Electric pulse drilling apparatus with hole cleaning passages

Abstract

An electrical pulse cutting device is disclosed that in one non-limiting embodiment includes a pair of electrodes that generate electrical pulses inside an object to disintegrate a section of the object into cuttings, and at least one flow passage in at least one of the electrodes to provide a passage for a fluid under pressure to move the cuttings away from the at least one of the electrodes.

1 . An electric pulse cutting device, comprising:
 a pair of electrodes that generates electrical pulses inside an object to disintegrate a section of the object into cuttings; and   at least one flow passage in at least one of the pair of electrodes to provide a passage for a fluid under pressure to move the cuttings away from the least one of the electrodes.   
     
     
         2 . The electric pulse cutting device of  claim 1 , wherein the pair of electrodes are configured to contact the object to pass electrical energy through a selected depth of the object to disintegrate the object. 
     
     
         3 . The electric pulse cutting device of  claim 1  further comprising a pulse generator that provides electrical energy to the pair of electrodes at a selected frequency. 
     
     
         4 . The electric pulse cutting device of  claim 2 , wherein the frequency is less 500 hertz. 
     
     
         5 . The electric pulse cutting device of  claim 1 , wherein the pair of electrodes includes a ground electrode that is at least partially outside one of an anode electrode and a cathode electrode and wherein the at least one fluid passage runs through the ground electrode. 
     
     
         6 . The electric pulse cutting device of  claim 5  further comprising at least one fluid passage through the anode electrode. 
     
     
         7 . A drilling apparatus for drilling wellbores, comprising:
 an electric pulse cutting device at a bottom end thereof, wherein the electric pulse device includes:   a ground electrode and an anode electrode for generating electrical pulses inside a rock formation in a wellbore to disintegrate the rock formation into cuttings; and   at least one fluid flow passage in one of the ground electrode and the anode electrode to provide a passage for a fluid under pressure to move the cuttings away from at least one of the ground electrode and the anode electrode;   
     
     
         8 . The drilling apparatus of  claim 7  further comprising: a sensor that provides measurements relating to a downhole parameter of interest and a controller that adjusts a parameter relating to an operation of the electric pulse cutting device in response to the downhole parameter of interest. 
     
     
         9 . The drilling apparatus of  claim 8 , wherein the downhole parameter of interest is selected from a group consisting of: rate of penetration of the electric pulse cutting device; vibration relating to the drilling apparatus; whirl relating to the electric pulse cutting device; and stick-slip of the electric pulse cutting device. 
     
     
         10 . The drilling apparatus of  claim 7 , wherein the ground electrode and the anode electrode are configured to contact the rock formation to pass electrical energy through a selected depth of the rock formation to disintegrate the rock formation into cuttings. 
     
     
         11 . The drilling apparatus of  claim 7  further comprising a pulse generator that provides electrical energy to the anode electrode and the ground electrode at a selected frequency. 
     
     
         12 . The drilling apparatus of  claim 7 , wherein the at least a portion of the ground electrode is at least partially outside a portion of the anode electrode and wherein the at least one fluid flow passage runs through the ground electrode. 
     
     
         13 . The drilling apparatus of  claim 8 , wherein the controller is located at one of: in a drilling assembly carrying the electric pulse bit; and at a surface location; and partially in a drilling assembly carrying the electric pulse bit and partially at a surface location. 
     
     
         14 . The drilling apparatus of  claim 7  further comprising a logging while drilling tool that determines a parameter of interest relating to formation surrounding the electrical pulse cutting device. 
     
     
         15 . A method of drilling a wellbore, the method comprising:
 conveying a drill string into a wellbore that includes an electric pulse cutting device at a bottom end of a drilling assembly, wherein the electric pulse cutting device includes a pair of electrodes and wherein at least one electrode includes a fluid flow passage therethrough to allow a fluid under pressure to pass therethrough to move the cuttings away from the at least one electrodes;   disintegrating rock at bottom of the wellbore into cuttings by generating electrical pulses via the pair of electrodes inside a selected depth of the rock; and   passing the fluid under pressure through the at least one fluid passage to move the cuttings away from the at least one of the electrodes during drilling of the wellbore.   
     
     
         16 . The method of  claim 15  further comprising determining a parameter of interest relating to the drill string during drilling and adjusting a drilling parameter in response to the determined parameter relating to the drill string. 
     
     
         17 . The method of  claim 16 , wherein the parameter of interest relating to the drill string is selected from a group consisting of: vibration; whirl; and stick-slip. 
     
     
         18 . The method of  claim 16 , wherein the drilling parameter is selected from a group consisting of: rate of penetration; weight on the electrical pulse cutting device; fluid flow rate; pulse frequency; temperature; and pressure. 
     
     
         19 . The method of  claim 15 , wherein the pair of electrodes includes a ground electrode that is at least partially outside one of an anode electrode and a cathode electrode. 
     
     
         20 . The method of  claim 19 , wherein the fluid flow passage runs through the ground electrode.