Cone pipe-following drill bit

Abstract

The invention discloses a cone follow-pipe drill bit, which belongs to the technical field of follow-pipe drilling, and comprises a rod body, the end part of the rod body is connected with a cone drill bit, a plurality of centralizing plates are circumferentially arranged on the side surface, far away from the cone drill bit, of the rod body, baffle rings are arranged on the outer sides of the centralizing plates, and a plurality of pairs of limiting locks are circumferentially arranged on the side surface, close to the cone drill bit, of the rod body. A limiting pin is rotationally arranged on each pair of limiting locks, and a scraper plate is connected to the limiting pins. The device is suitable for casing-following drilling construction of special stratums such as soil layers, sludge and pebbles which are extremely easy to collapse and difficult to form holes, and the defects of low efficiency, difficult deslagging and casing breakage caused by an air casing-following drilling process can be avoided while the simultaneous drilling function of the casing and the drill bit can be realized.

Description

Technical Field

[0001] The invention relates to a roller cone pipe-following drill bit, belonging to the technical field of pipe-following drilling. Background Art

[0002] As the drilling depth continues to increase, the underground conditions become more and more complicated, and the drilling technology is required to be gradually diversified to adapt to deep well construction. At present, domestic drilling technology mainly adopts mud circulation and air circulation. For conventional surface drilling construction, air-and-tube drilling technology is mostly used. At present, the air-and-tube drilling technology uses high-pressure air as the motive force. Through the impact of the down-the-hole hammer to break the formation, and then blow the cuttings out of the ground, the casing and the drill bit can be drilled at the same time, and the drilling can be done efficiently under stable formation conditions. However, since the air-and-tube drilling technology uses high-pressure air as the motive force, when constructing in special formations such as soil, silt, and pebbles that are extremely easy to collapse and difficult to form holes, air-and-tube drilling will be inefficient, difficult to discharge slag, and even the possibility of casing breakage caused by the collapse of the hole wall. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a roller cone follow-up drill bit that can realize the simultaneous drilling function of the casing and the drill bit while avoiding the defects of low efficiency, difficulty in slag removal and casing breakage caused by the air follow-up drilling process.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A roller drill bit comprises a rod body, the end of the rod body is connected to a roller drill bit, a plurality of straightening plates are circumferentially arranged on the side of the rod body away from the roller drill bit, a retaining ring is arranged on the outer side of the straightening plate, a plurality of pairs of limit locks are circumferentially arranged on the side of the rod body close to the roller drill bit, a limit pin is rotatably arranged on each pair of the limit locks, and a scraper plate is connected to the limit pin.

[0006] The outer diameter of the retaining ring is larger than the maximum inner diameter of the casing shoe step and smaller than the inner diameter of the casing; the diameter of the scraper plate is larger than the outer diameter of the casing when it is unfolded, and smaller than the minimum inner diameter of the casing shoe when it is retracted; the diameter of the roller drill bit is smaller than the minimum inner diameter of the casing shoe.

[0007] The diameter of the scraper plate when unfolded is the same as the diameter of the roller drill bit.

[0008] The limit lock is a cylindrical semi-open structure, and a limit lock hole and a limit lock limit are arranged on the limit lock. The limit pin passes through the limit lock holes of each pair of the limit locks, and the scraper plate contacts the limit lock when it is unfolded.

[0009] The rod body is connected to the roller drill bit via a threaded buckle.

[0010] A flat groove is planed and milled on the side surface of the end of the rod body away from the roller drill bit.

[0011] The end of the scraper plate is provided with alloy teeth.

[0012] The rod body and the centralizing plate are connected by welding.

[0013] The centralizing plate and the retaining ring are connected by welding.

[0014] The limiting pin and the scraper plate are connected by welding.

[0015] Beneficial effects of the invention: the invention provides a roller follow-up drill bit, the end of the rod body is connected to the roller drill bit, a plurality of straightening plates are circumferentially arranged on the side of the rod body, a retaining ring is arranged on the outer side of the straightening plate, a plurality of pairs of limit locks are circumferentially arranged on the rod body, a limit pin is rotatably arranged on each pair of limit locks, a scraper plate is connected to the limit pin, mud drilling is changed into the function of following the pipe drilling, the principle is the same as that of the air drilling tool, the casing and the casing shoe are welded, the drilling tool is inserted into the casing during use, and then the limit block is opened by forward rotation, and the casing shoe step is connected to the casing shoe. The follow-up drill bit is stuck. After drilling is completed, the follow-up drill bit is reversed and lifted out of the casing. This drill bit can meet the current follow-up drill bit construction in special strata such as soil, silt, and pebbles that are extremely easy to collapse and difficult to drill holes. Compared with traditional air follow-up drill bit construction, the roller follow-up drill bit can use mud drilling, and under soil, silt and other stratum conditions, it can solve the construction problems of low air follow-up drill bit efficiency, no slag discharge, and inability to use mud wall protection, greatly improving the construction success rate. At the same time, this process eliminates the use of air compressors and reduces construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a roller cone drill bit of the present invention;

