A method for drilling a geothermal well in a subterranean zone includes drilling, with a drill string, a wellbore of the geothermal well in the subterranean zone. An inherent temperature of the rock adjacent a rock face at a downhole end of the wellbore is at least 250° C. While drilling, a drilling fluid is flowed at a temperature at the rock face such that a difference between the inherent temperature of the rock adjacent the rock face and the temperature of the drilling fluid at the rock face is at least 100° C.

A method for drilling a geothermal well in a subterranean zone includes drilling, with a drill string, a wellbore of the geothermal well in the subterranean zone. An inherent temperature of the rock adjacent a rock face at a downhole end of the wellbore is at least 250° C. While drilling, a drilling fluid is flowed at a temperature at the rock face such that a difference between the inherent temperature of the rock adjacent the rock face and the temperature of the drilling fluid at the rock face is at least 100° C.

The systems and techniques described herein may allow for optimized boring through a variety of geologies. A plurality of different boring techniques may be utilized for boring through a geological formation, in order to suit the characteristics of various portions of the geological formation. The systems and techniques described herein includes determining geological features and adjusting operation of boring based on the geological features. In certain such embodiments, boring systems may include a bore head that includes a plurality of boring elements. Such boring elements may be contact and/or non-contact boring elements.

Some implementations of the present disclosure provide a laser drilling tool assembly comprising: (i) a body that includes: a first segment configured to receive an input beam from a laser source and couple the input beam to provide an irradiation beam to irradiate a downhole target, and a second segment housing one or more purging pipes; and (ii) a tool head that includes: a retractable nozzle; and one or more optical sensing elements mounted on the retractable nozzle, wherein when the downhole target is being irradiated by the irradiation beam, the retractable nozzle is extended towards the downhole target such that the one or more optical sensing elements are positioned closer to the downhole target.

A plasma tunnel boring machine including a plurality of plasma torches on the cutting head, and a plurality of nozzles on the cutting head to provide a stream to cool an area while the plasma torches are active, and a tractor providing propulsion to the cutting head, the tractor to move the cutting head to cut a tunnel.

A plasma tunnel boring machine including a plurality of plasma torches on the cutting head, and a plurality of nozzles on the cutting head to provide a stream to cool an area while the plasma torches are active, and a tractor providing propulsion to the cutting head, the tractor to move the cutting head to cut a tunnel.

Disclosed are systems and methods to bore or tunnel through various geologies in an autonomous or substantially autonomous manner including one or more non-contact boring elements that direct energy at the bore face to remove material from the bore face through fracture, spallation, and removal of the material. Systems can automatically execute methods to control a set of boring parameters that affect the flux of energy directed at the bore face. Systems can further automatically execute the methods to: monitor, direct, maintain, and/or adjust a set of boring controls, including for example a standoff distance between the system and the bore face, a temperature of exhaust gases directed at the bore face, a removal rate of material from the bore face, and/or a thermal or topological characterization of the bore face during boring operations.

The systems and techniques described herein may allow for optimized boring through a variety of geologies. A plurality of different boring techniques may be utilized for boring through a geological formation, in order to suit the characteristics of various portions of the geological formation. The systems and techniques described herein includes determining geological features and adjusting operation of boring based on the geological features. In certain such embodiments, boring systems may include a bore head that includes a plurality of boring elements. Such boring elements may be contact and/or non-contact boring elements.

The systems and techniques described herein may allow for optimized boring through a variety of geologies. A plurality of different boring techniques may be utilized for boring through a geological formation, in order to suit the characteristics of various portions of the geological formation. The systems and techniques described herein includes determining geological features and adjusting operation of boring based on the geological features. In certain such embodiments, boring systems may include a bore head that includes a plurality of boring elements. Such boring elements may be contact and/or non-contact boring elements.

Systems to bore or tunnel through various geologies in an autonomous or substantially autonomous manner can include one or more non-contact boring elements that direct energy at the bore face to remove material from the bore face through fracture, spallation, and removal of the material. The systems can automatically execute methods to control a set of boring parameters that affect the flux of energy directed at the bore face. Systems can further automatically execute the methods to trigger an optical sensor to capture images at the bore face, generate temperature profiles, identify spall fragments and hot zones and/or adjust a set of boring controls. For example, the system can execute methods to adjust a standoff distance between the system and the bore face, and adjust power and/or gas supply to the non-contact boring element.