HK1234117B - Ram accelerator system with endcap - Google Patents

Description

Ram accelerator system with end caps

priority

This application claims priority to U.S. non-provisional patent application serial number 14/708,932, filed May 11, 2015, entitled “Rampress Accelerator System with End Caps,” the contents of which are incorporated by reference into the present disclosure. U.S. non-provisional patent application serial number 14/708,932 claims priority to U.S. provisional patent application serial number 61/992,830, filed May 13, 2014, entitled “Rampress Accelerator System with End Caps,” the contents of which are incorporated by reference into the present disclosure.

Background of the Invention

Conventional drilling and excavation methods utilize a drill to create a hole in one or more layers of material to be penetrated. Excavation, quarrying, and tunneling may also utilize explosives placed in the hole and detonated to break up at least a portion of the material. The use of explosives creates additional safety and regulatory burdens, which increases operating costs. Typically, these methods involve drilling, blasting, material removal, and ground support, and are relatively slow methods for removing material to form the desired cavity (typically minutes to hours to days per linear foot, depending on the cross-sectional area being moved).

BRIEF DESCRIPTION OF THE DRAWINGS

Certain implementations and embodiments will now be described more fully below with reference to the accompanying drawings, in which various aspects are illustrated. However, the various aspects may be implemented in many different forms and should not be construed as limited to the implementations set forth herein. The drawings are not necessarily drawn to scale, and the relative proportions of the objects indicated may have been modified for ease of illustration and not as a limitation. Throughout the text, like numbers refer to like elements.

1 is an illustrative system for drilling or excavating using a ram accelerator including multiple sections containing one or more combustible gases configured to propel a projectile toward a working surface of material.

FIG. 2 illustrates a curved drilling path formed using punch accelerator drilling.

FIG3 illustrates a segment separator mechanism configured to reset a diaphragm that has been penetrated during projectile launch so that the seal between the various segments of the ram accelerator is maintained.

FIG. 4 illustrates a projectile configured to be accelerated using the ramjet burn effect.

FIG. 5 shows a projectile configured with an internal grinding core configured to provide abrasion of material upon and after impact.

FIG6 illustrates the fluid-fluid impact interaction of a projectile with geological material.

FIG7 illustrates the non-fluid-fluid impact interaction of a projectile with a geological material.

FIG8 shows additional details associated with the guide tube, as well as the reamer and other equipment that can be placed downhole.

9 illustrates a guide tube positioned downhole having a ejecta collector coupled to one or more ejecta channels configured to transport ejecta by impact to the surface for disposal.

10 shows a guide tube placed downhole with a reamer configured to be cooled by a fluid circulated above ground to remove at least a portion of the ejecta.

Figure 11 shows a guide pipe placed downhole to deploy a continuous concrete lining within a cavity.

FIG. 12 illustrates tunneling or excavation using a ram accelerator to drill multiple holes using multiple projectiles.

FIG. 13 shows an apparatus for removing a rock section defined by a hole drilled by a ram accelerator projectile.

FIG. 14 is a flow chart of a process for drilling a hole using a punch accelerator.

15 is a flow chart of a process for multiple firings of multiple projectiles wherein the firing pattern is adjusted between at least some of the firings.

16 illustrates a guide tube placed downhole with an end cap deployed and a system for forming an ullage portion in formation fluid within a borehole.

17 is a flow chart of a process utilizing end caps.

DETAILED DESCRIPTION

Conventional drilling and excavation techniques for penetrating materials typically rely on mechanical drill bits for cutting or grinding at the work surface. These materials may include metals, ceramics, geological materials, and the like. Tool wear and breakage on the mechanical drill bits slow these operations, thereby increasing costs. In addition, the rate of progress in cutting through materials (such as hard rock) is inhibited. Drilling can be used to construct water wells, oil wells, gas wells, underground pipelines, and the like. In addition, the impact of conventional techniques on the environment may be significant. For example, conventional drilling may require a large supply of water, which may not be easily achieved in arid regions. Therefore, resource extraction may be extremely expensive, time-consuming, or both.

This disclosure describes systems and techniques for using a ramjet accelerator to eject one or more projectiles toward a working face of geological material to form a hole. The ramjet accelerator includes a launch tube divided into multiple sections. Each section is configured to store one or more combustible gases. The projectile is lowered down the launch tube and passed through the multiple sections, where it is accelerated to a ramjet velocity. At the ramjet velocity, a ram-compression effect, at least in part provided by the projectile's shape, initiates combustion of the one or more combustible gases, thereby accelerating the projectile. In some implementations, the projectile can be accelerated to a hypervelocity. In some implementations, hypervelocity includes a velocity greater than or equal to 2 km/s upon ejection or exit from the ramjet accelerator launch tube. In some implementations, the projectile can be accelerated to a non-hypervelocity. In some implementations, non-hypervelocity includes a velocity less than 2 km/s.

Projectiles ejected from a ramjet accelerator impact a working surface of geological material. Projectiles traveling at ultrahigh velocities, typically due to the substantial kinetic energy in the projectiles, interact with the geological material at the working surface upon impact, forming a fluid-fluid interaction. This interaction forms a hole, typically cylindrical in shape. By firing a series of projectiles, holes can be formed or drilled through the geological material. In contrast, projectiles traveling at non-ultrahigh velocities interact with the geological material at the working surface, forming a solid-solid interaction. This interaction can fracture or pulverize the geological material, forming a cylindrical hole or a pit with a conical profile.

The segment separator mechanism is configured to provide one or more barriers between different segments in a ram accelerator containing one or more combustible gases. Each segment can be configured to contain one or more combustible gases under various conditions (such as a specific pressure, etc.). The segment separator mechanism can use a diaphragm, a valve, etc., which is configured to seal one or more segments. During the firing process, the projectile passes through the diaphragm, thereby breaking the seal, or the valve is opened before firing. A reel mechanism can be used to move the unused portion of the diaphragm into position, thereby restoring the seal. Other separator mechanisms (such as ball valves, plates, end caps, gravity gradients, etc.) can also be used. The separator mechanism can be configured to operate as a blowout preventer, a recoil device, etc. For example, the separator mechanism may include a ball valve that is configured to close when the downhole pressure exceeds a threshold pressure.

The hole formed by the impact of the projectile can be further guided or processed. A guide tube (also known as a "drift tube") can be inserted into the hole to prevent settling, guide the drilling path, deploy equipment, and so on. In some implementations, a reamer or movable spacer can be coupled to the guide tube and inserted downhole. The reamer can include one or more cutting or grinding surfaces configured to shape the hole into a substantially uniform cross-section. For example, the reamer can be configured to smooth the sides of the hole.

The reamer can also be configured to apply lateral force between the guide tube and the wall of the hole, thereby deflecting or otherwise directing drilling in a particular direction. This directionality enables the punch accelerator to form a curved drilling path.

The guide tube is configured to receive projectiles ejected from the ram accelerator and guide them toward the work face. A series of projectiles can be fired from the ram accelerator down the guide tube, allowing for continuous drilling operations. During operation, end caps can be used to improve system performance. Projectiles can penetrate the end caps to reach the work face. Other operations, such as inserting a continuous concrete lining into a hole, are also possible.

Projectiles, including material resulting from the impact of one or more projectiles on geological material, may be removed from the borehole. In some implementations, back pressure from the impact may propel the projectiles from the borehole. In some implementations, a working fluid (such as compressed air, water, etc.) may be injected into the borehole to assist in removing at least a portion of the projectiles. The injection may be performed continuously, before, during, or after the launch of the projectiles.

One or more ram accelerators can also be deployed to drill a number of holes for use in tunneling, excavation, and the like. Multiple accelerators can be fired sequentially or simultaneously to impact one or more target points on the working surface. After a number of holes are formed by projectile impact, various techniques can be used to remove the pieces of geological material defined by two or more holes close to each other. Mechanical force can be applied by a breaker to break, crush, or otherwise release the pieces of geological material from the main body of geological material at the working surface. In other implementations, conventional explosives can be placed in the holes drilled by the ram accelerator and detonated to break up the geological material.

In some implementations, conventional drilling techniques and equipment can be used in conjunction with ram accelerator drilling. For example, ram accelerator drilling can be used to reach a specific target depth. Once at the target depth, a conventional coring drill can be used to obtain a core sample from the rock formation at the target depth.

The described systems and techniques can be used to reduce the time, cost, and environmental requirements for resource extraction, resource exploration, construction, and the like. Furthermore, the punch accelerator drilling capability enables deeper exploration and mining of natural resources. Furthermore, the energy released during the impact process can be used to conduct geological surveys, such as reflection wave exploration, rock formation characterization, and the like.

Illustrative Systems, Instruments, and Processes

FIG1 is an illustrative system 100 for drilling or excavating using a ram accelerator 102. Ram accelerator 102 can be positioned a distance 104 from geological material 106 or a target material. Geological material 106 can include rock, dirt, ice, etc. Ram accelerator 102 has a body 108. Body 108 can include one or more materials such as steel, carbon fiber, ceramic, etc.