[0017] Figure 2 It is a structural schematic diagram of the pipe drilling tool in the present invention;

[0018] Figure 3 It is a schematic diagram of the structure of the limit pin and the scraper plate in the present invention;

[0019] Figure 4 It is a schematic diagram of the structure of the limit lock in the present invention;

[0020] Figure 5 It is a schematic diagram of the structure of the roller drill bit in the present invention;

[0021] The markings in the figure are as follows: 1-rod body; 2-straightening plate; 3-blocking ring; 4-limiting pin; 5-scraper plate; 6-limiting lock; 7-roller drill bit; 11-flat groove; 501-alloy tooth; 601-limiting lock hole; 602-limiting lock limit. DETAILED DESCRIPTION

[0022] Example 1

[0023] like Figure 1 As shown, the present invention discloses a roller pipe drill bit, which mainly includes a pipe drill tool and a roller drill bit 7. The pipe drill tool includes a rod body 1, a straightening plate 2, a retaining ring 3, a limit pin 4, a scraper plate 5 and a limit lock 6. The end of the rod body 1 is connected to the roller drill bit 7, and a plurality of straightening plates 2 are arranged circumferentially on the side of the rod body 1 away from the roller drill bit 7, and the straightening plates 2 play a role in guiding and straightening the drilling tool. A retaining ring 3 is arranged on the outside of the straightening plate 2. The outer diameter of the retaining ring 3 can be stuck with the step of the pipe casing boot, and the casing and the pipe drill bit are drilled at the same time during drilling. A plurality of pairs of limit locks 6 are arranged circumferentially on the side of the rod body 1 close to the roller drill bit 7, and a limit pin 4 is rotatably arranged on each pair of limit locks 6, and a scraper plate 5 is connected to the limit pin 4. When the limit lock 6 is working, it can limit the scraper plate 5 to be fully opened when the drilling tool rotates forward and closed when it rotates reversely, so that the pipe drill bit can be completely lifted out of the casing.

[0024] The working principle of the present invention is as follows: when working, the follow-up drill bit is inserted into the casing with the casing boot welded thereon, and the roller drill bit 7 and the scraper plate 5 are completely leaked out until the retaining ring 3 clamps the casing boot, the drill tool is rotated forward, and the scraper plate 5 is limited by the limit lock 6 and can be fully opened, and drilling begins. The drilling causes the roller drill bit 7 and the scraper plate 5 to break the formation at the same time, and the hole diameter will be slightly larger than the outer diameter of the casing. The casing follows up in real time with the drill tool. When drilling to the bedrock, the drill tool is reversed, and the scraper plate 5 is retracted. The maximum diameter of the scraper plate 5 after retraction is smaller than the inner diameter of the casing boot, and the follow-up drill bit can be smoothly lifted out of the hole, while the casing remains in the hole, thereby realizing the use of mud follow-up drilling construction.

[0025] The present invention changes mud drilling into a function of pipe drilling, and the principle is the same as that of air drilling tools. Compared with traditional air pipe drilling construction, the roller pipe drill bit can use mud drilling, and under soil, silt and other formation conditions, it can solve the construction problems of low efficiency of air pipe drilling, no slag discharge, and inability to use mud wall protection, thereby greatly improving the construction success rate. At the same time, this process eliminates the use of air compressors and reduces construction costs.

[0026] Example 2

[0027] like Figure 1 As shown, the present invention discloses a roller cone drill bit, which mainly includes a roller cone drill tool and a roller cone drill bit 7. The roller cone drill tool includes a rod body 1, a straightening plate 2, a retaining ring 3, a limit pin 4, a scraper plate 5 and a limit lock 6. The end of the rod body 1 is connected to the roller cone drill bit 7. The structure of the roller cone drill bit 7 is as shown in FIG. Figure 5As shown, the diameter of the roller drill bit 7 is smaller than the minimum inner diameter of the casing shoe, ensuring that the roller drill bit 7 can freely penetrate and withdraw from the casing shoe. The rod body 1 is connected to the roller drill bit 7 by a threaded buckle. A flat groove 11 is milled on the side of the end of the rod body 1 away from the roller drill bit 7 to facilitate the disassembly of the drilling tool. Four groups of straightening plates 2 are arranged circumferentially on the side of the rod body 1 away from the roller drill bit 7. The straightening plates 2 play the role of guiding and straightening the drilling tool. The rod body 1 and the straightening plates 2 are connected by welding.

