Reverse circulation positioning drill bit

Abstract

The invention belongs to the technical field of mineral exploitation equipment, and particularly relates to a reverse circulation positioning drill bit. The invention provides a reverse circulation positioning drill bit. The reverse circulation positioning drill bit comprises a drill column, cutting teeth, cutting blades, a first tool bit, a positioning drill tip and a second tool bit. A sand discharging channel is formed in the drill column, the lower end of the drill column is connected with the cutting blades, the cutting teeth are arranged on the outer edges of the cutting blades, and the first tool bits are embedded in the front ends of the cutting teeth. The positioning drill tip is arranged on the crown portion of the cutting blade, and the second tool bit is embedded in the front end of the positioning drill tip. In the application, under the action of gravity, drilling fluid flows downwards, and meanwhile, in the advancing process of the drill bit, rock debris enters the interior of the drill rod connected with the drill column through the sand discharging channel and returns upwards, and the rock debris upward returning efficiency can be remarkably improved by changing a circulation path. The reverse circulation positioning drill bit has the advantage of being high in drilling efficiency, continuous chip removal can be achieved, and the service life of the drill bit is prolonged.

Description

Technical Field

[0001] This application belongs to the field of mineral mining equipment technology, and in particular relates to a reverse circulation positioning drill bit. Background Technology

[0002] In recent years, with the in-depth implementation of my country's "Mine Safety Law," coal mine safety has risen to the level of a national strategy. Building a dual system of "proactive disaster prevention + emergency escape" has become an industry consensus, with providing safe, fast, and reliable escape routes for underground personnel being the last line of defense for ensuring their safety.

[0003] Currently, domestic coal mines generally use traditional small-diameter gas extraction wells (usually ≤500mm) as a reference for disaster prevention, but their aperture and structural strength cannot meet the needs of personnel escape (the "Construction Specification for Emergency Escape System in Coal Mines" requires the inner diameter of the escape passage to be ≥800mm).

[0004] Therefore, developing a reverse circulation positioning drill bit to address the technical shortcomings of existing technologies where the borehole diameter and strength of small-diameter gas extraction wells cannot meet the needs of personnel escape has become an urgent problem for those skilled in the art. Summary of the Invention

[0005] Therefore, it is necessary to provide a reverse circulation positioning drill bit to address the technical shortcomings of existing technologies, such as the inability of small-diameter gas extraction wells to meet the needs of personnel escape.

[0006] This application provides a reverse circulation positioning drill bit, which includes: a drill string, cutting teeth, cutting blades, a first cutting head, a positioning drill tip, and a second cutting head; the drill string has a sand discharge channel inside, the lower end of the drill string is connected to the cutting blades, the outer edge of the cutting blades is provided with the cutting teeth, and the front end of the cutting teeth is embedded with the first cutting head; the positioning drill tip is disposed on the crown of the cutting blades, and the front end of the positioning drill tip is embedded with the second cutting head.

[0007] In one embodiment, the reverse circulation positioning drill bit further includes a center frame, which is mounted on the drill string, and the bottom end of the center frame is connected to the side edge of the cutting blade.

[0008] In one embodiment, the center frame is a rectangular frame structure, the long side of the center frame is the same length as the distance between the two ends of the cutting blade, and the short side of the center frame is twice the diameter of the drill string.

[0009] In one embodiment, the reverse circulation positioning drill bit further includes a gauge-maintaining tooth disposed on the side of the center frame.

[0010] In one embodiment, the reverse circulation positioning drill bit further includes a connector mounted above the drill bit.

[0011] In one embodiment, the connector has a connecting buckle on its outer side and a connecting thread on its inner side.

[0012] In one embodiment, the cutting blade is provided with a drill chip removal hole, which is connected to the sand removal channel.

[0013] In one embodiment, the cutting edge length of the cutting tooth is 0.5 times the lateral width of the drill bit chip removal hole, and the cross-sectional area of ​​the drill bit chip removal hole is smaller than the cross-sectional area of ​​the sand removal channel.

[0014] In one embodiment, the spacing between adjacent cutting teeth is 13 cm, and the angle between the cutting teeth and the edge of the cutting blade is 90°.

[0015] In one embodiment, the cutting blade has a cross-shaped structure and the apex angle of the cutting blade is 118°.

