Apparatus and method for supplying electrical power to an electrocrushing drill

Abstract

An apparatus and method for controlling power delivered to a pulsed power system which includes a command charge switch for controlling when power produced by a primary power system is fed into a cable. The command charge switch also controls the power delivered to the pulsed power system in a bottom hole assembly.

What is claimed is: 
     
         1 . An apparatus for controlling power delivered to a down-hole pulsed power system in a bottom hole assembly comprising:
 a cable for providing power from a surface to said pulsed power system;   a command charge switch disposed between an end of said cable and a prime power system on the surface; and   said command charge switch firing on command to control when power produced by said primary power system is fed into said cable and controlling power provided to said pulsed power system.   
     
     
         2 . The apparatus of  claim 1  wherein said bottom hole assembly comprises a non-rotating drill bit. 
     
     
         3 . The apparatus of  claim 1  wherein said prime power system produces a medium voltage DC power to charge at least one capacitor of said prime power system, said capacitor connected by said command charge switch to said cable. 
     
     
         4 . The apparatus of  claim 3  wherein said command charge switch controls said medium voltage DC power on said prime power capacitor when switched on to said cable and transmitted to said pulsed power system. 
     
     
         5 . The apparatus of  claim 1  wherein said command charge switch controls a duration of a charge voltage on said pulsed power system in said bottom hole assembly. 
     
     
         6 . The apparatus of  claim 1  wherein said command charge switch controls a voltage waveform on said cable. 
     
     
         7 . The apparatus of  claim 1  wherein said prime power system dampens cable oscillations. 
     
     
         8 . The apparatus of  claim 7  wherein said prime power system comprises a diode-resistor set to dampen cable oscillations. 
     
     
         9 . A method for controlling power delivered to a pulsed power system using a command control switch comprising:
 disposing the pulsed power system in a bottom hole assembly;   providing power to the pulsed power system via a cable;   disposing a command charge switch between an end of the cable and a prime power system on the surface; and   firing the command charge switch thereby controlling when the power produced by the prime power system is fed into the cable and controlling the power delivered to the pulsed power system in the bottom hole assembly.   
     
     
         10 . The method of  claim 9  wherein the bottom hole assembly comprises a non-rotating drill bit. 
     
     
         11 . The method of  claim 9  further comprising the prime power system producing a medium voltage DC power to charge at least one prime power system capacitor that is connected to the cable by the command charge switch. 
     
     
         12 . The method of  claim 11  further comprising controlling when the medium voltage DC power on the prime power capacitor is switched on to the cable. 
     
     
         13 . The method of  claim 9  further comprising controlling a duration of charge voltage on the pulsed power system in the bottom hole assembly. 
     
     
         14 . The method of  claim 9  further comprising controlling a voltage waveform on the cable. 
     
     
         15 . The method of  claim 9  further comprising dampening cable oscillations.