Abstract: Geologic material in a borehole is weakened by accelerating a projectile into contact with the material. A drill bit is then used to bore through the weakened material. To accelerate the projectile, an endcap is placed in a conduit using a source of gas. The endcap isolates the conduit from the external environment. A projectile is then positioned in the conduit above the endcap. Movable members within the conduit are operated in sequence to enable single endcaps and projectiles to be moved into the conduit. Gas from the conduit is evacuated into an annulus between the conduit and a surrounding conduit, and a propellant material is provided into the conduit. The propellant material applies a force to the projectile to accelerate the projectile into contact with the geologic material. A fluid is circulated down a second annulus outside of the surrounding conduit to contact the drill bit and remove debris.

Abstract: Boreholes used for generating geothermal energy or other purposes are formed at least in part by accelerating projectiles toward geologic material. Interaction between a projectile and the geologic material may generate debris or other material. The temperature of this generated material may be used to determine the potential for generation of geothermal energy using the borehole. Based on the temperature of the material, a fluid having a different temperature than that of the material is provided into the borehole for generation of power using geothermal energy.

Abstract: Systems for drilling or tunneling include an assembly for accelerating a projectile into a region of geologic material. An interaction between the projectile and the geologic material extends a borehole and forms debris. The debris may be reduced in size by moving the debris to a crushing device. The reduced-size debris is then moved toward the surface using fluid movement. Water jets or other types of devices may be used to cut or deform a perimeter of a region of geologic material before the projectile is accelerated to control the shape of the borehole and the manner in which debris is broken from the geologic material.

Abstract: Spherical projectiles 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.

Abstract: 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.

Abstract: 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. An endcap may be deployed within a tube of the ram accelerator device to prevent incursion of formation pressure products such as oil, water, mud, gas, and so forth into a guide tube of the ram accelerator. During operation the projectile penetrates the endcap and at least a portion thereof impact a working face. In some implementations a purge gas may be used to form a ullage between the endcap and the working face.

Abstract: 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 includes one or more baffles that are downhole. 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. An endcap may be deployed within a tube of the ram accelerator device to prevent incursion of formation pressure products such as oil, water, mud, gas, and so forth into a guide tube of the ram accelerator. The endcap may be maintained in place within the hole at least in part by the one or more baffles. During operation the projectile penetrates the endcap and at least a portion thereof impacts a working face.

Abstract: 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.

Abstract: 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.

Abstract: 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. An endcap may be deployed within a tube of the ram accelerator device to prevent incursion of formation pressure products such as oil, water, mud, gas, and so forth into a guide tube of the ram accelerator. During operation the projectile penetrates the endcap and at least a portion thereof impacts a working face. A downhole end of the tube may be displaced laterally within the hole to change the direction of the hole.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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. An endcap may be deployed within a tube of the ram accelerator device to prevent incursion of formation pressure products such as oil, water, mud, gas, and so forth into a guide tube of the ram accelerator. During operation the projectile penetrates the endcap and at least a portion thereof impact a working face. In some implementations a purge gas may be used to form a ullage between the endcap and the working face.