US 12,352,166 B2
Apparatus, drilling arrangement and method for high voltage electro pulse drilling
Sirpa Launis, Tampere (FI); Jukka-Pekka Uusitalo, Tampere (FI); Jenni Rekola, Tampere (FI); Matthias Voigt, Tampere (FI); and Erik Anders, Tampere (FI)
Assigned to Sandvik Mining and Construction Oy, Tampere (FI)
Appl. No. 18/575,033
Filed by SANDVIK MINING AND CONSTRUCTION OY, Tampere (FI)
PCT Filed Jun. 30, 2022, PCT No. PCT/EP2022/068081
§ 371(c)(1), (2) Date Dec. 28, 2023,
PCT Pub. No. WO2023/275261, PCT Pub. Date Jan. 5, 2023.
Claims priority of application No. 21183403 (EP), filed on Jul. 2, 2021.
Prior Publication US 2024/0295148 A1, Sep. 5, 2024
Int. Cl. E21B 7/15 (2006.01); E21B 21/08 (2006.01)
CPC E21B 7/15 (2013.01) [E21B 21/08 (2013.01)] 11 Claims
OG exemplary drawing
 
8. A method for high voltage electro pulse drilling of rock, wherein the method comprises:
generating high voltage electrical pulses by means of at least one pulse generator;
executing the drilling by means of a drilling tool including at least one drill tube and a drill head connected to a distal end of the drill tube;
feeding the drilling tool in a drilling direction during the drilling;
feeding flushing fluid to the drill head for flushing removed rock material;
conducting the generated high voltage electrical pulses to at least one high voltage electrode on the drill head;
providing ground potential for at least one ground electrode on the drill head;
breaking the rock by transmitting the high voltage electrical pulses from the high voltage electrode to the ground electrode via the rock material;
generating the high voltage electrical pulses outside a drill hole to be drilled;
providing the ground potential via the at least one drill tube;
conducting the generated high voltage electrical pulses inside the at least one drill tube by means of a high voltage supply line;
connecting the high voltage supply line to at least one switch, which is located in connection with the drilling tool;
enhancing the high voltage electro pulses in the drilling tool by accelerating rise time of the pulses by means of a switch gap which is disposed between two opposing electrodes of the switch; and
preventing the flushing fluid flow from entering to the switch gap.