A PDC drill bit

Abstract

This invention belongs to the field of drilling equipment technology and discloses a PDC drill bit, including a body and multiple cutter wings. The body has flow holes for drilling fluid. Multiple cutter wings are spaced apart circumferentially on the body, and the cutter wings can slide relative to the body along its axial direction. The drilling fluid can drive the cutter wings to extend along the axial direction of the body. By enabling the cutter wings to move relative to the body along its axial direction, and by allowing the drilling fluid to drive the cutter wings to extend along the axial direction of the body, during drilling operations, the PDC drill bit drills into the formation under the drive of the drill pipe's drilling pressure. When the formation resistance experienced by the cutter wings is less than the driving force of the drilling fluid driving the cutter wings to extend, the cutter wings extend under the drive of the drilling fluid; when the formation resistance experienced by the cutter wings is greater than the driving force of the drilling fluid driving the cutter wings to extend, the cutter wings retract under the action of the formation. This allows each cutter wing of the PDC drill bit to automatically extend or retract according to its respective formation resistance, thereby effectively penetrating the formation.

Description

Technical Field

[0001] This invention relates to the field of drilling equipment technology, and more particularly to a PDC drill bit. Background Technology

[0002] Currently, the blades and body of PDC drill bits are mostly integrally formed, and the relative positions of the blades and body are fixed. In actual drilling production, there is often well deviation, and the formation also has a certain dip angle. Moreover, the formations often have soft and hard interlayers with many layers. The fixed relative positions of the blades and body will cause the blades on the drill bit to not enter the formation at the same time. When the formation changes in hardness, the drill bit is prone to sticking and slipping, which will prevent the drill bit from effectively penetrating the formation.

[0003] Therefore, there is an urgent need for a PDC drill bit to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a PDC drill bit in conditions such as highly deviated directional wells, steeply dipped formations, and interbedded soft and hard layers, in which each blade can automatically extend or retract according to the formation resistance it encounters, thus avoiding stick-slip phenomenon in the PDC drill bit and enabling it to effectively penetrate the formation.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A PDC drill bit, comprising:

[0007] The main body has flow holes for the flow of drilling fluid;

[0008] Multiple blades are circumferentially spaced on the body, the blades are slidable relative to the body along the axial direction of the body, and the drilling fluid can drive the blades to extend along the axial direction of the body.

[0009] Preferably, the body is provided with a first limiting groove extending along the axial direction of the blade, the first limiting groove is provided in a one-to-one correspondence with the blade, the blade is slidably disposed in the first limiting groove, and the two sides of the blade are in contact with the two side walls of the first limiting groove.

[0010] Preferably, the blade is provided with a second limiting groove extending along the axial direction of the body, and the body is provided with a first limiting protrusion that cooperates with the second limiting groove. The first limiting protrusion extends into the second limiting groove. When the blade extends along the axial direction of the body, the first limiting protrusion can abut against the lower groove wall of the second limiting groove. When the blade retracts along the axial direction of the body, the first limiting protrusion can abut against the upper groove wall of the second limiting groove.

[0011] Preferably, the PDC drill bit further includes a limiting sleeve fitted on the body, and the top of the cutter wing is provided with a third limiting groove extending along the axial direction of the body. The limiting sleeve extends into the third limiting groove to fasten the cutter wing to the outer side wall of the body.

[0012] Preferably, a fourth limiting groove is provided on the inner side wall of the third limiting groove near the main body, and a second limiting protrusion is provided on the limiting sleeve to cooperate with the fourth limiting groove. The second limiting protrusion extends into the third limiting groove, and the two sides of the second limiting protrusion are in contact with the two side walls of the fourth limiting groove.

[0013] Preferably, the PDC drill bit further includes a piston, and the top of the cutter blade is provided with a receiving groove extending along the axial direction of the body. The piston is slidably disposed in the receiving groove. An adjustment cavity is provided between the piston and the bottom of the receiving groove. The adjustment cavity communicates with the flow hole. The drilling fluid can drive the piston to extend out of the receiving groove along the axial direction of the body to abut against the body.

[0014] Preferably, the piston comprises:

[0015] The sliding part is sealed to the wall of the receiving groove;

[0016] A support portion is disposed at one end of the sliding portion near the bottom of the receiving groove. The support portion extends into the adjustment cavity, and the cross-sectional dimension of the support portion is smaller than the cross-sectional dimension of the receiving groove.

[0017] Preferably, the side of the blade near the flow hole is fitted with the outer wall of the body. The body is provided with a first connecting hole, which connects the flow hole and the outer side of the body. The blade is provided with a second connecting hole, which connects the adjustment cavity and the side of the blade near the connecting hole. The first connecting hole and the second connecting hole are connected and correspond one-to-one.

