Electromechanical Assembly for Routing Electrical Signals in Guns for Well Perforation

Abstract

An electromechanical switch for use in well perforating gun assemblies wells comprising an initial pass-through configuration where the switch passes an electrical connection from a shooting line through the switch's plunger to the neighboring gun until a pressure event acts on the switch causing the shooting line to disengage from the neighboring gun and connect to the internal detonator for subsequent firing sequence to trigger detonation.

What is claimed is: 
     
         1 . An electromechanical switching assembly comprising:
 a switch body having a first contact for electrically connecting to a shooting line;   the first contact being slideably mounted within the switch body and being electrically connected to a second contact,   the second contact being slideably mounted within the switch body and protracted from one end of the switch body forming a plunger sensitive to pressure of a predetermined threshold;   pressure causing the second contact to retract into the switch body, transferring movement to the first contact which disengages from the second contact and electrically connects to a third contact.   
     
     
         2 . The assembly of  claim 1  wherein the first contact has a compression spring extending to the second contact to maintain electrical connection between the two contacts. 
     
     
         3 . The assembly of  claim 1  wherein the second contact is encircled by a flexible/compressible O-ring fitting inside one end of the switch body and preventing leakage therebetween. 
     
     
         4 . The assembly of  claim 3  wherein the second contact is encircled by a second flexible/compressible O-ring fitting inside one end of the switch body behind and spaced apart from the first O-ring and preventing leakage therebetween. 
     
     
         5 . The assembly of  claim 1  wherein the second contact is urged by a spring toward the third contact, the spring held in a compressed state until the threshold pressure is applied. 
     
     
         6 . The assembly of  claim 5  wherein the spring is held in a compressed state by a threaded portion of the contact screwed to the housing of the switch, the threads breaking under the threshold pressure and freeing the first contact to be moved by the spring. 
     
     
         7 . The assembly of  claim 5  wherein the spring is held in a compressed state by a beveled portion of the second contact being greater than the inside of the switch body and mating with a beveled opening at one end of the switch body. 
     
     
         8 . A method of electrically connecting a plurality of perforating gun assemblies wherein a shooting line is connected to a switch in the first gun, the switch being configured to pass an electrical signal from the shooting line to the second gun's shooting line through a plunger; the plunger reacting to pressure from an explosion in the second gun, disconnecting the shooting line from the second gun and an internal spring urging the shooting line to connect to the first gun's internal detonator. 
     
     
         9 . The method as described in  claim 8  wherein the plunger comprises a compression spring between the shooting line and the back end of the plunger to ensure electrical contact until the pressure reaction. 
     
     
         10 . The method as described in  claim 8  wherein the plunger comprises a threading joint holding a spring in compression until a pressure threshold breaks away the thread allowing the spring to reconnect the shooting line to the first gun's detonator.