A drill bit with impact rock breaking function

Abstract

This invention provides a drill bit with rock-breaking impact function, comprising: a drill bit body, wherein a flow channel for drilling fluid is provided within the drill bit body, the flow channel extending axially through the drill bit body; an impeller mechanism disposed in the flow channel; a cam mechanism fixedly connected to the impeller mechanism; and a plurality of pin impact mechanisms disposed inside the drill bit body, wherein the first end of the pin impact mechanism contacts the working end face of the cam mechanism; wherein the impeller mechanism can drive the cam mechanism to rotate under the action of drilling fluid, causing the cam mechanism to drive the pin impact mechanisms to alternately extend outward and retract to reset, thereby impacting and breaking the rock at the bottom of the well.

Description

Technical Field

[0001] This invention belongs to the fields of oil and gas drilling engineering, mining engineering, geological drilling, tunnel engineering, hydrology and trenchless technology equipment, and specifically relates to a drill bit with impact rock breaking function. Background Technology

[0002] PDC drill bits, commonly used in drilling operations, rely on high-hardness, wear-resistant, and self-sharpening polycrystalline diamond composite (PDC teeth) as cutting elements to shear and break rocks. Due to their advantages such as high mechanical drilling speed, long service life, and low drilling cost in soft to medium-hard formations, PDC drill bits are widely used in oil and gas exploration and development.

[0003] However, while existing drill bits with PDC (diamond-diamond) teeth possess high hardness, their impact resistance and thermal wear resistance are insufficient. When drilling through heterogeneous formations such as hard formations, highly abrasive formations, interbedded soft and hard layers, and conglomerate layers, PDC teeth are prone to wear failure, chipping failure, and thermal failure. The most typical failure mode is impact chipping of the diamond layer in the PDC teeth, which significantly reduces the drill bit's cutting efficiency and service life. Typically, the most vulnerable location for composite chipping on the drill bit is the crown tip, where cutting speeds are relatively high. Failure of the cutting teeth in this area creates annular grooves on the cutter body, subsequently leading to a loss of the PDC drill bit's cutting ability. These factors severely impact drilling progress.

[0004] Currently, in some existing drilling operations, axial or circumferential impactors are installed in the drill string at the top of the PDC drill bit to convert the hydraulic energy of the drilling fluid into the impact kinetic energy of the impactor. The impact load is transmitted downward, giving the drill bit both cutting and rock-breaking capabilities. Although this can improve the overall rock-breaking efficiency and drilling speed of the drill bit to some extent, the PDC drill bit has limited impact resistance. Improper configuration of impact force parameters and formation heterogeneity can lead to PDC tooth impact failure, resulting in premature failure of the entire drill bit. Summary of the Invention

[0005] In view of the technical problems mentioned above, the present invention aims to provide a drill bit with impact rock breaking function. This drill bit can convert the hydraulic energy of drilling fluid into impact energy for breaking rocks and generate periodic impacts, which significantly improves the rock breaking efficiency of the entire drill bit, while avoiding problems such as PDC tooth breakage and tooth chipping caused by impact on the entire drill bit.

[0006] Therefore, according to the present invention, a drill bit with rock-breaking impact function is provided, comprising: a drill bit body, wherein a flow channel for drilling fluid to flow through is provided in the drill bit body, the flow channel extending axially through the drill bit body; an impeller mechanism disposed in the flow channel; a cam mechanism fixedly connected to the impeller mechanism; and a plurality of pin impact mechanisms disposed inside the drill bit body, wherein the first end of the pin impact mechanism contacts the working end face of the cam mechanism; wherein the impeller mechanism can drive the cam mechanism to rotate under the action of drilling fluid, so that the cam mechanism drives the pin impact mechanism to alternately extend outward and retract to reset, thereby impacting and breaking the rock at the bottom of the well.

[0007] In one embodiment, the ejector pin impact mechanism includes an ejector pin, and a mounting portion is provided inside the drill bit body. The ejector pin is mounted in the mounting portion and can extend or retract from the mounting portion.

[0008] In one embodiment, the ejector pin includes a first body configured as a cylinder and a second body fixedly connected to the first body, wherein the diameter of the first body is larger than the diameter of the second body, thereby forming a first step at the connection between the first body and the second body.

[0009] In one embodiment, impact teeth are provided at the axial outer end of the second body.

[0010] In one embodiment, an elastic element is sleeved on the second body, and a second step with its end face facing inward is provided on the inner wall of the mounting part. The two ends of the elastic element abut against the first step and the second step respectively, and the pin impact mechanism is reset by retracting the elastic element.

