A drill bit for preventing drilling

Abstract

The present invention discloses an anti-drilling bit, comprising an upper body, a lower body, a cone and teeth, wherein: the lower body is suspended and connected below the upper body, and a rotation limit fit is formed between the upper body and the lower body; the cone is a cone structure, and the cone forms a rotation fit with the lower body along its central axis; a roller assembly is suspended on the cone waist cone section, and the roller assembly forms an axial sliding and circumferential rolling fit along the cone central axis. The present invention limits the depth of the teeth entering the rock when the drilling pressure is too large and the drill torque is too large, reduces the rotation resistance and torque of the cone drill bit, avoids drilling and loosening, protects the drill teeth, reduces the destructive force on the drill bit and the drill string, and can change the torque controller to limit the torque borne by the drill bit to a certain range.

Description

Technical Field

[0001] The invention relates to an anti-drilling tool in the field of oil drilling tools, in particular to an anti-drilling drill bit. Background Art

[0002] Conventional roller bits use teeth to impact and press into the rock and slide and shear to break the rock when the drill bit rotates under a certain drilling pressure. When the drilling pressure increases, the rolling resistance of the roller increases, the teeth are pressed too deep into the rock, and the sliding shear rock breaking resistance increases. When the drilling pressure is too high, the rolling resistance of the roller increases sharply, the roller bit is stuck, and the torque continues to increase. When the torque reaches the critical point of rock breaking, the roller torque is released instantly, and the drill bit speed increases. At this time, the teeth are easily damaged, the drill bit speed instantly exceeds the drill string speed, and the joint in the middle of the drill string is easy to loosen, which has a great destructive force on both the drill bit and the drill string. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a drill bit that prevents drilling from being stuck, so as to limit the depth of the teeth penetrating into the rock when the drilling pressure is too large and the torque of the drill bit is too large, reduce the rotational resistance of the roller drill bit, reduce the torque applied to the drill bit, avoid drilling stuck by the roller drill bit, protect the drill bit teeth, avoid loosening of the drill string joint, reduce the destructive force on the drill bit and the drill string, and can change the torque controller to limit the torque applied to the drill bit to a certain range.

[0004] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0005] A drill bit for preventing drilling from being stuck comprises an upper body 1, a lower body 6, a cone 13 and teeth distributed on the upper body 1, the lower body 6 and the cone 13, wherein: the lower body 6 is suspended and connected below the upper body 1, and a rotational limit fit is formed between the upper body 1 and the lower body 6; the cone 13 is a cone structure, and the cone 13 forms a rotational fit with the lower body 6 along its central axis; a roller assembly is suspended in the waist cone section of the cone 13, and the roller assembly forms an axial sliding and circumferential rolling fit along the central axis of the cone 13.

[0006] The above scheme further comprises:

[0007] The lower part of the upper body 1 is connected to the lower body 6 through a suspension device 12, and the torque controller 4 is used to perform rotational limit matching at the mating part of the upper body 1 and the lower body 6. An annular boss extends from the lower surface of the upper body 1, and teeth are provided on the annular boss to form an upper gear 3; a groove inclined inward and downward is provided in the lower body 6, and a square sleeve 8 with an outer circle and an inner square is provided in the groove in the lower body 6; a top hole 9 is provided in the gear 13, and the groove in the lower body 6 keeps the same axis as the top hole 9 in the gear 13; the square sleeve 8 goes deep into the top hole 9 in the gear 13, and an outer square sleeve 10 is installed in the square sleeve 8, and the square sleeve 10 and the square sleeve 8 constitute a spiral transmission pair for axial sliding and circumferential limited rotation; The sleeve 10 is axially provided with a threaded hole, in which a bolt 7 is installed, and the top of the bolt is fixedly connected to a lower gear 5 that meshes with the upper gear 3; a driving arm 15 is suspended at the bottom of the square sleeve 10, and the square sleeve 10 and the driving arm 15 form a rotational fit, and the square sleeve 10 and the bolt 7 are axially rotationally matched and drive the driving arm 15 to reciprocate along the center axis of the cone; a bottom hole 11 is opened on the waist cone surface of the cone 13, the driving arm 15 is installed in the cone 13, and the roller 17 is connected to the outer periphery of the driving arm 15 through a thrust bearing 16; when the driving arm 15 and the roller 17 move axially along the bolt 7 to the top dead center, the roller 17 retracts into the outer surface of the cone 13; the aforementioned driving arm 15, thrust bearing 16 and roller 17 constitute a roller assembly.

