Perforating gun with switch cartridge

Abstract

An apparatus for selectively firing a perforating gun having a plurality of gun assemblies includes a plurality of cartridge assemblies. Each cartridge assembly is associated with a gun assembly of the plurality of gun assemblies. Each cartridge assembly includes a body having a cavity, an input contact configured to receive a signal, and a throughput contact configured to convey the signal. The perforating gun may include a carrier and at least one bulkhead.

1 . An apparatus for use in a wellbore, comprising:
 a first gun assembly having:
 a first charge tube having a longitudinal axis defined by an axis that passes through centers of opposing ends of the charge tube; 
 a first detonator cord disposed along the first charge tube, 
 a first signal-conveying wire disposed along the first charge tube, 
 a first coupler affixed to an end of the first charge tube, the first coupler including:
 a receptacle receiving an end of the detonator cord, and 
 a coupler contact electrically connected to the first signal conveying wire, and 
 
 a first cartridge assembly including:
 a body, 
 an input contact positioned on the body and electrically coupled to the coupler contact, 
 a throughput contact positioned on the body, 
 a switch disposed in the body, the switch being electrically connected to the input contact and the throughput contact, and 
 an initiating element disposed in the body and electrically connected to the switch, the initiating element being energetically coupled to the end of the detonator cord in the receptacle, wherein the switch and the initiating element at least partially overlap along the longitudinal axis; and 
 
 a first signal transfer assembly electrically coupled to the throughput contact; and 
   a second gun assembly having:
 a second charge tube, 
 a second detonator cord disposed along the second charge tube, 
 a second signal-conveying wire disposed along the second charge tube, the second signal-conveying wire being electrically coupled to the first contact assembly, 
 a second coupler affixed to an end of the second charge tube, the second coupler including:
 a receptacle receiving an end of the second detonator cord, and 
 a coupler contact electrically connected to the second signal conveying wire; and 
 
 a second cartridge assembly including:
 a body, 
 an input contact electrically positioned on the body and coupled to the second coupler contact, 
 a throughput contact positioned on the body, 
 a switch disposed in the body, the switch being electrically connected to at least the input contact, and 
 an initiating element disposed in the body and electrically connected to the switch, the initiating element being energetically coupled to the end of the second detonator cord in the receptacle. 
 
   
     
     
         2 . The apparatus of  claim 1 , wherein the switch of the second cartridge is also connected to the throughput contact of the second cartridge, and wherein the second gun includes a second signal transfer assembly electrically coupled to the throughput contact of the second cartridge assembly, and further comprising:
 a third gun assembly having:
 a third charge tube, 
 a third detonator cord disposed along the third charge tube, 
 a third signal-conveying wire disposed along the third charge tube, the third signal-conveying wire being electrically coupled to the second contact assembly, 
 a third coupler affixed to an end of the third charge tube, the third coupler including:
 a receptacle receiving an end of the third detonator cord, and 
 a coupler contact electrically connected to the third signal conveying wire; and 
 
 a third cartridge assembly including:
 a body, 
 an input contact electrically positioned on the body and coupled to the third coupler contact, 
 a throughput contact positioned on the body, 
 a switch disposed in the body, the switch being electrically connected to at least the input contact, and 
 an initiating element disposed in the body and electrically connected to the switch, the initiating element being energetically coupled to the end of the third detonator cord in the receptacle. 
 
   
     
     
         3 . An apparatus for use with a gun assembly having charge tube with a longitudinal axis defined by an axis that passes through centers of opposing ends of the charge tube, a detonator cord disposed along the charge tube, and a signal-conveying wire disposed along the charge tube, the apparatus comprising:
 a switch having an initiating element;   a coupler configured to be received at an end of the charge tube, the coupler including:
 a receptacle receiving an end of the detonator cord, and 
 a coupler contact electrically connected to the signal conveying wire; and 
   a cartridge assembly engagable with the coupler, the cartridge assembly including:
 a body configured to receive the switch and the initiating element, 
 an input contact positioned on the body, and 
 a throughput contact positioned on the body, 
  wherein engaging the cartridge assembly with the coupler simultaneously electrically couples the input contact to the coupler contact and energetically couples the initiating element with the end of the detonator cord, and 
  wherein the switch and the initiating element are positioned in a parallel, side-by-side arrangement to at least partially overlap along the longitudinal axis. 
   
     
     
         4 . The apparatus of  claim 3 , wherein the initiation element is intersected by the longitudinal axis and the switch is radially offset from the longitudinal axis. 
     
     
         5 . The apparatus of  claim 3 , wherein the switch and the initiating element partially overlap along the longitudinal axis. 
     
