A power-tuned downhole composite damper and method of operation thereof

Abstract

The application belongs to the technical field of oil and gas drilling and relates to a power tuning downhole composite damper and a working method thereof. The power tuning downhole composite damper comprises a mandrel for transmitting the power of a drill string. A disc spring shell and a torsion shaft shell are sleeved on the mandrel. A first upper step and a first lower step are formed in the disc spring shell, and a second upper step and a second lower step are formed in the mandrel. A disc spring assembly is arranged between the first upper step and the first lower step and between the second upper step and the second lower step. The disc spring shell and the torsion shaft shell are in contact, and a torsion counterweight and a torsion power piston are arranged between the mandrel and the torsion shaft shell. The torsion power piston is connected to the torsion counterweight through a plurality of flexible steel wire ropes, the torsion power piston is connected to the mandrel through a spline, and a damping and shock absorption structure is arranged between the torsion shaft shell and the torsion power piston. The power tuning downhole composite damper can reduce the axial jumping and torsional vibration of a drill bit caused by the rock breaking process, protect downhole drilling tools and prolong the service life of the drilling tools.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil and gas drilling, and relates to a power-tuned downhole composite damper and a working method thereof. BACKGROUND

[0002] In the process of oil and gas drilling, downhole vibration is inevitably caused due to rock breaking of a drill bit, and severe downhole vibration is easy to cause failure or even fracture of downhole equipment such as a drill pipe, a drill collar, LWD, MWD, PTWD, a steering drilling tool and a drill bit, and directly affects drilling efficiency and resource exploration efficiency. According to statistics, non-operation time (NPT) caused by drill string vibration and impact accounts for 25% of total NPT every year. In particular, in the process of drilling in gravel strata and hard strata, and deep wells and ultra-deep wells, downhole vibration is more obvious, leading to frequent accidents of drill pipe fracture and falling into a well and sharp increase of drill bit consumption. Therefore, a technology for inhibiting downhole harmful vibration and a matching device become necessary in the above drilling process. The key to inhibiting downhole vibration lies in effective control of the strength of a vibration source, i.e., drill bit vibration, especially strong downhole vibration in the process of drilling in hard and brittle strata, gravel strata and other serious strata, so as to ensure continuous and stable high-efficiency rock breaking of the drill bit, and balance rock breaking efficiency and drill bit life, thereby reducing downhole risks and improving drilling speed.

[0003] At present, a conventional damper is mostly a spring damping damper, and the inhibiting effect on axial vibration is relatively obvious. However, downhole vibration exists in multiple forms, including axial vibration and torsional vibration and other complex vibrations, and multiple vibrations may be coupled and developed, which will pose a great threat to downhole drilling tools. In addition, in the process of drilling by a PDC drill bit, torsional vibration becomes the main vibration form, and obviously the inhibiting effect of the conventional spring damping damper on complex vibration working conditions is limited. SUMMARY

[0004] In order to overcome the above-mentioned defects of the prior art, the purpose of the present application is to provide a power-tuned downhole composite damper and a working method thereof. The present application can simultaneously reduce axial jumping and torsional vibration of a drill bit caused by a rock breaking process, and thereby inhibit drill string vibration from a main source, protect downhole drilling tools and prolong the service life of the drilling tools.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] The present application discloses a power-tuned downhole composite damper, which comprises a mandrel, a disc spring shell and a torsional shaft shell are sleeved on the mandrel, a first upper step and a first lower step are formed in the disc spring shell, a second upper step and a second lower step are formed in the mandrel, and a disc spring assembly is arranged between the first upper step and the first lower step and between the second upper step and the second lower step.

[0007] The disc spring shell and the torsion shaft shell are in contact, and a torsion counterweight and a torsion power piston are arranged between the mandrel and the torsion shaft shell, the torsion power piston is connected to the torsion counterweight through a plurality of flexible steel wires, the torsion power piston is connected to the mandrel through a spline, and a damping shock-absorbing structure is arranged between the torsion shaft shell and the torsion power piston.

