . When the communication ASIC  541  is “activated,” the ERC pin charges the ERC capacitor. Communication ASIC  541  can be used to either open or close the bus  560  and the high voltage wire  550 . By charging ERC  543 , communication ASIC  541  closes the communications bus  560  and the high voltage wire  550  to the next perf gun assembly in the gun train. In some embodiments, the communication ASIC  541  is only used to close switches connecting the other guns, and it does not ARM or FIRE the perf gun. Firing ASIC  542  is utilized to ARM and FIRE the perf gun. During installation, when a gun assembly is installed in the control system, the communication ASIC of the installed gun assembly is activated, which in turn, allows the next gun assembly in the gun train to be connected based on the logic high state of the ERC pin on the ASIC that was just activated. When the system is first turned on, only one gun assembly is initially detected. Once this gun assembly is activated (by charging the ERC for that communication ASIC), a second gun assembly is detected by the control system. When the second communication ASIC is activated, then a third gun assembly will be detected by the control system, and so on. Eventually the end of the gun train is reached. In this manner, the software at the top of the well in the control panel box  30  that the user uses can “build” the gun train in the correct order by associating each ASIC&#39;s unique address with its order in the gun train. 
         [0046]    Referring to  FIG. 6 , flow diagram  600  illustrates the “in-shop” assembly process of the perf gun train. In step  610 , an installer runs the wires (e.g., bus  412  and high voltage wire  411 —see  FIG. 4 ) through the perf gun  410  and then in step  620 , the tandem sub  420  is attached to the perf gun  410 . In step  630 , the wires are then run through the tandem sub  420  and the detonator (e.g., detonator cord  421 —see  FIG. 4 ) is connected. The switch sub  430  is then connected to the tandem sub  420  in step  640 . In step  650 , the tandem sub  420  is connected to an assembly tester so that an assembly test is run. 
         [0047]    If the assembly test has passed, the next perf gun assembly is assembled as discussed above. If not, then in step  655 , the switch sub  430  is removed and replaced. 
         [0048]    If in step  650 , it is determined that all perf gun assemblies have been installed, then in step  660 , a setting tool is attached. The user installs a switch sub for the setting tool (the switch sub of the setting tool is different from that of a switch sub for firing a gun), and then a “quick change” assembly is attached to the switch sub of the setting tool in step  665 . A quick change assembly connects the top sub to the wire line. In step  670 , the detonator for the setting tool is connected. In step  675 , the setting tool is connected to the firing head, and lastly in step  680 , the plug is connected to the firing head. 
         [0049]      FIG. 7  illustrates a flow diagram  700  for assembling the perf gun train and the top sub in the field. In the field, a user has an entire gun train, with all the perf gun assemblies (switch subs, tandem subs, and perf guns), setting tool, plug, etc. The whole gun train, which can be a  25 -foot long pipe, is connected to the top sub that is in the field. In step  710 , the user connects the top sub to the quick change assembly, and then runs a functional test on the top sub to ensure functional operation (see step  720 ). If the functional test passes, in step  730 , the tester is disconnected and the gun train is connected to the top sub. 
         [0050]      FIG. 8  provides a flow diagram  800  for employment of the system. The computer system (e.g., control panel  10 ) is turned on in step  805  with the addressable switch software. A COM port is selected (in step  810 ) and a key switch on an in-truck panel is turned to auxiliary (in step  815 ). The control box (e.g., control panel box  30 ) is turned on (in step  820 ) and the in-truck panel is armed to connect the control box (e.g., control panel box  30 ) to the wireline (e.g., wireline  40 ) (in step  825 ). The number of switches (corresponding to the number of perf gun assemblies) is then chosen in step  830 . 
         [0051]    Upon selecting the number of switches, if there is an error, it will be indicted in  840 . At that point, a red light indicates (in  845 ) that one or more addresses are not responding, which requires troubleshooting. In addition, the addressable switch software is exited on the PC (e.g., control panel  10 ), the control box (e.g., control panel box  30 ) is turned off, and the in-truck box is disarmed. 
         [0052]    If no errors are presented, then a switch to be command is selected via the PC (e.g., control panel  10 ) (see step  850 ). If STATUS is selected (see  FIG. 2 ) at step  860 , and the command is executed in  861 , the PC provides a status indication of the selected switch in step  862 . If ARMED is selected (see  FIG. 2 ) at step  870 , and the command is executed in  871 , the selected switch is armed (step  872 ). In some embodiments, the PC (e.g., control panel  10 ) can also DISARM the selected switch. If DEPLOYED (FIRED) is selected (see  FIG. 2 ) at step  880 , and the command is executed in  881 , the selected switch will deploy (fire) in step  862 . In some embodiments, where accelerometers are installed in the switch subs  420 , the PC will receive the accelerometer data confirming that the perf gun explosives have detonated or indicating that the selected perf gun a failed to fire. For example, in some embodiments the top sub includes an accelerometer that transmits the accelerometer data to the PC (e.g., control panel  10 ). In some embodiments, individual perf gun assemblies can include accelerometers in addition to or instead of the accelerometer in the top gun. 
         [0053]    After a command is executed, the system determines whether another command is being indicated in step  890 . If all commands are completed, the system is disconnected in step  895 . 
         [0054]    Finally,  FIGS. 9 and 10  are processes for recovery  900  and redress  1000 . After a gun train has been employed, it is pulled out of the hole. Via  FIGS. 9 and 10 , the electronics are then tested, both the top sub and the switch subs to ensure that they remain functional. If they are still functioning, the user can put them back in the queue and build them up on the next gun train. If they are not functional, they can put them aside. It is anticipated that the electronics are sufficiently insulated from the environment so that they can be re-used multiple times. 
         [0055]    Accordingly, in  FIG. 9 , all guns are disconnected from the top sub in step  910 , a functional test is run in step  920 , and if it passes, the top sub will be reused (via step  940 ). Otherwise, it is disconnected in step  930 . In  FIG. 10 , the switch subs are disconnected from the tandem subs in step  1010 , the functional test is run in step  1020 , and the switch subs are kept if functional, via step  1040 , or otherwise discarded via step  1030 . 
         [0056]    It will be appreciated to those skilled in the art that the preceding examples and embodiments are exemplary and not limiting to the scope of the present invention. It is intended that all permutations, enhancements, equivalents, combinations, and improvements thereto that are apparent to those skilled in the art upon a reading of the specification and a study of the drawings are included within the true spirit and scope of the present invention. It is therefore intended that the following appended claims include all such modifications, permutations and equivalents as fall within the true spirit and scope of the present invention.