A type of shock-absorbing drill collar

Abstract

This utility model discloses a vibration-damping drill collar, belonging to the technical field of oil drilling tools. The vibration-damping drill collar includes a drill collar body, a shell fitted in the middle of the drill collar body, and a vibration-damping sleeve, a vibration-damping spring, and a damping ring disposed between the drill collar body and the shell. The vibration-damping spring is fixed to the inner wall of the shell by a support column and a support sleeve. The vibration-damping drill collar also includes a suppression mechanism connected in series at one end of the drill collar body and a drill bit connected to the suppression mechanism. The suppression mechanism includes a splined shaft, which drivesly connects the drill collar body and the drill bit. The suppression mechanism also includes a torsion spring fitted on the splined shaft, and two friction discs, a first friction disc and a second friction disc, fitted on the splined shaft and capable of sliding and rubbing against each other. This utility model, through the synergistic effect of the central vibration-damping mechanism and the suppression mechanism, solves the problem in the prior art of simultaneously and effectively suppressing central vibration and torsional vibration, achieving dual vibration reduction and comprehensively improving the working stability of the drill bit.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling and production tools, and in particular to a shock-absorbing drill collar. Background Technology

[0002] Drill collars are an important component of the drill string assembly in oil and gas drilling operations. Their main functions are to provide drilling pressure, stabilize the drill bit, and control the wellbore trajectory. During drilling, especially when encountering hard or complex formations, the interaction between the drill bit and the formation will generate strong impacts and vibrations.

[0003] These vibrations are complex, including axial vibrations caused by drilling pressure fluctuations, radial vibrations caused by drill string rotation imbalances or wellbore collisions, and torsional vibrations caused by the drill bit stick-slip effect. These vibrations are transmitted upwards along the rigid drill collars, which not only severely reduces drilling efficiency but also exacerbates the wear and fatigue damage of drill bits, drill collars, and other downhole instruments, and may even lead to serious accidents such as drill string breakage.

[0004] To mitigate these harmful vibrations, some drill collars with vibration damping functions have emerged in the existing technology. However, the existing vibration damping drill collars have a simple structural design, and the vibration damping mechanism is only for a specific vibration mode. For example, some vibration damping drill collars use springs or hydraulic systems to buffer axial and radial impacts, but they are still close to rigid connections when transmitting torque and cannot effectively suppress high-frequency torsional vibrations. Other torsional dampers focus on absorbing torque fluctuations, but ignore the absorption of axial and radial vibrations in the middle of the drill collar.

[0005] Therefore, this utility model proposes a vibration-damping drill collar to overcome the shortcomings of the prior art. Utility Model Content

[0006] In view of the problems in the existing technology of vibration-damping drill collars, such as incomplete vibration-damping function, simple structural design, and inability to simultaneously and effectively suppress axial or radial vibration in the middle of the drill collar and torsional vibration transmitted to the drill bit end, this utility model aims to provide a vibration-damping drill collar with an improved structure that can effectively solve the above problems.

[0007] This utility model provides a vibration-damping drill collar, comprising: a drill collar body, a shell, a vibration-damping sleeve, a vibration-damping spring, and a damping ring. The shell is fitted around the middle outer periphery of the drill collar body, the vibration-damping sleeve is disposed between the drill collar body and the shell, one end of the vibration-damping spring elastically abuts against the vibration-damping sleeve, and the damping ring is disposed around the vibration-damping spring and cooperates with the vibration-damping spring to attenuate vibration.

[0008] The vibration-damping drill collar also includes a damping mechanism and a drill bit. The damping mechanism is connected in series at one end of the drill collar body, and the drill bit is connected to the end of the damping mechanism away from the drill collar body.

[0009] The suppression mechanism includes a spline shaft, the axis of which coincides with the axis of the drill collar body, and one end of the spline shaft is connected to the drill collar body in a driving connection, while the other end of the spline shaft is connected to the drill bit in a driving connection.

[0010] Furthermore, the suppression mechanism also includes a torsion spring fitted around the outer periphery of the spline shaft and friction disc one and friction disc two fitted on the spline shaft, wherein friction disc one and friction disc two are configured to slide and rub against each other when the spline shaft rotates.

[0011] Preferably, the shock-absorbing drill collar further includes a support column and a support sleeve, which are fixedly connected to the inner wall of the housing to fix and connect the other end of the shock-absorbing spring, providing a stable mounting base for the central shock-absorbing mechanism.

[0012] Preferably, the shock-absorbing drill collar further includes a positioning disk and a positioning pin. The positioning disk is rotatably mounted on the housing, the positioning pin is connected to the positioning disk, and the positioning pin passes through the positioning disk and is inserted into the inner cavity of the shock-absorbing spring to ensure the accurate positioning of the shock-absorbing spring.