[0008] Further, the disc spring assembly comprises a disc spring group, and disc spring washers are arranged at two ends of the disc spring group.

[0009] Further, a spline shell is sleeved on the mandrel, the spline shell is connected to the mandrel through a spline, the spline shell is fixedly connected to the disc spring shell, and a first upper step is arranged on the spline shell.

[0010] Further, a damping piston is sleeved on the mandrel, a second lower step is arranged on the damping piston, and the damping piston is fixedly sleeved on the mandrel.

[0011] Further, an annular damping flow channel is arranged between the mandrel and the disc spring shell, and hydraulic oil is added in the annular damping flow channel.

[0012] Further, the annular damping flow channel is located between the damping piston and the disc spring shell, the annular damping flow channel comprises an upper damping flow channel and a lower damping flow channel, the upper damping flow channel and the lower damping flow channel are arranged on the disc spring shell, and the upper damping flow channel and the lower damping flow channel are in communication.

[0013] Further, a bearing upper end cover and a bearing lower end cover are sleeved on the mandrel, the bearing lower end cover is fixedly connected to the mandrel, the bearing upper end cover is fixedly connected to a torsion shaft, a bearing group is arranged between the bearing upper end cover and the bearing lower end cover, the bearing upper end cover is fixedly connected to the torsion shaft, the torsion shaft is connected to a torsion counterweight, the torsion shaft, the bearing upper end cover and the torsion counterweight are located between the mandrel and the torsion shaft shell, and the bearing group and the bearing lower end cover are located between the torsion shaft and the mandrel.

[0014] Further, the torsion counterweight is sleeved on the mandrel, the bearing lower end cover is arranged between the torsion counterweight and the mandrel, and the torsion counterweight is located above the torsion power piston.

[0015] Further, the damping shock-absorbing structure comprises a low-pressure chamber and a high-pressure chamber, the low-pressure chamber and the high-pressure chamber are located between the torsion shaft shell and the torsion power piston, a low-pressure damping hole in communication with the low-pressure chamber is arranged on the torsion shaft shell, and a high-pressure damping hole in communication with the high-pressure chamber is arranged on the torsion power piston.

[0016] The torsion power piston is fixedly connected to a sliding piston, a piston nozzle is sleeved in the sliding piston, a nozzle clasp is arranged at a port of the piston nozzle, and the inner hole of the mandrel, the high-pressure chamber, the high-pressure damping hole, the inner hole of the sliding piston and the inner hole of the piston nozzle are in communication.

[0017] The application further discloses a working method of the power-tuned downhole composite damper.

[0018] When the core shaft encounters torsional vibration, the torsional power piston also appears torsional vibration under the action of the spline of the core shaft, a rotational speed difference appears between the torsional counterweight and the torsional power piston, the flexible steel wire rope starts to be twisted and wound, the axial vertical length of the flexible steel wire rope is shortened and the torsional power piston is pulled upward, and the torsional power piston continuously consumes torsional vibration energy under the action of the damping shock-absorbing structure, so that the purpose of inhibiting torsional vibration of the drill string is achieved.

[0019] When the core shaft vibrates downward or the disc spring shell jumps upward relative to the core shaft when the torsional shaft shell drives the disc spring shell, the first lower step pushes the disc spring assembly upward, the second upper step limits the upward movement of the disc spring assembly, the disc spring assembly is compressed, a spring damping system is formed, and the upward vibration of the disc spring shell or the downward vibration of the core shaft is inhibited.

[0020] When the core shaft vibrates upward or the disc spring shell jumps downward relative to the core shaft, the first upper step pushes the disc spring assembly downward, the second lower step limits the downward movement of the disc spring assembly, the disc spring assembly is compressed, a spring damping system is formed, and the downward vibration of the disc spring shell or the upward vibration of the core shaft is inhibited.

