PDC (Polycrystalline Diamond Compact) drill bit with impact function

Abstract

The invention belongs to the technical field of oil and gas drilling, and particularly relates to a PDC drill bit with an impact function. The PDC drill bit with the impact function comprises a drill bit body, a channel used for flowing of drilling fluid is formed in the drill bit body, and a punch is arranged in the drill bit body and linearly reciprocates with the central axis of the punch at a certain angle. The end, close to the working end of the drill bit body, of the punch can exceed the range of the drill bit body in the reciprocating motion process. The impact drill bit can solve the problem that an existing impact drill bit easily causes failure of PDC teeth.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas drilling, and in particular relates to a PDC drill bit with an impact function. Background Art

[0002] PDC drill bits rely on high-hardness, wear-resistant, self-sharpening polycrystalline diamond composite pieces (PDC teeth or cutting teeth for short) as cutting elements to shear and crush rocks.

[0003] PDC drill bits have high mechanical penetration speed, long service life and low drilling cost in soft to medium-hard formations, so they are widely used in the drilling of oil and gas wells.

[0004] Although PDC teeth have high hardness, due to the limitations of impact resistance and thermal wear resistance, PDC drill bits are prone to rapid wear and impact damage of the composite pieces when drilling in hard formations, highly abrasive formations, and severely inhomogeneous formations (soft and hard interlayers, gravel layers, etc.), which greatly reduces the cutting efficiency and working life of the drill bit.

[0005] In the existing field of drilling equipment technology, an axial or circumferential impactor is provided on the drill bit to convert the pressure energy of the drilling fluid into the kinetic energy of the impactor. The kinetic energy of the impactor directly acts on the drill bit, which can improve the drilling efficiency of the drill bit to a certain extent. However, the impact resistance of the PDC teeth on the drill bit is limited, which sometimes leads to the failure of the PDC teeth due to impact, thereby causing the premature failure of the entire drill bit. Summary of the invention

[0006] In view of the above-mentioned technical problems, the present invention aims to provide a PDC drill bit with an impact function, which can solve the problem that the existing impact drill bits easily cause PDC teeth to fail.

[0007] According to the present invention, a PDC drill bit with an impact function is provided, comprising a drill bit body, wherein a channel for the circulation of drilling fluid is arranged inside the drill bit body.

[0008] A punch is arranged in the drill body and reciprocates linearly at a certain angle to the central axis thereof. The punch is arranged so that an end of the punch close to the working end of the drill body can exceed the range of the drill body during the reciprocating motion.

[0009] In a preferred embodiment, the angle between the movement axis of the punch and the central axis of the drill body ranges from 0 to 45 degrees.

[0010] In a preferred embodiment, the punch is eccentrically arranged in the drill body.

[0011] In a preferred embodiment, an impact mechanism is provided in the channel of the drill bit body, and the impact mechanism is configured to respond to the mechanical energy of the drilling fluid flow in the channel to drive the punch to reciprocate.

[0012] In a preferred embodiment, the impact mechanism comprises:

[0013] An impeller rotatably disposed in the channel, wherein the rotation axis of the impeller is perpendicular to the central axis of the channel;

[0014] A transmission rod, both ends of which are respectively connected to the impeller and the punch in a hinged manner, and a hinge axis between the transmission rod and the impeller is offset and parallel to the rotation axis of the impeller.

[0015] In a preferred embodiment, the impact mechanism further comprises:

[0016] A guide block fixedly disposed in the channel;

[0017] A sliding block is slidably arranged on the guide block, one end of the sliding block is hinged to the transmission rod, and the other end is connected to the punch.

[0018] In a preferred embodiment, the impact mechanism further includes a vertical connecting rod and a horizontal connecting rod, and the slider is connected to the punch via the vertical connecting rod and the horizontal connecting rod.

[0019] In a preferred embodiment, the distance between the rotation axis of the impeller and the moving trajectory of the slider is in the range of 0 to 10 mm.

[0020] In a preferred embodiment, the moving trajectory of the punch is parallel to the central axis of the drill body, and the distance between the moving trajectory of the punch and the central axis of the drill body ranges from 0 to 2 / 3R, where R is the radius of the drill body.

