A PDC bit torque self-balancing device

Abstract

The application provides a PDC drill bit torque self-balancing device, which is an energy storage device in a drill bit body or a connecting joint. The device is mainly composed of a torsional spring, an energy storage body, a base, a core pipe and a bearing. When the drill bit rotates steadily, the energy storage device stores energy without releasing. When the drill bit encounters resistance and suddenly slows down, the energy storage device releases energy, applies impact force to the drill bit and provides more energy to assist the drill bit in breaking rocks. When the drill bit accelerates after overcoming the resistance, the energy storage device starts to store energy and reduces the acceleration of the drill bit. Through the device, the continuous process of energy storage, release, impact and re-storage of the drill bit is realized, the torque fluctuation and vibration of the drill bit are reduced in the process, harmful vibration is converted into energy for assisting the drill bit in breaking rocks, the torque fluctuation and vibration of the drill bit are improved, the service life of the drill bit is prolonged and the mechanical drilling speed is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to an auxiliary rock-breaking downhole tool in the field of petroleum and geological drilling, in particular to a PDC drill bit torque self-balancing device. BACKGROUND

[0002] At present, the drill bit used in petroleum geological drilling is mainly PDC drill bit, and the cutting tooth of the PDC drill bit is polycrystalline diamond compact. In the working process, the rock is broken by scraping the rock. In soft to medium-hard strata, it has the characteristics of fast drilling speed and long footage. However, during the drilling process of the drill bit, soft and hard alternating strata are often encountered, which leads to unstable working state of the drill bit, severe torque fluctuation, and even drill bit stop and slip phenomenon, thereby causing impact damage of PDC cutting teeth and premature scrap of the drill bit. SUMMARY

[0003] The purpose of the present application is to overcome the shortcomings of the prior art and provide a PDC drill bit torque self-balancing device.

[0004] The technical scheme is as follows:

[0005] A PDC drill bit torque self-balancing device, comprising an upper joint and a lower joint connected in sequence, and further comprising an energy storage device, an impact structure and a support structure arranged inside the upper joint and the lower joint;

[0006] The support structure comprises a core pipe and a sealing cover fixedly arranged on the upper end of the core pipe, and the lower end of the core pipe is fixedly connected with a base.

[0007] The energy storage device comprises an energy storage body rotatably sleeved on the core pipe and an elastic connecting piece, the upper end of the elastic connecting piece is fixedly connected with the energy storage body, the lower end is fixedly connected with the base, and the lower end of the energy storage body is connected with the base through an impact mechanism.

[0008] Further, the impact structure comprises a spline one arranged on the base and a spline two arranged on the lower end of the energy storage body, and the spline one and the spline two form a spline impact mechanism.

[0009] Further, the support structure further comprises a lower bearing and an upper bearing, and the two ends of the energy storage body are respectively supported by the lower bearing and the upper bearing.

[0010] Further, the base is connected with the lower joint through a fixing screw.

[0011] Further, the lower joint is connected with the upper joint through a thread.

[0012] Further, the core pipe is connected with the base through a thread.

[0013] Further, an upper sealing ring is arranged between the upper joint and the sealing cover.

[0014] Further, a seal is arranged between the core pipe and the sealing cover.

[0015] Further, an intermediate seal ring is arranged between the lower joint and the upper joint.

[0016] Further, the elastic connecting member comprises a torsion spring, a disc spring, a solid elastomer or a liquid elastomer.

[0017] The present application has the following advantages:

[0018] The PDC drill bit torque self-balancing device provided by the present application is an energy storage device, which can be installed in a drill bit body or a joint connected with the drill bit or other tools. The energy storage device is divided into two parts, one part is used for storing potential energy by using a torsion spring, and the other part is used for storing mechanical energy by using an energy storage body. When the drill bit rotates stably, the energy storage device stores energy and does not release energy. When the drill bit suddenly slows down due to resistance, the energy storage device releases energy, applies impact force to the drill bit, and provides more energy to assist the drill bit in breaking rocks. When the drill bit accelerates rotation after overcoming resistance, the energy storage device starts to store energy, reduces the acceleration of the drill bit, and reduces the impact damage of the drill bit. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The present application is a cross-sectional view of the PDC drill bit torque self-balancing device.

[0020] Figure 2 The present application is a transverse cross-sectional view of the PDC drill bit torque self-balancing device along the A-A section.

[0021] In the figure:

[0022] 1, lower seal ring, 2, fixing screw, 3, base, 4, lower bearing, 5, lower joint, 6, intermediate seal ring, 7, core pipe, 8, torsion spring, 9, energy storage body, 10, upper bearing, 11, upper seal ring, 12, sealing cover, 13, seal, 14, upper joint, 31, spline one, 91, spline two. DETAILED DESCRIPTION

[0023] The present application will be further described in detail below with reference to the accompanying drawings.

[0024] Referring to the drawings, a PDC drill bit torque self-balancing device comprises a lower seal ring 1, a fixing screw 2, a base 3, a lower bearing 4, a lower joint 5, an intermediate seal ring 6, a core pipe 7, a torsion spring 8, an energy storage body 9, an upper bearing 10, an upper seal ring 11, a sealing cover 12, a seal 13, and an upper joint 14.

[0025] The upper joint 14, the lower joint 5, and the drill bit are sequentially fixed and connected from top to bottom, and a space for arranging an energy storage device, an impact structure, and a support structure is arranged inside.