[0011] In one embodiment, the angle γ between the central axis of the ejector pin impact mechanism and the axis of the drill bit body ranges from 0°≤|γ|≤90°.

[0012] In one embodiment, the ejector pin impact mechanism is configured to have an eccentricity e between it and the cam mechanism, and the value of the eccentricity ranges from 0 to e to 10 mm.

[0013] In one embodiment, the stroke h of the reciprocating motion of the ejector pin impact mechanism is in the range of 2 ≤ h ≤ 10 mm.

[0014] In one embodiment, a plurality of blades are provided on the outer peripheral surface of the drill bit body, and the blades are provided with PDC cutting teeth. The drill bit body can rotate with the upper drill string and drive the blades and the PDC cutting teeth to rotate to cut and break rocks, thereby enabling the drill bit to perform combined impact and cutting rock breaking.

[0015] In one embodiment, a nozzle is provided in the blade wing, and the nozzle spray direction is set towards the PDC cutting teeth and the ejector pin impact mechanism for cleaning the PDC cutting teeth and the ejector pin impact mechanism.

[0016] Compared with the prior art, the advantages of this application are:

[0017] The drill bit with impact rock-breaking function according to the present invention can convert the hydraulic energy of drilling fluid into impact energy for rock breaking and generate periodic impacts, greatly improving the overall energy utilization rate of the drill bit. Utilizing a hybrid impact-cutting rock-breaking mode, the overall rock-breaking efficiency of the drill bit is significantly improved. The drill bit uses a cam mechanism and a push-pin impact mechanism to generate impact vibrations, driving the drill bit body to produce impact vibrations at a certain frequency. This reduces the sliding drilling friction near the drill bit and the bottom drill string assembly, reduces the encapsulation force of bottom sand on the drill bit, and effectively avoids drill bit dragging and mud buildup. Attached Figure Description

[0018] The present invention will now be described with reference to the accompanying drawings.

[0019] Figure 1 The structure of the drill bit with impact rock-breaking function according to the present invention is schematically shown.

[0020] Figure 2 schematically shown Figure 1 The radial tooth arrangement of the drill bit is shown.

[0021] Figure 3 This is a schematic diagram showing the cooperation between the cam mechanism and the ejector pin impact mechanism.

[0022] Figure 4 The structure of the ejector pin impact mechanism is schematically shown.

[0023] Figure 5 The structure of the impeller mechanism is shown schematically.

[0024] Figure 6 The structure of one embodiment of the cam mechanism is schematically shown.

[0025] Figure 7 This is a schematic diagram of the stroke of the cam mechanism and the ejector pin impact mechanism.

[0026] Figure 8 This is a schematic diagram of the impact angle of the ejector pin impact mechanism.

[0027] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0028] The invention will now be described with reference to the accompanying drawings.

[0029] In this application, it should be noted that the directional terms or qualifiers such as "up" and "down" used in this application are all in reference to the appendix. Figure 1 In other words, they are not used to define the absolute position of the components involved, but can vary depending on the specific circumstances.

[0030] Figure 1 The structure of a drill bit 100 with impact rock-breaking function according to the present invention is schematically shown. Figure 1 As shown, the drill bit 100 includes a drill bit body 1, cutter wings 2 disposed outside the drill bit body 1, and an impeller mechanism 3, a cam mechanism 4, and a push pin impact mechanism 5 disposed inside the drill bit body 1. The impeller mechanism 3 can rotate under the action of high-speed drilling fluid, and the impeller mechanism 3 can drive the cam mechanism 4 to rotate, thereby causing the high side and low side of the cam mechanism 4 to alternately contact the push pin impact mechanism 5, thereby driving the push pin impact mechanism 5 to continuously extend or retract and reset, thus impacting and breaking the rock 8 at the bottom of the well, so that the drill bit 100 has the function of impact rock breaking. At the same time, the cutter wings 2 are provided with PDC cutting teeth 21. The drill bit body 1 is used to connect with the upper drilling tool (not shown). The upper drilling tool can drive the drill bit body 1 to rotate, thereby driving the cutter wings 2 to rotate to cut and break the rock. Thus, the push pin impact mechanism 5 forms independent impact vibration inside the drill bit body 1, while the PDC cutting teeth 21 on the cutter wings 2 adopt the cutting rock breaking method, so that the drill bit 100 has both impact rock breaking and cutting rock breaking functions.