[0008] The above scheme also includes:

[0009] The driving arm 15 is a multi-fork arm structure, and a plurality of bottom holes 11 are opened on the surface of the gear wheel corresponding to the number of fork arms. The outer periphery of each fork arm is connected to the roller 17 through a thrust bearing 16.

[0010] The driving arm 15 is a cross-shaped four-fork arm structure; the number of the gears 13 is 3; and each gear 13 is equipped with a roller assembly.

[0011] The torque controller 4 includes an upper boss 18 and a lower boss 20 respectively fixed on the upper body 1 and the lower body 6 , and an elastic deformation device 19 is installed between the upper boss 18 and the lower boss 20 .

[0012] The deformation device 19 is a spring.

[0013] The torque controllers 4 are arranged in plurality along the circumference of the drill cross section.

[0014] The suspension device 12 comprises a suspension bearing 2 .

[0015] A centralizer 14 is installed between the square sleeve 10 and the inner wall of the top hole 9.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) when the drilling pressure is too high, the roller protrudes from the surface of the cone as the drill bit torque increases, limiting the depth of the teeth digging into the rock and preventing the cone drill bit from being stuck; (2) when the drill bit torque is too high, the protruding roller can rotate on its own, reducing the rotational resistance of the cone drill bit and the torque applied to the drill bit; (3) by changing the torque controller, the torque applied to the drill bit is limited to a certain range; (4) the drill bit teeth are protected, the drill string joint is prevented from being loosened, and the destructive force on the drill bit and the drill string is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the anti-drilling bit of the present invention.

[0018] Figure 2 It is a cross-sectional view of the anti-drilling drill bit of the present invention in one working posture.

[0019] Figure 3 It is a cross-sectional view of the anti-drilling-blocking drill bit of the present invention in another working posture.

[0020] Figure 4 for Figure 2 Section view along section AA.

[0021] Figure 5 for Figure 2 Cross-sectional view along section BB.

[0022] Figure 6 for Figure 2 Cross-sectional view along section CC.

[0023] Markings in the figure: 1. upper body, 2. suspension bearing, 3. upper gear, 4. torque controller, 5. lower gear, 6. lower body, 7. bolt, 8. square sleeve, 9. top hole, 10. square sleeve, 11. bottom hole, 12. suspension device, 13. gear, 14. stabilizer, 15. driving arm, 16. thrust bearing, 17. roller, 18. upper boss, 19. deformation device (spring), 20. lower boss. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0025] See attached Figure 1 The present invention discloses a drill bit for preventing drilling from being stuck, which is a roller cone drill bit, comprising a body, a water hole, a roller cone, and teeth (cutting teeth) distributed on the body and the roller cone.

[0026] Reference Figure 2 , 34, the main body is divided into an upper body 1 and a lower body 6 from top to bottom, and the lower body 6 is connected to the upper body 1 through a suspension device 12; the suspension device 12 limits the lower body 6 to only perform rotational movement relative to the upper body 1 through a suspension bearing 2. The relative rotation of the upper body 1 and the lower body 6 is controlled by a torque controller 4, and the torque controller 4 includes an upper boss 18 and a lower boss 20 respectively fixed on the upper body 1 and the lower body 6, and an elastic deformation device 19 is installed between the upper boss 18 and the lower boss 20. The deformation device 19 is deformed according to the torque between the upper boss 18 and the lower boss 20, so that the distance between the upper boss 18 and the lower boss 20 changes.

