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.
Systems for forming or extending a tunnel or shaft within geologic material may include a ram accelerator assembly for accelerating one or more projectiles into geologic material to weaken a region of the geologic material. The projectile(s) pre-condition the geologic material, such as by forming one or more holes in a central region of the material or to define a perimeter of the region to be displaced. A cutting tool or subsequent projectile impacts may then be used to remove the weakened material. The voids formed by the first projectile(s) cause compressive forces from subsequent impacts or cutting operations to be converted to tension forces that more efficiently break geologic material, which may fall into the voids created by the first projectile(s). The voids created by the projectile impacts may also control the material that is removed and the shape of a resulting section of the tunnel or shaft.
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.
Systems for forming or extending a tunnel or shaft within a working surface may include a ram accelerator assembly for accelerating a projectile into geologic material to weaken a region of the geologic material. A cutting tool may then be used to remove the weakened material more rapidly, with lower energy use and less wear on the cutting tool than use of the cutting tool independently. A collection assembly may be used to move debris away from the working surface while the projectile and cutting operations are performed to enable generally continuous use of the system. The number of projectiles that are accelerated and the rate at which projectiles are used may be controlled based on characteristics of the geologic material and the rate at which created debris may be removed, allowing an operation to be optimized for speed, cost, stability, or other factors.
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.
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.
E21B 47/14 - Moyens pour la transmission de signaux de mesure ou signaux de commande du puits vers la surface, ou de la surface vers le puits, p.ex. pour la diagraphie pendant le forage utilisant des ondes acoustiques
E21B 7/00 - Procédés ou matériels particuliers pour le forage
E21B 44/00 - Systèmes de commande automatique spécialement adaptés aux opérations de forage, c. à d. systèmes à fonctionnement autonome ayant pour rôle d'exécuter ou de modifier une opération de forage sans l'intervention d'un opérateur humain, p.ex. systèmes de ; Systèmes spécialement adaptés à la surveillance de plusieurs variables ou conditions de forage
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.
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.
E21B 7/00 - Procédés ou matériels particuliers pour le forage
F41A 1/00 - Propulsion de projectiles caractérisée par l'utilisation de charges propulsives combustibles ou explosives
F41A 1/02 - Propulsion de projectiles en survitesse utilisant des moyens successifs pour augmenter la force propulsive, p.ex. utilisant la combustion de plusieurs charges propulsives, allumées l'une après l'autre et disposées le long du tube de l'arme; Propulsion multi-étages de projectiles
F41A 1/04 - Propulsion de projectiles utilisant la combustion d'une charge propulsive liquide ou gazeuse, p.ex. d'un hypergol
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 impact a working face.
E21B 7/00 - Procédés ou matériels particuliers pour le forage
F41A 1/00 - Propulsion de projectiles caractérisée par l'utilisation de charges propulsives combustibles ou explosives
F41A 1/02 - Propulsion de projectiles en survitesse utilisant des moyens successifs pour augmenter la force propulsive, p.ex. utilisant la combustion de plusieurs charges propulsives, allumées l'une après l'autre et disposées le long du tube de l'arme; Propulsion multi-étages de projectiles
F41A 1/04 - Propulsion de projectiles utilisant la combustion d'une charge propulsive liquide ou gazeuse, p.ex. d'un hypergol
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.
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. In some implementations a purge gas may be used to form a ullage between the endcap and the working face.
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.
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