[0031] According to the present invention, such as Figure 1 and Figure 2 As shown, multiple cutter wings 2 are provided on the outside of the drill bit body 1, and the multiple cutter wings 2 are evenly spaced on the outer peripheral surface of the drill bit body 1. Multiple PDC cutting teeth 21 are provided on the cutter wings 2. The cutter wings 2 and PDC cutting teeth 21 can rotate with the drill bit body 1, thereby effectively cutting and breaking the rock at the bottom of the well.

[0032] like Figure 1 As shown, a flow channel 11 is provided inside the drill bit body 1, which is used for the flow of drilling fluid. The flow channel 11 extends axially through the drill bit body 1. During drilling, high-speed drilling fluid can flow through the flow channel 11.

[0033] The impeller mechanism 3 is disposed in the flow channel 11 within the drill bit body 1. The installation method of the impeller mechanism 3 is not limited; for example, it can be mounted on the inner wall of the flow channel 11 via a mounting base, or it can be mounted within the flow channel 11 via a bearing suspension method, or it can be fixedly mounted above the cam mechanism 4 via an impeller shaft. The impeller mechanism 3 includes an impeller shaft and blades 31 (see...). Figure 5The blades 31 extend spirally along the impeller shaft. The high-speed drilling fluid flowing through the flow channel 11 enables the impeller mechanism 3 to rotate.

[0034] like Figure 1 As shown, the cam mechanism 4 is fixedly connected to the lower end of the impeller mechanism 3. Specifically, the cam mechanism 4 is fixedly connected to the impeller shaft of the impeller mechanism 3. The connection between the impeller mechanism 3 and the cam mechanism 4 can be achieved by means of bolts, couplings, flexible shafts, etc. Multiple connection methods provide more possibilities for the commercialization of the drill bit 100 with impact rock-breaking function according to the present invention.

[0035] According to the present invention, a plurality of ejector pin impact mechanisms 5 are provided inside the drill bit body 1, and the first end of the ejector pin impact mechanism 5 ( Figure 1 The left end of the cam mechanism 4 is in contact with the working end face of the cam mechanism 4. Figure 3 As shown, the ejector pin impact mechanism 5 includes an ejector pin 51, and a mounting portion 12 is provided inside the drill bit body 1 (see...). Figure 2 The ejector pin 51 is installed inside the mounting portion 12. The ejector pin impact mechanism 5 is configured to allow the second end of the ejector pin 51 to extend out of or retract into the mounting portion 12. In the circumferential direction, the ejector pin impact mechanism 5 is positioned on the drill body 1 corresponding to the cutter wing 2.

[0036] like Figure 3 As shown, the ejector pin 51 includes a first body 511 with a cylindrical structure and a second body 512 fixedly connected to the first body 511. The diameter of the first body 511 is larger than the diameter of the second body 512, thus forming a first step at the connection between the first body 511 and the second body 512. An elastic member 6 is sleeved on the second body 512. Meanwhile, a second step 121 is provided on the inner wall of the mounting portion 12 inside the drill bit body 1, with the end face of the second step 121 facing the interior of the drill bit body 1. The ejector pin 51 is installed inside the mounting portion 12, and the two ends of the elastic member 6 abut against the first step and the second step 121, respectively. The first end (axial inner end) of the first body 511 contacts the working end face of the cam mechanism 4. The ejector pin impact mechanism 5 can achieve retraction and reset through the elastic member 6, thereby driving the ejector pin impact mechanism 5 to continuously and alternately extend and retract as the cam mechanism 4 rotates. In one embodiment, the elastic member 6 is a spring.

[0037] like Figure 4As shown, an impact tooth 51 is provided at the axial outer end of the second body 512. The impact tooth 51 can be, for example, a conical tooth, an axe-shaped tooth, or a spherical tooth. The ejector pin impact mechanism 5 can be constructed as a single piece of cemented carbide, or a customized impact tooth 51 can be provided at the front end of the ejector pin impact mechanism 5. Different tooth shapes can correspond to different formation conditions, thereby broadening the application range of the drill bit 100. In addition, the impact vibration characteristics generated by the ejector pin impact mechanism 5 can be adjusted according to the needs of rock breaking. The individually provided impact tooth 51 can effectively break the rock at the bottom of the well, which can avoid the failure of the PDC cutting tooth 21 caused by applying impact load to the entire drill bit 100 using a conventional impactor, thereby extending the service life of the drill bit 100.