The ramjet accelerator 102 includes a propulsion mechanism 110. The propulsion mechanism 110 may include an air gun, an electromagnetic launcher, a solid explosive charge, a liquid explosive charge, a backpressure system, or the like. The propulsion mechanism 110 operates by providing a relative differential velocity between the projectile 118 and the particles in the one or more combustible gases, the differential velocity being equal to or greater than a ram velocity. The ram velocity is the velocity of the projectile 118 relative to the particles in the one or more combustible gases at which the ram effect occurs. In some implementations, at least a portion of the launch tube 116 within the propulsion mechanism 110 may be maintained under a vacuum prior to launch.

In the example depicted here, the propulsion mechanism comprises a pilot gas gun including an igniter 112 coupled to a chamber 114. Chamber 114 can be configured to contain one or more flammable, explosive, or explosive materials that produce an energy reaction when ignited by igniter 112. In the depicted airgun implementation, chamber 114 is coupled to a launch tube 116, within which a projectile 118 is positioned. In some implementations, projectile 118 can include or be adjacent to a tampon 120 configured to at least temporarily seal chamber 114 from launch tube 116. Tampon 120 can be attached, integral but frangible, or separate from projectile 118 but in contact therewith. One or more explosion-proof holes 122 can be provided to release reaction byproducts. In some implementations, launch tube 116 can be smooth, rifled, include one or more guide rails or other guiding features, and the like. The launch tube 116 or portions thereof may be maintained at a pressure lower than the pressure of the ambient atmosphere. For example, portions of the launch tube 116, such as those in the propulsion mechanism 110, may be evacuated to a pressure of less than 25 Torr.

The propulsion mechanism 110 is configured to initiate a ram pressure effect using the projectile 118. The ram pressure effect causes one or more flammable gases to be compressed by the projectile 118 and subsequently combust near the back side of the projectile 118. This compression causes the one or more flammable gases to heat, thereby triggering ignition. The ignition gases, combusting in an exothermic reaction, impart a pulse to the projectile 118 as it accelerates downward along the launch tube 116. In some implementations, a pyrotechnic igniter may be used to assist or initiate ignition. The pyrotechnic igniter may be attached to a portion of the projectile 118 or may be located within the launch tube.

The propulsion mechanism 110 can use electromagnetics, solid explosive charges, liquid explosive charges, stored compressed gas, or the like to propel the projectile 118 down the launch tube 116 at ram pressure velocity. In some implementations, a backpressure system can be used. The backpressure system accelerates at least a portion of one or more combustible gases through the stationary projectile 118, thereby creating a ram pressure effect in the initially stationary projectile 118. For example, while the projectile is resting within the launch tube 116, a combustible gas mixture under high pressure can be discharged from a port within the launch tube 116 through the projectile 118. This relative differential velocity achieves ram pressure velocity, and the ram pressure combustion effect begins, propelling the projectile 118 down the launch tube 116. Hybrid systems can also be used, in which the projectile 118 moves while backpressure is applied.

The projectile 118 passes from the propulsion mechanism 110 along the launch tube 116 into one or more ramjet acceleration sections 124. The ramjet acceleration sections 124 (or "sections") may be demarcated by section separator mechanisms 126. The section separator mechanisms 126 are configured to maintain a combustible gas mixture 128 that has been admitted to a section 124 via one or more inlet valves 130 in a particular section 124. Each of the different sections 124 may have a different combustible gas mixture 128.

The segment separator mechanism 126 may include valves (such as ball valves), diaphragms, gravity gradients, liquids, end caps, or other structures or materials that are configured to substantially maintain the different combustible gas mixtures 128 within their respective segments 124. In one implementation described below with respect to FIG. 3 , the diaphragms may be deployed using a reel mechanism, thereby allowing the diaphragms to be relatively quickly reset after being penetrated by a projectile 118 during operation of the ramjet 1022. In other implementations, the launch tube 116 may be arranged at an angle that is not perpendicular to the local vertical so that gravity maintains the different combustible gas mixtures 128 at different heights based on their relative densities. For example, the lighter combustible gas mixture 128 "floats" above the heavier combustible gas mixture 128, which sinks or remains at the bottom of the launch tube 116. In another example, the fluid at the bottom of the hole 134 may provide a seal, thereby allowing the guide tube 136 to be filled with the combustible gas mixture 128 and used as the ram acceleration section 124 .

In this illustration, four sectors 124(1)-(4) are depicted as being maintained by five sector separator mechanisms 126(1)-(5). When ready for operation, each of sectors 124(1)-(4) is filled with a combustible gas mixture 128(1)-(4). In other implementations, a different number of sectors 124, sector separator mechanisms 126, etc. may be used.

The combustible gas mixture 128 may include one or more combustible gases. The one or more combustible gases may include an oxidant or oxidizing agent. For example, the combustible gas mixture 128 may include hydrogen and oxygen in a ratio of 2:1. Other combustible gas mixtures may also be used, such as silane and carbon dioxide. The combustible gas mixture 128 may be provided by extracting from the ambient atmosphere, electrolyzing a material (such as water) by a solid or liquid gas generator using solid materials that chemically react to release the combustible gas from a previously stored gas or liquid, or the like.

The combustible gas mixture 128 may be the same or may differ between the sections 124. These differences may include chemical composition, pressure, temperature, and the like. For example, the density of the combustible gas mixture 128 in each of the sections 124(1)-(4) may decrease along the launch tube 116 such that section 124(1) maintains the combustible gas 128 at a higher pressure than section 124(4). In another example, the combustible gas mixture 128(1) in section 124(1) may include oxygen and propane, while the combustible gas mixture 128(3) may include oxygen and hydrogen.

One or more sensors 132 may be configured at one or more locations along the ram accelerometer 102. These sensors may include pressure sensors, chemical sensors, density sensors, fatigue sensors, strain gauges, accelerometers, proximity sensors, and the like.

The ram accelerator 102 is configured to eject projectiles 118 from an ejection end of a launch tube 116 and toward a geological material 106 or other working surface of the geological material 106. Upon impact, a hole 134 may be formed. The ejection end is the portion of the ram accelerator 102 proximate to the feed 134.

A series of projectiles 118 can be fired one after another to form a hole that grows in length with each impact. The ramjet 102 can accelerate the projectiles 118 to hypervelocities. As used herein, hypervelocities include velocities greater than or equal to 2 km/s when ejected or exiting the ramjet launch tube.

In some implementations, the projectile may be accelerated to a non-hypervelocity. Non-hypervelocity includes velocities less than 2 km/s. Hypervelocity or non-hypervelocity may also be characterized based on the interaction of the projectile 118 with the geological material 106 or other geological materials 106. For example, hypervelocity impacts are characterized by fluid-fluid type interactions, while non-hypervelocity impacts are not. These interactions are described in more detail below with respect to Figures 6 and 7.

In some implementations, a guide tube 136 may be inserted into the bore 134. The interior of the guide tube 136 may be smooth, rifled, include one or more guide rails or other guiding features, and the like. The guide tube 136 provides a path for the projectile 118 to travel from the ram accelerator 102 to the portion of the geological material 106 to be drilled. The guide tube 136 may also be used to prevent subsidence, guide the drilling path, deploy instruments, deploy reamers, and the like. Thus, the guide tube 136 may follow the drilling path 138 formed by the successive impacts of the projectile 118. The guide tube 136 may include multiple sections coupled together, such as by threads, clamps, and the like. The guide tube 136 may be circular, oval, rectangular, triangular, or described as having a polygonal cross-section. The guide tube 136 may include one or more pipes or other structures nested within one another. For example, the guide tube 136 may include an inner and outer tube mounted coaxially, or the inner tube may be positioned against one side of the outer tube.

Compared to conventional drilling, using the impact of projectiles 118 to form the hole 134 results in increased drilling speed by minimizing the stoppages associated with adding more guide tubes 136. For example, after repeating the following operation, the standoff distance 104 can be increased to a distance of 0 to 100 feet. After extending the hole 134 using several projectiles 118, the firing can be stopped while one or more additional guide tubes 136 are inserted. In comparison, conventional drilling may involve stopping every 10 feet to add a new drill pipe section, which results in slower progress.

The direction of the drilling path 138 can be changed by modifying one or more firing parameters of the ram accelerator 102, moving the guide tube 136, etc. For example, a reamer on the guide tube 136 can apply lateral pressure by pushing against the wall of the hole 134, thereby bending or tilting the guide tube 136 in a particular direction.

The ejecta collector 140 is configured to collect or capture at least a portion of the ejecta resulting from the impact of one or more projectiles 118. The ejecta collector 140 may be positioned near the top of the aperture 134, such as being coupled to the guide tube 136.

In some implementations, the drill chuck 142 can be mechanically coupled to the guide tube 136, allowing the guide tube 136 to be raised, lowered, rotated, tilted, etc. Because the geological material 106 is removed by the impact of the projectile 118, the end of the guide tube 136 does not bear the loads associated with traditional mechanical drilling techniques. Therefore, the drill chuck 142 with the punch accelerator system can apply less torque to the guide tube 136 than conventional drilling.

The ram accelerator 102 may be used in conjunction with conventional drilling techniques. This will be discussed in more detail below with respect to FIG.