[0021] In a preferred embodiment, the punch exceeds the drill body by a distance greater than 0 and less than or equal to 5 mm during the reciprocating motion.

[0022] Compared with the prior art, the advantages of the present application are as follows.

[0023] The present invention provides an impact mechanism in the drill bit body. The impact mechanism is a purely mechanical structure. The drilling fluid flows through the impeller to drive the impeller to rotate. The impeller drives the punch to reciprocate through the transmission rod. The energy transmission efficiency is high, there is no need to hold pressure, and the damage to the drill bit body is reduced, which is beneficial to extending the service life of the drill bit.

[0024] At the same time, during the reciprocating motion, the punch can exceed the range of the drill bit body and intermittently participate in scraping and breaking the rock, further improving the rock breaking efficiency of the drill bit and solving the technical problem of low rock breaking efficiency in hard formations that are difficult to drill in deep wells.

[0025] The punch generates vibrations of a certain frequency inside the drill bit body, which reduces the contact pressure between the drill bit and the wellbore, and reduces the contact area between the wellbore and the well wall, thereby reducing the friction resistance between the wellbore and the well wall, and reducing the possibility of decompression of the drill bit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be described below with reference to the accompanying drawings.

[0027] Figure 1 A schematic diagram showing an embodiment of a PDC drill bit with an impact function according to the present invention;

[0028] Figure 2 A perspective schematic diagram showing an embodiment of an impact mechanism according to the present invention;

[0029] Figure 3 A schematic side view of an embodiment of an impact mechanism according to the present invention is shown;

[0030] Figure 4 A schematic diagram showing the distance of the punch extending beyond the drill body according to the present invention;

[0031] Figure 5 A schematic diagram showing the angle between the punch and the central axis of the drill body according to the present invention;

[0032] Figure 6 A schematic structural diagram of an impeller according to the present invention is shown.

[0033] In the figure: 1. drill bit body; 11. channel; 12. blade; 13. cutting tooth; 14. main body; 2. punch; 21. impact tooth; 3. impact mechanism; 31. impeller; 311. impeller rotating shaft; 312. eccentric crank; 32. transmission rod; 33. guide block; 34. slider; 35. vertical connecting rod; 36. horizontal connecting rod; 37. first articulated shaft; 100. PDC drill bit with impact function.

[0034] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0035] The present invention will be described below with reference to the accompanying drawings.

[0036] It should be noted that the directional terms or qualifiers "upper" and "lower" used in this application are all directed to the referenced Figure 1They are not intended to define the absolute positions of the components involved, but may vary depending on the specific circumstances.

[0037] Figure 1 The structure of the PDC drill bit 100 with impact function according to the present invention is shown. Figure 1 As shown, the PDC drill bit 100 with impact function comprises a drill bit body 1, and a channel 11 for the circulation of drilling fluid is arranged inside the drill bit body 1.

[0038] In a specific embodiment, the drill bit body 1 includes a main body 14, a plurality of blades 12 are evenly arranged along the circumferential direction at the lower end of the main body 14, and a plurality of cutting teeth 13 are evenly distributed on each blade wing 12, and the cutting teeth 13 are made of PDC material.

[0039] According to the present invention, a punch 2 is arranged in the drill body 1 and reciprocates linearly at a certain angle to its central axis. The punch 2 is arranged so that its end close to the working end of the drill body 1 can exceed the range of the drill body 1 during the reciprocating motion.

[0040] Through this arrangement, the impact generated by the PDC drill bit 100 with impact function directly acts on the rock-breaking punch 2, and the cutting teeth 13 are no longer subjected to impact loads, thereby reducing the probability of impact failure of the cutting teeth 13 and helping to extend the service life of the PDC drill bit 100 with impact function.

[0041] Specifically, Figure 5 As shown, the included angle between the moving axis of the punch 2 (moving trajectory of the punch 2) and the central axis of the drill body 1 ranges from 0 to 45 degrees, that is, Figure 5 The value range of the angle a is 0≤a≤45°.

[0042] The angle a is controlled within a certain range, so that the PDC drill bit 100 with an impact function can impact and crush rocks in each area of ​​the drill bit, thereby increasing the diversity of drill bit design and broadening the application range of the drill bit.