[0027] In this embodiment, the suspension device 12 is an overlapped fit of inner and outer convex edges; the deformation device 19 is a spring; and a plurality of torque controllers 4 can be arranged along the circumference of the drill cross section to adjust the proportional relationship between torque and deformation.

[0028] Reference Figure 5 and 6 , the cone 13 is suspended on the lower body 6 at a certain inclination (the suspension method is similar to that of the upper body 1 and the lower body 6), a top hole 9 is provided in the cone 13, and a square sleeve 8 with an outer circle and an inner square is provided in the lower body 6, and the square sleeve 8 goes deep into the top hole 9. The square sleeve 8 is equipped with an outer square sleeve 10, and the square sleeve 10 and the square sleeve 8 form a square sleeve that can slide relative to each other and limit rotation. A straightener 14 is installed between the square sleeve 10 and the inner wall of the top hole 9. A threaded hole is opened above the square sleeve 10, and a bolt 7 is installed in the threaded hole. The top of the bolt 7 is fixedly connected to the lower gear 5. An annular boss extends from the lower surface of the upper body 1 to form an upper gear 3. The upper gear 3 and the lower gear 5 mesh with each other to form a gear transmission, which converts the rotation of the upper body 1 relative to the lower body 6 into the rotation of the bolt 7, and the rotation of the bolt 7 causes the square sleeve 10 to slide relative to the square sleeve 8.

[0029] A driving arm 15 is suspended at the bottom of the square sleeve 10. The square sleeve 10 and the driving arm 15 form a rotational fit, and the square sleeve 10 can drive the driving arm 15 to reciprocate along the center line of the gear. The driving arm 15 is a multi-fork arm structure, and the end of each fork arm is connected to the roller 17 through a thrust bearing 16. A bottom hole 11 is provided on the central surface of the gear 13 (also called a waist cone), and the driving arm 15 is installed in the gear 13 and the end of each fork arm extends out from the bottom hole 11. The roller 17 is annularly mounted on the driving arm 15 in the middle of the gear 13. The driving arm 15 cannot rotate relative to the gear 13, but the roller 17 can rotate relative to the gear 13. When the driving arm 15 drives the roller 17 to move along the axis of rotation of the gear 13, the roller 17 can extend or retract into the surface of the gear 13 (refer to Figure 2 and 3 ).

[0030] The relative rotation amount or relative rotation angle of the upper body 1 and the lower body 6 is controlled by the torque controller 4. When the torque on the roller bit is too large, the deformation device 19 in the torque controller 4 is compressed and deformed, and the upper body 1 and the lower body 6 rotate relative to each other by a certain angle. Since the upper gear 3 and the lower gear 5 are meshed with each other, the rotation of the bolt 7 causes the square sleeve 10 to drive the driving arm 15 to slide along the axis of the roller 13, and the roller 17 extends out of the surface of the roller 13. As the roller 17 extends out of the surface of the roller 13, a part of the drilling pressure is loaded on the roller 17. Since the depth of the teeth entering the rock is limited and the self-rotation resistance of the roller 17 is very small, the rotation resistance of the roller bit is reduced, and the torque on the drill bit is reduced. In contrast to the above process, the deformation of the deformation device 19 of the upper boss 18 and the lower boss 20 begins to recover, the relative rotation angle of the upper body 1 and the lower body 6 is reduced, and the bolt 7 drives the driving arm 15 to slide in the opposite direction along the axis of the roller 13 through the square sleeve 10, the part extending out of the surface of the roller 13 is reduced, and the teeth enter the rock more.

[0031] In this way, even if the drilling pressure is too high, the depth of the teeth entering the rock can be controlled, reducing the rotational resistance and torque of the roller drill bit, avoiding the roller drill bit from being stuck, protecting the drill bit teeth, avoiding the loosening of the drill string joints, and reducing the destructive force on both the drill bit and the drill string.

