Tri-cone drill assembly

Abstract

This invention relates to a tricone drilling assembly having a drilling direction and a rotation direction. The tricone drilling assembly includes at least a set of three rotatable drilling cones. Each drilling cone includes a conical tooth seat and a set of teeth arranged along the conical tooth seat in a plurality of concentric cutting rings. Each cutting ring generally surrounds the conical tooth seat at a specific cone height. Each tooth protrudes outward from the conical tooth seat. The drilling cones generally lack cutting grooves or interlocking areas between adjacent cutting rings. The size and shape of each tooth are configured to suppress interference with teeth on adjacent drilling cones of the set of three drilling cones.

Description

Cross-reference to related applications

[0001] This application claims priority to Australian Provisional Application No. 2023903179, filed on October 4, 2023, the contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates generally to the field of drilling, and more specifically to the field of tricone drilling. Background Technology

[0003] Tricone drills are widely used for drilling into geological structures and in a variety of industries, from mining exploration to water well and / or oil and gas derrick construction. A tricone drill head includes a central shank that is mounted to the drill string, from which three "legs" extend longitudinally. Drum cones are mounted to the ends of each leg, with multiple "teeth" arranged on the surface of each cone. These teeth are typically round, wedge-shaped, or bullet-shaped, and any edges are usually rounded. As the tricone drill rotates, the cones also rotate or roll on the surface of the structure being drilled, and the teeth impact with it to cause fracturing and hammering.

[0004] Those skilled in the art will understand that tricone drill bits are not designed using a "one-size-fits-all" approach—each tricone drill bit is designed to drill into structures of a specific hardness, and a specific variable is the level of tricone drag. Tricone drag occurs when a particular tricone temporarily stops rolling, thus the rotation of the tricone drill bit causes the tricone and its teeth to slide, slip, or otherwise be dragged across the structure surface. The rate of tricone drag is affected by the "offset" between the tricones, or the lateral movement of each tricone away from the geometric center of the tricone drill bit. Tricone drill bits for soft formations typically have an increased offset between the tricones, resulting in increased tricone drag—which causes the soft formation to be sheared or eroded by the teeth of the dragging tricones, while also being impacted by the teeth of the rolling tricones. However, tricone drill bits for harder formations use gradually decreasing offset values. Greater tricone drag leads to faster wear and degradation of the tricone teeth, which is exacerbated with increasing formation hardness, while the effectiveness of erosion becomes more limited.

[0005] Referring to the prior art tricone drilling rig assembly P10 Figure 1 The existing tri-cone drill assembly comprises three distinct drill cones P12A-C. Each cone is designed with a “cutting groove” or interlocking area P14, which is an open space, recess, or otherwise “blank” and open area that mates with the toothed ring P16 of one of the other two cones—in the prior art Figure 1In this design, the cutting grooves P14, specifically marked on the first unique roller cone P12A and the third unique roller cone P12C, match the third row of teeth P16 on the second unique roller cone P12B. These cutting grooves provide space for the teeth of the other two roller cones to move through and prevent the roller cones from impacting, meshing, or otherwise interfering with each other, because the presence of drag means that the rotation of adjacent roller cones cannot be relied upon to remain asynchronous with each other.

[0006] Reference Figure 2A and Figure 2B It depicts a drill face, which is a circular area to be cut, enlarged, scraped, punched, or otherwise drilled by a tricone drill assembly, and is further subdivided into a set of "drill face rings", each of which corresponds to a tooth ring of one of the drill cones. Figure 2A An exemplary cutting pattern is depicted of a prior art tricone drill assembly P10 rotated 120°, wherein different profile line styles (horizontal, rising diagonal, and falling diagonal) depict the areas cut by each individual prior art drill cone P12A-C, while Figure 2B The same exemplary cutting pattern is depicted when a tricone drill assembly P10 of the exemplary prior art is rotated completely 360°. As shown, the effect of requiring cutting grooves in the prior art tricone drill assembly is that each borehole face ring (on average) is cut by only one tooth ring on one drill cone, because cutting grooves / interlocking areas are arranged at matching positions on the other two prior art drill cones. Exceptions are typically in the outermost position, where the teeth of adjacent drill cones may be too far apart to interfere with each other, or in the innermost position, where the teeth of each cone can be arranged to protrude at different angles so as not to interfere with each other. Therefore, a “complete cut” of the entire borehole face area is only achieved when the entire tricone drill assembly has been rotated 360°.