[0013] Preferably, the shock-absorbing drill collar further includes a sealing ring, which is disposed at the end connection gap between the outer shell and the drill collar body to achieve a seal and prevent external impurities from entering the shock-absorbing mechanism.

[0014] Preferably, the suppression mechanism further includes a positioning sleeve, which is coaxially fitted onto the spline shaft and specifically serves as a mounting carrier for the torsion spring and the second friction disc, ensuring the coaxiality of these components.

[0015] Preferably, the suppression mechanism further includes a thrust bearing, which is fitted onto the spline shaft and disposed in the stacked structure of the first friction disc and the second friction disc, in order to reduce motion wear and improve service life when the components rotate relative to each other.

[0016] Preferably, the suppression mechanism further includes a limiting ring, which is fixed to the outer periphery of the spline shaft. The limiting ring is used to limit the axial movement range of the spline shaft and effectively prevent parts from detaching, thereby improving the structural reliability of the suppression mechanism.

[0017] Preferably, the transmission connection between the spline shaft and the drill collar body is a spline connection to reliably transmit torque, and the transmission connection between the spline shaft and the drill bit is a threaded connection to facilitate the installation and replacement of the drill bit.

[0018] This utility model has the following beneficial effects:

[0019] 1. This utility model solves the problems of the prior art where the drill collar is difficult to effectively suppress central vibration and torsional vibration at the same time and has a single vibration reduction function. It achieves dual vibration reduction and comprehensively improves the working stability of the drill bit by setting a central vibration reduction mechanism consisting of a vibration damping sleeve, vibration damping spring and damping ring between the outer shell and the drill collar body, and setting a suppression mechanism consisting of a spline shaft, torsion spring and friction disc in series between the drill collar body and the drill bit.

[0020] 2. This utility model solves the problems of poor absorption of axial and radial vibration in the middle of the drill collar and slow vibration attenuation in the prior art by setting a shock-absorbing sleeve, using a shock-absorbing spring to provide elastic buffer and using a damping ring for damping. It achieves rapid absorption of the impact energy in the middle and shortens the vibration duration.

[0021] 3. This utility model solves the problem in the prior art that the torsional impact of the drill bit is rigidly transmitted, leading to stick-slip or damage to the drill bit, by setting a torsion spring and a friction disc. The torsion spring absorbs the torsional impact force through its elastic torsion, while the relative sliding friction between the friction discs consumes the torsional vibration energy. Attached Figure Description

[0022] Figure 1 This is a front perspective view of a shock-absorbing drill collar proposed in this utility model;

[0023] Figure 2 This is a partial structural exploded view of the outer shell of a shock-absorbing drill collar proposed in this utility model;

[0024] Figure 3 This is a partial structural breakdown diagram of the damping ring of a shock-absorbing drill collar proposed in this utility model;

[0025] Figure 4 This is a partial structural spline shaft disassembly diagram of a shock-absorbing drill collar proposed in this utility model.

[0026] Legend:

[0027] 1. Drill collar body; 2. Suppression mechanism; 201. Drill bit; 202. Splined shaft; 203. Torsion spring; 204. Positioning sleeve; 205. Limiting retaining ring; 206. Friction disc one; 207. Friction disc two; 208. Thrust bearing; 3. Housing; 4. Shock-absorbing sleeve; 5. Positioning disc; 6. Positioning pin; 7. Shock-absorbing spring; 8. Damping ring; 9. Support pin; 10. Sealing retaining ring; 11. Support sleeve. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0029] Example:

[0030] Please refer to Figures 1 to 4 This utility model provides a vibration-damping drill collar, which aims to solve the problem in the prior art that it is difficult to simultaneously and effectively suppress axial or radial vibration generated in the middle of the drill collar, as well as high-frequency torsional vibration transmitted from the drill head.

[0031] like Figure 1 , Figure 2 and Figure 3 As shown, the vibration-damping drill collar includes a drill collar body 1 and a housing 3 fitted around the outer periphery of the middle part of the drill collar body 1; the core of the technical solution of the vibration-damping drill collar lies in setting a central vibration damping mechanism between the drill collar body 1 and the housing 3, and a suppression mechanism 2 connected in series at one end of the drill collar body 1.

[0032] The central damping mechanism is used to counteract the vibration in the middle of the drill collar. Specifically, it includes a damping sleeve 4 disposed between the drill collar body 1 and the outer shell 3. The central damping mechanism also includes a damping spring 7, one end of which elastically abuts against the damping sleeve 4 to provide elastic buffering for the damping sleeve 4. The central damping mechanism also includes a damping ring 8, which is disposed around the damping spring 7 and works in conjunction with the damping spring 7 to attenuate the vibration amplitude and duration.