[0021] Compared with the prior art, the application has the following beneficial effects:

[0022] The present application comprises a mandrel for transmitting power of a drill string. A disc spring housing and a torsion shaft housing are sleeved on the mandrel. The disc spring housing is used for isolating a disc spring assembly from the outside world and assisting the disc spring assembly in damping the drill string. A first upper step and a first lower step are formed on the disc spring housing, and a second upper step and a second lower step are formed on the mandrel. A disc spring assembly is arranged between the first upper step and the first lower step and between the second upper step and the second lower step. When the disc spring housing and the mandrel have axial relative vibration, the disc spring assembly cooperates with the first upper step, the first lower step, the second upper step and the second lower step to suppress the vibration of the disc spring housing and the mandrel. The disc spring housing and the torsion shaft housing are in contact. The axial upward vibration of the torsion shaft housing can be transmitted to the disc spring housing, and then the axial vibration is suppressed by the disc spring assembly. The torsion shaft housing is used for isolating a torsion weight, a torsion power piston and a damping and damping structure from the outside world. The torsion weight and the torsion power piston are arranged between the mandrel and the torsion shaft housing. The torsion power piston is connected to the torsion weight through a plurality of flexible steel wire ropes. The torsion power piston is connected to the mandrel through a spline. The damping and damping structure is arranged between the torsion shaft housing and the torsion power piston. When the mandrel has torsional vibration, the mandrel drives the torsion power piston to vibrate synchronously. The torsion power piston and the torsion weight have a speed difference. Then the flexible steel wire ropes are twisted and wound. The axial vertical length of the flexible steel wire ropes is shortened and the torsion power piston is pulled upward. The torsion power piston continuously consumes the torsional vibration energy under the action of the damping and damping structure, so as to suppress the torsional vibration of the drill string. The present application can simultaneously reduce the axial jumping and the torsional vibration of the drill bit caused by the rock breaking process, so as to suppress the drill string vibration from the main source, protect the downhole drilling tool and prolong the service life of the drilling tool.

[0023] The method of the present application is as follows: when the mandrel encounters torsional vibration, the torsion power piston has torsional vibration under the action of the spline of the mandrel. A speed difference appears between the torsion weight and the torsion power piston. The axial vertical length of the flexible steel wire ropes is shortened and the torsion power piston is pulled upward. The torsion power piston continuously consumes the torsional vibration energy under the action of the damping and damping structure, so as to suppress the torsional vibration of the drill string. When the mandrel vibrates downward or the torsion shaft housing drives the disc spring housing to jump upward relative to the mandrel, the first lower step drives the disc spring assembly to move upward, the second upper step limits the upward movement of the disc spring assembly, the disc spring assembly is compressed, a spring damping system is formed, and the upward vibration of the disc spring housing or the downward vibration of the mandrel is suppressed. When the mandrel vibrates upward or the disc spring housing jumps downward relative to the mandrel, the first upper step drives the disc spring assembly to move downward, the second lower step limits the downward movement of the disc spring assembly, the disc spring assembly is compressed, a spring damping system is formed, and the downward vibration of the disc spring housing or the upward vibration of the mandrel is suppressed. The method of the present application can simultaneously reduce the axial jumping and the torsional vibration of the drill bit caused by the rock breaking process, so as to suppress the drill string vibration from the main source, protect the downhole drilling tool and prolong the service life of the drilling tool. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic diagram of the overall structure of the present application;

[0025] Figure 2 is a sectional view of the upper section of the composite damper of the present application;

[0026] Figure 3 is a sectional view of the middle section of the composite damper of the present application;

[0027] Figure 4 is a sectional view of the lower section of the composite damper of the present application;

[0028] Figure 5 is a sectional view of the lower section of the composite damper of the present application; Figure 1 and Figure 2 is a sectional view of the lower section of the composite damper of the present application;

[0029] Figure 6 is a sectional view of the lower section of the composite damper of the present application; Figure 1 and Figure 4 is a sectional view of the lower section of the composite damper of the present application;

[0030] Figure 7 is a sectional view of the lower section of the composite damper of the present application;