[0038] According to the present invention, the cam mechanism 4 can be constructed as a planar cam with a single protrusion, two protrusions, or multiple protrusions. The impeller mechanism 3 can drive the cam mechanism 4 to rotate in a horizontal plane under the drive of drilling fluid, thereby realizing the continuous alternating extension and retraction of the push pin impact mechanism 5. Figure 3 As shown, the ejector pin impact mechanism 5 is configured to have an eccentricity e with the cam mechanism 4, and the preferred reasonable range of the eccentricity is 0≤e≤10mm. On the one hand, the existence of this eccentricity is beneficial to the reasonable assembly and arrangement of the cam mechanism 4 and the ejector pin impact mechanism 5 inside the drill bit body 1. On the other hand, controlling the eccentricity within a certain range can improve the energy utilization rate of the cam mechanism 4 and the ejector pin impact mechanism 5.

[0039] exist Figure 6 In the illustrated embodiment, the cam mechanism 4 has two protruding structures, and two ejector pin impact mechanisms 5 are disposed within the drill bit body 1. The two ejector pin impact mechanisms 5 can be symmetrically distributed. Thus, one rotation of the cam mechanism 4 drives the ejector pin impact mechanism 5 to impact the rock twice, generating rock-breaking impact on both sides of the drill bit body 1. This structure of the drill bit 100 increases the number and frequency of rock-breaking impacts, effectively increasing the energy utilization rate of the cam mechanism 4 and significantly improving the overall rock-breaking efficiency of the drill bit 100. It is understood that the ejector pin impact mechanism 5 can be a single unit or multiple units.

[0040] In this embodiment, the height of the protrusion of the cam mechanism 4 determines the linear reciprocating stroke h of the ejector pin impact mechanism 5. It is important to understand that the difference between the inner and outer radii of the cam mechanism 4 is the linear reciprocating stroke h of the ejector pin impact mechanism 5. Figure 7 As shown, the reasonable range of stroke h for the ejector pin impact mechanism 5 is 2 ≤ h ≤ 10 mm. This range of stroke h effectively ensures the reliability of the ejector pin impact mechanism 5 in breaking rocks and avoids excessive impact vibration on the drill bit due to excessive stroke, thus preventing disruption of the smooth cutting process of the PDC teeth and affecting the service life of the drill bit.

[0041] According to the present invention, such as Figure 8 As shown, the impact angle γ between the central axis of the ejector pin impact mechanism 5 and the axis of the drill bit body 1 ranges from 0 ≤ |γ| ≤ 90°. Controlling the impact angle γ within a certain range allows for control over the effective range of the ejector pin impact mechanism 5, further enhancing the rock-breaking effect and improving the overall rock-breaking efficiency of the drill bit 100. Therefore, the drill bit 100 can employ different structural parameters according to specific circumstances, achieving a personalized design for rock-breaking impact.

[0042] like Figure 1 As shown, a nozzle 7 is provided in the cutter blade 2, and the spray direction of the nozzle 7 is set towards the PDC cutting teeth 21 and the ejector pin impact mechanism 5. The high-speed drilling fluid sprayed from the nozzle 7 can clean the rock cuttings on the cutter blade 2, PDC cutting teeth 21 and ejector pin impact mechanism 5, thereby effectively preventing mud packing from forming on the drill bit 100. This ensures that the ejector pin 51 can reciprocate smoothly, effectively preventing jamming, which is very beneficial to ensuring the rock-breaking function of the drill bit 100.

[0043] The working process of the drill bit 100 with rock-breaking function according to the present invention is briefly described below. When the drill bit 100 is drilling downhole, the drill bit body 1 rotates under the drive of the upper drill string (not shown), driving the cutter blades 2 and PDC cutting teeth 21 to rotate and break the rock. Simultaneously, high-speed drilling fluid flows through the flow channel 11, driving the impeller mechanism 3 to rotate. The impeller mechanism 3 drives the cam mechanism 4 to rotate in a planar motion. During the rotation, the high and low sides of the cam mechanism 4 alternately contact the axial inner end face of the ejector pin impact mechanism 5. When the cam mechanism 4 rotates to the point where the high side contacts the ejector pin impact mechanism 5, the ejector pin impact mechanism 5 compresses the elastic element 6 and extends outward, thereby impacting and breaking the rock 8 at the bottom of the well. When the cam mechanism 4 rotates to the point where the low side contacts the ejector pin impact mechanism 5, the ejector pin impact mechanism 5 retracts inward under the action of the elastic element 6, completing its reset. Thus, the impeller mechanism 3 and the cam mechanism 4 continue to rotate, driving the ejector pin impact mechanism 5 to continuously extend, retract, and reset, performing reciprocating motion, thereby impacting and breaking the rock 8 at the bottom of the well. The ejector pin impact mechanism 5 generates independent impact vibration in the drill bit body 1, and the PDC cutting teeth 21 on the drill bit blade 2 still adopt the cutting and rock breaking method, so that the drill bit 100 has both impact and cutting rock breaking functions.