[0016] In summary, this application provides a reverse circulation positioning drill bit, comprising: a drill string, cutting teeth, cutting blades, a first cutting head, a positioning drill tip, and a second cutting head; the drill string has a sand discharge channel inside, the lower end of the drill string is connected to the cutting blades, the outer edge of the cutting blades is provided with the cutting teeth, and the front end of the cutting teeth is embedded with the first cutting head; the positioning drill tip is disposed at the crown of the cutting blades, and the front end of the positioning drill tip is embedded with the second cutting head. In this application, under the action of gravity, the drilling fluid flows downward, and at the same time, during the advance of the drill bit, rock cuttings enter the drill pipe connected to the drill string through the sand discharge channel and return upward. By modifying the circulation path, the efficiency of rock cuttings return can be significantly improved. The reverse circulation positioning drill bit provided by this application has the advantages of high drilling efficiency, continuous cuttings removal, and extended drill bit life; in addition, the reverse circulation positioning drill bit reduces mud consumption and waste mud treatment pressure, is economical and environmentally friendly, and performs excellently in large-diameter boreholes. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 A schematic diagram of the structure of a reverse circulation positioning drill bit provided in the technical solution of this application embodiment; Figure 2 A top view of a reverse circulation positioning drill bit provided in the technical solution of this application embodiment; Figure 3 A bottom view of a reverse circulation positioning drill bit provided in the technical solution of this application embodiment; The components include: 1. Connector; 2. Drill string; 3. Center frame; 4. Gauge protection teeth; 5. Cutting teeth; 6. Cutting blade; 7. First cutting head; 8. Positioning drill tip; 9. Second cutting head; 10. Drill bit chip removal hole; 11. Connecting thread; 12. Connecting buckle; and 13. Sand removal channel. Detailed Implementation

[0019] This application provides a reverse circulation positioning drill bit to address the technical deficiency in the prior art where the borehole diameter and strength of small-diameter gas extraction wells cannot meet the needs of personnel escape.

[0020] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0021] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0023] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0026] Please see Figures 1 to 3 This application provides a reverse circulation positioning drill bit, including: a drill string 2, cutting teeth 5, cutting blades 6, a first cutting head 7, a positioning drill tip 8, and a second cutting head 9; the drill string 2 has a sand discharge channel 13 inside, the lower end of the drill string 2 is connected to the cutting blades 6, the outer edge of the cutting blades 6 is provided with cutting teeth 5, and the front end of the cutting teeth 5 is inlaid with the first cutting head 7; the positioning drill tip 8 is disposed on the crown of the cutting blades 6, and the front end of the positioning drill tip 8 is inlaid with the second cutting head 9.

[0027] The reverse circulation positioning drill bit provided in this application embodiment, after the drill bit is connected to the external drill rod, firstly positions the part to be drilled by the positioning drill tip 8 set at the foremost end. The positioning drill tip 8 is aligned with the center of the hole to be drilled. At this time, the second cutter head 9 connected to the positioning drill tip 8 effectively protects the positioning drill tip 8 and reduces the wear of the positioning drill tip 8. Then, the drilling and rock breaking process is carried out. At this time, the cutting blade 6 drives the cutting teeth 5 to rotate at high speed, and the rock breaking is completed under the action of the first cutter head 7. Furthermore, the rock debris produced by rock breaking enters the sand discharge channel 13 and is discharged upward along the drill string 2, which is the origin of the reverse circulation in the reverse circulation positioning drill bit.

[0028] To further optimize the technical solution and enhance the structural stability of the reverse circulation positioning drill bit, ensuring that it does not become loose during drilling, the reverse circulation positioning drill bit provided in this application embodiment further includes: a center frame 3, which is installed on the drill string 2, and the bottom end of the center frame 3 is connected to the side edge of the cutting blade 6. The center frame 3 is connected to both the drill string 2 and the cutting blade 6, serving as a structural support and providing stable structural support for all components of the reverse circulation positioning drill bit. Simultaneously, the connection between the center frame 3 and the side edge of the cutting blade 6 further centrally fixes the cutting blade 6, ensuring that the cutting blade 6 can rotate around the central axis of the drill string 2 during drilling, preventing drill bit deviation due to uneven force on the cutting blade 6, and effectively ensuring the verticality and diameter accuracy of the borehole. Furthermore, it also disperses the impact force generated by the cutting blade 6 during drilling due to rock breaking or other hard materials, effectively protecting the drill string 2 from excessive stress damage.