[0031] wherein: 1, mandrel; 2, spline housing; 3, disc spring assembly; 4, disc spring set; 5, disc spring housing; 6, disc spring washer; 7, annular damping flow channel; 7-1, upper damping flow channel; 7-2, lower damping flow channel; 8, damping piston; 9, torsion shaft housing; 10, bearing upper end cover; 11, bearing set; 12, torsion shaft; 13, bearing lower end cover; 14, torsion counterweight; 15, steel wire rope buckle; 16, flexible steel wire rope; 17, torsion power piston; 18, set screw; 19, low pressure damping hole; 20, high pressure damping hole; 21, sliding piston; 22, piston nozzle; 23, nozzle snap spring; 24, damping shock absorbing structure; 25, low pressure chamber; 26, high pressure chamber; 27, first upper step; 28, second upper step; 29, first lower step; 30, second lower step. DETAILED DESCRIPTION

[0032] In order to make the personnel in the technical field better understand the present application scheme, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person of ordinary skill in the art without making creative labor should belong to the protection scope of the present application.

[0033] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless the contrary is indicated. For example, the description of the present application is not intended to be limited to the particular forms shown in the drawings as these can he provided for purposes of example and illustration only. It will be apparent to one of ordinary skill in the art that numerous modifications, both to materials and methods, can be practiced within the scope of the present application. It is intended that the description of the present application contained herein be considered in a descriptive sense only and not limiting. It is intended that the present application be considered as encompassing all such modifications.

[0034] The present application is further described in detail by way of reference only to the attached drawings wherein:

[0035] Referring to Figure 1 The present application discloses a power tuning type downhole composite shock absorber, comprising a core shaft 1, the core shaft 1 is used for transmitting the power of a drill string. A disc spring shell 5 and a torsion shaft shell 9 are sleeved on the core shaft 1, referring to Figure 2 The disc spring shell 5 is used for isolating the disc spring assembly 3 from the outside world and assisting the disc spring assembly 3 in damping the drill string. A first upper step 27 and a first lower step 29 are formed on the disc spring shell 5, and a second upper step 28 and a second lower step 30 are formed on the core shaft 1, and the disc spring assembly 3 is arranged between the first upper step 27 and the first lower step 29 and between the second upper step 28 and the second lower step 30, so that the disc spring assembly 3 can suppress the vibration of the disc spring shell 5 and the core shaft 1 when the disc spring shell 5 and the core shaft 1 vibrate axially. The disc spring shell 5 and the torsion shaft shell 9 are in contact, and the axial vibration of the torsion shaft shell 9 can be transmitted to the disc spring shell 5, and then suppressed by the disc spring assembly 3, and the torsion shaft shell 9 is used for isolating the torsion weight 14, the torsion power piston 17 and the damping shock absorbing structure 24 from the outside world. Referring to Figure 3 and Figure 4, the torsion shaft shell 9 and the torsion power piston 17 are provided with a damping shock-absorbing structure 24.

[0036] Referring to Figure 1 In another possible embodiment of the present application, the following is modified adaptively according to the situation. The core shaft 1 is provided with the disc spring shell 5 and the torsion shaft shell 9, referring to Figure 2 The disc spring shell 5 and the core shaft 1 are provided with the disc spring assembly 3, the disc spring shell 5 is provided with the first upper step 27 and the first lower step 29, the core shaft 1 is provided with the second upper step 28 and the second lower step 30, the first upper step 27 and the second upper step 28 are located at one end of the disc spring assembly 3, and the first lower step 29 and the second lower step 30 are located at the other end of the disc spring assembly 3.

[0037] Referring to Figure 3 and Figure 4 The disc spring shell 5 and the torsion shaft shell 9 are in contact, the core shaft 1 and the torsion shaft shell 9 are provided with the torsion weight 14 and the torsion power piston 17, the torsion power piston 17 is connected to the torsion weight 14 through a plurality of flexible steel wires 16, the torsion power piston 17 is connected to the core shaft 1 through a spline, and the torsion shaft shell 9 and the torsion power piston 17 are provided with the damping shock-absorbing structure 24.