[0043] In a preferred embodiment, Figure 1 and Figure 4 As shown, the motion trajectory of the punch 2 is parallel to the central axis of the drill body 1 .

[0044] In a preferred embodiment, on the basis that the motion trajectory of the punch 2 is parallel to the central axis of the drill body 1 , the distance between the motion trajectory of the punch 2 and the central axis of the drill body 1 ranges from 0 to 2 / 3R.

[0045] Here, R refers to the radius of the drill body 1, and R specifically refers to the distance S from the radial edge of the blade 12 to the central axis of the main body 14. Figure 4As shown, 0≤S≤2 / 3R.

[0046] Through this arrangement, the punch 2 is located at different radial positions of the drill bit body 1, which can improve the rock breaking efficiency in different areas of the drill bit. In the actual working process, it can be personalized according to specific drilling processes and conditions to expand the scope of application of the drill bit.

[0047] In a preferred embodiment, the punch 2 is eccentrically disposed in the drill body 1 , that is, there is a certain distance between the movement trajectory of the punch 2 and the central axis of the drill body 1 .

[0048] Furthermore, the distance that the punch 2 exceeds the drill body 1 during the reciprocating motion is greater than 0 and less than or equal to 5 mm. Figure 4 As shown, the punch 2 also includes an impact tooth 21 arranged at the lower end. When the punch 2 moves to the lowermost end, the lowermost end of the impact tooth 21 is lower than the lowermost end of the cutting tooth 13. The distance between the lowermost end of the impact tooth 21 and the lowermost end of the cutting tooth 13 is set to M, and the value range of M is 0 <M≤5mm。

[0049] With this arrangement, the lowest position of the impact teeth 21 will be intermittently lower than the cutting teeth 13 during the impact process, so that the impact teeth 21 break the rock by impact, and the cutting teeth 13 break the rock by scraping. In addition, when designing the drill bit, the relative position of the punch 2 and the cutting teeth 13 can be adjusted according to different rock types and drilling methods, thereby improving the adaptability of the PDC drill bit 100 with impact function to the formation and improving the rock breaking efficiency.

[0050] In a preferred embodiment, the impact teeth 21 are any one of conical teeth, wedge-shaped teeth, and spherical teeth, or a combination of several of them. Different types of impact teeth 21 are arranged on the punch 2, which can be applied to formations with different hardness, and provide an optional solution for the selection of the PDC drill bit 100 with impact function.

[0051] Preferably, the position where the punch 2 protrudes from the drill body 1 is located within the setting range of the cutting teeth 13 .

[0052] According to the present invention, in a specific embodiment, an impact mechanism 3 is disposed in the channel 11 of the drill body 1 , and the impact mechanism 3 is configured to respond to the mechanical energy of the drilling fluid flow in the channel 11 to drive the punch 2 to reciprocate.

[0053] In this embodiment, if Figure 1 to Figure 3 As shown, the impact mechanism 3 includes an impeller 31 rotatably disposed in the channel 11 , and the rotation axis of the impeller 31 is perpendicular to the central axis of the channel 11 .

[0054] like Figure 6As shown, the two impellers 31 are arranged as a left-right symmetrical structure, and an eccentric crank 312 is eccentrically arranged between the two left-right symmetrical impellers 31, that is, the two impellers 31 of this embodiment rotate synchronously under the fixed connection of the eccentric crank 312, and an impeller rotating shaft 311 is arranged at the central axis of the ends of the two impellers 31 away from each other.

[0055] The impeller 31 is rotatably arranged in the drill bit body 1 through the impeller rotating shaft 311, and is located in the channel 11. The central axis of the impeller rotating shaft 311 is perpendicular to the central axis of the drill bit body 1. When the drilling fluid flows in the channel 11, the impeller 31 can continuously rotate under the push of the drilling fluid.

[0056] The central axis of the eccentric crank 312 is parallel to the central axis of the impeller 31 , and the central axis of the eccentric crank 312 does not coincide with the central axis of the impeller 31 . A transmission rod 32 is hingedly provided on the eccentric crank 312 , and the lower end of the transmission rod 32 is connected to the punch 2 .