[0007] Tricone drilling rig assemblies typically feature air and / or water or mud nozzles arranged to blow cuttings away from the borehole face, preventing the drill cones from unnecessarily drilling into already separated material. Further reference is made to existing technology. Figure 1 and Figure 2A In particular, the existing tricone drill assembly P10, utilizing the cutting groove P14, drills into the borehole face 24 by forming a "groove" surrounded by un-drilled material. Figure 2AThe cross-sectional section of the borehole face ring represents the grooves cut by the teeth of the corresponding prior art drill cone P12, while the empty borehole face ring corresponds to the un-drilled material. These grooves provide space for rock cuttings to get stuck and embedded within them. Air, water, or mud blown from the nozzle simply passes through the grooves, removing only a portion of the rock cuttings. Because the grooves are only fully "flattened" after the prior art tri-cone drill assembly has completed a full 360° rotation, each prior art drill cone P12 continuously encounters and re-drills the separated rock cuttings. Rock cuttings can also get stuck directly in the cutting groove P14, eventually accumulating enough to be worn away by the teeth of adjacent drill cones. These "re-drilled" rock cuttings cause additional and unnecessary wear on the teeth of the prior art drill cone P12, resulting in a shortened service life.

[0008] Polycrystalline diamond composite (PDC) drill bits work in a very different way than tricone drill bits. A PDC drill bit consists of a single head with multiple planar teeth extending outwards at an angle from that head. Instead of drilling through repeated impacts and rock fracturing, the entire PDC drill bit rotates as a single entity, and the teeth are "scraped" across the surface of the rock structure, thus cutting, scraping, or reaming the hole into the rock formation. Because PDC drill bits rely primarily on shear or cutting forces, they are well-suited for soft formations or formations prone to shear failure.

[0009] It would be advantageous to provide a hybrid drilling apparatus capable of simultaneously drilling into harder rock formations using both percussion and scraping drilling techniques to increase drilling rates. It would also be advantageous to provide an apparatus that allows each borehole face ring to be cut, reamed, punched, or otherwise drilled by all three drill bits, potentially accelerating drilling rates. Finally, it would be advantageous to provide an apparatus that could extend drill bit life by suppressing unnecessary re-cutting. These and other advantages may be provided by one or more embodiments disclosed herein. Summary of the Invention

[0010] In a first aspect, the present invention includes a tricone drilling assembly having a drilling direction and a rotation direction, the tricone drilling assembly including at least one set of three rotatable drilling cones, each drilling cone including: a conical tooth seat, and a set of teeth arranged along the conical tooth seat in a plurality of concentric cutting rings, each cutting ring substantially surrounding the conical tooth seat at a specific cone height, wherein each tooth protrudes outward from the conical tooth seat, the drilling cone substantially lacks a cutting groove or a meshing area between adjacent cutting rings, and the size and shape of each tooth are configured to suppress interference with teeth on adjacent drilling cones of the set of three drilling cones.

[0011] In an embodiment, the rotation of the tri-drill assembly in the rotational direction defines a drilling surface, which is a circular area to be cut, reamed, scraped, punched, or otherwise drilled by a set of teeth of each drill wheel. The drilling surface is divided into concentrically arranged drilling rings, each corresponding to a specific wheel height. For each drill wheel of the tri-drill assembly, a plurality of concentric cutting rings are arranged such that at least one cutting ring is provided at each corresponding specific wheel height, such that each drilling ring is cut, reamed, scraped, punched, or otherwise drilled by each drill wheel of the tri-drill assembly. In an embodiment, the projection height of each tooth in at least one ring is less than or equal to half the minimum distance between the base of the specific tooth and the surface of the conical tooth seat of the adjacent drill wheel. In an embodiment, each of the three drill wheels in this set is substantially identical to each other.

[0012] In an embodiment, the tricone drill assembly may consist of three roller drill bits connected together, wherein each roller drill bit includes: a shank subassembly shaped to form one-third of the shank of the tricone drill and having a first inner surface and a second inner surface, each first inner surface being in contact with the second inner surface of the shank subassembly of a single roller drill bit of the three roller drill bits; a leg base located on the outer surface of the shank subassembly; a leg extending from the leg base; and one of the three drill cones rotatably mounted to a cone mount disposed at the distal end of the leg; wherein the centerline of the leg extending from the leg base to the cone mount is substantially straight; and the leg is inclined in the direction of rotation of the tricone drill assembly relative to the drilling direction of the tricone drill assembly.

[0013] In an embodiment, for each roller drill bit, a first inner surface and a second inner surface are defined by a first face plane and a second face plane projected through them, respectively, the first face plane and the second face plane intersecting at a longitudinal axis; the angle between the first face plane and the second face plane about the longitudinal axis is approximately 120°; and the first inner surface and the second inner surface are angled relative to the leg base, such that the centerline of the leg is laterally inclined relative to the longitudinal axis in the rotation direction of the tricone drill.

[0014] In one embodiment, each roller drill bit further includes a channel formed in the shank, the channel being located on the leeward side of the outrigger relative to the rotation direction of the tricone drill. In another embodiment, each roller drill bit further includes a jet nozzle disposed on the leeward side of the outrigger relative to the rotation direction of the tricone drill, or the leeward side, the jet nozzle being adapted to direct air or other fluid toward the surface being drilled by the tricone drill.