[0018] Preferably, the body includes:

[0019] End cap;

[0020] The mounting part is fixedly connected to the bottom end of the end cap, and the blade is slidably disposed on the mounting part. The sliding part can extend out of the receiving groove and abut against the bottom end of the end cap.

[0021] Preferably, PDC plates are provided on both sides of the blade wing.

[0022] The beneficial effects of this invention are:

[0023] The PDC drill bit provided by this invention allows the cutter wings to move relative to the main body along its axial direction, and the drilling fluid can drive the cutter wings to extend along the main body's axial direction. During drilling operations, the PDC drill bit drills into the formation under the drive of the drill pipe's drilling pressure. When the formation resistance experienced by the cutter wings is less than the driving force of the drilling fluid driving the cutter wings to extend, the cutter wings extend under the drive of the drilling fluid; when the formation resistance experienced by the cutter wings is greater than the driving force of the drilling fluid driving the cutter wings to extend, the cutter wings retract under the action of the formation. This allows the PDC drill bit to automatically extend or retract according to the formation resistance it experiences in conditions such as highly deviated directional wells, steeply dipped formations, and interlayers of soft and hard materials, preventing stick-slip phenomena and thus enabling effective formation penetration. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the PDC drill bit provided in an embodiment of the present invention;

[0025] Figure 2 This is an exploded view of the PDC drill bit provided in an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the mounting portion of the PDC drill bit provided in an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the cutter blade of the PDC drill bit provided in an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the limiting sleeve of the PDC drill bit provided in an embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the piston structure of the PDC drill bit provided in an embodiment of the present invention.

[0030] In the picture:

[0031] 1. Body; 11. Flow hole; 12. First limiting groove; 13. First limiting protrusion; 14. First connecting hole; 15. End cap; 16. Mounting part;

[0032] 2. Blade wing; 21. Second limiting groove; 22. Third limiting groove; 23. Fourth limiting groove; 24. Receiving groove; 25. Second connecting hole; 26. PDC piece;

[0033] 3. Limiting sleeve; 31. Second limiting protrusion;

[0034] 4. Piston; 41. Sliding part; 42. Support part. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0036] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0039] like Figure 1 and Figure 2 As shown, this embodiment provides a PDC drill bit, including a body 1 and multiple blades 2. The body 1 is provided with a flow hole 11 for drilling fluid to flow through. The multiple blades 2 are arranged circumferentially on the body 1, and the blades 2 can slide relative to the body 1 along the axial direction of the body 1. The drilling fluid can drive the blades 2 to extend along the axial direction of the body 1.

[0040] The PDC drill bit provided in this embodiment allows the blades 2 to move relative to the body 1 along its axial direction, and the drilling fluid can drive the blades 2 to extend along the body 1's axial direction. During drilling operations, the PDC drill bit drills into the formation under the drive of the drill pipe's drilling pressure. When the formation resistance experienced by the blades 2 is less than the driving force of the drilling fluid driving the blades 2 to extend, the blades 2 extend under the drive of the drilling fluid; when the formation resistance experienced by the blades 2 is greater than the driving force of the drilling fluid driving the blades 2 to extend, the blades 2 retract under the action of the formation. This allows the PDC drill bit to automatically extend or retract according to the formation resistance it experiences in conditions such as highly deviated directional wells, steeply dipped formations, and interlayers of soft and hard phases, preventing the PDC drill bit from sticking and slipping, thus enabling it to effectively penetrate the formation.

[0041] Specifically, such as Figure 2 As shown, in this embodiment, the body 1 includes an end cap 15 and a mounting portion 16. The top of the end cap 15 is provided with an external thread. When using the PDC drill bit, the PDC drill bit needs to be installed on the drill pipe. The external thread on the top of the end cap 15 facilitates the installation of the PDC drill bit. The mounting portion 16 is fixedly connected to the bottom end of the end cap 15, and the cutter blade 2 is slidably mounted on the mounting portion 16. The bottom end of the mounting portion 16 is provided with a nozzle hole, and a flow hole 11 communicates with the nozzle hole, allowing drilling fluid to be ejected through the nozzle hole.

[0042] Optionally, such as Figure 1-3 As shown, the main body 1 is provided with a first limiting groove 12 extending along the axial direction of the blade wing 2. The first limiting groove 12 is provided one-to-one with the blade wing 2, and the blade wing 2 is slidably disposed in the first limiting groove 12. The two sides of the blade wing 2 are in contact with the two side walls of the first limiting groove 12. By providing the first limiting groove 12, the blade wing 2 can rotate with the main body 1. Specifically, in this embodiment, the first limiting groove 12 is provided on the mounting part 16.