[0038] The core shaft 1 is used for transmitting the power of the drill string. The disc spring shell 5 is used for isolating the disc spring assembly 3 from the outside world and assisting the disc spring assembly 3 in damping the drill string. The torsion shaft shell 9 can transmit the axial upward vibration to the disc spring shell 5, and then suppress the axial vibration through the disc spring assembly 3. The torsion shaft shell 9 is used for isolating the torsion weight 14, the torsion power piston 17 and the damping shock-absorbing structure 24 from the outside world.

[0039] In specific work, when the disc spring shell 5 and the mandrel 1 jump relative to each other, the disc spring shell 5 and the mandrel 1 extrude the disc spring assembly 3 through the first upper step 27, the first lower step 29, the second upper step 28 and the second lower step 30, the disc spring assembly 3 is compressed, a spring damping system is formed, and the relative vibration of the disc spring shell 5 and the mandrel 1 is inhibited. When the mandrel 1 encounters torsional vibration, the torsional power piston 17 also appears torsional vibration under the action of the spline of the mandrel 1. At this time, a speed difference appears between the torsional counterweight 14 and the torsional power piston 17, the axial vertical length of the flexible steel wire rope 16 is shortened and the torsional power piston 17 is pulled upward, and the torsional power piston 17 continuously consumes the torsional vibration energy under the action of the damping shock-absorbing structure 24, so that the purpose of inhibiting the torsional vibration of the drill string is achieved.

[0040] Embodiment one:

[0041] Referring to Figure 1 The embodiment discloses a power-tuned downhole composite damper, which comprises a mandrel 1, a disc spring shell 5 and a torsional shaft shell 9 are sleeved on the mandrel 1, a first upper step 27 and a first lower step 29 are formed in the disc spring shell 5, a second upper step 28 and a second lower step 30 are formed in the mandrel 1, and a disc spring assembly 3 is arranged between the first upper step 27 and the first lower step 29 and between the second upper step 28 and the second lower step 30.

[0042] The disc spring shell 5 and the torsional shaft shell 9 are in contact, a torsional counterweight 14 and a torsional power piston 17 are arranged between the mandrel 1 and the torsional shaft shell 9, the torsional power piston 17 is connected to the torsional counterweight 14 through a plurality of flexible steel wire ropes 16, the torsional power piston 17 is connected to the mandrel 1 through a spline, and a damping shock-absorbing structure 24 is arranged between the torsional shaft shell 9 and the torsional power piston 17.

[0043] The disc spring assembly 3 comprises a disc spring group 4, and disc spring washers 6 are arranged at two ends of the disc spring group 4. The disc spring group 4 is subjected to pressure through the disc spring washers 6 by the first upper step 27, the first lower step 29, the second upper step 28 and the second lower step 30.

[0044] Embodiment two:

[0045] Referring to Figure 1 The embodiment discloses a power-tuned downhole composite damper, which comprises a mandrel 1, a disc spring shell 5 and a torsional shaft shell 9 are sleeved on the mandrel 1, a first upper step 27 and a first lower step 29 are formed in the disc spring shell 5, a second upper step 28 and a second lower step 30 are formed in the mandrel 1, and a disc spring assembly 3 is arranged between the first upper step 27 and the first lower step 29 and between the second upper step 28 and the second lower step 30.

[0046] The disc spring shell 5 and the torsion shaft shell 9 are in contact, the torsion counterweight 14 and the torsion power piston 17 are arranged between the mandrel 1 and the torsion shaft shell 9, the torsion power piston 17 is connected to the torsion counterweight 14 through a plurality of flexible steel wire ropes 16, the torsion power piston 17 is connected to the mandrel 1 through a spline connection, and the damping shock-absorbing structure 24 is arranged between the torsion shaft shell 9 and the torsion power piston 17.

[0047] Referring to Figure 5 The spline shell 2 is arranged on the mandrel 1 in a sleeving mode, the spline shell 2 is connected to the mandrel 1 through a spline connection, the spline shell 2 is fixedly connected to the disc spring shell 5, and the first upper step 27 is arranged on the spline shell 2.