[0015] In one embodiment, the tooth includes a tooth body having at least a root portion and a distal portion, the distal portion including an impact head, which is a generally solid and hardened protrusion, and a generally flat scraping surface, the scraping surface being at least partially defined by generally unrounded scraping edges.

[0016] In one embodiment, the distal portion of the tooth body is shaped to substantially form an impact head; and a scraping surface extends along at least a portion of the length of the tooth body, with the distal end of the scraping surface close to the distal ends of the tooth body and the impact head.

[0017] In one embodiment, the impact head includes a convex angle projecting laterally from the distal portion of the tooth body, or is at least partially formed by the convex angle, the convex angle having a lateral projection height defined by a convex angle ridge; the convex angle extends along at least a portion of the length of the distal portion, and the distal end of the convex angle is located at the distal end of the distal portion; the scraping surface includes the distal surface of the tooth, the distal surface extending at least partially onto the distal end of the convex angle.

[0018] In one embodiment, a portion of the convex ridge has a positive slope with increasing curvature towards its distal end. In another embodiment, a portion of the convex ridge has a positive slope with decreasing curvature towards its distal end. In yet another embodiment, the distal end of the tooth has a generally teardrop-shaped cross-section.

[0019] In an embodiment, the rotation of a particular drill bit causes each tooth in a particular toothed ring to be carried along the drilling direction of the tri-drill assembly, and each tooth is arranged within the particular toothed ring such that, when carried along the drilling direction of the tri-drill assembly, the scraping surface of the tooth generally points in the rotation direction of the tri-drill assembly.

[0020] Further or alternative embodiments of the invention may be disclosed herein, or will become apparent to those skilled in the art from the disclosure herein. These and other embodiments are considered to fall within the scope and spirit of the invention. Attached Figure Description

[0021] Embodiments of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 The existing tricone drilling rig assembly is described; Figure 2A and Figure 2B The cutting pattern of a prior art tricone drilling rig assembly is depicted; Figure 3 An embodiment of the tricone drilling rig assembly of the present invention is described; Figure 4 This is a side view of a single roller tooth in the above embodiment; Figure 5A and Figure 5B The cutting pattern of an embodiment of the present invention is depicted; Figure 6 and Figure 7 An embodiment of the roller drill bit of the present invention is described; Figure 8A and Figure 8B Alternative embodiments of the tricone drilling rig assembly of the present invention are described; Figure 9 and Figure 10 An embodiment of the roller drill bit of the present invention is described; Figure 11 Various embodiments of the teeth of the present invention are described; and Figure 12 This is a side view of the tooth arrangement in an embodiment of the drill bit cone of the present invention. Detailed Implementation

[0022] In the embodiments and with reference to Figure 3 and Figure 4 The present invention relates to a tricone drilling assembly 10, which has a defined drilling direction 12 during operation (in... Figure 3 The described layout directly from Figure 3 (Outward and towards the observer) and a defined direction of rotation 14. In an embodiment, the tricone drill assembly 10 includes at least one set of three drill cones 16 capable of rotation. Each drill cone 16 may include a conical tooth base 18 (i.e., its conical body) and a set of teeth 20, which are concentrically arranged along the conical tooth base 18 into a plurality of cutting rings 22, 22-1 to 22-n. Figure 3 and Figure 4 The depicted embodiment has seven cutting rings 22-1 to 22-7, but more or fewer cutting rings 22 may be present depending on drilling requirements without departing from the scope of the invention. For clarity, Figure 4 Other teeth besides the teeth 20 visible at the outline edge are not shown; instead, the cutting rings 22 are defined by dashed lines. As shown and as those skilled in the art will understand, each cutting ring 22 surrounds the conical tooth base 18 approximately at a specific tooth height h relative to the base of the tooth. Figure 4 The height h of the third cutting ring 22 is shown in the diagram, and each tooth 20 protrudes outward from the conical tooth base 18. In this embodiment, the drill cone 16 may substantially lack a cutting groove or a meshing area between adjacent cutting rings 22, and the size and shape of each tooth 20 are configured to suppress interference with the teeth 20 on adjacent drill cones 16 in the tri-cone drill assembly 10. This is comparable to the drill cone P10 depicted in the prior art. Figure 1 In contrast, the prior art drill bit P10 has a cutting groove P14 between the cutting rings P16 of adjacent teeth.