In some implementations, an electronic control system 144 can be coupled to the ramjet 102, one or more sensors 132, one or more sensors in the projectile 118, and the like. The control system 144 can include one or more processors, memories, interfaces, and the like configured to facilitate operation of the ramjet 102. The control system 144 can be coupled to one or more segment separator mechanisms 126, the inlet valves 130, and the sensors 132 to coordinate the configuration of the ramjet 102 to eject the projectiles 118. For example, the control system 144 can fill a particular segment 124 with a particular combustible gas mixture 128 and recommend using a particular projectile 118 type to form a particular hole 134 in a particular geological material 106.

In some implementations, a baffle or annular member may be placed within the ram acceleration section 124 instead of, or in addition to, the section separator mechanism 126. The baffle is configured to allow the projectile 118 to pass therethrough during operation.

Other mechanisms may also be present, not depicted here. For example, the injection system may be configured to inject one or more materials into the wake of the projectile 118. These materials may be used to clean the launch tube 116, clean the guide tube 136, remove debris, and the like. For example, powdered silica may be injected into the wake of the projectile 118 such that at least a portion of the silica is carried with the wake, pushed down the launch tube 116 by the wake, or both.

In some implementations, a drift tube can be positioned between the launch tube 116 and the guide tube 136 or aperture 134. The drift tube can be configured to provide a constant passage for the projectile 118 between the two.

FIG2 illustrates a scenario 200 in which a curved drilling path 138 is formed at least in part by drilling with a ram accelerator. In this illustration, a working point is shown at 202, at ground level 204. At working point 202, a support structure 206 holds the ram accelerator 102. For example, the support structure 206 may include a boom, a crane, scaffolding, or the like. In some implementations, the total length of the ram accelerator 102 may be between 75 feet and 300 feet. The support structure 206 is configured to maintain the launch tube 116 in a desired orientation and in a substantially straight position during firing. By minimizing deflection of the launch tube 116 during firing of the projectile 118, the side loads applied to the body 108 are reduced. In some implementations, multiple ram accelerators 102 may be moved in and out of positions in front of the aperture 134 to fire the projectile 118, allowing one ram accelerator 102 to be loaded while another ram accelerator 102 is being fired.

The ram accelerator 102 can be positioned vertically or horizontally at an angle, depending on the specific task. For example, when drilling a well, the ram accelerator 102 can be positioned substantially vertically. In contrast, when excavating a tunnel, the ram accelerator 102 can be positioned substantially horizontally.

The drilling path 138 may be configured to meander or curve along one or more radii of curvature. The radii of curvature may be determined at least in part based on the side loads imposed on the guide tube 136 as the projectile 118 is conveyed within the guide tube 136.

The ability to bend allows the drilling path 138 to be oriented so that a specific point in the space below the ground plane 204 can be reached or a specific area can be avoided. For example, the drilling path 138 can be configured to travel around a subsurface reservoir. In this illustration, the drilling path 138 passes through several layers of geological formations 208 to reach a final target depth 210. At the target depth 210, or at other points in the drilling path 138 during the impact process, the ejecta resulting from the impact of the projectile 118 can be analyzed to determine the composition of the various geological formations 208 passed by the end of the drilling path 138.

In some implementations, the ram accelerator 102 or a portion thereof may extend within or be positioned within the bore 134. For example, the ram accelerator 102 may be lowered along the guide tube 136, and firing may begin at a depth below ground level. In another implementation, the guide tube 136 or a portion thereof may serve as an additional ram accelerator section 124. For example, prior to impact, the lower portion of the guide tube 136 within the bore 134 may be filled with a combustible gas to provide acceleration.

Drilling with the ram accelerator 102 can be used in conjunction with conventional drilling techniques. For example, the ram accelerator 102 can be used to quickly reach a previously designated target depth 210 level. At this point, the use of the ram accelerator 102 can be discontinued, and conventional drilling techniques can be used to perform operations such as cutting core samples using the holes 134 formed by the projectiles 118. When core sampling or other operations have been completed at the desired distance, the use of the ram accelerator 102 can be resumed, and additional projectiles 118 can be used to increase the length of the drilling path 138.

In another embodiment, the projectile 118 can be shaped to capture or measure material properties of the geological material 106 in flight, or to analyze material interactions between the material comprising the projectile 118 and the geological material 106 or other target material. Samples of the projectile 118 fragments can be recovered from the hole 134, such as by core drilling or projectile recovery. In addition, sensors in the projectile 118 can transmit information back to the control system 144.

3 illustrates a mechanism 300 of one implementation of the sector separator mechanism 126. As described above, several techniques and mechanisms may be used to maintain different combustible gas mixtures 128 within a particular ramjet accelerator sector 124.

The mechanism 300 depicted here may be arranged at one or more ends of a particular section 124. For example, the mechanism 300 may be between sections 124(1) and 124(2) as shown here, at the injection end of section 124(4) containing the combustible gas mixture 128(4), and so on.

A gap 302 may be provided between the ramjet accelerator sections 124. A diaphragm 304 extends through the gap 302, or in front of the launch tube 116 when on the injection end. The diaphragm 304 is configured to maintain the combustible gas mixture 128 within the respective sections, prevent ambient atmosphere from entering the evacuation section 124, and the like.

The diaphragm 304 can comprise one or more materials, including but not limited to metal, plastic, ceramic, and the like. For example, the diaphragm 304 can comprise aluminum, steel, copper, polyester film, and the like. In some implementations, a carrier or support matrix or structure can be disposed around at least a portion of the diaphragm 304 that is configured to be penetrated by the projectile 118 during firing. The portion of the diaphragm 304 that is configured to be penetrated can differ from the carrier in one or more aspects. For example, the carrier can be thicker, have a different composition, and the like. In some implementations, the portion of the diaphragm 304 that is configured to be penetrated can be scored or otherwise designed to facilitate penetration by the projectile 118.

The supply reel 306 may store a plurality of membranes 304 , or membrane material, in a carrier strip, and the pierced membranes will be taken up by the take-up reel 308 .

The seal between the segments 124 and the diaphragm 304 can be maintained by compressing a portion of the diaphragm 304 or the carrier, thereby retaining the diaphragm 304 between a first seal assembly 310 on the first ram accelerator segment 124(1) and a corresponding second seal assembly 312 on the second ram accelerator segment 124(2). The second seal assembly 312 is depicted here as being configured to be displaced toward or away from the first seal assembly 310 as indicated by arrow 314 to allow the seal to be made or broken and to move the diaphragm 304.

During the process of evacuating or filling the section 124 with the combustible gas mixture 128, the intact septum 304, as sealed between the first sealing assembly 310 and the second sealing assembly 312, seals the section 124. During the firing process, the projectile 118 penetrates the septum 304, thereby leaving a hole. After firing, the material is wound from the supply reel 306 to the take-up reel 308, allowing the intact septum 304 to enter the launch tube 116 and then be sealed by the sealing assembly.

The housing 316 may be configured to enclose reels, seal components, and the like. Various access ports or port covers may be provided to allow for maintenance, such as removal or placement of the supply reel 306, take-up reel 308, and the like. A disconnect joint 318 may be provided to allow for separation of the first ram accelerator section 124(1) from the second ram accelerator section 124(2). The housing 316, disconnect joint 318, and other structures may be configured to maintain alignment of the launch tube 116 during operation. The housing 316 may be configured with one or more pressure relief valves 320. These valves 320 may be used to relieve pressure resulting from operation of the ram accelerator 102, change atmospheric pressure, and the like.

While the first ram accelerator section 124 ( 1 ) is depicted separate from the second ram accelerator section 124 ( 2 ) in this example, it should be understood that the mechanism 300 may be employed between other sections 124 and at the ends of other sections 124 .

In other implementations, instead of a spool, the septum 304 can be arranged as plates or sheets of material. A feed mechanism can be configured to change these plates or sheets to replace the pierced septum 304 with an intact septum.

The segment separator mechanism 126 may include a plate, such as a gate valve, configured to slide in and out of the launch tube 116. Other valves, such as ball valves, may also be used. One or more of these various mechanisms may be used with the same launch tube 116 during the same firing operation. For example, the mechanism 300 may be used at the ejection end of the ram accelerator 102, while a ball valve or gate valve may be used between the segments 124.

The segment separator mechanism 126 can be configured to fit within the guide tube 136, or to be placed within the bore 134. This arrangement allows the ram acceleration segment 124 to extend downwardly along the bore 134. For example, the mechanism 300 can be deployed downwardly into the bore 134, such as a traveling series of projectiles 118 can be fired downwardly into the bore.

4 shows several views 400 of the design of the projectile 118. The side view 402 depicts the projectile 118 as having a front face 404, a back face 406, a rod penetrator 408, an inner body 410, and an outer assembly 412. The front face 404 is configured to exit the launch tube 116 before the back face 406 during launch.

The rod penetrator 408 may comprise one or more materials, such as metal, ceramic, plastic, etc. For example, the rod penetrator 408 may comprise copper, depleted uranium, etc.

The inner body 410 of the projectile 118 may include a fixed plastic material or other material to be entrained into the hole 134, such as, for example, explosives, hole cleaners, impermeability agents, water, or ice. A plastic explosive or a specialized explosive may be embedded in the rod penetrator 408. As the projectile 118 penetrates the geological material 106, the explosive is entrained into the hole 134, where it can be detonated. In another embodiment, the outer housing 412 may be connected to a pull cord configured to draw a separate explosive into the hole 134.