[0043] like Figure 1 As shown, PDC plates 26 are provided on both sides of the blade 2. The specific arrangement of the PDC plates is a conventional technology in this field and will not be described in detail here.

[0044] Optionally, such as Figure 3 and Figure 4As shown, the blade wing 2 is provided with a second limiting groove 21 extending along the axial direction of the body 1, and the body 1 is provided with a first limiting protrusion 13 that cooperates with the second limiting groove 21. The first limiting protrusion 13 extends into the second limiting groove 21. When the blade wing 2 extends along the axial direction of the body 1, the first limiting protrusion 13 can abut against the lower groove wall of the second limiting groove 21. When the blade wing 2 retracts along the axial direction of the body 1, the first limiting protrusion 13 can abut against the upper groove wall of the second limiting groove 21. By providing a second limiting groove 21 on the blade wing 2 and a first limiting protrusion 13 on the body 1, the blade wing 2 is limited along the axial direction of the body 1. That is, the extreme position when the blade wing 2 extends is when the upper groove wall of the second limiting groove 21 abuts against the first limiting protrusion 13, and the extreme position when the blade wing 2 retracts is when the lower groove wall of the second limiting groove 21 abuts against the first limiting protrusion 13. Specifically, in this embodiment, the first limiting protrusion 13 is provided on the mounting portion 16. Preferably, when the blade 2 is retracted to its limit position, the upper end surface of the blade 2 abuts against the bottom surface of the mounting portion 16.

[0045] Optionally, such as Figure 4 and Figure 5 As shown, the top of the cutter wing 2 is provided with a third limiting groove 22 extending along the axial direction of the body 1. The PDC drill bit also includes a limiting sleeve 3 sleeved on the body 1. The limiting sleeve 3 extends into the third limiting groove 22 to fasten the cutter wing 2 to the outer side wall of the body 1. By providing the limiting sleeve 3, the cutter wing 2 is prevented from separating from the body 1 radially.

[0046] Furthermore, such as Figure 4 and Figure 5 As shown, a fourth limiting groove 23 is provided on the inner wall of the third limiting groove 22 near the main body 1. A second limiting protrusion 31 is provided on the limiting sleeve 3 to cooperate with the fourth limiting groove 23. The second limiting protrusion 31 extends into the third limiting groove 22, and the two sides of the second limiting protrusion 31 are in contact with the two side walls of the fourth limiting groove 23, thereby preventing relative rotation between the limiting sleeve 3 and the main body 1. Specifically, in this embodiment, an external thread is provided on the outer surface of the limiting sleeve 3, and it is screwed and fixed to the end cap 15 by the external thread.

[0047] Optionally, such as Figure 2 and Figure 4As shown, the top of the cutter wing 2 is provided with a receiving groove 24 extending axially along the body 1. The PDC drill bit also includes a piston 4 slidably disposed within the receiving groove 24. An adjustment cavity is provided between the piston 4 and the bottom of the receiving groove 24, and the adjustment cavity communicates with the flow hole 11. Drilling fluid can drive the piston 4 to extend out of the receiving groove 24 axially along the body 1 to abut against the body 1. During drilling operations, the receiving cavity is filled with drilling fluid, and the top of the piston 4 abuts against the body 1. When the formation below the blade 2 is relatively soft, and the formation resistance experienced by the blade 2 is less than the driving force of the drilling fluid that causes the blade 2 to extend, the drilling fluid entering the regulating chamber through the flow hole 11 drives the piston 4 to extend from the receiving groove 24. Since the top of the piston 4 abuts against the body 1, the blade 2 extends under the action of the reaction force. When the formation below the blade 2 is relatively hard, and the formation resistance experienced by the blade 2 is greater than the driving force of the drilling fluid that causes the blade 2 to extend, the blade 2 retracts under the action of the formation resistance as the PDC drill bit moves downward under the drive of the drill pipe drilling pressure.

[0048] Optionally, such as Figure 2 and Figure 6 As shown, the piston 4 includes a sliding part 41 and a supporting part 42. The sliding part 41 is sealed to the wall of the receiving groove 24. Specifically, a sealing ring is fitted on the sliding part 41 to achieve a seal between the sliding part 41 and the wall of the receiving groove 24. The supporting part 42 is located at one end of the sliding part 41 near the bottom of the receiving groove 24. The supporting part 42 extends into the adjustment cavity, and its cross-sectional dimension is smaller than that of the receiving groove 24. By providing the supporting part 42 at the bottom of the sliding part 41, the bottom of the sliding part 41 is prevented from contacting the bottom of the receiving groove 24, ensuring that the adjustment cavity always exists. Specifically, in this embodiment, the piston 4 is a cylindrical two-stage piston, with the sliding part 41 and the supporting part 42 being the first stage of the two-stage piston.