[0023] Without limiting the invention theoretically, it is envisioned that the drilling rate of the tri-cone drilling assembly 10 could be increased by providing a drilling cone 16 with a "complete" set of teeth (i.e., without cutting grooves, meshing areas, or other gaps between the tooth rings). See also... Figure 5A and Figure 5B Furthermore, at least for illustrative purposes, a drilling surface 24 is depicted, which is a circular region that will be cut, reamed, scraped, punched, or otherwise drilled by the teeth of each drill cone 16 during rotation of the tricycle drill assembly 10. Also, at least for illustrative purposes, the drilling surface 24 can be subdivided into concentrically arranged drilling surface rings 26, each corresponding to a specific cone height, and subsequently defining a portion of the drilling surface that will be cut, reamed, scraped, punched, or otherwise drilled by the teeth of the cutting ring at that specific cone height. Figure 5A An exemplary cutting pattern depicting a tri-cone drill assembly 10 rotated 120° according to an embodiment of the present invention is shown, wherein different profile line styles (horizontal, rising diagonal, and falling diagonal) depict the areas cut by each individual drill cone 16A-C, while Figure 5B The same exemplary cutting pattern is depicted through a complete 360° rotation. As shown, the entire drill face 24 can be cut, enlarged, punched, or otherwise drilled by rotating 120°, achieving three “complete cuts” through a complete 360° rotation of the tri-cone drill assembly 10 of the present invention. Since there are no cutting grooves or interlocking areas, a plurality of concentric cutting rings 22 of each drill cone 16 are arranged such that at least one cutting ring 22 is provided at each corresponding specific cone height (and therefore for the corresponding drill face ring 26), such that each drill face ring 26 is cut, enlarged, scraped, punched, or otherwise drilled by the cutting rings 22 of all drill cones 16 of the tri-cone drill assembly 10.

[0024] Compare again with reference Figure 2A and Figure 2B As previously discussed, the effect of requiring cutting grooves in existing tricone drilling rig assemblies is that each borehole face ring corresponds to only one cutting ring for one drilling rig cone, because cutting grooves / interlocking areas are arranged at matching specific heights on the other two existing drilling rig cones (where, except for the outermost position, the teeth of adjacent drilling rig cones may be too far apart to interfere with each other). Figure 5A and Figure 5B and Figure 2A and Figure 2BIn comparison, it can be seen that existing tricone drilling rig assemblies require a complete 360° rotation to achieve a "complete cut," meaning the entire drilled surface 24 is cut, enlarged, scraped, drilled, or otherwise drilled. In contrast, the present invention achieves the same coverage area with only a 120° rotation, and the complete 360° rotation allows the tricone drilling rig assembly 10 of the present invention to perform three cuts, enlargements, scrapes, drills, or other drilling operations on the entire drilled surface 24. This enables improved drilling rates and / or may also allow the use of shorter teeth to prevent or suppress interference between the drill cones 16 without negatively impacting the drilling rate.

[0025] Again, without limiting the scope of the invention theoretically, it is envisioned that providing a drill bit 16 with a "complete" set of teeth could improve cuttings removal and suppress unnecessary "re-drilling" of cuttings. (See also...) Figure 5A and existing technologies Figure 2A In contrast, those skilled in the art will understand that no significant grooves are formed during drilling, thus the ability of cuttings to be entrained by the flow of high-pressure air, water, or mud and thus unable to be removed is ineffective, suppressed, mitigated, or otherwise reduced. This could mean that cuttings are removed more completely from the borehole face 24, resulting in the drill bit 16 drilling more continuously into un-drilled rock material, and so for a higher proportion of the operating time. The reduction in the amount of cuttings "re-drilled" can subsequently extend the working life of the drill bit. Furthermore, more complete removal of cuttings from the borehole face 24 can further improve the penetration rate, so even if the working life of a particular drill bit is not extended, the amount of useful borehole material provided within that life can be significantly increased—that is, embodiments of drill bit 16 with a "complete" set of teeth may be able to drill deeper and / or faster than prior art drill bit 12 with a cutting groove P14.

[0026] In an embodiment, the protrusion height of each tooth 20 in at least one cutting ring 22 may be less than or equal to half the minimum distance between the base of that particular tooth (i.e., where the tooth 20 contacts the conical tooth seat 18) and the surface of the conical tooth seat 18 of the adjacent tooth. By keeping the protrusion height of the tooth at half or less of the distance between the tooth and the tooth, it can be ensured that the teeth of adjacent toothed rings never come into contact with each other.

[0027] In this embodiment, each of the three drill bits 16, 16A-C can be substantially identical to each other. This can reduce manufacturing costs by requiring fewer different molds, production lines, etc.

[0028] In the embodiments and with reference to Figure 6 and Figure 7The tricone drill assembly 10 can be formed from three roller drill bits 28 connected together. In a further embodiment, each roller drill bit 28 may include a shank sub-assembly 30 shaped to form one-third of the shank of the tricone drill assembly 10; a leg base 32 located on the outer surface of the shank sub-assembly 30; a leg 34 extending from the leg base 32; and one of the three drill bits 16 rotatably mounted to a bit cone mount disposed at the distal end of the leg 34. In an embodiment, the shank sub-assembly 30 may have a first inner surface 36 and a second inner surface 38, each first inner surface 36 abutting the second inner surface 38 of the shank sub-assembly 30 of a separate adjacent roller drill bit 28 to form the shank of the tricone drill assembly 10. In an embodiment, the centerline 40 of the leg 34 extends from the leg base 32 to the bit cone mount 18 and is generally straight. Ideally, there is no twisting or bending along the length of the leg 34.

