A downhole drilling system is disclosed. The downhole drilling system may include a pulse-generating circuit electrically coupled to a power source configured to provide an alternating current at a frequency and an input voltage, the pulse-generating circuit comprising an input stage circuit electrically coupled to the power source, the input stage circuit configured to control the alternating current in the pulse-generating circuit; a transformer circuit electrically coupled to the input stage circuit, the transformer circuit comprising an open-core transformer configured to generate an output voltage higher than the input voltage; and an output stage circuit electrically coupled to the transformer circuit, the output stage circuit configured to store energy for an electric pulse; and a drill bit including a first electrode and a second electrode electrically coupled to the output stage circuit to receive the electric pulse from the pulse-generating circuit.

Drill bit (230) for a drilling tool (1) comprising a drill bit member (231) which delimits a through-channel (231C) for the passage of the fluid flow and comprising an external surface (232), from which there extend a plurality of drilling members (233) which are uniformly distributed over the external surface (232), each drilling member (233) comprising a fin (233A) which extends from the external surface (232) and a plurality of drilling teeth (233B) which extend from the fin (233A) and which each comprise a base (233B1) and a cutting element (233B2) which is arranged at the end of the base (233B1), the drill bit comprising a high-voltage electrode (232C) which is arranged at the centre of the central facial opening (231A1) and each drilling member (233) comprising an earth electrode (233C) which is positioned at the end of the fin (233A), at the high-voltage electrode (232C), so as to at least partially extend in line with the central facial opening (231A1).

An electrocrushing drill bit comprises a bit body and at least one electrode coupled to a power source and the bit body, wherein the at least one electrode having a distal portion for engaging with a surface of a wellbore. The electrocrushing drill bit comprises a ground structure coupled to the bit body proximate to the at least one electrode and having a distal portion for engaging with the surface of the wellbore, wherein the ground structure comprises a transverse ground structure.

An electrocrushing drill bit comprises a bit body and at least one electrode coupled to a power source and the bit body, wherein the at least one electrode having a distal portion for engaging with a surface of a wellbore. The electrocrushing drill bit comprises a ground structure coupled to the bit body proximate to the at least one electrode and having a distal portion for engaging with the surface of the wellbore, wherein the ground structure comprises a transverse ground structure.

Systems, devices, and methods for a microwave energy applicator. The applicator may define an internal channel having one or more longitudinal ridges inside the channel configured to focus energy. The ridges may be moveable. A reflector may be located near an exit of the applicator. In some embodiments, the applicator may define a channel having a decrease in cross-sectional area with a dielectric filler therein, acting to transition from a lower to a higher permittivity material. The various embodiments of the applicator may be attached to a waveguide, which may be an articulable robotic arm having rotatable waveguide segments attached with a microwave generator. The applicator may alter an energy level of microwaves travelling therethrough, for example, to concentrate the energy for application at a rock face in a mine site.

A method and apparatus for breaking mineral particles comprising suspending the particles in a liquid flowing in a conduction path, the liquid comprising a dielectric constant higher than the particles and wherein an electric voltage pulse is sent to electrodes to pass an electric field in the mineral particles with sufficient stress to fracture the mineral particles.

A method and apparatus for breaking mineral particles comprising suspending the particles in a liquid flowing in a conduction path, the liquid comprising a dielectric constant higher than the particles and wherein an electric voltage pulse is sent to electrodes to pass an electric field in the mineral particles with sufficient stress to fracture the mineral particles.

A method for mining using a laser to cause spalling includes the steps of generating and delivering a laser beam to a work surface of a geological strata having a sought after mineral to be removed from the stratum; moving the laser beam about three perpendicular axes so that a focal point of the laser beam moves across the working surface and rapidly increases the surface temperature of the working surface; providing a source of a cooling media, and delivering the cooling media to the working surface so as to rapidly cool the working surface subsequent to the rapid surface temperature increase generated by the laser beam so as to effect a fracturing of the working surface and to generate a plurality of chips from the working surface; and removing the chips spalled from the working surface

A method for mining using a laser to cause spalling includes the steps of generating and delivering a laser beam to a work surface of a geological strata having a sought after mineral to be removed from the stratum; moving the laser beam about three perpendicular axes so that a focal point of the laser beam moves across the working surface and rapidly increases the surface temperature of the working surface; providing a source of a cooling media, and delivering the cooling media to the working surface so as to rapidly cool the working surface subsequent to the rapid surface temperature increase generated by the laser beam so as to effect a fracturing of the working surface and to generate a plurality of chips from the working surface; and removing the chips spalled from the working surface

A system for excavating a rock face using microwaves. The system may include a microwave generator, an articulable robotic arm with a plurality of rotatably connected rigid waveguide segments, an applicator attached to a distal end of the robotic arm, and a robotic control system. The system produces microwaves with the microwave generator and moves the robotic arm such that the applicator moves along the rock face as the microwaves exit the applicator to precondition the rock face for excavation. Various patterns of microwave treatment, and controls based on sensor feedback, may be implemented.