In some implementations, at least a portion of the projectile 118 can include a material that is combustible under the conditions present during at least a portion of the firing sequence of the ramjet accelerator 102. For example, the outer casing 412 can include aluminum. In some implementations, the projectile 118 can omit an onboard propellant.

The back side 406 of the projectile 118 may also include a filler 120120 adapted to prevent the combustible gas mixture 128 from escaping through the projectile 118 as the projectile 118 accelerates through each section of the launch tube 116. The filler 120 may be an integral part of the projectile 118 or a separate and removable unit. The cross section 414 shows a view along the plane indicated by line A-A.

As depicted, the projectile 118 may also include one or more fins 416, rails, or other guidance features. For example, the projectile 118 may be rifled to induce a spiral. The fins 416 may be positioned on the front 404, back 406, or both of the projectile 118 to provide guidance during launch and ejection. The fins 416 may be coated with an abrasive material to help clean the launch tube 116 as the projectile 118 penetrates the geological material 106. In some implementations, one or more of the fins 416 may include an abrasive tip 418. In some implementations, the body of the projectile 118 may extend outward to form the fins or other guidance features. The abrasive tip 418 may be used to clean the guide tube 136 as the projectile 118 passes through.

In some implementations, the projectile 118 may incorporate one or more sensors or other devices. The sensors may include accelerometers, temperature sensors, gyroscopes, and the like. Information from these sensors may be transmitted back to a receiving device using radio frequency, optical transmission, acoustic transmission, and the like. This information may be used to modify one or more firing parameters, characterize the material within the aperture 134, and the like.

5 shows several views 500 of another projectile 118 design. As shown here in side view 502 showing a cross section, the projectile 118 has a front face 504 and a back face 506.

Within the projectile 118 is a rod-type penetrator 408. Although the penetrator is depicted as a rod, in other implementations, the penetrator may have one or more other shapes, such as a prismatic solid.

Similar to the above, the projectile 118 may include a central core 506 and an outer core 508. In some implementations, one or both of these may be omitted. Also as described above, the projectile 118 may include an inner body 410 and an outer shell 412, although they may have different shapes than those described above with respect to FIG. 4 .

The projectile 118 may include a pyrotechnic igniter 510. The pyrotechnic igniter 510 may be configured to initiate, maintain, or otherwise support combustion of the combustible gas mixture 128 during the firing process.

Cross-section 512 shows a view along the plane indicated by line B-B. As depicted, projectile 118 may not be radially symmetrical. In some implementations, the shape of projectile 118 may be configured to provide guidance or guidance for projectile 118. For example, projectile 118 may have a wedge-shaped or chisel-shaped shape. As described above, projectile 118 may also include one or more fins 416, rails, or other guidance features.

Projectile 118 may include one or more abrasive materials. The abrasive materials may be disposed within or on projectile 118 and configured to provide an abrasive action upon impacting the working surface of geological material 106. The abrasive materials may include diamond, garnet, silicon carbide, tungsten, or copper. For example, core 506 may include an abrasive material that may be layered between the inner core and outer core 508 of rod penetrator 408.

6 shows a sequence 600 of fluid-fluid interactions such as occurs during penetration of a projectile 118 ejected from a ram accelerator 102 into a working face of geological material 106. In this illustration, time is indicated as increasing going down the page, as indicated by arrow 602.

In one implementation, a projectile 118 having a length-to-diameter ratio of approximately 10:1 or greater impacts the working face of geological material 106 at high velocity. Penetration at velocities exceeding approximately 800 m/s results in a penetration depth approximately two or more times the length of projectile 118. Furthermore, the diameter of the resulting hole 134 is approximately twice the diameter of the impacting projectile 118. This additional increase in the velocity of projectile 118 results in an increased penetration depth of geological material 106. As the velocity of projectile 118 increases, the front of projectile 118 begins to mushroom upon impacting the working face of geological material 106. This impact creates a fluid-fluid interaction zone 604, which causes erosion or vaporization of projectile 118. The back pressure caused by the impact can propel ejecta 606 or other materials, such as cuttings removed from hole 134 by a reamer. The ejecta 606 can include particles of varying sizes, ranging from fine dust to larger pieces of material. In some implementations, the ejecta 606 can include one or more materials used in other industrial processes. For example, the carbon-containing ejecta 606 may include buckyballs or nanoparticles suitable for other applications such as medicine, chemical engineering, printing, and the like.

The higher the velocity, the more thoroughly the projectile 118 erodes, and thus the "cleaner" or emptier the space formed by the high-speed impact, leaving behind a larger diameter and deeper hole 134. Additionally, the hole 134 will have no or almost no remaining material from the projectile 118 because the projectile 118 and a portion of the geological material 106 have been vaporized.

7 shows a sequence 700 of non-fluid-fluid interactions such as occurs during the penetration of a projectile 118 at a relatively low velocity through a face of geological material 106. In this illustration, time is indicated as increasing going down the page, as indicated by arrow 702.

At lower velocities, such as when the projectile 118 is ejected from the ramjet 102 at a velocity less than 2 km/s, the portion of the geological material 106 proximate the projectile 118 begins to fracture in the fracture zone 704. The ejecta 606 may be ejected from the point of impact. Rather than vaporizing the projectile 118 and a portion of the geological material 106, as would occur in a fluid-fluid interaction, the impact may pulverize or fracture individual pieces of the geological material 106.

As described above, the back pressure caused by the impact may push the ejecta 606 out of the aperture 134 .

FIG8 illustrates a mechanism 800 including a guide tube 136 equipped with an inner tube 802 and an outer tube 804. The inner tube 802 can be positioned relative to the outer tube 804 by one or more positioning devices 806. In some implementations, the positioning devices 806 can include a collar or a ring. The positioning devices 806 can include one or more apertures or passages to allow material (such as fluids, projectiles 606, etc.) to pass through. The positioning devices 806 can be configured to allow relative movement between the inner tube 802 and the outer tube 804, such as rotation, translation, etc.

The space between the inner guide tube 802 and the outer guide tube 804 can form one or more fluid distribution channels 808. The fluid distribution channels 808 can be used to transport ejecta 606, fluids (such as cooling or hydraulic fluids), lining materials, and the like. The fluid distribution channels 808 are configured to receive fluid from a fluid supply unit 810 via one or more fluid lines 812. The fluid distribution channels 808 can include a coaxial arrangement of one pipe within another, with a sleeve comprising the space between the inner and outer pipes. The fluid can circulate in a closed loop or be used in an open loop.

The inner tube 802 is arranged within the outer tube 804. In some implementations, the tubes can be collinear with each other. Additional tubes can be added to provide additional functionality, such as additional fluid distribution tubes 808.

One or more reamers 814 are coupled to the fluid distribution channel 814 and disposed within the bore 134. The reamers 814 can be configured to provide various functions. These functions can include providing a substantially uniform cross-section of the bore 134 by cutting, scraping, grinding, and the like. Another function provided by the reamers 814 can be to act as a bearing between the wall of the bore 134 and the guide tube 136. The fluid from the fluid supply unit 810 can be configured to cool, lubricate, and, in some implementations, power the reamers 814.

The reamer 814 can also be configured with one or more actuators or other mechanisms to generate one or more lateral movements 816. These lateral movements 816 displace at least a portion of the guide tube 136 relative to the wall of the bore 134, thereby tilting, deflecting, or bending one or more portions of the guide tube 136. Thus, the point of impact of the projectile 118 can be offset. By selectively applying lateral movements 816 at one or more reamers 814 within the bore 134, the position of subsequent projectiles 118 can be impacted, and the resulting direction of the drilling path 138 can be altered. For example, the drilling path 138 can bend due to the lateral movements 816.

A reamer 814, or other support mechanisms such as rollers, guides, collars, etc., may be positioned along the guide tube 136. These mechanisms may prevent or minimize Euler buckling of the guide tube 136 during operation.

In some implementations, the path of the projectile 118 can also be altered by other mechanisms, such as a projectile director 812. The projectile director 818 can be disposed at one or more locations, such as at the guide tube 136, at the end of the guide tube 136, near the working face of the geological material 106, etc. The projectile director 818 can include a structure configured to deflect or shift the projectile 118 upon exiting the guide tube 136.

As described above, the guide tube 136, or the ram accelerator 102 if a guide tube is not used, can be spaced apart from the working surface of the geological material 106 by a distance 104. The standoff distance 104 can vary based at least in part on the depth, the material in the hole 134, the firing parameters, etc. In some implementations, the standoff distance 104 can be 2 feet or more.

As drilling progresses, additional sections of guide tube 136 may be coupled to those in bore 134. As shown here, guide tube 136(1) in bore 134 may be coupled to guide tube 136(2). In some implementations, inner tube 802 and outer tube 804 may be joined in separate operations. For example, inner tube 802(2) may be joined to inner tube 802(1) in bore 134, one or more positioning devices 806 may be put in place, and outer tube 804(2) may likewise be joined to outer tube 804(1).