[0029] In the embodiments and specifically referred to Figure 7 The support leg 34 can be tilted relative to the drilling direction 12 of the tricone drilling assembly 10 in the rotation direction 14 of the tricone drilling assembly 10. As shown, the support leg 34 is tilted, and the tilt extends along its substantially entire length. To further illustrate this embodiment, refer to... Figure 8A and Figure 8B The text describes a tricone drilling rig assembly 10 with a typical "straight leg" arrangement. Figure 8A The 10 is a tricone drilling rig assembly with tilted legs 34, wherein the tilt is relative to the drilling direction 12 toward the rotation direction 14.

[0030] Without limiting the scope of the invention theoretically, it is conceivable that tilting the outriggers toward the drilling rotation direction would increase their load-bearing capacity, as the centerline of each outrigger would be more aligned with the force. This could be particularly advantageous in embodiments of the invention that might experience an increased rate of drag, since the accompanying drag forces—especially when drilling into hard rock surfaces—could otherwise be enormous and potentially damage the outriggers of the tricone drill. In particular, it is thought that using embodiments of the invention including drill cones 16 with “complete” sets of teeth (i.e., without cutting grooves or interlocking areas) would result in increased forces applied to the tricone drill assembly 10, due to the above and in comparison... Figure 2A and Figure 2B and Figure 5A and Figure 5B The increased penetration capability of the drilled surface is shown. These forces may include drag forces, impact forces, and other forces that the tricone drill assembly 10 typically experiences during operation. It is envisioned that the outriggers 34, tilted in the direction of rotation 14, can provide improved resistance to these aggravated forces, as the outriggers "tilt" into the opposing forces and can counteract them more directly.

[0031] In an embodiment, the first inner surface 36 and the second inner surface 38 may be angled relative to the leg base 32, such that the centerline 40 of the leg 34 is tangentially inclined relative to the longitudinal axis 42 (which coincides with the drilling direction 12), and as a result, the leg 34 itself is "tilted". In an ideal embodiment, the leg 34 is not twisted, bent, arced, or otherwise shaped along its length to cause tilting, nor is the leg base 32 otherwise shaped to cause tangential displacement of the drill bit 16. Instead, in at least one embodiment, tangential displacement can be caused by shaping the first inner surface 36 and the second inner surface 38. This can be achieved by cutting, reaming, planing, or other methods.

[0032] Further, shaping the first inner surface 36 and the second inner surface 38 to tilt the leg 34 laterally could, in some embodiments, make the manufacture or production of the roller drill bit 28 of this embodiment more efficient, because existing molds or castings can be modified instead of designing entirely new molds, whereas if the leg is twisted as may be known in the prior art, then entirely new molds may have to be designed.

[0033] Reference Figure 9 and Figure 10 The image depicts an unformed "leg lug" of an embodiment of the invention, namely a casting of the roller drill bit 28 awaiting the final machining stage. Figure 9 and Figure 10 The image depicts an uncut first inner surface 36 and a second inner surface 38, a leg base located on the outer surface of the handle subassembly 30, a leg 34 extending generally longitudinally from the leg base, and a toothed gear rotatably mounted to the distal end of the leg. Figure 10 (Not shown in the figure). As shown, the initial longitudinal axis 42-1 and the leg centerline 40 are approximately aligned. As previously discussed, the longitudinal axis 42—that is, the intersection of the first and second planes—is similar to the centerline of the shank formed by the three shank sub-assemblies joined together, and therefore is also aligned with the drilling direction 12 of the tricone drill assembly 10. Therefore, the leg 34 extends approximately parallel to the initial longitudinal axis 42-1, and currently approximately parallel to the drilling direction 12 of the tricone drill assembly 10.

[0034] By cutting, reaming, or otherwise reshaping the first inner surface 36 along the cutting plane 44, the angle of the longitudinal axis 42 can be changed from the initial position 42-1 to be aligned with the adjusted longitudinal axis 42-2, which thus causes the leg centerline 40 to be tangentially tilted relative to it. The second surface can then be cut, reamed, or otherwise shaped along another cutting plane (not depicted) to ensure that the angle between the first and second surface planes about the adjusted longitudinal axis 42-2 is substantially or essentially 120°, and to further adjust the angle between the longitudinal axis and the leg centerline 40, and / or control their alignment relative to other reference frames. For example, cutting the first inner surface 36 and the second inner surface 38 at a specific angle may result in the legs 34 of the constructed tricone drill head opening outwards and tilting laterally, which may be desirable or undesirable depending on the characteristics of the drilled structure.