[0057] With this arrangement, when the impeller 31 rotates continuously under the action of the drilling fluid, the impeller 31 drives the transmission rod 32 to move up and down continuously through the eccentric crank 312, thereby driving the punch 2 to move up and down continuously.

[0058] Furthermore, the impact mechanism 3 also includes a guide block 33 and a sliding block 34 .

[0059] The guide block 33 is fixedly arranged in the drill body 1 and the external language channel 11 , and the length direction of the guide block 33 is parallel to the moving track of the punch 2 .

[0060] The slider 34 is slidably arranged on the guide block 33, and the moving direction of the slider 34 is parallel to the moving track of the punch 2. One end of the slider 34 is hinged to the transmission rod 32 through the first hinge shaft 37, and the other end is connected to the punch 2.

[0061] By providing the guide block 33 and the slider 34, a guiding function is provided for the reciprocating movement of the punch 2, so that the movement of the punch 2 is smoother.

[0062] In a preferred embodiment, the impact mechanism 3 further includes a vertical connecting rod 35 and a horizontal connecting rod 36 , and the slider 34 is connected to the punch 2 via the vertical connecting rod 35 and the horizontal connecting rod 36 .

[0063] like Figure 1 As shown, the vertical connecting rod 35 is coaxially fixedly arranged at the lower end of the slider 34 , the transverse connecting rod 36 is fixedly arranged at the lower end of the vertical connecting rod 35 , and one end of the transverse connecting rod 36 away from the vertical connecting rod 35 is fixedly connected to the punch 2 .

[0064] It is easy to understand that a space for the horizontal connecting rod 36 and the vertical connecting rod 35 to move is provided in the drill body 1, and the space for the horizontal connecting rod 36 and the vertical connecting rod 35 to move in the drill body 1 is not limited to Figure 1 The structure shown.

[0065] In this embodiment, the distance between the rotation axis of the impeller 31 and the moving trajectory of the slider 34 is in the range of 0 to 10 mm. Figure 3 As shown, a straight line parallel to the slider 34 and intersecting the central axis of the first hinge shaft 37 is defined as the moving trajectory of the slider 34, and a distance between the rotation axis of the impeller 31 and the moving trajectory of the slider 34 is defined as H, 0≤H≤10mm.

[0066] In a preferred embodiment, the central axis of the impeller 31 coincides with the moving track of the slider 34. That is, the distance H between the rotation axis of the impeller 31 and the moving track of the slider 34 is 0.

[0067] When H=0, the impact generated by the impact mechanism 3 is relatively uniform, forming a vibration of a certain frequency, which can not only break the rock, but also protect the cutting teeth 13, thereby increasing the service life of the PDC drill bit 100 with an impact function, while reducing the wrapping force and friction force between the PDC drill bit 100 with an impact function and the well wall, thereby reducing the occurrence of drill bit decompression.

[0068] In another preferred embodiment, the central axis of the impeller 31 does not coincide with the moving trajectory of the slider 34. That is, the distance H between the central axis of the impeller 31 and the moving trajectory of the slider 34 has a value range of: 0 <H≤10mm。

[0069] Through this arrangement, an eccentric impact mechanism 3 is formed, which can make the speed of the slider 34 inconsistent during impact and return, and control the distance between the central axis of the impeller 31 and the motion trajectory of the slider 34 within the range of this embodiment, so that the impact speed of the slider 34 is greater, thereby improving the impact work of the PDC drill bit 100 with an impact function and improving the rock breaking efficiency of the PDC drill bit 100 with an impact function.

[0070] According to the present invention, when the PDC drill bit 100 with impact function works underground, the drilling fluid drives the impeller 31 to rotate at high speed, and the impeller 31 drives the eccentric crank 312 to rotate at high speed, thereby driving the transmission rod 32 to move up and down, forming a typical crank-connecting rod mechanism.