9 illustrates a mechanism 900 for using a fluid, such as the discharge resulting from the firing of the ram accelerator 102, to propel the ejecta 606 or other material, such as chips removed from the hole 134 by the reamer 814. In this illustration, the guide tube 136 is depicted with one or more reamers 814. The fluid distribution conduits 808 or other mechanisms described herein may also be used in conjunction with the mechanism 900.

Ram accelerator exhaust 902 ("exhaust") or another working fluid is pushed down the guide tube 136. The working fluid may include gas or other gases under pressure, water or other fluids, slurry, etc. The exhaust 902 pushes the ejecta 606 into one or more ejecta transport channels 904. In one implementation, the ejecta transport channels 904 may include the space between the guide tube 136 and the wall of the hole 134. In another implementation, the ejecta transport channels 904 may include the space between the guide tube 136 and another conduit coaxial with the guide tube 136. The ejecta transport channels 904 are configured to carry the ejecta 606 from the hole 134 to the ejecta collector 140.

A series of one-way valves 906 may be arranged within the ejecta transport passage 904. The one-way valves 906 are configured to enable the discharge 902 and ejecta 606 to migrate away from the distal end of the orifice 134 toward the ejecta collector 140. For example, a pressure wave generated by a projectile 118 traveling downward along the guide tube 136 pushes the ejecta 606 along the ejecta transport passage 904 through the one-way valves 906. As the pressure decreases, larger pieces of the ejecta 606 may fall but are prevented from returning to the end of the orifice 134 by the one-way valves 906. With each successive pressure wave resulting from a successive projectile 118 or other injectant or discharge 902 of another working fluid, a given piece of the ejecta 606 migrates through successive one-way valves 906 to the surface. At the surface, the ejecta collector 140 transports the ejecta 606 for disposal.

The ejecta 606 at the surface may be analyzed to determine the composition of the geological material 106 in the hole 134. In some implementations, the projectiles 118 may be configured with predetermined elements or tracking materials so that the analysis can be associated with one or more specific projectiles 118. For example, coded markers may be injected into the discharge 902, placed on or within the projectiles 118, and so on.

10 illustrates a mechanism 1000 for using fluid to operate a reamer 814 or other device in a bore 134 and remove ejecta 606. As described above, the guide tube 136 may be equipped with one or more fluid distribution channels 808. The fluid distribution channels 808 may be configured to provide fluid from the fluid supply unit 810 to one or more devices or outlets in the bore 134.

In this illustration, one or more of the reamers 814 are configured to include one or more fluid outlet ports 1002. The fluid outlet ports 1002 are configured to disperse at least a portion of the fluid from the fluid distribution channel 808 into the hole 134. This fluid can be used to convey ejecta 606 or other material (such as cuttings removed by the reamers 814) away. As described above, a series of one-way valves 906 are configured to direct the ejecta 606 or other debris toward the ejecta collector 140. In some implementations, fluid lift assist ports 1004 can be periodically arranged along the fluid distribution channel 808. The fluid lift assist ports 1004 can be configured to assist in moving the ejecta 606 or other debris toward the ejecta collector 140 by providing a pressurized fluid jet. The fluid outlet ports 1002, the fluid lift assist ports 1004, or both can be metered to provide a fixed or adjustable flow rate.

The movement of the fluid containing the projectiles 606 or other debris from the fluid outlet port 1002 and the fluid lift assist port 1004 can work in conjunction with the pressure from the exhaust 902 to clear the projectiles 606 or other debris from the bore 134. In some implementations, various projectile 118 combinations can be used to pre-detonate or clear debris from the bore 134 before firing a particular projectile 118.

As described above, the ram accelerator 102 can work in conjunction with conventional drilling techniques. In some implementations, the end of the guide tube 136 in the hole 134 can be equipped with a cutting or grinding drill bit. For example, a coring drill bit can allow core sampling.

FIG11 shows a mechanism 1100 for deploying a liner within a borehole 134. A concrete delivery sleeve 1102 or other mechanism (such as a piping system) is configured to receive concrete from a concrete pumping unit 1004 via one or more supply lines 1106. Concrete flows through the concrete delivery sleeve 1102 to one or more concrete outlet ports 1108 within the borehole 134. The concrete is configured to fill the space between the wall of the borehole 134 and the guide tube 136. Other materials, such as bentonite, crop straw, cotton, thickeners (e.g., guar gum, xanthan gum, etc.), may also be used instead of or in addition to concrete.

As drilling continues, such as by continued impacts of projectiles 118 fired by the ram accelerator 102, the guide tube 136 can be inserted further downward into the hole 134, and concrete can continue to be pumped and extruded from the concrete outlet port 1108, thereby forming the concrete lining 1110. In other implementations, materials other than concrete can also be used to provide the lining of the hole 134.

In some implementations, seal 1112 is provided to minimize or prevent concrete from flowing into the working surface of hole 134 that is the target of projectile 118. Mechanism 1100 may be combined with other mechanisms described herein, such as reamer mechanism 800, ejection 606 removal mechanisms 900 and 1000, and the like.

In one embodiment, the concrete may include a release agent or lubricant. The release agent may be configured to facilitate movement of the guide tube 136 relative to the concrete lining 1110. In another embodiment, the release agent may be emitted from another set of outlet ports. A mechanism may also be provided that is configured to deploy a disposable plastic layer between the guide tube 136 and the concrete lining 1110. This layer may be provided as a liquid or solid. For example, the plastic layer may include polytetrafluoroethylene ("PTFE"), polyethylene, etc.

In some implementations, a drill bit or other cutting tool can be attached to the tip of the guide tube 136. For example, a three-cone drill can be attached to the end of the guide tube 136. The cutting tool can have an aperture through which the projectile 112 can pass and impact the work surface. The cutting tool can be operated during the impact process, or can be idle during the impact process.

FIG12 illustrates a mechanism 1200 for tunneling or excavating using one or more ram accelerators 102. Multiple accelerators 102(1)-(N) may be fired sequentially or simultaneously to impact one or more target points on a working face, thereby forming a plurality of holes 134. The impacts may be configured in a predetermined pattern to generate one or more focused shock waves within the geological material 106. These shock waves are configured to fragment or displace geological material 106 that is not vaporized upon impact.

As shown here, six ram accelerators 102(1)-(6) are arranged in front of a working face. One or more projectiles 118 are launched from each of the ram accelerators 102, thereby forming corresponding holes 134(1)-(6). The plurality of ram accelerators 102(1)-(N) can be moved toward a target in a translational, rotational, or both manner, in groups or independently, and a plurality of holes 134 are drilled in the working face of the geological material 106.

In another implementation, a single ram accelerator 102 may be moved toward a target in a translational, rotational, or both manner and drill a plurality of holes 134 in a working face of the geological material 106 .

After the holes 134 are formed by the impact of the projectile 118, various techniques can be used to remove a piece or section of the geological material 106. A geological material section 1202 is a portion of the geological material 106 defined by two or more holes that are close to each other. For example, four holes 134 arranged in a square define a section of the geological material 106 that can be removed, as described below with respect to FIG. 13 .

As described above, the use of a ram-accelerated projectile 118 allows for the rapid formation of a hole 134 in the geological material 106. This can result in a reduction in the time and costs associated with tunneling.

FIG13 illustrates an apparatus and process 1300 for removing rock segments defined by a hole drilled by a ram accelerator projectile 118 or conventional drilling techniques. During the fragmentation 1302 process, the ram accelerator 102 may include a mechanism for fragmenting geological material segments 1304. For example, the ram accelerator 102 may include a linear breaker device 1306 including one or more pusher arms 1308 that move according to a pusher arm motion 1310. The pusher arms 1308 may be inserted between the geological material segments 1304, and mechanical force may be applied by the pusher arms 1308 to break, fragment, or otherwise release individual pieces of geological material 106 from the main body of geological material 106 at the working face, thereby forming displaced geological material segments 1312.

In some implementations, a rotary breaker device 1314 that moves according to a rotational motion 1316 can be used instead of or in addition to the linear breaker device 1306. The rotary breaker device 1314 breaks up the geological material segments 1304 by applying mechanical force during operation. After breaking 1318, a removal device 1320 transports the displaced geological material segments 1312 out of the hole 134. For example, the removal device 1320 can include a bucket loader.

FIG14 shows a flow chart 1400 of an exemplary process 1400 for penetrating geological material 106 using an ultra-high-speed ram accelerator 102. At block 1402, one or more ram accelerators 102 are positioned at a working site 202 to drill holes for use in tunneling, excavation, etc. The ram accelerators 102 may be positioned vertically, horizontally, or diagonally at a distance from the working face of the geological material 106 to be penetrated.

At block 1404, while the ram accelerators 102 are positioned, firing parameters are determined for each of the ram accelerators 102, such as, for example, the type of projectile 118, the composition, hardness, and density of the geological material 106, the number of stages in the corresponding ram accelerator, the firing angle, and other environmental conditions (including air pressure and temperature). At block 1406, upon determining the firing parameters, one or more projectiles 118 are selected based at least in part on the firing parameters, and the selected one or more projectiles 118 are loaded into the ram accelerator 102, as described at block 1408.