[0035] In some embodiments, the roller drill bit shown in FIG8 can be produced by providing additional manufacturing steps after the roller drill bit 28 is produced by known methods. In an embodiment, the roller drill bit "lug," i.e., the unfinished roller drill bit 28, can be produced by known processes, and the final machining step may include machining the first inner surface 36 or the second inner surface 38 to tangentially tilt the leg 34. In an alternative embodiment, the invention may include a method for modifying an existing mold, casting, or similar template to shape the first inner surface 36 and the second inner surface 38, either by including additional material to allow for angular reshaping, or by directly forming the first inner surface 36 and the second inner surface 38 at the correct angle to induce the desired tangential tilt in the leg 34. Both embodiments are considered to enable efficient and cost-effective implementation because they can be implemented by modifying existing production lines and processes for tricone drill rig components.

[0036] In further embodiments and referring back to the reference Figure 7 The roller drill bit 28 may include a channel 46 formed in the shank sub-assembly 30 and located on the leeward side of the outrigger 34. The channel 46 may provide a path for rock cuttings to exit from the path of the tricone drill head assembly 10. The channel 46 may be arranged to be partially shielded by the outrigger 34.

[0037] In one embodiment, the roller drill bit 28 may include a jet nozzle 48 disposed on the leeward side of the outrigger 34. The jet nozzle 48 may be adapted to direct air or other fluid toward the borehole face 24 to remove and expel cuttings from the path of the tricone drill head assembly 10.

[0038] In the embodiments and with reference to Figure 11The tooth 20 of the tricone drill assembly may include a tooth body 50 having at least a root portion 52 and a distal portion 54, the distal portion 54 including an impact head 56, a generally solid and hardened projection, and a generally flat scraping surface 58 defined at least partially by a generally unrounded scraping edge 60. As those skilled in the art will understand, the impact head 56 need not be a structure defined on the tool body 50. Rather, the term "impact head" refers to a portion of the drill bit 20 that is generally solid and hardened and is shaped, arranged, or otherwise adapted to impact, hammer, fracture, or otherwise destroy the hard rock of the drilled hole structure. In some embodiments, such as depicted in tooth 20A, the impact head 56 may at least partially include or include a specialized projection extending from the tool body. In other embodiments, such as depicted in tooth 20B, the impact head 56 may be a distal region of the tool body 50. In some embodiments, at least a portion of the tool body 50 may form the remainder of the impact head 56; that is, if a protrusion is present, it may form only a portion of the impact head 56. In embodiments, the scraping surface 58 and the scraping edge 60 are shaped, arranged, or otherwise adapted to scrape, shave, and / or shear the hard rock of the drilled hole.

[0039] In the embodiment of drill bit tooth 20A and further refer to Figure 11 The impact head 56 of the drill bit 20A may include a convex angle 62 or be at least partially formed by a convex angle 62, which laterally projects from the distal portion of the tooth body 50. In an ideal embodiment, the convex angle 62 extends along at least a portion of the length of the distal portion 54, and the distal end of the convex angle 62 is located at, adjacent to, or otherwise coincides with the distal end of the distal portion 54. The convex angle 62 may have a lateral projection height defined by a convex angle ridge, which is not necessarily a defined structure but rather a “local maximum” of the convex angle or a theoretical line defining the two-dimensional shape of the convex angle along the length of the tooth 20A. In this embodiment, the scraping surface 58 may include the distal surface of the drill bit 20, and the distal end surface (and therefore the scraping surface) may extend to the distal end of the convex angle 62.

[0040] In the embodiments and specifically referred to Figure 11 The side view of tooth 20A shown shows that a portion of the convex ridge, towards its distal end, may have a positive slope with increasing curvature. In an embodiment, a portion of the convex ridge, towards its distal end, may have a positive slope with decreasing curvature. Those skilled in the art will understand that these embodiments are not mutually exclusive and may coexist in different portions of the convex angle 62. In a further embodiment, the convex angle 62 may have a gradual slope from the root portion 52 near the tooth 20 to the convex peak 64 near the distal end of the tooth 20.

[0041] In an embodiment, the distal end of the tooth may have a generally teardrop-shaped cross-section, formed by a combination of a convex angle 62 and a tooth body 50. The side surface of the convex angle 62 may be flat, or it may be curved or rounded. In some embodiments, one side of the convex angle may be rounded, while the other side is at least partially flat.

[0042] Further reference Figure 11 An alternative embodiment of the drill bit 20B may include a tooth body 50, which is substantially capped at its distal end by an impact head 56. In this embodiment, the scraping surface 58 may be laterally facing and may extend along at least a portion of the length of the tooth body 50. In a further embodiment, the distal end of the scraping surface 58 may be close to or substantially aligned with the distal ends of the tool body 50 and the impact head 56.

