Communicating through a barrier in a well

Abstract

A technique that is usable with a well includes communicating a ballistic wave from a first point in a well to a second point in the well without propagating the ballistic wave along a detonating cord. The first and second points are separated by at least one foot. The technique includes responding to the ballistic wave near the second point to activate a downhole tool.

1 . A method usable with a well, comprising:
 communicating a ballistic wave from a first point in the well to a second point in the well without propagating the ballistic wave along a detonating cord, the first and second points being separated by at least one foot; and   responding to the ballistic wave near the second point to actuate a downhole tool.   
   
   
       2 . The method of  claim 1 , wherein the downhole tool comprises a perforating gun. 
   
   
       3 . The method of  claim 1 , wherein the communicating comprises:
 communicating through a communication barrier.   
   
   
       4 . The method of  claim 3 , wherein the communication barrier comprises a casing joint. 
   
   
       5 . The method of  claim 1 , wherein the downhole tool comprises a casing conveyed perforating gun. 
   
   
       6 . The method of  claim 1 , further comprising:
 generating the ballistic wave in response to the propagation of a detonation wave along a detonating cord.   
   
   
       7 . A system usable with a well, comprising:
 a ballistic generator located at a first point in the well to generate a ballistic wave; and   a tool being located at a second point in the well to respond to the ballistic wave,   wherein the ballistic wave does not propagate along a detonating cord between the first and second points, and the first and second points are separated by at least one foot.   
   
   
       8 . The system of  claim 7 , wherein the tool comprises a perforating gun. 
   
   
       9 . The system of  claim 7 , wherein the communicating comprises:
 communicating through a communication barrier.   
   
   
       10 . The system of  claim 9 , wherein the communication barrier comprises a casing joint. 
   
   
       11 . The system of  claim 7 , wherein the tool comprises a casing conveyed perforating gun. 
   
   
       12 . The system of  claim 7 , further comprising:
 generating the ballistic wave in response to the propagation of a detonation wave along a detonating cord.