At block 1410, each of the ramjet accelerators 102 is configured based at least in part on the determined firing parameters. At block 1412, each of the ramjet accelerators 102 is then primed using a solid gas generator or a plurality of combustible gas mixtures. After priming one or more ramjet accelerators 102, one or more of the loaded projectiles 118 are launched according to the determined firing parameters. For example, the projectiles 118 are accelerated to a ramjet velocity along the launch tube 116 and through multiple sections, and ejected from the ramjet accelerator 102, thereby forming or enlarging one or more holes 134 in the working face of the geological material 106.

As described above, the back pressure caused by the impact can push the ejecta 606 out of the hole 134. In some implementations, a working fluid (such as compressed air, water, etc.) can be injected into the hole 134 to assist in removing at least a portion of the ejecta 606. Each of the holes 134 formed by the impact of the projectile 118 at ultra-high speed can be further processed. At block 1418, the guide tube 136 can be inserted into the hole 134 to prevent settling, deploy instruments, etc. In some implementations, the reamer 814 coupled to the guide tube 136 can be inserted down into the hole 134 and configured to provide a substantially uniform cross-section.

FIG15 illustrates an illustrative process 1500 for using a hypervelocity ramjet accelerator 102 to fire multiple projectiles 118 downwardly along a single hole 134 to penetrate a geological material 106, such that the hole 134 penetrates deeper into the geological material 106 with each subsequent projectile 118. At block 1502, the mechanics of the geological material 106 are determined. At block 1504, a set of initial firing parameters is determined based, at least in part, on the mechanics of the geological material 106. At block 1506, the ramjet accelerator 102 is configured for firing based, at least in part, on the initial set of firing parameters. Once the ramjet accelerator 102 is configured, at block 1508, the projectiles 118 are fired toward a working surface of the geological material 106 to form one or more holes 134. At block 1510, the impact results of the projectiles 118 on the working surface are determined. In some embodiments, the ram accelerator 102 may need to be reconfigured before loading and firing a subsequent projectile 118 into the hole 134. At block 1512, second firing parameters are determined based at least in part on the impact results. At block 1514, the subsequent projectile 118 is fired from the ram accelerator 102, configured using the second set of firing parameters, toward the working face of the geological material 106. This process may be repeated until the desired penetration depth is reached.

FIG16 illustrates a mechanism 1600 including a guide tube disposed downhole with an end cap and a system for forming an ullage portion in formation fluid within a borehole. In this illustration, a guide tube 136 is depicted. However, in other implementations, the mechanism may be used in conjunction with a drift tube. An end cap 1602 may be placed within the guide tube 136 to provide at least a partial seal between the interior of the guide tube 136 and formation fluid 1604, along which the projectile 118 may pass downward, and which may accumulate at a working surface within the borehole 134. For example, the formation fluid 1604 may include drilling mud, oil, water, slurry, gas, and the like.

In one implementation, an end cap 1602 may be deployed to the end of the guide tube 136 proximate the working face. The end cap 1602 may form at least a partial seal, thereby preventing or inhibiting formation fluid 1604 from flowing into the portion of the guide tube 136 within which the projectile 118 travels.

The ullage fluid supply unit 1606 is configured to provide ullage fluid or purge gas to one or more ullage outlet ports 1610 proximate the working surface via one or more ullage fluid supply channels 1608. The ullage fluid may include a gas or a liquid. Gaseous ullage fluids may include, but are not limited to, helium, hydrogen, carbon dioxide, nitrogen, and the like. In some implementations, the ullage fluid may be flammable or explosive, such as the combustible gas mixture 128 described above.

The ullage fluid may be injected into a volume at least partially bounded by the end cap 1602 and the working face. The ullage fluid may be applied at a pressure equal to or greater than the pressure of the surrounding formation fluid 1604. The ullage fluid is injected to form an ullage portion 1612, or to form an air pocket in the formation fluid 1604. For example, where the ullage fluid comprises gas, the ullage portion 1612 comprises space occupied by the gas, thereby displacing at least some of the formation fluid 1604. The displacement may reduce or prevent intrusion of the formation fluid 1604, or a portion thereof, from the borehole 134. The air pocket may occupy all or a portion of the volume between the approach portion of the drilling equipment and the working face. The ullage portion 1612 provides a compressible volume within which pieces of ejecta 606 and other impact products may be at least temporarily dispersed.

In some implementations, the ullage fluid can be applied in a transient or "burp" mode, thereby briefly creating the ullage portion 1612. In the presence of the ullage portion 1612, the ram accelerator 102 can be configured to fire the projectile 118 through the end cap 1602, the ullage portion 1612, and into the working surface.

In some implementations, the ram accelerator 102 can utilize a baffled tube ram accelerator configuration, also known as a "baffled tube" ram accelerator. A baffled tube ram accelerator can include a series of baffles or annular rings configured to control the displacement of the combustible gas mixture 128 during the passage of the projectile 118. A baffled tube ram accelerator can be used in place of or in addition to the segment separator mechanism 126 described above.

In one implementation, end cap 1604 can provide ullage portion 1612, thereby displacing at least a portion of formation fluid 1604. End cap 1604 can include foam, an expansion matrix, a balloon, a structure configured to expand and maintain a seal with directed light 136, or the like. In some implementations, end cap 1604 can include a combustible material. End cap 1604 can be configured to contact a working face (such as ejecta 606), or can be separated from the working face by formation fluid 1604 before ullage portion 1612 is formed.

In some implementations, multiple end caps 1604 may be employed within the guide tube 136 , within the ram accelerator 102 , etc. For example, the end caps 1602 may be configured to perform one or more functions similar to or the same as the segment separator mechanism 126 .

In some implementations, chemical or pyrotechnic devices may be used instead of applying an ullage fluid to form the ullage portion 1612. For example, a pyrotechnic gas generator charge may be arranged and configured to generate a gas to form the ullage portion 1612 in the formation fluid 1604. In another example, a chemical gas generator may be configured to emit a gas upon contact with a reactant, such as a component of the formation fluid 1604.

The projectile 118 can be configured to generate an ullage of fluid. For example, the tip of the projectile 118 can be configured to vaporize and emit a gas, causing the ullage portion 1612 to form.

The control system 144 may coordinate the operation of one or more of the ram accelerator 102, the fluid supply unit 810, or the ullage fluid supply unit 1606. For example, the control system 144 may be configured to provide a sudden or temporary increase in the pressure of the fluid distributed downwardly to the orifice 134 prior to or during the ram accelerator 102. Similarly, the ullage fluid supply unit 1606 may be configured to provide an ullage fluid prior to impact of the projectile 118 to form the ullage portion 1612.

In some implementations, the guide tube 136 or the portion of the ram accelerator 102 at the bore 134 can include one or more segment separator mechanisms 126. For example, a segment separator mechanism 126(7) in the guide tube 136 divides the guide tube 136 into a first portion 1614(1) and a second portion 1614(2). The segment separator mechanism 126(7) can be opened or otherwise configured to allow the projectile 118 to enter downwardly at a working surface at the end of the bore 134.

The end cap delivery system 1616 is configured to deliver one or more end caps 1602 into the guide tube 136 so that they are proximate to the end of the guide tube 136 proximate the working surface. In one implementation, the end cap delivery system 1616 can be configured to insert the end cap 1602 into the interior of the guide tube 136, such as into the first portion 1614(1) of the guide tube 134, such as through an access port or other passageway. The segment separator mechanism 126(7) can be opened or otherwise configured to allow the end cap 1602 to pass through to the second portion 1614(2) of the guide tube 136. During the firing process of the ram accelerator 102, the access port between the end cap delivery system 1616 and the guide tube 136 can be closed.

The end cap 1602 is configured to provide a barrier between a portion of the guide tube 136 and the geological material 106 to be drilled. This barrier separates the interior of the guide tube 136 from the environment outside the guide tube 136. The end cap 1602 can be held in place using hydraulic or pneumatic pressure, mechanical retaining devices (such as castellations or forks), or the like. For example, the guide tube 136 can be narrowed or constricted at the end near the working face, such as by one or more collars or other features. This constriction can retain the end cap 1602 at the end of the guide tube 136. In another implementation, a movable robotic arm or other feature can lock and retain the end cap 1602 in place.

The end cap 1602 can also maintain a pressure differential across the end cap 1602. For example, the guide tube 136 can be maintained at a first pressure, while the volume outside the guide tube 136 (such as the formation fluid 1604) can be at a second pressure different from the first pressure. In some implementations, the end cap 1602 itself can be pressurized to a third pressure different from the first and second pressures.

End cap 1602 can be constructed from one or more of the following materials: plastic, polymer, ceramic, elastomer, metal, or a composite material. End cap 1602 can include a rigid structure, a semi-rigid structure, a flexible structure, or a combination thereof. For example, end cap 1602 can include an expandable frame covered by a plastic or metal shell. In another example, end cap 1602 can include an inflatable structure, such as a balloon. The structure of end cap 1602 can be configured to maintain a barrier between the interior of guide tube 136 and the external environment within the aperture, but be permeable to projectile 118.