[0033] Furthermore, in order to stably support the shock-absorbing spring 7, the central shock-absorbing mechanism is also provided with a support column 9 and a support sleeve 11. The support column 9 and the support sleeve 11 are fixedly connected to the inner wall of the outer shell 3 and are used to fix and connect the other end of the shock-absorbing spring 7.

[0034] Furthermore, in order to ensure the accuracy of the damping position, the central damping mechanism is also equipped with a positioning plate 5 and a positioning column 6. The positioning plate 5 is rotatably mounted on the outer shell 3, and the positioning column 6 is connected to the positioning plate 5. The positioning column 6 passes through the positioning plate 5 and is inserted into the inner cavity of the damping spring 7.

[0035] Furthermore, in order to reduce the entry of impurities, the central shock absorption mechanism is also equipped with a sealing ring 10, which is located at the end connection gap between the outer shell 3 and the drill collar body 1 for sealing.

[0036] Please refer to Figure 1 , Figure 2and Figure 4 The suppression mechanism 2 is connected in series at one end of the drill collar body 1, and the other end of the suppression mechanism 2 is connected to the drill bit 201. The core component of the suppression mechanism 2 includes a spline shaft 202. The axis of the spline shaft 202 coincides with the axis of the drill collar body 1. One end of the spline shaft 202 is connected to the drill collar body 1 by a spline connection, and the other end of the spline shaft 202 is connected to the drill bit 201 by a threaded connection.

[0037] The suppression mechanism 2 also includes a torsion spring 203 fitted around the spline shaft 202, which is used to absorb torsional impact; the suppression mechanism 2 also includes a friction disk 1 206 and a friction disk 207, which are both fitted on the spline shaft 202 and configured to slide and rub against each other when the spline shaft 202 rotates, thereby consuming vibration energy through friction.

[0038] To achieve the above structure, the suppression mechanism 2 also includes a positioning sleeve 204, which is coaxially fitted onto the spline shaft 202. The positioning sleeve 204 serves as a mounting carrier for the torsion spring 203 and the second friction disc 207. The suppression mechanism 2 also includes a thrust bearing 208, which is fitted onto the spline shaft 202. The thrust bearing 208 is disposed in the stacked structure of the first friction disc 206 and the second friction disc 207 to reduce motion wear. The suppression mechanism 2 also includes a limiting ring 205, which is fixed to the outer periphery of the spline shaft 202. The limiting ring 205 is used to limit the axial movement range of the spline shaft 202 and prevent parts from detaching.

[0039] In a preferred embodiment, in order to stably support the shock-absorbing spring 7, the shock-absorbing drill collar also includes a support column 9 and a support sleeve 11. The support column 9 and the support sleeve 11 are fixedly connected to the inner wall of the housing 3 and are used to fix and connect the other end of the shock-absorbing spring 7.

[0040] As another preferred embodiment, in order to ensure the accuracy of the damping position, the damping drill collar also includes a positioning disk 5 and a positioning pin 6. The positioning disk 5 is rotatably mounted on the housing 3, and the positioning pin 6 is connected to the positioning disk 5. The positioning pin 6 passes through the positioning disk 5 and is inserted into the inner cavity of the damping spring 7.

[0041] As another preferred embodiment, in order to prevent impurities from entering and improve sealing, the shock-absorbing drill collar also includes a sealing ring 10, which is disposed at the end connection gap between the housing 3 and the drill collar body 1.

[0042] In another preferred embodiment, in order to reliably install the torsion spring 203 and the second friction disc 207, the suppression mechanism 2 also includes a positioning sleeve 204, which is coaxially fitted onto the spline shaft 202 and serves as a mounting carrier for the torsion spring 203 and the second friction disc 207.

[0043] As another preferred embodiment, in order to reduce wear when the friction disc rotates, the suppression mechanism 2 also includes a thrust bearing 208, which is mounted on the spline shaft 202 and disposed in the stacked structure of friction disc one 206 and friction disc two 207.

[0044] As another preferred embodiment, in order to prevent the spline shaft 202 from axially moving and the parts from falling off, the suppression mechanism 2 also includes a limiting ring 205, which is fixed to the outer periphery of the spline shaft 202 to limit the axial movement range of the spline shaft 202.

[0045] As another preferred embodiment, in order to achieve reliable torque transmission, the transmission connection between the spline shaft 202 and the drill collar body 1 is preferably a spline connection, and the transmission connection between the spline shaft 202 and the drill bit 201 is preferably a threaded connection.

[0046] Working principle: When the drill collar generates axial or radial vibration in the middle during drilling, the shock-absorbing sleeve 4, which is set between the drill collar body 1 and the outer shell 3, will be compressed or displaced. The shock-absorbing spring 7 will then undergo elastic deformation, thereby providing elastic buffer to absorb the vibration impact force. At the same time, the damping ring 8 works together with the shock-absorbing spring 7 to quickly attenuate the amplitude and duration of the vibration through the damping effect. The entire central shock absorption process is stably supported by the support column 9 and support sleeve 11, which are fixedly connected to the inner wall of the outer shell 3. The positioning column 6 is inserted into the inner cavity of the shock-absorbing spring 7 under the guidance of the positioning plate 5, ensuring the accuracy of the shock absorption position. The sealing ring 10 seals the gap between the outer shell 3 and the drill collar body 1 to prevent impurities from entering.