[0029] To further optimize the technical solution, in the embodiment of this application, the center frame 3 has a rectangular frame structure. The long side of the center frame 3 is equidistant from the two ends of the cutting blade 6, and the short side of the center frame 3 is twice the diameter of the drill string 2. The bottom edge of the rectangular frame structure of the center frame 3 connects to the two side edges of the cutting blade 6, effectively preventing the cutting blade 6 from deflecting during drilling and ensuring that the drilling process remains linear. Simultaneously, the rectangular frame design of the center frame 3 and its corresponding length makes it compact and lightweight, ensuring that the center frame 3 will not cause any additional adverse effects on the drilling process after installation, and also ensuring sufficient structural stability.

[0030] The reverse circulation positioning drill bit provided in this application embodiment further includes: a gauge-keeping tooth 4, which is disposed on the side of the center frame 3. The gauge-keeping tooth 4 disposed on the side of the center frame 3 can prevent the wear of the various components of the reverse circulation positioning drill bit by external rocks during the tunneling process, effectively extending its service life; the gauge-keeping tooth 4 can also limit the cutting blade 6, preventing the first cutter head 7 connected to the cutting blade 6 from shaking or being squeezed and enlarged during the drilling process, ensuring that the borehole diameter meets the preset requirements, and better achieving the accuracy of the drilling position.

[0031] To facilitate connection with external drill pipes or other drilling tool components, the reverse circulation positioning drill bit provided in this application embodiment further includes a connector 1, which is installed above the drill bit. This connector 1 connection structure effectively ensures the stability of power transmission and the sealing of the drilling fluid flow path during drilling.

[0032] To further optimize the technical solution, in the technical solution provided in this application embodiment, the outer side of the connector 1 is provided with a connecting buckle 12, and the inner side of the connector 1 is provided with a connecting thread 11. The connecting buckle 12 can quickly connect the drill bit with the corresponding slot of the external drill rod or other drilling tool components, improving the stability and reliability of the connection structure and effectively improving the efficiency of connection and installation. It can prevent the reverse circulation positioning drill bit from separating from the drill rod due to high-speed rotation and vibration during drilling, effectively simplifying the installation and disassembly process and improving work efficiency. The connecting thread 11 set inside the connector 1 plays an auxiliary role in fixing and sealing. It cooperates with the external thread of the external drill rod to further enhance the connection strength, while ensuring the sealing of the slag discharge process. It effectively prevents the high-pressure airflow or slag in the sand discharge channel 13 from leaking from the connection gap, ensuring the negative pressure suction effect of reverse circulation slag discharge.

[0033] To further optimize the technical solution, in the technical solution provided in this application embodiment, the cutting blade 6 is provided with a drill bit chip removal hole 10, which is connected to the sand removal channel 13. The connection between the drill bit chip removal hole 10 and the sand removal channel 13 allows the drilled rock debris to be better collected and enter the sand removal channel 13, thus assisting in chip removal and preventing accumulation inside the sand removal channel 13.

[0034] To further optimize the technical solution, in the embodiment of this application, the cutting edge length of the cutting tooth 5 is 0.5 times the transverse width of the drill bit chip removal hole 10, and the cross-sectional area of ​​the drill bit chip removal hole 10 is smaller than the cross-sectional area of ​​the sand removal channel 13. The design that the cutting edge length of the cutting tooth 5 is 0.5 times the transverse width of the drill bit chip removal hole 10, while ensuring drilling efficiency, further optimizes the chip removal effect and prevents the accumulation of slag. At the same time, the design that the cross-sectional area of ​​the drill bit chip removal hole 10 is smaller than the cross-sectional area of ​​the sand removal channel 13 can further prevent the sand removal channel 13 from becoming clogged.

[0035] To further optimize the technical solution, in the embodiment of this application, the spacing between adjacent cutting teeth 5 is 13 cm, and the angle between the cutting teeth 5 and the edge of the cutting blade 6 is 90°. The design of a spacing of 13 cm between adjacent cutting teeth 5 ensures drilling into rock while effectively preventing teeth from getting stuck; at the same time, the design of a 90° angle between the cutting teeth 5 and the edge of the cutting blade 6, while ensuring drilling into rock, also prevents wear on the cutting teeth 5.

