A shaft drilling machine slag scraping device

Abstract

This invention discloses a cuttings scraping device for a vertical shaft drilling rig, comprising a drill bit body and a rock-breaking roller cutter. The rock-breaking roller cutter is disposed on the end face of the drill bit body and faces the bottom of the well. A cuttings discharge hole is axially formed in the center of the drill bit body. A vertical cuttings scraping structure is installed on the end face of the drill bit body and fits against the bottom of the well. The vertical cuttings scraping structure rotates synchronously with the drill bit body, pushing the rock cuttings towards the cuttings discharge hole. The drill bit body drives the rock-breaking roller cutter to rotate circumferentially, forming an annular rock-breaking trajectory surface on the bottom of the well. By setting a vertical cuttings scraping structure that rotates synchronously with the drill bit body, the rock cuttings deposited on the bottom of the well can be pushed, enabling them to move towards the cuttings discharge hole in a timely manner. The vertical cuttings scraping structure is set on each rotation to achieve relay pushing of cuttings, that is, continuous pushing of cuttings in the radial direction, pushing all the rock cuttings towards the cuttings discharge hole, ensuring the effectiveness of cuttings removal and avoiding the formation of mud-covered drill bits.

Description

Technical Field

[0001] This invention relates to the field of technology. Specifically, it relates to a slag scraping device for vertical shaft drilling rigs. Background Technology

[0002] Well drilling is a technique that uses large vertical shaft drilling rigs to drill wells from top to bottom on the surface, achieving full-face operation and drilling without going down into the well. In the first stage of well drilling, the well is enlarged from top to bottom, and the direction of slag circulation is shown in the attached figure. Figure 1 As indicated by the arrow, the cuttings are removed through a bottom-up reverse circulation process using mud diluted with air. During drilling, the vertical shaft drilling rig's upper power system drives the drill pipe and drill bit to rotate, which in turn drives the rock-breaking rollers to rotate and break the rock. The broken rock cuttings concentrate near the cuttings discharge hole at the center of the drill bit, thus achieving cuttings removal through the aforementioned principle.

[0003] In actual drilling operations, cuttings cannot be collected in a timely and complete manner near the cuttings discharge hole. A considerable portion of the cuttings accumulates at various locations at the bottom of the well, forming uneven cuttings deposition zones. Under these circumstances, the cuttings within the deposition zone are repeatedly crushed by the rock-breaking cutter, resulting in excessive wear of the cutter. Furthermore, the cuttings can coat the rock-breaking cutter, creating a mud-covered drill bit phenomenon, which can further cause the drill bit to get stuck, leading to premature failure of some cutters, increasing drill bit retrieval time and cutter replacement costs, severely restricting drilling efficiency and increasing drilling costs. Patent document CN102877849A discloses a novel vertical shaft drilling rig cutter structure. A spiral-shaped slurry scraper is installed on the bottom of the cutting disc, extending from the edge to the center. During the rotation of the cutting disc, the spiral-shaped slurry scraper pushes the cuttings towards the discharge port. However, during the scraping process, the entire cross-section is scraped at once, resulting in a large amount of cuttings being collected within the spiral-shaped slurry scraper during rock breaking, which severely consumes drilling power. When a large amount of rock debris is drawn into the spiral-shaped slurry scraper, it completely envelops the rock-breaking cutter, causing mud-covering. Because the linear velocity at the edge of the cutting disc is higher than that on the inner side, and the outer opening of the spiral-shaped slurry scraper is wider than the inner opening, a large amount of rock debris is quickly scraped into the outer opening of the spiral-shaped slurry scraper. The large amount of rock debris flows rapidly to the narrower inner position. The pressure of the rock debris-slurry mixture is higher the closer to the inside, and the more severe the enveloping of the inner rock-breaking cutter becomes, which exacerbates the mud-covering phenomenon and the wear of the rock-breaking cutter. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a slag scraping device for vertical shaft drilling rigs that reduces the occurrence of mud-covered drilling phenomena.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a cuttings scraping device for a vertical shaft drilling rig, comprising a drill bit body and a rock-breaking roller cutter, wherein the rock-breaking roller cutter is disposed on the end face of the drill bit body and faces the bottom of the well, and a cuttings discharge hole is axially formed in the center of the drill bit body; a vertical cuttings scraping structure is installed on the end face of the drill bit body, the vertical cuttings scraping structure is attached to the bottom of the well, and the vertical cuttings scraping structure rotates synchronously with the drill bit body to push the rock cuttings toward the cuttings discharge hole; the drill bit body drives the rock-breaking roller cutter to rotate circumferentially to form an annular rock-breaking trajectory surface on the bottom of the well, and at least one vertical cuttings scraping structure is arranged within any one of the annular rock-breaking trajectory surfaces.