[0047] When the drill bit 201 encounters a torsional impact during rotation, the impact force is transmitted to the spline shaft 202 through the threaded connection. Since the spline shaft 202 is connected to the drill collar body 1 via the spline connection, the torsional impact force causes the torsion spring 203 mounted on the spline shaft 202 to undergo torsional deformation. The elastic restoring force of the torsion spring 203 offsets part of the impact energy. At the same time, the torsional vibration causes the friction disc 1 206 and friction disc 207 mounted on the spline shaft 202 to slide relative to each other. The sliding friction between the two friction discs consumes a large amount of vibration energy, further suppressing the torsional vibration. The positioning sleeve 204 provides a mounting carrier for the torsion spring 203 and friction disc 207, the thrust bearing 208 reduces the wear of the rotational motion, and the limit retaining ring 205 restricts the axial movement range of the spline shaft 202.

[0048] Through the synergistic effect of the aforementioned central damping mechanism and suppression mechanism 2, the problem of simultaneously and effectively suppressing central vibration and torsional vibration in the existing technology is solved, thereby improving the stability of drill collar operation.

Claims

1. A vibration-damping drill collar, comprising: The drill collar body (1), the outer shell (3), the shock-absorbing sleeve (4), the shock-absorbing spring (7) and the damping ring (8) are disposed between the drill collar body (1) and the outer shell (3). The outer shell (3) is fitted around the middle outer periphery of the drill collar body (1). One end of the shock-absorbing spring (7) is elastically abutted against the shock-absorbing sleeve (4). The damping ring (8) is disposed around the shock-absorbing spring (7) and cooperates with the shock-absorbing spring (7) to dampen vibration. Its features are, The shock-absorbing drill collar also includes a suppression mechanism (2) and a drill bit (201). The suppression mechanism (2) is connected in series to one end of the drill collar body (1), and the drill bit (201) is connected to the end of the suppression mechanism (2) away from the drill collar body (1). The suppression mechanism (2) includes: a spline shaft (202), a torsion spring (203), a friction disk one (206), and a friction disk two (207). The axis of the spline shaft (202) coincides with the axis of the drill collar body (1). One end of the spline shaft (202) is connected to the drill collar body (1) and the other end is connected to the drill bit (201). The torsion spring (203) is fitted on the outer periphery of the spline shaft (202) to absorb torsional impact. The friction disk one (206) and the friction disk two (207) are both fitted on the spline shaft (202) and are configured to slide and rub against each other when the spline shaft (202) rotates.

2. The vibration-damping drill collar according to claim 1, characterized in that, The shock-absorbing drill collar also includes a support column (9) and a support sleeve (11), which are fixedly connected to the inner wall of the outer shell (3) and are used to fix and connect the other end of the shock-absorbing spring (7).

3. A vibration-damping drill collar according to claim 1, characterized in that, The shock-absorbing drill collar also includes a positioning disk (5) and a positioning pin (6). The positioning disk (5) is rotatably mounted on the outer shell (3). The positioning pin (6) is connected to the positioning disk (5). The positioning pin (6) passes through the positioning disk (5) and is inserted into the inner cavity of the shock-absorbing spring (7).

4. A vibration-damping drill collar according to claim 1, characterized in that, The shock-absorbing drill collar also includes a sealing ring (10), which is disposed at the end connection gap between the outer shell (3) and the drill collar body (1) for sealing.

5. A vibration-damping drill collar according to claim 1, characterized in that, The suppression mechanism (2) also includes a positioning sleeve (204), which is coaxially fitted onto the spline shaft (202) and serves as a mounting carrier for the torsion spring (203) and the friction disc (207).

6. A vibration-damping drill collar according to claim 1, characterized in that, The suppression mechanism (2) also includes a thrust bearing (208), which is fitted onto the spline shaft (202) and disposed in the stacked structure of the first friction disk (206) and the second friction disk (207) to reduce motion wear.

7. A vibration-damping drill collar according to claim 1, characterized in that, The suppression mechanism (2) further includes a limiting ring (205), which is fixed to the outer periphery of the spline shaft (202) to limit the axial movement range of the spline shaft (202) and prevent the parts from detaching.

8. A vibration-damping drill collar according to claim 1, characterized in that, The transmission connection between the spline shaft (202) and the drill collar (1) is a spline connection; the transmission connection between the spline shaft (202) and the drill bit (201) is a threaded connection.

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