End cap 1602 can be positioned at the downhole end of guide tube 136 using one or more techniques. Positioning end cap 1602 can be performed using one or more of the following implementations. In a first implementation, end cap 1602 can be pulled toward the bottom of guide tube 136 by gravity. For example, end cap 1602 can sink to the bottom of guide tube 136. In a second implementation, end cap delivery system 1616 can use hydraulic or pneumatic pressure to displace end cap 1602. For example, pressurized gas (such as one or more flammable gases) can be injected into guide tube 136 to apply pressure to end cap 1602. This pressure can displace end cap 1602 toward the end of guide tube 136 proximate to geological material 106. The one or more flammable gases can be used to provide a dye to projectile 118 during operation, or can be ignited to increase pressure within a portion of guide tube 136 and displace end cap 1602. In a third implementation, negative pressure can be applied to the end of guide tube 136 proximate to geological material 106. For example, formation fluid 1604 can be extracted using a suction pump to create a pressure differential in the fluid. The force exerted on end cap 1602 by the pressure differential can cause end cap 1606 to displace toward the end of guide tube 136 near the working surface. In a fourth implementation, a mechanical component (such as a push arm, a rail system, etc.) can be used to apply the mechanical pressure to displace end cap 1602. For example, the mechanical component can include an arm or rod that pushes end cap 1602 downward along guide tube 136 and into the desired position.

In some implementations, a non-combustible gas may be injected between the ram accelerator 102 and the working surface of the geological material 106 before accelerating the projectile. For example, an inert gas (such as carbon dioxide or nitrogen) may be injected into the guide tube 136 at a pressure greater than or equal to the pressure of the formation fluid 1604. At some depths, this may include pressures greater than 6000 kilopascals. This operation may be performed by the ullage fluid supply unit 1606 to form a gas pocket, or ullage portion 1612, at the end of the guide tube 136 before placing the end cap 1602. The end cap 1602 may then be placed to form a barrier between the formation fluid 1604 and other debris and the guide tube 136.

In one implementation, the undercut portion 1612 can be formed before the end cap 1602 is placed. For example, the undercut portion 1612 can be formed first, and then the end cap 1602 can be placed in place. In another implementation, the end cap 1602 can be placed first, and the undercut portion 1612 can be formed subsequently. These processes can be combined. For example, the undercut portion 1612 can be formed or maintained before the end cap 1602 is placed in place, and after the end cap 1602 is placed in place and before firing.

During firing, the segment separator mechanism 126(7) may be opened or otherwise configured to allow the projectile 118 to pass through. After the projectile 118 passes through, the segment separator mechanism 126(7) may be closed or otherwise configured to provide a seal or barrier between the first portion 1614(1) and the second portion 1614(2) of the guide tube 136. This may prevent formation fluids, ejecta 606, or other materials from intruding into the portion of the guide tube 136 between the segment separator mechanism 126(7) and the ram accelerator 102.

In some implementations, the end cap 1602 can be removed from the guide tube 136 or can be destroyed before the projectile 118 passes through. For example, the shock wave propelling the projectile 118 can destroy the projectile 118 before the projectile 118 reaches the end cap 1602.

In some implementations, an auger or other mechanism may be provided that is configured to remove ejecta 606 from the volume proximate the work surface. For example, the end of the guide tube 136 may have one or more auger blades attached such that rotation moves the ejecta 606 away from the work surface and into the ejecta transport channel 904.

FIG. 17 is a flow chart 1700 illustrating a process for utilizing the end cap 1602 in conjunction with the ram accelerator 102 to drill one or more holes.

Block 1702 inserts the end cap 1602 into the first end of the guide tube 136. The first end of the guide tube 136 may be proximate to the ram accelerator 102, while the second end of the guide tube 136 may generally be at an opposite end proximate to the working surface. In one implementation, an end cap delivery system 1616 may insert the end cap 1602 into the interior of the guide tube 136 through an access port. In some implementations, the end cap delivery system 1616 may be operable to displace the end cap 1602 proximate to the end of the guide tube 136 proximate to the working surface, such as at the bottom of a hole. For example, the end cap delivery system 1616 may utilize pressurized gas, combustion, mechanical components, or other mechanical mechanisms to position the end cap 1602 at the bottom of the guide tube 136.

In some implementations, block 1704 may form an ullage portion 1612 or air pocket before displacement of the end cap 1602. This displaces formation fluid 1604 away from the end of the guide tube 136.

Block 1706 places the end cap 1602 in a position proximate the second end of the guide tube 136. The end cap 1602 may be held in this position by one or more frictions with the inner wall of the guide tube 136, one or more mechanical members, continuous pressure applied by the end cap delivery system 1616, or the like.

Block 1708 launches the projectile 118 from the ram accelerator 102 through the guide tube 136. Prior to or concurrently with the launch, one or more of the segment separator mechanisms 126 can be configured to allow the projectile 118 to pass therethrough. In some implementations, prior to or concurrently with the launch of the projectile 118, the accumulation fluid supply unit 1606 can form an ullage portion 1612 in the formation fluid 1604 between the end cap 1602 and the working face.

Block 1710 utilizes the projectile 118 to penetrate the end cap 1602. In some implementations, the end cap 1602 may be destroyed before being penetrated by the projectile 118. For example, a shock wave or other phenomenon may damage or destroy the end cap 1602 before the projectile 118 reaches the end cap 1602. Prior to penetration or destruction of the end cap 1602, the end cap 1602 provides a barrier between the formation fluid 1604, the ejecta 606, or other materials outside the guide tube 136.

Block 1712 utilizes the projectile 118 to penetrate the work surface. After penetration, one or more of the segment separator mechanisms 126 in the guide tube 136, the ram accelerator 102, or both can be closed. Another end cap 1602 can be deployed by the end cap delivery system 1616, and the process can continue. In some implementations, the end cap delivery system 1616 can be configured to deliver the end cap 1602 immediately after the projectile 118 has passed through. For example, the end cap delivery system 1616 can be located within the ram accelerator 102 and can launch the end cap 1602 at a non-hypervelocity through the launch tube 116 and then through the guide tube 136.

In yet another implementation, the end cap 1602 may be attached, integral but breakable, or separate from but in contact with the projectile 118. For example, a portion of the projectile 118 may be larger than the exit aperture of the guide tube 136 and may be configured to separate or detach from the main body of the projectile 118 to function as the end cap 1602.

The following clauses provide additional descriptions of various embodiments and configurations:

1. A method for forming a hole, the method comprising:

inserting an end cap into the first end of the guide tube;

placing the end cap proximate a second end of the guide tube, wherein the second end is proximate a working face comprising geological material;

The projectile is loaded into the ramjet accelerator, where:

The projectile is configured to generate a ramjet effect combustion reaction in one or more combustible gases within the ramjet accelerator; and

The output end of the ram accelerator is coupled to the first end of the guide tube;

raising the projectile to a certain ram velocity;

accelerating the projectile along at least a portion of the ramjet accelerator by burning one or more combustible gases in a ramjet combustion effect; and

The projectile is used to penetrate the end cap before exiting the guide tube.

2. The method of clause 1, further comprising:

A barrier is formed between the second end of the ram accelerator and the geological material using the end cap.

3. The method of one or more of clauses 1 or 2, further comprising holding the end cap in place.

4. The method according to one or more of clauses 1 to 3, wherein the placing comprises:

The one or more combustible gases are injected under pressure at one or more points between the end cap and the first end of the ram accelerator, wherein the one or more combustible gases apply aerodynamic pressure to displace the end cap along the ram accelerator.

5. The method according to one or more of clauses 1 to 4, wherein the placing comprises:

injecting a gas into the ram accelerator at one or more points between the end cap and a first end of the ram accelerator; and

The gas is ignited.

6. The method according to one or more of clauses 1 to 5, further comprising:

Prior to accelerating the projectile, a non-combustible gas is injected between the second end of the ramjet accelerator and the working surface, wherein the gas is at a pressure greater than 6000 kPa.

7. The method according to one or more of clauses 1 to 6, further comprising:

Prior to placing the end cap, a non-combustible gas is injected between the second end of the ram accelerator and the working surface, wherein the gas is at a pressure greater than 6000 kPa.

8. A method comprising:

deploying a conduit in the bore, the conduit comprising a first end proximate an entrance to the bore and a second end proximate a working surface;

deploying an end cap proximate the second end of the pipe; and

A projectile is propelled through the end cap at a velocity greater than or equal to 2 km/s using a ram pressure effect between the projectile and one or more combustible gases within at least a portion of the conduit.

9. The method of clause 8, further comprising:

Gas is applied to the volume in the bore between the end cap and the working face at a pressure greater than or equal to formation fluid pressure.

10. The method according to one or more of clauses 8 to 9, further comprising:

An air pocket is formed in the hole between the end cap and at least a portion of the working surface.

11. The method according to one or more of clauses 8 to 10, further comprising:

After firing, the valve between the first end of the guide tube and the second end of the guide tube is closed.

12. A method as described in one or more of clauses 8 to 11, wherein deploying the end cap includes injecting gas under pressure at one or more points between the end cap and the first end of the pipe, wherein the gas applies pneumatic pressure to cause the end cap to shift toward the second end of the pipe.

13. The method of one or more of clauses 8 to 12, wherein deploying the end cap comprises applying a negative fluid pressure external to the second end of the pipe to draw the end cap toward the second end of the pipe.