[0036] To further optimize the technical solution, in the embodiment of this application, the cutting blade 6 has a cross-shaped structure with a apex angle of 118°. The cross-shaped layout divides the cutting blade 6 into four evenly distributed cutting areas, maximizing the use of the circumferential space during the rotation of the reverse circulation positioning drill bit and avoiding localized cutting blind spots and uneven rock-breaking efficiency. Simultaneously, during drilling, the rock debris generated accumulates at the cross-shaped intersection, i.e., the center position, allowing for debris accumulation without additional structural guidance. Furthermore, the drill bit's chip removal hole 10 can be positioned at this intersection, further effectively preventing blockage caused by rock debris accumulation. The 118° apex angle design of the cutting blade 6, according to calculations, effectively ensures drilling efficiency and reduces wear, lowering equipment losses for the reverse circulation positioning drill bit.

[0037] In summary, this application provides a reverse circulation positioning drill bit, comprising: a drill string, cutting teeth, cutting blades, a first cutting head, a positioning drill tip, and a second cutting head; the drill string has a sand discharge channel inside, the lower end of the drill string is connected to the cutting blades, the outer edge of the cutting blades is provided with the cutting teeth, and the front end of the cutting teeth is embedded with the first cutting head; the positioning drill tip is disposed at the crown of the cutting blades, and the front end of the positioning drill tip is embedded with the second cutting head. In this application, under the action of gravity, the drilling fluid flows downward, and at the same time, during the advance of the drill bit, rock cuttings enter the drill pipe connected to the drill string through the sand discharge channel and return upward. By modifying the circulation path, the efficiency of rock cuttings return can be significantly improved. The reverse circulation positioning drill bit provided by this application has the advantages of high drilling efficiency, continuous cuttings removal, and extended drill bit life; in addition, the reverse circulation positioning drill bit reduces mud consumption and waste mud treatment pressure, is economical and environmentally friendly, and performs excellently in large-diameter boreholes.

[0038] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. Furthermore, other implementation methods can be derived from the above embodiments, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure.

[0039] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A reverse circulation orientation bit characterized by, The reverse circulation positioning drill bit comprises a drill string, a cutting tooth, a cutting blade, a first cutter head, a positioning drill tip and a second cutter head; the inside of the drill string is provided with a sand discharge channel, the lower end of the drill string is connected with the cutting blade, the outer edge of the cutting blade is provided with the cutting tooth, the front end of the cutting tooth is inlaid with the first cutter head; the positioning drill tip is arranged on the crown of the cutting blade, and the front end of the positioning drill tip is inlaid with the second cutter head.

2. The reverse circulation orientation bit of claim 1, wherein, The reverse circulation positioning drill bit further comprises a center frame, which is installed on the drill string, and the bottom end of the center frame is connected with the side edge of the cutting blade.

3. The reverse circulation orientation drill bit of claim 2, wherein, The center frame is a rectangular frame structure, the length of the long side of the center frame is equal to the distance between the two ends of the cutting blade, and the length of the short side of the center frame is 2 times the diameter of the drill string.

4. The reverse circulation orientation bit of claim 2 or 3, wherein, The reverse circulation positioning drill bit further comprises a gauge tooth, which is arranged on the side of the center frame.

5. The reverse circulation orientation drill bit of claims 1 or 2, wherein, The reverse circulation positioning drill bit further comprises a joint, which is installed above the drill bit.

6. The reverse circulation orientation drill bit of claim 5, wherein, The outside of the joint is provided with a connecting buckle, and the inside of the joint is provided with a connecting thread.

7. The reverse circulation orientation drill bit of claim 1, wherein, The cutting blade is provided with a drill bit chip removal hole, which is in communication with the sand discharge channel.

8. The reverse circulation orientation drill bit of claim 7, wherein, The cutting tooth has an edge length of 0.5 times the transverse width of the drill bit chip removal hole, and the cross-sectional area of the drill bit chip removal hole is smaller than that of the sand discharge channel.

9. The reverse circulation orientation drill bit of claim 1, wherein, The distance between adjacent cutting teeth is 13 cm, and the included angle between the cutting tooth and the edge of the cutting blade is 90°.

10. The reverse circulation orientation drill bit of claim 1, wherein, The cutting blade has a "cross" structure, and the top angle of the cutting blade is 118°.

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