[0028] A retaining ring 3 is arranged on the outside of the straightening plate 2, and the straightening plate 2 and the retaining ring 3 are connected by welding. The outer diameter of the retaining ring 3 is larger than the maximum inner diameter of the casing shoe step and smaller than the inner diameter of the casing. The outer diameter of the retaining ring 3 can be stuck with the casing shoe step of the follower pipe to prevent the casing shoe from passing through the follower pipe drilling tool. During drilling, the casing and the follower pipe drill bit are drilled at the same time. Three pairs of limit locks 6 are circumferentially arranged on the side of the rod body 1 close to the roller drill bit 7. During operation, the limit locks can limit the scraper plate from being fully opened and closed. A limit pin 4 is rotatably arranged on each pair of limit locks 6, and a scraper plate 5 is connected to the limit pin 4. The limit pin 4 and the scraper plate 5 are connected by welding. As shown in FIG. Figure 2 and Figure 3 As shown, the scraper plate 5 is welded with alloy teeth 501 at the end, which will cut the uncut part of the roller drill bit 7 during drilling, thereby ensuring that the borehole diameter is larger than the casing diameter and that the casing is followed in real time without formation resistance. When the limit lock 6 is working, it can limit the scraper plate 5 to be fully opened when the drilling tool rotates forward and closed when it rotates reversely, so that the follow-up drill bit can be completely pulled out of the casing.

[0029] like Figure 4 As shown, the limit lock 6 is a cylindrical semi-open structure, and the limit lock 6 is provided with a limit lock hole 601 and a limit lock limit 602. The limit pin 4 passes through the limit lock hole 601 of each pair of limit locks 6. When the drilling tool rotates forward, the scraper plate is unfolded by the friction of the formation. When the scraper plate 5 is unfolded, it contacts the limit lock limit 602. The scraper plate 5 can be unfolded to the maximum diameter and is limited by the limit lock limit 602. When the scraper plate 5 is unfolded, the diameter is larger than the outer diameter of the casing. When the drilling tool is reversed, the scraper plate is retracted by the friction of the formation. When retracted, the diameter is smaller than the minimum inner diameter of the casing shoe to ensure that it can pass through the casing shoe. When the scraper plate 5 is unfolded, the diameter is the same as the diameter of the roller drill bit 7.

[0030] During construction, the present invention inserts the follow-up drill bit into the casing with the casing boot welded thereon, and allows the drill bit and the scraper plate to completely leak out until the retaining ring clamps the casing boot. The drill tool is rotated forward, and the scraper plate is limited by the limit lock and can be fully opened to start drilling. The drilling causes the roller drill bit and the scraper to break the stratum at the same time, and the hole diameter will be larger than the outer diameter of the casing. The casing can follow up with the drill tool in real time. When the target depth is reached, the drill tool is reversed, and the scraper plate is retracted. The maximum diameter of the retracted scraper plate is smaller than the inner diameter of the casing boot. The follow-up drill bit can be smoothly lifted out of the hole, and the casing remains in the hole, thereby realizing the use of mud follow-up drilling construction.

[0031] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A roller cone drill bit, characterized by: The invention comprises a rod body (1), an end of the rod body (1) is connected to a roller drill bit (7), a plurality of straightening plates (2) are circumferentially arranged on the side of the rod body (1) away from the roller drill bit (7), a retaining ring (3) is arranged on the outside of the straightening plate (2), and a plurality of pairs of limit locks (6) are circumferentially arranged on the side of the rod body (1) close to the roller drill bit (7), a limit pin (4) is rotatably arranged on each pair of the limit locks (6), and a scraper plate (5) is connected to the limit pin (4).

2. The roller cone drill bit according to claim 1, characterized in that: The outer diameter of the retaining ring (3) is larger than the maximum inner diameter of the casing shoe step and smaller than the inner diameter of the casing; the diameter of the scraper plate (5) is larger than the outer diameter of the casing when it is expanded, and smaller than the minimum inner diameter of the casing shoe when it is retracted; the diameter of the roller drill bit (7) is smaller than the minimum inner diameter of the casing shoe.

3. The roller cone pipe drill bit according to claim 2, characterized in that: The diameter of the scraper plate (5) when unfolded is the same as the diameter of the roller drill bit (7).

4. The roller cone drill bit according to claim 1, characterized in that: The limit lock (6) is a cylindrical semi-open structure, and a limit lock hole (601) and a limit lock limit (602) are provided on the limit lock (6). The limit pin (4) passes through the limit lock hole (601) of each pair of the limit locks (6), and the scraper plate (5) contacts the limit lock limit (602) when it is unfolded.

5. The roller cone pipe drill bit according to claim 1, characterized in that: The rod body (1) and the roller drill bit (7) are connected via a threaded buckle.

6. The roller cone pipe drill bit according to claim 1, characterized in that: A flat groove (11) is milled on the side surface of the end of the rod body (1) away from the roller drill bit (7).

7. The roller cone drill bit according to claim 1, characterized in that: The end of the scraper plate (5) is provided with alloy teeth (501).

8. The roller cone pipe drill bit according to claim 1, characterized in that: The rod body (1) and the centralizing plate (2) are connected by welding.

9. The roller cone pipe drill bit according to claim 1, characterized in that: The centralizing plate (2) and the retaining ring (3) are connected by welding.

10. The roller cone pipe drill bit according to claim 1, characterized in that: The limiting pin (4) and the scraper plate (5) are connected by welding.

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