[0049] Optionally, such as Figure 2-4 As shown, the side of the blade wing 2 near the flow hole 11 is fitted against the outer wall of the body 1. The body 1 is provided with a first connecting hole 14, which connects the flow hole 11 to the outer side of the body 1. The blade wing 2 is provided with a second connecting hole 25, which connects the adjustment cavity to the side of the blade wing 2 near the connecting hole. The first connecting hole 14 and the second connecting hole 25 are connected and correspond one-to-one. The second connecting hole 25 extends along the axial direction of the body 1, so that the first connecting hole 14 and the second connecting hole 25 remain connected during the extension and retraction of the blade wing 2.

[0050] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A PDC drill bit, characterized in that, include: The body (1) is provided with a flow hole (11) for the flow of drilling fluid. Multiple blades (2) are arranged circumferentially on the body (1), the blades (2) are slidable relative to the body (1) along the axial direction of the body (1), and the drilling fluid can drive the blades (2) to extend along the axial direction of the body (1). The piston (4) has a receiving groove (24) extending along the axial direction of the body (1) at the top of the blade (2). The piston (4) is slidably disposed in the receiving groove (24). An adjustment cavity is provided between the piston (4) and the bottom of the receiving groove (24). The adjustment cavity is connected to the flow hole (11). The drilling fluid can drive the piston (4) to extend out of the receiving groove (24) along the axial direction of the body (1) to abut against the body (1). The blade (2) is provided with a second limiting groove (21) extending along the axial direction of the body (1). The body (1) is provided with a first limiting protrusion (13) that cooperates with the second limiting groove (21). The first limiting protrusion (13) extends into the second limiting groove (21). When the blade (2) extends along the axial direction of the body (1), the first limiting protrusion (13) can abut against the lower groove wall of the second limiting groove (21). When the blade (2) retracts along the axial direction of the body (1), the first limiting protrusion (13) can abut against the upper groove wall of the second limiting groove (21).

2. The PDC drill bit according to claim 1, characterized in that, The main body (1) is provided with a first limiting groove (12) extending along the axial direction of the blade (2). The first limiting groove (12) is provided in a one-to-one correspondence with the blade (2). The blade (2) is slidably disposed in the first limiting groove (12). The two sides of the blade (2) are in contact with the two side walls of the first limiting groove (12).

3. The PDC drill bit according to claim 1, characterized in that, It also includes a limiting sleeve (3) fitted on the body (1), and the top of the blade (2) is provided with a third limiting groove (22) extending along the axial direction of the body (1). The limiting sleeve (3) extends into the third limiting groove (22) to fasten the blade (2) to the outer wall of the body (1).

4. The PDC drill bit according to claim 3, characterized in that, The third limiting groove (22) is provided with a fourth limiting groove (23) on the inner side wall near the body (1). The limiting sleeve (3) is provided with a second limiting protrusion (31) that cooperates with the fourth limiting groove (23). The second limiting protrusion (31) extends into the third limiting groove (22), and the two sides of the second limiting protrusion (31) are in contact with the two side walls of the fourth limiting groove (23).

5. The PDC drill bit according to claim 1, characterized in that, The blade (2) is attached to the outer wall of the body (1) on the side near the flow hole (11). The body (1) is provided with a first connecting hole (14), which connects the flow hole (11) and the outer side of the body (1). The blade (2) is provided with a second connecting hole (25), which connects the adjustment cavity and the side of the blade (2) near the first connecting hole (14). The first connecting hole (14) and the second connecting hole (25) are connected and correspond to each other.

6. The PDC drill bit according to claim 5, characterized in that, The piston (4) includes: The sliding part (41) is sealed to the wall of the receiving groove (24); A support part (42) is provided at one end of the sliding part (41) near the bottom of the receiving groove (24). The support part (42) extends into the adjustment cavity. The cross-sectional dimension of the support part (42) is smaller than the cross-sectional dimension of the receiving groove (24).

7. The PDC drill bit according to claim 6, characterized in that, The body (1) includes: End cap (15); The mounting part (16) is fixedly connected to the bottom end of the end cap (15). The blade (2) is slidably disposed on the mounting part (16). The sliding part (41) can extend out of the receiving groove (24) and abut against the bottom end of the end cap (15).

8. The PDC drill bit according to claim 1, characterized in that, PDC plates (26) are provided on both sides of the blade (2).

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