14. The method of one or more of clauses 8 to 13, wherein deploying the end cap comprises pushing the end cap to the second end of the pipe using a mechanical member.

15. The method of one or more of clauses 8 to 14, wherein deploying the end cap comprises lowering the end cap to the second end of the pipe using a mechanical member.

16. A system comprising:

projectile;

a ram accelerator, the ram accelerator accelerating the projectile;

a guide tube having a first end coupled to an exit aperture of the ram accelerator and a second end opposite the first end; and

End cap.

17. The system of clause 16, further comprising:

An end cap delivery system is configured to deploy the end cap through the interior of the guide tube to a position proximate the second end of the guide tube, and wherein the deployed end cap provides a barrier between the interior of the guide tube and the environment outside the guide tube.

18. The system of one or more of clauses 16 to 17, wherein the end cap comprises one or more of the following materials:

plastic,

polymer,

ceramics,

Elastomers,

metal, or

Composite materials.

19. The system of one or more of clauses 16 to 18, further comprising:

A retaining mechanism is provided for retaining the end cap proximate the second end before the projectile penetrates the end cap.

20. The system of one or more of clauses 16 to 19, wherein the guide tube comprises one or more valves, wherein each valve, when open, allows passage of the end cap and the projectile, and each valve, when closed, prevents fluid from flowing from one portion of the guide tube to another.

21. A method for drilling a hole, the method comprising:

deploying a drift tube or guide tube in the borehole, the drift tube or guide tube comprising a first end proximate an entrance to the borehole and a second end proximate a working surface;

deploying an end cap at the second end of the drift tube or guide tube;

applying a purge gas to a volume outside the end cap and proximate the working surface; and

A ramjet accelerator is used to fire a ramjet-propelled projectile into the first end of the drift or guide tube.

22. The method of clause 21, wherein the purge gas forms an ullage portion in the contents of the hole before the projectile penetrates.

23. The method of one or more of clauses 21 to 22, wherein the purge gas forms a bubble in contact with at least a portion of the end cap before the projectile passes through the end cap.

24. The method of one or more of clauses 21 to 23, wherein the end cap is destroyed upon impact of the projectile.

25. The method of one or more of clauses 21 to 24, wherein the end cap is penetrated by the projectile.

26. The method of one or more of clauses 21 to 25, wherein the projectile substantially penetrates the end cap and at least a portion of the projectile impacts at least a portion of the working surface.

27. The method of one or more of clauses 21 to 26, wherein the end cap comprises a combustible material.

28. The method of one or more of clauses 21 to 27, wherein the end cap has a shape comprising one or more of the following:

Columnar,

spherical, or

Biconvex or convex lens shape.

29. The method of one or more of clauses 21 to 28, wherein the end cap has a shape comprising a concave shape configured to receive the projectile.

30. The method of one or more of clauses 21 to 30, wherein the end cap forms at least a partial seal between the interior of the drift or guide tube and the fluid in the bore.

31. The method of one or more of clauses 21 to 31, wherein the end cap comprises a material configured to expand or swell, and further wherein the end cap provides a seal between the first and second ends of the drift or guide tube. For example, the end cap may comprise a water-permeable covering filled with a hydrophilic material, such as silicone gel. Other materials, such as calcium hydroxide, vitreous silica, iron oxide, aluminum oxide, and the like, may also be used. Upon exposure to water within formation fluid 1604, end cap 1602 may swell to seal guide tube 136.

32. The method of one or more of clauses 21 to 32, wherein the end cap comprises a structure configured to change from a first physical configuration to a second physical configuration, wherein the second physical configuration exhibits a greater width than the first physical configuration, and further wherein the end cap provides a seal between the first end and the second end of the drift tube or guide tube. For example, the end cap may comprise a plurality of mechanical members that are displaceable such that they provide radial pressure, thereby increasing the diameter of the end cap to form a seal.

33. The method of one or more of clauses 21 to 32, wherein deploying the end cap comprises one or more of the following operations:

pulling the end cap toward the second end of the drift tube or guide tube by gravity,

applying positive fluid pressure at the first end of the drift or guide tube to draw the end cap toward the second end of the drift or guide tube,

applying negative fluid pressure externally of the second end of the drift tube or guide tube to pull the end cap toward the second end of the drift tube or guide tube, or

The end cap is pushed to the second end of the drift tube or guide tube using a mechanical member.

In some implementations, a series of ball valves or other segment separator mechanisms 126 can be actuated to allow the end cap 1602 to be advanced to the portion of the pipeline proximate the working surface.

34. A method for drilling a hole, the method comprising:

deploying a conduit in the bore, the conduit comprising a first end proximate an entrance to the bore and a second end proximate a working surface;

deploying an end cap at the second end of the drift tube or guide tube; and

A ramjet accelerator is used to fire a ramjet-propelled projectile into the first end of the drift or guide tube and through the end cap to the working surface.

35. The method of clause 34, wherein the ram accelerator comprises a baffle tube ram accelerator.

36. The method according to one or more of clauses 34 to 35, further comprising:

A purge gas is applied to a volume outside the end cap and proximate the working face to form a cavity within the formation fluid.

The technology described herein can be used to drill holes 134 in geological materials 106 or other materials in Earth or non-Earth environments. For example, the system 100 as described can be used to drill holes 134 on Earth, on the Moon, on Mars, on asteroids, and so on.

The ram accelerator 102 can also be used in industrial applications, such as for material production, manufacturing, etc. In these applications, the target may include materials such as metal, plastic, wood, ceramic, etc. For example, in the shipbuilding process, large high-strength steel plates may need to have holes formed for piping systems, propeller shafts, hole covers, etc. The ram accelerator 102 can be configured to fire one or more of the projectiles 118 through one or more pieces of metal to form holes. A large opening can be formed by a plurality of smaller openings around the desired opening periphery. Subsequently, conventional cutting methods (such as plasma torches, saws, etc.) can be used to remove the remaining material and ultimately form an opening for use. In addition to the opening, the impact performed by the projectile 112 is also used to form other features, such as depressions within the target. Therefore, the use of the ram accelerator 102 in these industrial applications can achieve manufacturing with materials that are difficult to cut, grind, or otherwise process.

Furthermore, the projectile 118 can be configured such that, during impact, a specific material is deposited within the impact region. For example, the projectile 118 can include carbon such that, upon impact with a target, a diamond coating forms on the resulting surface of the opening due to the impact pressure. A return block or other mechanism can be provided to capture the ejected object 606, the post-impact portion of the projectile 118, and the like. For example, the ram accelerator 102 can be configured to be fired through target material and toward a pool of water.

One or more of the mechanisms or techniques of the present disclosure may be utilized in other ways. For example, the ramjet accelerator 102 may be used to launch a payload into a flight or operational trajectory.

Those skilled in the art will readily recognize that some of the steps or operations shown in the above figures may be eliminated, combined, subdivided, performed in parallel, or performed in an alternate order. Furthermore, the above methods may be implemented as one or more software programs for a computer system and encoded as instructions executable on one or more processors in a computer-readable storage medium. Independent instances of these programs may be executed on independent computer systems or distributed across independent computer systems.

Although certain steps have been described as being performed by certain devices, processes, or entities, this is not required and those of ordinary skill in the art will appreciate various alternative implementations.

In addition, those skilled in the art will recognize that the above technology can be used in a variety of devices, environments and situations. Although the present disclosure is written with respect to specific embodiments and implementations, those skilled in the art may also propose various changes and modifications, and the present disclosure is intended to cover such changes and modifications that fall within the scope of the appended claims.

Claims (7)

1. A method for forming a hole, the method comprising: Insert the end cap into the first end of the guide tube; The end cap is placed near the second end of the guide tube, wherein the second end is close to the working face containing geological material; The projectile is loaded into the ramjet accelerator, wherein: The projectile is configured to generate a ram-effect combustion reaction in one or more combustible gases within the ram accelerator; and The output end of the ram accelerator is coupled to the first end of the guide tube; The projectile is raised to a certain stamping speed; The projectile is accelerated along at least a portion of the ramjet accelerator by burning one or more combustible gases under the ramjet combustion effect; and Before leaving the guide tube, the projectile penetrates the end cap. 2. The method of claim 1, further comprising: The end cap forms a barrier between the second end of the ramjet accelerator and the geological material. 3. The method of claim 1, further comprising holding the end cap in place. 4. The method of claim 1, wherein the placement comprises: Under pressure, one or more combustible gases are injected at one or more points between the end cap and the first end of the ram accelerator, wherein the one or more combustible gases apply pneumatic pressure to displace the end cap along the ram accelerator. 5. The method of claim 1, wherein the placement comprises: In the ram accelerator, gas is injected at one or more points between the end cap and the first end of the ram accelerator; and Ignite the gas. 6. The method of claim 1, further comprising: Before accelerating the projectile, a non-combustible gas is injected between the second end of the ramjet accelerator and the working surface, wherein the gas is at a pressure greater than 6000 kPa. 7. The method of claim 1, further comprising: Before placing the end cap, a non-combustible gas is injected between the second end of the stamping accelerator and the working surface, wherein the gas is at a pressure greater than 6000 kPa.