[0043] Figure 12 This is a side view of the tri-cone drilling rig assembly 10 according to an embodiment of the present invention, although only a single drilling cone 16 is visible for clarity. (Refer to...) Figure 12In an embodiment, a plurality of cutting rings 22 on the drill cones 16 of the tri-cone drill assembly 10 are at least partially formed by the embodiments of teeth 20A, B described above, which may be arranged such that the scraping surface 58 abuts against the borehole surface in a specific direction. As previously described, the tri-cone drill assembly 10 rotates in a specific direction of rotation 14, and each drill cone 16 is also capable of rotating about its axis. It is understood that the rotation of a particular drill cone 16 sequentially causes each tooth 20 in a particular tooth ring to face (or point toward) the drilling direction 12 of the tri-cone drill assembly 10, at which point it abuts against the borehole surface 24. In an embodiment, each tooth 20 is arranged within a particular cutting ring 22 such that, when abutted as described above, the scraping surface 58 of the tooth 20 generally points in the direction of rotation 14 of the tri-cone drill assembly 10. As an alternative interpretation, each drill cone tooth 20 may be arranged within a specific cutting ring 22 such that, when rotated and positioned by the drill cone 16 at its furthest point from the drill shank, the scraping surface 58 of that specific drill cone tooth 20 generally points in the rotational direction 14 of the tri-cone drill assembly 10. In some embodiments, particularly those employing drill cone teeth 20A with a lateral projection convex angle 62, the drill cone teeth 20A may be arranged such that the scraping surface 58 forms an angle θ relative to the rotational direction 14 of the drill shank. The arrangement of the teeth 20A within the drill cone 16 and their projection direction relative to the cone may be varied to alter the angle θ, for example, to increase or decrease the severity or intensity of cutting, reaming, scraping, or chiseling actions caused when the associated drill cone 16 is not rotating (i.e., when the teeth 20A are dragged across the structure of the drilled hole). As used herein, the term "generally pointing" should therefore be understood to mean that the scraping surface 58 is not required to be exactly facing the rotation direction 14 of the tricone drill assembly 10, but rather that the scraping surface is primarily facing the rotation direction 14. In the embodiment, the magnitude of sin(θ) is greater than or equal to 0.5.

[0044] Without limiting the scope of the invention theoretically, when the drill wheel 16 of a tricone drill rotates, the drill wheel teeth 20 mounted thereon are expected to impact the structure of the drilled hole (i.e., the drill face 24). Specifically, rotation of the drill wheel 16 in the rotation direction 14 will present the impact head 56 of the teeth 20 to the drill face 24. Conversely, when a particular drill wheel 16 is not rotating, it will be dragged across the drill face 24 by the overall rotation of the drill shank. In this case, the teeth 20 on the portion of the drill wheel 16 abutting the drill face 24 will be able to cut, chisel, or otherwise scrape the abutting surface, as the scraping surface 58 will move in the rotation direction 14 of the tricone drill assembly 10. In a further embodiment, where the teeth 20A include a convex angle 62 with a convex peak 64, it is envisioned that this peak can facilitate significantly concentrated cutting or chiseling against the drill face 24.

[0045] Further reference Figure 12The embodiments of the invention depicted herein are therefore considered to enable the associated tricone drill rig to increase penetration into hard rock surfaces by having a 56 impact head and a scraping surface 58 generally facing the direction of rotation 14. In particular, embodiments of this aspect are considered to combine the beneficial characteristics of polycrystalline diamond composite (PDC) drill bits, which are typically designed to drill by applying scraping or chiseling actions, with those of conventional tricone drill rigs shaped to drill by applying fracturing, hammering, or impact actions.

[0046] While the present invention has been described with reference to the preferred embodiments described above, those skilled in the art will understand that the invention is not limited to these embodiments, but can be practiced in many other forms, variations, and modifications than those specifically described. The invention includes all such variations and modifications. The invention also includes all steps, features, components, and / or devices mentioned or indicated individually or collectively in the specification, and any and all combinations of any two or more steps or features.

[0047] In this specification, unless the context clearly indicates otherwise, the word "including" is not intended to have the exclusive meaning of words such as "consisting of only," but rather to have a non-exclusive meaning, namely, "including at least." Other forms of this word, such as "including," are equally applicable in terms of grammatical variation.

[0048] Other definitions of the selected terms used herein can be found in the specific embodiments of the invention and apply throughout. Unless otherwise defined, all other scientific and technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0049] Any commitments made in this document should be understood to apply to some embodiments of the invention and are not intended to constitute a commitment to the invention in all embodiments. Where a commitment is deemed applicable to all embodiments of the invention, the applicant / patentee reserves the right to remove it from the specification at a later date, and they do not rely on such commitments to obtain acceptance or subsequent grant of a patent in any country.

Claims

1. A tri-cone drilling rig assembly, the tri-cone drilling rig assembly having a drilling direction and a rotation direction, the tri-cone drilling rig assembly comprising at least one set of three rotatable drilling cones, each drilling cone comprising: Conical tooth base; as well as A set of teeth, the set of teeth being arranged into multiple concentric cutting rings along the conical tooth base, each cutting ring substantially surrounding the conical tooth base at a specific tooth height; Each tooth protrudes outward from the conical tooth base; The drill bit cones generally lack cutting grooves or interlocking areas between adjacent cutting rings; and The size and shape of each tooth are configured to suppress interference with the teeth on the adjacent drill deflectors of the set of three drill deflectors.