[0006] In the aforementioned vertical shaft drilling rig slag scraping device, one end of the vertical slag scraping structure is close to the axis of the drill bit body, and the other end of the vertical slag scraping structure away from the axis of the drill bit body is deflected forward along the radial direction of the drill bit body in the direction of rotation of the drill bit body.

[0007] The above-mentioned vertical shaft drilling rig slag scraping device, wherein the drill bit body drives the vertical slag scraping structure to rotate circumferentially to form an annular slag scraping surface on the bottom of the well, and two adjacent annular slag scraping surfaces are joined together.

[0008] In the aforementioned vertical shaft drilling rig slag scraping device, two adjacent vertical slag scraping structural members in the radial direction of the drill bit body are staggered in the circumferential direction.

[0009] The aforementioned vertical shaft drilling rig cuttings scraping device includes a vertical cuttings scraping structure comprising a flat base plate and an arc-shaped plow plate. The flat base plate faces the bottom of the well, and the arc-shaped plow plate stands on the flat base plate, with one side of the arc-shaped plow plate fixedly connected to the flat base plate. In the rotation direction of the drill bit body: the front edge of the flat base plate is in contact with the bottom of the well, and the side wall of the arc-shaped plow plate facing the cuttings is concave.

[0010] In the aforementioned vertical shaft drilling rig slag scraping device, the radius of the concave surface of the arc-shaped plow plate gradually increases from the end away from the axis of the drill bit body to the end close to the axis of the drill bit body.

[0011] In the above-mentioned vertical shaft drilling rig slag scraping device, in the rotation direction of the drill bit body: the front edge of the flat bottom plate is in contact with the bottom of the well, the angle between the flat bottom plate and the bottom of the well is greater than zero degrees, and the bottom edge of the arc-shaped plow plate is fixedly connected to the front edge of the flat bottom plate.

[0012] The aforementioned vertical shaft drilling rig slag scraping device has a curved arm fixedly connected to the vertical slag scraping structure, and a mounting base is hinged to the other end of the curved arm via a pin. The mounting base is fixedly installed on the end face of the drill bit body.

[0013] In the aforementioned vertical shaft drilling rig slag scraping device, a torsion spring is sleeved on the pin shaft, one end of the torsion spring presses on the mounting base, and the other end of the torsion spring presses on the crank arm.

[0014] In the aforementioned vertical shaft drilling rig slag scraping device, in the rotation direction of the drill bit body: the end of the curved arm away from the mounting base extends towards the rear of the mounting base.

[0015] The technical solution of the present invention achieves the following beneficial technical effects:

[0016] 1. By setting up a vertical scraper structure that rotates synchronously with the drill bit body, the rock cuttings deposited on the bottom of the well can be pushed and moved to the slag discharge hole in a timely manner. A vertical scraper structure is set up on each circle to achieve relay slag pushing, that is, continuous slag pushing in the radial direction, pushing all the rock cuttings to the slag discharge hole position, ensuring the slag discharge effect and avoiding the generation of mud-covered drill bit.

[0017] 2. By incorporating a crank arm, mounting base, and torsion spring, the slag scraping structure can swing upwards to avoid obstacles when they protrude from the bottom of the well, ensuring the drill bit can operate normally. Furthermore, during normal slag scraping, the vertical slag scraping structure remains in contact with the bottom of the well, guaranteeing effective slag scraping.

[0018] 3. By staggering multiple vertical cuttings scraping structures at different radii, the cuttings are pushed inward layer by layer, avoiding excessive resistance and achieving a balance between scraping efficiency and tool wear rate. This also effectively prevents mud buildup. In other words, the multiple staggered vertical cuttings scraping structures ensure that there is no excessive cuttings at the bottom of the well. Even if cuttings in one ring are not scraped, those in adjacent rings are. As the rock-breaking roller passes through, the loose cuttings are dispersed under the pressure of the roller, preventing excessive cuttings from causing roller wear and avoiding mud buildup. In summary, this invention ensures timely and complete removal of cuttings while preventing excessive wear of the rock-breaking roller and mud buildup. This increases the service life of the rock-breaking roller, reduces drilling time and roller replacement costs, and improves drilling efficiency while reducing drilling costs. Attached Figure Description

[0019] Figure 1 A schematic diagram of the longitudinal cross-sectional structure of a rock-breaking drill bit in the prior art;

[0020] Figure 2 A schematic diagram of the longitudinal cross-sectional structure of the vertical shaft drilling rig slag scraping device of the present invention installed on the drill bit body;

[0021] Figure 3 A plan view of the cuttings scraping device for vertical shaft drilling rigs of the present invention installed on the end face of the drill bit body;

[0022] Figure 4 A schematic diagram of the annular rock-breaking trajectory surface at the bottom of the well according to the present invention;

[0023] Figure 5 A schematic diagram of the assembly of the vertical slag scraper structure, the curved arm, and the mounting base of the present invention;

[0024] Figure 6 A three-dimensional structural diagram of the vertical slag scraping structure of the present invention;

[0025] Figure 7 A schematic diagram of the slag scraping device of the present invention in normal working condition;

[0026] Figure 8 A schematic diagram of the obstacle avoidance state of the slag scraping device of the present invention.

