Methods for generating boreholes used for generating geothermal energy or other purposes include forming the borehole by accelerating a projectile into contact with geologic material. Interaction between the projectile and the geologic material generates an acoustic signal, such as vibrations within the formation, that is detected using acoustic sensors along a drilling conduit, at the surface, or within a separate borehole. Characteristics of the geologic material, such as hardness, porosity, or the presence of fractures, may be determined based on characteristics of the acoustic signal. The direction in which the borehole is extended may be modified based on the characteristics of the geologic material, such as to create a borehole that intersects one or more fractures for generation of geothermal energy.

A ram accelerator device may utilize rails arranged within a guide tube that may be emplaced downhole. The rails may serve to direct a hypervelocity projectile along the length of the guide tube. The rails may carry utilities or provide other services to operate the system. For example, electrical wiring for power, control signaling, and so forth, may be placed within the rails. In another example, gasses may be delivered by the rails.

A blast hole measurement and logging apparatus, which generally comprises a housing configured to operatively house a solid-state LiDAR sensor array configured to transmit and steer pulses of light into a blast hole by shifting a phase of the pulses through the array to compile volumetric data of the sensor's field-of-view. Also included is a processor configured to receive the volumetric data from the LiDAR sensor, the volumetric data indicative of an internal volume of the blast hole which is useable in calculating an explosive charge according to a blast plan, the processor configured to store and/or transmit the volumetric data.

An energy transfer device (10) is provided that is capable of transferring the energy output from one pyrotechnic device (52) to another device (78) for initiating firing thereof. Device (10) comprises a device housing (12) in which a deformable device insert (14) is received. Device insert (14) comprises a central passageway (34) for transmitting the output from a pyrotechnic device (52), including energy, gasses, and/or solids, to another pyrotechnic device (78). The passageway (34) conducts the pyrotechnic device output to a precise location on the second pyrotechnic device (78) where firing is most effectively initiated. The energy transfer device (10) may be employed as a part of a tool (44) used in well completion operations.

A drill string comprises a mechanical drill bit and a ram accelerator with a launch tube proximate to the mechanical drill bit. A projectile accelerated by the ram accelerator exits the mechanical drill bit through an orifice and impacts a geologic formation. The impact weakens a portion of the formation, enabling the drill bit to penetrate the weakened portion more easily. An endcap may be used to prevent outside material from entering the ram accelerator. The projectile may pass through or otherwise displace the endcap during operation. The launch tube may be positioned at an angle relative to the drill bit such that projectiles impact and weaken the formation on a particular side. Contact between the drill bit and the formation may direct the drill bit toward the weakened side, enabling the ram accelerator to be used to steer the drill bit.

An apparatus, method and insulation medium for inserting and insulating a charge medium within a borehole includes a charge tube comprised of an elongate tube having a length and diameter sufficient for containing a desired quantity of a charge medium. A charge medium in a pumpable form is provided for substantially filling the charge tube. An insulation medium in a pumpable form is provided for substantially encapsulating the charge tube and substantially filling an annular space between the charge tube and the borehole for insulating the charge tube from a downhole environment in which the charge tube is to be inserted. A detonator is inserted within the charge medium proximate a distal end of the charge tube and a charge cable extends from the detonator through the charge tube and exits from the charge tube.

A wellbore or other type of hole in a geologic formation or other material, such as concrete or other manmade structures, may be formed by accelerating perforating charges containing detonable material through a tubular string. Movement of a fluid, such as drilling mud, may be used to transport perforating charges to a bottom hole assembly. In the bottom hole assembly, a propellant material may be used to accelerate the perforating charges, such as by using a ram acceleration mechanism. The perforating charges may be shaped to at least partially penetrate a surface of the hole. Detonation of the perforating charge may displace, stress, or fracture the geologic material. Movement of the fluid may remove displaced geologic material and detonated material from the perforating charge from the hole.

A hole in geologic material, such as a wellbore, may be extended by impacting the working face of the hole with high velocity projectiles. A tube may be placed within the hole, and the lower end of the tube may be sealed to prevent ingress of material from the hole into the tube. A projectile may be accelerated through the tube, such as by igniting a combustible gas mixture to impart a force to the projectile. The impact of the projectile may extend the hole. In some cases, accelerated projectiles may be used in conjunction with a drill bit to drill a wellbore or other type of hole.

An apparatus, rock drilling rig and drilling method is provided. The apparatus provides position control data for controlling positioning a rock drilling unit of a rock drilling rig arranged for drilling transverse drill hole patterns in an underground tunnel. The apparatus includes a teaching feature for gathering data on manually controlled movements at the location of the drill hole pattern and to thereby detect a movement path, which is collision free. The data on the taught collision free movement path is implemented when controlling the rock drilling unit during an actual drilling phase.

One or more ram accelerator devices may be used to form one or more holes in geologic or other material. These holes may be used for drilling, tunnel boring, excavation, and so forth. The ram accelerator devices propel projectiles which are accelerated by combustion of one or more combustible gasses in a ram effect to reach velocities exceeding 500 meters per second.