[0026] The support structure comprises a core tube 7 and a sealing cover 12 fixed to the upper end of the core tube 7, the sealing cover 12 is fixed to an upper joint 14, and the lower end of the core tube 7 is connected to the base 3 through screw threads.

[0027] The energy storage device comprises an energy storage body 9 and a torsion spring 8, the upper end of the energy storage body 9 is provided with an upper bearing 10 between the energy storage body 9 and the sealing cover 12, and the lower end of the energy storage body 9 is provided with a step for installing a lower bearing 4, and the lower bearing 4 is installed between the steps.

[0028] The upper end of the torsion spring 8 is fixedly connected to the energy storage body 9, and the lower end of the torsion spring 8 is fixedly connected to the base 3, and the lower end of the energy storage body 9 is connected to the base 3 through an impact mechanism.

[0029] The impact structure comprises a spline one 31 arranged on the base 3 and a spline two 91 arranged on the lower end of the energy storage body 9, the spline one 31 and the spline two 91 form a spline impact mechanism, and spline teeth of the spline one 31 and the spline two 91 are arranged alternately and leave a rotating space in the middle.

[0030] The two ends of the energy storage body 9 are supported by the lower bearing 4 and the upper bearing 10.

[0031] The base 3 is connected to the lower joint 5 through a fixing screw 2.

[0032] The lower joint 5 is connected to the upper joint 14 through screw threads.

[0033] The upper joint 14 and the sealing cover 12 are provided with an upper sealing ring 11.

[0034] The core tube 7 and the sealing cover 12 are provided with a sealing element 13.

[0035] The lower joint 5 and the upper joint 14 are provided with an intermediate sealing ring 6.

[0036] The elastic connecting element can also be a disc spring, a solid elastomer or a liquid elastomer.

[0037] Working principle:

[0038] The energy storage body 9 is flexibly connected to the base 3 through the torsion spring 8, the energy storage body 9 is installed between the lower joint 5 and the upper joint 14, the base 3 is connected to the lower joint 5 through the fixing screw 2, the lower joint 5 is connected to the upper joint 14 through screw threads, and the core tube 7 is connected to the base 3 through screw threads. The two ends of the energy storage body 9 are supported by the lower bearing 4 and the upper bearing 10, the core tube 7 supports the torsion spring 8 and serves as a mud passage.

[0039] The upper joint 14 and the sealing cover 12 are provided with the upper sealing ring 11, the core tube 7 and the sealing cover 12 are provided with the sealing element 13, and the lower joint and the upper joint are provided with the intermediate sealing ring 6.

[0040] When the drill bit rotates, the torsion spring 8 rotates with the drill bit through the connection with the base 3 and produces elastic deformation to drive the energy storage body 9 to rotate, and the torsion spring 8 and the energy storage body 9 start to store energy.

[0041] When the drill bit rotates at a constant speed, the stored energy is not released.

[0042] When the drill bit rotates at a constant speed, the stored energy is not released.

[0043] When the drill bit rotates at a constant speed, the stored energy is not released.

[0044] The energy storage device can be part of the entire drill bit body, and the energy storage body 9 is flexibly connected with the drill bit through the torsion spring 8.

[0045] Although the embodiments of the present application have been shown and described, it should be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A PDC bit torque self-balancing device comprising an upper joint (14) and a lower joint (5) connected in sequence, characterized in that, The energy storage device, the impact structure and the support structure are arranged inside the upper joint (14) and the lower joint (5); The support structure comprises a core tube and a sealing cover (12) fixed to the upper end of the core tube, and the lower end of the core tube is fixedly connected to the base (3); The energy storage device comprises an energy storage body (9) rotatably sleeved on the core tube and an elastic connecting member, the upper end of the elastic connecting member is fixedly connected to the energy storage body (9), the lower end of the elastic connecting member is fixedly connected to the base (3), and the lower end of the energy storage body (9) is connected to the base (3) through the impact mechanism; The impact structure comprises a spline one (31) arranged on the base (3) and a spline two (91) arranged on the lower end of the energy storage body (9), and the spline one (31) and the spline two (91) constitute a spline impact mechanism; The support structure further comprises a lower bearing (4) and an upper bearing (10), and the two ends of the energy storage body (9) are respectively supported by the lower bearing (4) and the upper bearing (10); The base (3) is connected to the lower joint (5) through a fixing screw (2).

2. The PDC bit torque self-balancing device of claim 1, wherein, The lower joint (5) is connected to the upper joint (14) through a threaded connection.

3. The PDC bit torque self-balancing device of claim 1, wherein, The core tube is connected to the base (3) through a threaded connection.

4. The PDC bit torque self-balancing device of claim 1, wherein, An upper sealing ring (11) is arranged between the upper joint (14) and the sealing cover (12).

5. The PDC bit torque self-balancing device of claim 1, wherein, A sealing member (13) is arranged between the core tube and the sealing cover (12).

6. The PDC bit torque self-balancing device of claim 1, wherein, An intermediate sealing ring (6) is arranged between the lower joint (5) and the upper joint (14).

7. The PDC bit torque self-balancing device of claim 1, wherein, The elastic connecting member comprises a torsion spring (8), a disc spring, a solid elastomer or a liquid elastomer.

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