[0027] The reference numerals in the figure are as follows: 1-Wellside; 2-Well Bottom; 3-Drill Pipe; 4-Drill Bit Body; 5-Rock Breaking Roller Cutter; 6-Vertical Slag Scraper Structure; 601-Flat Base Plate; 602-Arc-Shaped Plow Plate; 7-Slag Discharge Hole; 8-Mounting Base; 9-Crank Arm; 10-Pin Shaft; 11-Torsion Spring; 12-Annular Rock Breaking Track Surface. Detailed Implementation

[0028] This embodiment provides a vertical shaft drilling rig slag scraping device, such as... Figure 2-3 As shown, the drill bit includes a drill body 4 and a rock-breaking cutter 5. The rock-breaking cutter 5 is disposed on the end face of the drill body 4 and faces the bottom of the well 2. A slag discharge hole 7 is axially formed in the center of the drill body 4. A vertical slag scraper 6 is installed on the end face of the drill body 4. The vertical slag scraper 6 is attached to the bottom of the well 2. The vertical slag scraper 6 rotates synchronously with the drill body 4, pushing the rock cuttings towards the slag discharge hole 7. Figure 3-4 As shown, the drill bit body 4 drives the rock-breaking roller cutter 5 to rotate circumferentially on the bottom of the well 2 to form an annular rock-breaking trajectory surface 12. At least one vertical scraper structure 6 is arranged on any one of the annular rock-breaking trajectory surfaces 12. In this embodiment, two vertical scraper structures 6 are equally spaced on the annular rock-breaking trajectory surface 12 on the outer ring of the drill bit body 4 to improve scraping efficiency and balance scraping resistance. One vertical scraper structure 6 is arranged on each inner ring of the drill bit body 4 with a smaller diameter. By setting the vertical scraper structure 6 that rotates synchronously with the drill bit body 4, the rock cuttings deposited on the bottom of the well 2 can be pushed so that the rock cuttings can move to the slag discharge hole 7 in a timely manner.

[0029] like Figure 2-3As shown, one end of the vertical scraper structure 6 is close to the axis of the drill bit body 4, and the other end of the vertical scraper structure 6 away from the axis of the drill bit body 4 is inclined forward along the radial direction of the drill bit body 4 in the direction of rotation of the drill bit body 4. The drill bit body 4 drives the vertical scraper structure 6 to rotate circumferentially to form an annular scraping surface on the bottom of the well 2. Two adjacent annular scraping surfaces are joined together. Two adjacent vertical scraper structures 6 in the radial direction of the drill bit body 4 are staggered in the circumferential direction. Vertical scraper structures 6 are set on each circle to achieve relay scraping, that is, continuous scraping in the radial direction, pushing all the rock cuttings to the position of the slag discharge hole 7, ensuring the slag discharge effect. By setting multiple vertical scraper structures 6 staggered at different radii, the rock cuttings are pushed inward layer by layer in circles, which can avoid the formation of excessive resistance and achieve a balance between scraping efficiency and tool wear speed, and can also effectively avoid the generation of mud-covered drill bits.

[0030] like Figure 5-6 As shown, the vertical scraper structure 6 includes a flat base plate 601 and an arc-shaped plow plate 602. The flat base plate 601 is positioned facing the bottom of the well 2, and the arc-shaped plow plate 602 stands on the flat base plate 601, with one side of the arc-shaped plow plate 602 fixedly connected to the flat base plate 601. In the rotation direction of the drill bit body 4: the front edge of the flat base plate 601 is in contact with the bottom of the well 2, and the side wall of the arc-shaped plow plate 602 facing the rock cuttings is concave. The radius of the concave surface of the arc-shaped plow plate 602 gradually increases from the end away from the axis of the drill bit body 4 to the end close to the axis of the drill bit body 4. In the rotation direction of the drill bit body 4: the front edge of the flat base plate 601 is in contact with the bottom of the well 2, and the angle between the flat base plate 601 and the bottom of the well 2 is greater than zero degrees. The bottom edge of the arc-shaped plow plate 602 is fixedly connected to the front edge of the flat base plate 601.