[0044] The drill bit 100 with impact rock-breaking function according to the present invention can convert the hydraulic energy of drilling fluid into impact energy for rock breaking and generate periodic impacts. The high-speed rotating impeller mechanism can significantly increase the number and frequency of impact rock breaking, greatly improving the overall energy utilization rate of the drill bit. By utilizing the impact-cutting hybrid rock-breaking mode, the rock-breaking efficiency of the entire drill bit is significantly improved. The drill bit 100 generates impact vibrations using the cam mechanism 4 and the ejector pin impact mechanism 5. The ejector pin impact mechanism 5 forms an independent impact motion in the drill bit body 1, avoiding the impact failure of the PDC cutting teeth 21 caused by applying impact loads to the entire drill bit 100 using an impactor. This improves the rock-breaking efficiency of the drill bit without affecting its service life. At the same time, the drill bit 100 generates impact vibrations of a certain frequency through the ejector pin impact mechanism 5 itself, reducing the friction of the drill bit 100 and the area near the bottom drill string assembly during sliding drilling, reducing the wrapping force of bottom sand on the drill bit, and effectively preventing drill bit dragging and mud packing phenomena.

[0045] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0048] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A drill bit with impact rock-breaking function, comprising: The drill bit body (1) has a flow channel (11) for drilling fluid to flow through it, and the flow channel extends through the drill bit body axially. The impeller mechanism (3) is installed in the flow channel; A cam mechanism (4) fixedly connected to the lower end of the impeller mechanism; and Several ejector pin impact mechanisms (5) are disposed inside the drill bit body, and the first end of the ejector pin impact mechanism is in contact with the working end face of the cam mechanism. The impeller mechanism can drive the cam mechanism to rotate in the horizontal plane under the action of drilling fluid, so that the cam mechanism drives the pin impact mechanism to extend and retract laterally alternately, thereby impacting and breaking the rock at the bottom of the well.

2. The drill bit according to claim 1, characterized in that, The ejector pin impact mechanism includes an ejector pin (51), and an installation part (12) is provided inside the drill bit body. The ejector pin is installed in the installation part and can extend or retract from the installation part.

3. The drill bit according to claim 2, characterized in that, The ejector pin includes a first body (511) configured as a cylinder and a second body (512) fixedly connected to the first body. The diameter of the first body is larger than the diameter of the second body, thereby forming a first step at the connection between the first body and the second body.

4. The drill bit according to claim 3, characterized in that, Impact teeth (52) are provided at the outer axial end of the second body.

5. The drill bit according to claim 3, characterized in that, An elastic element (6) is fitted onto the second body, and a second step (121) with its end face facing inward is provided on the inner wall of the mounting part. The two ends of the elastic element abut against the first step and the second step respectively, and the pin impact mechanism is reset by the retraction of the elastic element.

6. The drill bit according to any one of claims 1 to 3, characterized in that, The angle γ between the central axis of the ejector pin impact mechanism and the axis of the drill bit body is in the range of 0°≤|γ|≤90°.

7. The drill bit according to any one of claims 1 to 3, characterized in that, The ejector pin impact mechanism is configured to have an eccentricity e with the cam mechanism, and the value of the eccentricity is in the range of 0≤e≤10mm.

8. The drill bit according to any one of claims 1 to 3, characterized in that, The stroke h of the reciprocating motion of the ejector pin impact mechanism is in the range of 2≤h≤10mm.

9. The drill bit according to claim 1, characterized in that, Multiple blades (2) are provided on the outer peripheral surface of the drill bit body, and PDC cutting teeth (21) are provided on the blades. The drill bit body can rotate with the upper drill string, and drive the cutter blades and the PDC cutting teeth to rotate to cut and break rocks, thereby enabling the drill bit to perform combined impact and cutting rock breaking.

10. The drill bit according to claim 9, characterized in that, A nozzle (7) is provided in the blade wing, and the spray direction of the nozzle is set towards the PDC cutting teeth and the ejector pin impact mechanism for cleaning the PDC cutting teeth and the ejector pin impact mechanism.

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