[0071] At this time, the slider 34 generates vertical up and down motion under the constraint of the guide block 33, driving the vertical connecting rod 35 and the horizontal connecting rod 36 to generate up and down motion, and the horizontal connecting rod 36 drives the punch 2 to reciprocate in the blade 12. Further, when the punch 2 is parallel to the central axis of the drill body 1, a vertical up and down impact motion can be generated. When the punch 2 forms a certain angle with the central axis of the drill body 1, an oblique up and down impact motion can be generated, thereby driving the impact teeth 21 to intermittently participate in crushing the formation.

[0072] According to the present invention, the PDC drill bit 100 with impact function relies on the impact mechanism 3 to form impacts of a certain frequency in the drill bit body 1. The present invention is a purely mechanical transmission structure with high energy transfer efficiency, no need for pressure holding, and reduced damage to the drill string and the drill bit, which is beneficial to extending the service life of the drill bit.

[0073] The present invention utilizes the energy of drilling fluid to break rocks, thereby improving the utilization rate of drilling fluid energy. The PDC drill bit 100 with impact function of the present invention breaks the bottom of the well by a mixed impact-scraping method, thereby improving the drilling efficiency of the drill bit.

[0074] The present invention provides impact through the punch 2 to prevent the cutting teeth 13 from directly bearing the impact, which can effectively break rocks and prevent the cutting teeth 13 from failing due to impact, thereby increasing the service life of the PDC drill bit 100 with an impact function.

[0075] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0076] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0077] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0078] Finally, it should be noted that the above is only a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A PDC drill bit with impact function, comprising a drill bit body (1), wherein a channel (11) for the circulation of drilling fluid is arranged inside the drill bit body (1), characterized in that: A punch (2) is arranged inside the drill body (1) and is capable of linearly reciprocating at a certain angle to the central axis of the drill body (1). The punch (2) is arranged so that an end thereof close to the working end of the drill body (1) can exceed the range of the drill body (1) during the reciprocating movement.

2. The PDC drill bit with impact function according to claim 1, characterized in that: The included angle between the movement axis of the punch (2) and the central axis of the drill body (1) is in the range of 0 to 45 degrees.

3. The PDC drill bit with impact function according to claim 1, characterized in that: The punch (2) is arranged in the drill body (1) in an eccentric manner.

4. The PDC drill bit with impact function according to any one of claims 1 to 3, characterized in that: An impact mechanism (3) is arranged in the channel (11) of the drill bit body (1), and the impact mechanism (3) is configured to respond to the mechanical energy of the drilling fluid flow in the channel (11) to drive the punch (2) to reciprocate.

5. The PDC drill bit with impact function according to claim 4, characterized in that: The impact mechanism (3) comprises: an impeller (31) rotatably arranged in the channel (11), wherein the rotation axis of the impeller (31) is perpendicular to the central axis of the channel (11); A transmission rod (32), the two ends of which are respectively connected to the impeller (31) and the punch (2) in a hinged manner, and the hinge axis between the transmission rod (32) and the impeller (31) is offset and parallel to the rotation axis of the impeller (31).

6. The PDC drill bit with impact function according to claim 5, characterized in that: The impact mechanism (3) further comprises: a guide block (33) fixedly arranged in the channel (11); A slider (34) is slidably arranged on the guide block (33), one end of the slider (34) is hinged to the transmission rod (32), and the other end is connected to the punch (2).

7. The PDC drill bit with impact function according to claim 6, characterized in that: The impact mechanism (3) further comprises a vertical connecting rod (35) and a horizontal connecting rod (36), and the sliding block (34) is connected to the punch (2) via the vertical connecting rod (35) and the horizontal connecting rod (36).

8. The PDC drill bit with impact function according to claim 6, characterized in that: The distance between the rotation axis of the impeller (31) and the moving track line of the slider (34) is in the range of 0 to 10 mm.

9. The PDC drill bit with impact function according to claim 1, characterized in that: The moving trajectory of the punch (2) is parallel to the central axis of the drill body (1), and the distance between the moving trajectory of the punch (2) and the central axis of the drill body (1) is in the range of 0 to 2 / 3R, where R is the radius of the drill body (1).

10. The PDC drill bit with impact function according to claim 1, characterized in that: The distance that the punch (2) exceeds the drill bit body (1) during the reciprocating motion is greater than 0 and less than or equal to 5 mm.

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