[0031] like Figure 5 As shown, a curved arm 9 is fixedly connected to the vertical scraper structure 6. The curved arm 9 is fixedly connected to the top of the flat base plate 601. The other end of the curved arm 9 is hinged to a mounting base 8 via a pin 10. The mounting base 8 is fixedly installed on the end face of the drill bit body 4. A torsion spring 11 is sleeved on the pin 10. One end of the torsion spring 11 presses against the mounting base 8, and the other end of the torsion spring 11 presses against the curved arm 9. In the rotation direction of the drill bit body 4, the end of the curved arm 9 away from the mounting base 8 extends towards the rear of the mounting base 8. By setting the curved arm 9, the mounting base 8, and the torsion spring 11, as shown... Figure 8 As shown, when there is a protruding obstacle on the bottom of the well 2, the slag scraping structure 6 can swing upward to avoid the obstacle, ensuring that the drill bit can operate normally, and ensuring that the vertical slag scraping structure 6 can always be in contact with the bottom of the well 2 during normal slag scraping, thus ensuring the slag scraping effect.

[0032] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A slag scraping device for a vertical shaft drilling rig, comprising a drill bit body (4) and a rock-breaking cutter (5), wherein the rock-breaking cutter (5) is disposed on the end face of the drill bit body (4) and faces the bottom of the well (2), and a slag discharge hole (7) is provided axially in the center of the drill bit body (4), characterized in that, A vertical scraper structure (6) is installed on the end face of the drill bit body (4). The vertical scraper structure (6) is attached to the bottom of the well (2). The vertical scraper structure (6) rotates synchronously with the drill bit body (4) to push the rock cuttings toward the position of the slag discharge hole (7). The drill bit body (4) drives the rock breaking roller (5) to rotate circumferentially on the bottom of the well (2) to form an annular rock breaking trajectory surface (12). At least one vertical scraper structure (6) is arranged in any one of the annular rock breaking trajectory surfaces (12). One end of the vertical slag scraper (6) is close to the axis of the drill bit body (4), and the other end of the vertical slag scraper (6) away from the axis of the drill bit body (4) is deflected in front of the rotation direction of the drill bit body (4) along the radial direction of the drill bit body (4). The drill bit body (4) drives the vertical slag scraping structure (6) to rotate circumferentially to form an annular slag scraping surface on the bottom of the well (2), and two adjacent annular slag scraping surfaces are joined together. The vertical scraper structure (6) includes a flat base plate (601) and an arc-shaped plow plate (602). The flat base plate (601) is set facing the bottom of the well (2). The arc-shaped plow plate (602) stands on the flat base plate (601), and one side of the arc-shaped plow plate (602) is fixedly connected to the flat base plate (601). In the rotation direction of the drill bit body (4): the front edge of the flat base plate (601) is in contact with the bottom of the well (2), and the side wall of the arc-shaped plow plate (602) facing the rock cuttings is concave.

2. The slag scraping device for a vertical shaft drilling rig according to claim 1, characterized in that, The two adjacent vertical scraper structures (6) in the radial direction of the drill bit body (4) are staggered in the circumferential direction.

3. The slag scraping device for a vertical shaft drilling rig according to claim 1, characterized in that, The radius of the concave surface of the arc-shaped plow plate (602) gradually increases from the end away from the axis of the drill body (4) to the end close to the axis of the drill body (4).

4. The slag scraping device for a vertical shaft drilling rig according to claim 1, characterized in that, In the rotation direction of the drill bit body (4): the front edge of the flat bottom plate (601) is in contact with the bottom of the well (2), the angle between the flat bottom plate (601) and the bottom of the well (2) is greater than zero degrees, and the bottom edge of the arc-shaped plow plate (602) is fixedly connected to the front edge of the flat bottom plate (601).

5. A vertical shaft drilling rig slag scraping device according to claim 1, characterized in that, A crank arm (9) is fixedly connected to the vertical slag scraper structure (6), and the other end of the crank arm (9) is hinged to a mounting seat (8) via a pin (10). The mounting seat (8) is fixedly installed on the end face of the drill bit body (4).

6. A vertical shaft drilling rig slag scraping device according to claim 5, characterized in that, A torsion spring (11) is fitted on the pin (10), one end of the torsion spring (11) presses on the mounting base (8), and the other end of the torsion spring (11) presses on the crank arm (9).

7. A vertical shaft drilling rig slag scraping device according to claim 5, characterized in that, In the rotational direction of the drill body (4): the end of the crank arm (9) away from the mounting base (8) extends toward the rear of the mounting base (8).

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