2. The tricone drilling rig assembly according to claim 1, wherein: The rotation of the tricone drilling assembly in the rotational direction defines the drilling surface, which is a circular area that will be cut, enlarged, scraped, punched, or otherwise drilled by the set of teeth of each drilling cone. The drilling surface is divided into concentrically arranged drilling surface rings, each drilling surface ring corresponding to a specific roller height; For each drill cone of the tricone drill assembly, the plurality of concentric cutting rings are arranged such that at least one cutting ring is provided at each corresponding specific cone height; This allows each drill facet to be cut, enlarged, scraped, punched, or otherwise drilled by each drill wheel of the tricone drill assembly.

3. The tricone drilling rig assembly according to claim 1, wherein, The protrusion height of each tooth in at least one of the rings is less than or equal to half the minimum distance between the base of the particular tooth and the surface of the conical tooth seat of the adjacent drill bit cone.

4. The tricone drilling rig assembly according to any one of claims 1 to 3, wherein, Each of the three drill bits in the set is substantially the same as the others.

5. The tricone drilling assembly according to any one of claims 1 to 4, comprising three roller drill bits connected together, wherein each roller drill bit includes: A shank subassembly, the shank subassembly being shaped to form one-third of the shank of the tricone drill, and having a first inner surface and a second inner surface, each first inner surface being in contact with the second inner surface of the shank subassembly of one of the three roller drill bits; The leg base is located on the outer surface of the handle subassembly; A support leg, the support leg extending from the base of the support leg; and One of the three drill bits is rotatably mounted to a bit mount located at the distal end of the outrigger; Wherein, the center line of the support leg extending from its base to the toothed wheel mount is approximately straight; and The outrigger is tilted relative to the drilling direction of the tricone drilling assembly in the direction of rotation of the tricone drilling assembly.

6. The tricone drilling rig assembly according to claim 5, wherein, For each roller drill bit: The first inner surface and the second inner surface are respectively defined by a first facial plane and a second facial plane through which the projection passes, and the first facial plane and the second facial plane intersect at a longitudinal axis. The angle between the first facial plane and the second facial plane about the longitudinal axis is approximately 120°; and The first inner surface and the second inner surface are angled relative to the base of the support leg, such that the centerline of the support leg is laterally inclined relative to the longitudinal axis in the rotation direction of the tricone drill.

7. The tricone drill assembly of claim 6, wherein each roller bit further includes a channel formed in the shank, the channel being located on the leeward side of the outrigger relative to the rotation direction of the tricone drill.

8. The tricone drill assembly of claim 6 or 7, wherein each roller drill bit further comprises a jet nozzle arranged on the leeward side of the outrigger relative to the rotation direction of the tricone drill, the jet nozzle being adapted to direct air or other fluid toward the surface being drilled by the tricone drill.

9. A tooth for a tricone drilling rig assembly according to any one of claims 1 to 8, the tooth comprising: A tooth body having at least a root portion and a distal portion, the distal portion including an impact head, the impact head being a generally solid and hardened protrusion; as well as A generally flat scraped surface, which is at least partially defined by generally unrounded scraped edges.

10. The drill bit tooth according to claim 9, wherein, The distal portion of the tooth is shaped to substantially form the impact head; and The scraping surface extends along at least a portion of the length of the tooth body, with the distal end of the scraping surface close to the distal end of the tooth body and the impact head.

11. The tooth according to claim 9, wherein: The impact head includes a convex angle projecting laterally from the distal portion of the tooth body, or is at least partially formed by the convex angle, the convex angle having a lateral projection height defined by the convex angle ridge line; The convex angle extends along at least a portion of the length of the distal portion, and the distal end of the convex angle is located at the distal end of the distal portion. The scraping surface includes the distal surface of the tooth, which extends at least partially onto the distal end of the convex angle.

12. The tooth according to claim 11, wherein, A portion of the convex ridge line, toward its distal end, has a positive slope with increasing curvature.

13. The tooth according to claim 11 or 12, wherein, A portion of the convex ridge line, toward its distal end, has a positive slope with decreasing curvature.

14. The tooth according to any one of claims 11 to 13, wherein, The distal end of the tooth has a roughly teardrop-shaped cross-section.

15. The tricone drilling rig assembly according to any one of claims 1 to 8, wherein, The plurality of toothed rings are formed at least in part by the teeth of any one of claims 9 to 14; Furthermore, the rotation of a specific drill bit cone sequentially causes each tooth in a specific toothed ring to bear a load along the drilling direction of the three-cone drill assembly; and Each tooth is arranged within the specific tooth ring such that, when carried along the drilling direction of the tricone drilling assembly, the scraping surface of the tooth generally points in the rotational direction of the tricone drilling assembly.

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