[0032] Multiple torque controllers 4 can be set, and the torque borne by the drill bit can be maintained at a relatively constant level by adjusting the number and elastic modulus of the deformation devices 19, that is, adjusting the torque controller can limit the torque borne by the drill bit to a certain range; the number of gears 13 can be 1 or more; the driving arm 15 is a multi-fork arm structure, and the end of each fork arm is connected to the roller 17 through a thrust bearing 16, and the surface of the gear wheel is also provided with multiple bottom holes 11 corresponding to the number of forks; multiple rollers 17 can be connected in series on each gear 13.

[0033] In this embodiment, four torque controllers 4 are evenly arranged, and the deformation device 19 is a spring or a disc spring. There are three gears 13, and the multi-fork arm structure of the driving arm 15 is a cross-shaped four-fork arm structure. Four bottom holes 11 are correspondingly opened on the surface of the gear, and each gear 13 is equipped with a roller 17.

Claims

1. An anti-drilling drill bit, comprising an upper body, a lower body, a cone, and teeth distributed on the upper body, the lower body, and the cone, characterized in that: The lower body is suspended and connected to the lower part of the upper body, and a rotation limit fit is formed between the upper body and the lower body; the cone is a cone structure, and the cone forms a rotation fit with the lower body along its central axis; a roller assembly is suspended at the cone waist cone section, and the roller assembly forms an axial sliding fit along the central axis of the cone; the lower part of the upper body is connected to the lower body through a suspension device, and a rotation limit fit is performed at the mating part of the upper body and the lower body through a torque controller, and an annular boss extends from the lower surface of the upper body, and teeth are provided on the annular boss to form an upper gear; a groove inclined inwardly and downwardly is provided in the lower body, and a square sleeve with an outer circle and an inner square is provided in the groove provided in the lower body; a top hole is provided in the cone, and the groove provided in the lower body keeps the same axis as the top hole provided in the cone; the square sleeve goes down into the top hole provided in the cone, and the square sleeve is equipped with an outer square A square sleeve, the square sleeve and the square sleeve form a spiral transmission pair with axial sliding and circumferential limited rotation; a threaded hole is axially arranged on the square sleeve, a bolt is installed in the threaded hole, and a lower gear meshing with the upper gear is fixedly connected to the top of the bolt; a driving arm is suspended at the bottom of the square sleeve, the square sleeve and the driving arm form a rotational fit, and the square sleeve and the bolt are axially rotated and drive the driving arm to reciprocate along the center axis of the cone; a bottom hole is opened on the cone waist cone surface, the driving arm is installed in the cone, and the roller is connected to the outer periphery of the driving arm through a thrust bearing; when the driving arm and the roller move axially along the bolt to the upper dead point, the roller retracts into the outer surface of the cone; the aforementioned driving arm, thrust bearing and roller form a roller assembly; the suspension device includes a suspension bearing; a centralizer is installed between the square sleeve and the inner wall of the top hole.

2. The anti-drilling drill bit according to claim 1, characterized in that: The driving arm is a multi-fork arm structure, and a plurality of bottom holes are opened on the surface of the gear wheel corresponding to the number of fork arms, and the outer periphery of each fork arm is connected to the roller through a thrust bearing.

3. The anti-drilling drill bit according to claim 2, characterized in that: The driving arm is a cross-shaped four-fork arm structure; the number of the gears is 3; and each gear is equipped with a roller assembly.

4. The anti-drilling drill bit according to claim 1, characterized in that: The torque controller comprises an upper boss and a lower boss respectively fixed on the upper body and the lower body, and an elastic deformation device is arranged between the upper boss and the lower boss.

5. The anti-drilling drill bit according to claim 4, characterized in that: The deformation device is a spring.

6. The anti-drilling drill bit according to claim 5, characterized in that: The torque controllers are arranged in plurality along the circumference of the drill bit cross section.

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