Multimodal rock disintegration by non-contact thermal effect, spallation, melting, evaporation of a rock through a movable electric arc, arc thermal expansion and subsequent shock pressure wave allows in comparison with currently available and known technologies to drill into the rock by direct action of the electric arc and heat flows generated by the electric arc. The principle of the disintegration is based on the electric arc generation, force action to it and pressing it towards the rock intended to disintegrate, which causes heating of the rock so that a phase change and thermal disintegration of the rock occurs. Subsequently, the crushed rock is transported by a fluid streams, which are involved in stabilizing and guiding of the electric arc, from the area between the rock and the electric arc, which is the area of the rock disintegration.

Multimodal rock disintegration by non-contact thermal effect, spallation, melting, evaporation of a rock through a movable electric arc, arc thermal expansion and subsequent shock pressure wave allows in comparison with currently available and known technologies to drill into the rock by direct action of the electric arc and heat flows generated by the electric arc. The principle of the disintegration is based on the electric arc generation, force action to it and pressing it towards the rock intended to disintegrate, which causes heating of the rock so that a phase change and thermal disintegration of the rock occurs. Subsequently, the crushed rock is transported by a fluid streams, which are involved in stabilizing and guiding of the electric arc, from the area between the rock and the electric arc, which is the area of the rock disintegration.

A high power laser drilling system utilizing an electric motor laser bottom hole assembly. A high power laser beam travels within the electric motor for performing a laser operation. A system includes a down hole electrical motor having a hollow rotor for conveying a high power laser beam having a wavelength less than 1060 nm through the electrical motor.

A high power laser drilling system utilizing an electric motor laser bottom hole assembly. A high power laser beam travels within the electric motor for performing a laser operation. A system includes a down hole electrical motor having a hollow rotor for conveying a high power laser beam having a wavelength less than 1060 nm through the electrical motor.

A first characteristic of a first discharge of electrodes of a pulse power drilling assembly in a borehole of a subterranean formation is determined. The first characteristic is based on a measurement of the first discharge. A second characteristic of a second discharge of the electrodes is determined. The second discharge occurs after the first discharge, and the second characteristic is based on a measurement of the second discharge. A difference between the first characteristic and the second characteristic is determined. A boundary layer of the subterranean formation is determined based on the difference.

A first characteristic of a first discharge of electrodes of a pulse power drilling assembly in a borehole of a subterranean formation is determined. The first characteristic is based on a measurement of the first discharge. A second characteristic of a second discharge of the electrodes is determined. The second discharge occurs after the first discharge, and the second characteristic is based on a measurement of the second discharge. A difference between the first characteristic and the second characteristic is determined. A boundary layer of the subterranean formation is determined based on the difference.

A system for extracting oil and gas includes at least one drilling rod having an elongated body and a working head positioned at the distal end of the elongated body, wherein the working head has a proximal end and a distal end, a first mechanical drilling device positioned at the distal end of the working head, a second mechanical drilling device position at the proximal end of the working head, a central laser emitter positioned at the distal end of the working head, at least one lateral emitter positioned on a side wall of the working head between the distal end and the proximal end, a fiber optic cable positioned within a lumen of the elongated body and coupled to the central laser emitter and the at least one lateral emitter, and a laser source coupled to and supplying a laser beam to the fiber optic cable.

One method includes position an antenna inside a wellbore in a location corresponding to a formation where near wellbore damage occurs; wherein the wellbore extends from a surface of a hydrocarbon reservoir downward into the subterranean structure of the hydrocarbon reservoir; transmitting an electromagnetic (EM) wave to the antenna; and irradiating, from the antenna, at least a portion of the EM wave at the formation, wherein the portion of the EM wave removes the near wellbore damage at the formation.

One method includes position an antenna inside a wellbore in a location corresponding to a formation where near wellbore damage occurs; wherein the wellbore extends from a surface of a hydrocarbon reservoir downward into the subterranean structure of the hydrocarbon reservoir; transmitting an electromagnetic (EM) wave to the antenna; and irradiating, from the antenna, at least a portion of the EM wave at the formation, wherein the portion of the EM wave removes the near wellbore damage at the formation.

An example laser tool is configured to operate within a wellbore of a hydrocarbon-bearing rock formation. The laser tool includes one or more optical transmission media as part of an optical path originating at a laser generator configured to generate a laser beam having an axis. The laser tool includes an optical element for receiving the laser beam from the one or more optical transmission media and for output to the hydrocarbon-bearing rock formation. The laser tool includes a purging head for removing dust or vapor from a path of the laser beam. The purging head is for discharging two or more purging gas streams. The purging head may include a coaxial flow assembly and a helical flow assembly. A coaxial purging gas stream may flow in a direction parallel to the axis. A helical purging gas stream may flow in a helical pattern around and substantially along the axis.