     
         6 . The apparatus of  claim 3 , wherein the initiating element is a metal member configured to generate heat with the application of electrical energy. 
     
     
         7 . The apparatus of  claim 3 , wherein the initiating element is configured to output sufficient thermal energy to detonate an energetic material. 
     
     
         8 . The apparatus of  claim 7 , wherein the energetic material is one of: (i) the detonator cord, and (ii) a booster charge. 
     
     
         9 . The apparatus of  claim 3 , wherein the switch is programmed to initiate the firing of a selected perforating gun of a plurality of perforating guns. 
     
     
         10 . The apparatus of  claim 3 , wherein the coupler includes a body having an interior in which the cartridge assembly is received. 
     
     
         11 . The apparatus of  claim 10  wherein the coupler contact includes a coupler contact surface and a wiring contact, wherein the coupler contact surface is an electrically conductive member that is exposed to the interior of the body, and wherein the wiring contact has a electrically conductive portion that is exposed to the exterior of the body. 
     
     
         12 . The apparatus of  claim 11 , wherein the input contact includes an external input contact that projects from an exterior wall of the body, the external input contact configured to compressively contact the coupler contact surface. 
     
     
         13 . The apparatus of  claim 12 , wherein the input contact further includes an end configured to electrically connect with the switch. 
     
     
         14 . The apparatus of  claim 13 , wherein the throughput contact includes an external throughput contact and an end, wherein the external throughput contact is configured to electrically connect with the switch, and wherein the end is configured to electrically connect with an adjacent cartridge assembly. 
     
     
         15 . A method for perforating a formation, comprising:
 forming a perforating tool with a plurality of gun assemblies;   configuring a selected gun assembly of the plurality of gun assemblies to have:
 a charge tube having a longitudinal axis defined by an axis that passes through centers of opposing ends of the charge tube; 
 a detonator cord disposed along the charge tube, 
 a signal-conveying wire disposed along the charge tube, 
 a switch having an initiating element; 
 a coupler configured to be received at an end of the charge tube, the coupler including:
 a receptacle receiving an end of the detonator cord, and 
 a coupler contact electrically connected to the signal conveying wire; and 
 
 a cartridge assembly engagable with the coupler, the cartridge assembly including:
 a body, 
 an input contact positioned on the body, and 
 a throughput contact positioned on the body, 
  wherein engaging the cartridge assembly with the coupler simultaneously electrically couples the input contact to the coupler contact and energetically couples the initiating element with the end of the detonator cord, and 
  wherein the switch and the initiating element are positioned in a parallel, side-by-side arrangement to at least partially overlap along the longitudinal axis; 
 
   conveying the perforating tool into a wellbore formed in the formation; and   transmitting a firing signal to fire the selected gun assembly.   
     
     
         16 . The method of  claim 15 , further comprising programming the switch to initiate the firing of the selected perforating gun of a plurality of perforating guns. 
     
     
         17 . The method of  claim 15 , wherein the coupler includes a coupler body having an interior in which the cartridge assembly is received. 
     
     
         18 . The method of  claim 17 , wherein the coupler contact includes a coupler contact surface and a wiring contact, wherein the coupler contact surface is an electrically conductive member that is exposed to the interior of the coupler body, and wherein the wiring contact has a electrically conductive portion that is exposed to the exterior of the coupler body. 
     
     
         19 . The method of  claim 17 , wherein the input contact includes an external input contact that projects from an exterior wall of the coupler body, the external input contact configured to compressively contact the coupler contact surface. 
     
     
         20 . The method of  claim 15 , further comprising:
 configuring a second selected gun assembly of the plurality of gun assemblies to have:
 a charge tube having a longitudinal axis defined by an axis that passes through centers of opposing ends of the charge tube; 
 a detonator cord disposed along the charge tube, 
 a signal-conveying wire disposed along the charge tube, 
 a switch having an initiating element; 
 a coupler configured to be received at an end of the charge tube, the coupler including:
 a receptacle receiving an end of the detonator cord, and 
 a coupler contact electrically connected to the signal conveying wire; and 
 
 a cartridge assembly engagable with the coupler, the cartridge assembly including:
 a body, 
 an input contact positioned on the body, and 
 a throughput contact positioned on the body, 
  wherein engaging the cartridge assembly with the coupler simultaneously electrically couples the input contact to the coupler contact and energetically couples the initiating element with the end of the detonator cord, and 
  wherein the switch and the initiating element are positioned in a parallel, side-by-side arrangement to at least partially overlap along the longitudinal axis; and 
 
   transmitting a second firing signal to fire the second selected gun assembly.