[0048] The damping piston 8 is arranged on the mandrel 1 in a sleeving mode, the second lower step 30 is arranged on the damping piston 8, and the damping piston 8 is fixedly arranged on the mandrel 1. The disc spring assembly 3 and the disc spring shell 5 are supported by the mandrel 1 through the damping piston 8.

[0049] The annular damping flow channel 7 is arranged between the mandrel 1 and the disc spring shell 5, and hydraulic oil is added into the annular damping flow channel 7.

[0050] The annular damping flow channel 7 is located between the damping piston 8 and the disc spring shell 5, the annular damping flow channel 7 comprises an upper damping flow channel 7-1 and a lower damping flow channel 7-2, the upper damping flow channel 7-1 and the lower damping flow channel 7-2 are both arranged on the disc spring shell 5, the upper damping flow channel 7-1 and the lower damping flow channel 7-2 are in communication, the upper damping flow channel 7-1 and the damping piston 8 form an upper damping cavity due to the fact that the disc spring shell 5 is arranged on the damping piston 8, the lower damping flow channel 7-2 and the damping piston 8 form a lower damping cavity, and the upper damping flow channel 7-1 and the lower damping flow channel 7-2 are in communication, that is, the upper damping cavity and the lower damping cavity are in communication. When the disc spring shell 5 and the mandrel 1 jump relatively, the hydraulic oil flows between the upper damping cavity and the lower damping cavity, and the relative vibration between the disc spring shell 5 and the mandrel 1 is inhibited at the same time.

[0051] Embodiment three

[0052] Referring to Figure 1 The embodiment discloses a power-tuned downhole composite shock absorber, which comprises a mandrel 1, a disc spring shell 5 and a torsion shaft shell 9 are arranged on the mandrel 1 in a sleeving mode, a first upper step 27 and a first lower step 29 are arranged on the disc spring shell 5, a second upper step 28 and a second lower step 30 are arranged on the mandrel 1, and a disc spring assembly 3 is arranged between the first upper step 27 and the first lower step 29 and between the second upper step 28 and the second lower step 30.

[0053] The disc spring shell 5 and the torsion shaft shell 9 are in contact, and the torsion counterweight 14 and the torsion power piston 17 are arranged between the mandrel 1 and the torsion shaft shell 9, the torsion power piston 17 is connected with the torsion counterweight 14 through a plurality of flexible steel wire ropes 16, the torsion power piston 17 is connected with the mandrel 1 through a spline connection, and the damping shock-absorbing structure 24 is arranged between the torsion shaft shell 9 and the torsion power piston 17.

[0054] The bearing lower end cover 13 is fixedly connected with the mandrel 1, the bearing upper end cover 10 is fixedly connected with the torsion shaft 12, the bearing group 11 is arranged between the bearing upper end cover 10 and the bearing lower end cover 13, the bearing upper end cover 10 is fixedly connected with the torsion shaft 12, the torsion shaft 12 is connected with the torsion counterweight 14, the torsion shaft 12, the bearing upper end cover 10 and the torsion counterweight 14 are located between the mandrel 1 and the torsion shaft shell 9, and the bearing group 11 and the bearing lower end cover 13 are located between the torsion shaft 12 and the mandrel 1.

[0055] The torsion counterweight 14 is sleeved on the mandrel 1, and the bearing lower end cover 13 is arranged between the torsion counterweight 14 and the mandrel 1, and the torsion counterweight 14 is located above the torsion power piston 17.

[0056] Embodiment four:

[0057] Referring to Figure 1 The embodiment discloses a power tuning type downhole composite shock absorber, which comprises a mandrel 1, a disc spring shell 5 and a torsion shaft shell 9 are sleeved on the mandrel 1, a first upper step 27 and a first lower step 29 are formed in the disc spring shell 5, a second upper step 28 and a second lower step 30 are formed in the mandrel 1, and a disc spring assembly 3 is arranged between the first upper step 27 and the first lower step 29 and between the second upper step 28 and the second lower step 30.

[0058] The disc spring shell 5 and the torsion shaft shell 9 are in contact, and the torsion counterweight 14 and the torsion power piston 17 are arranged between the mandrel 1 and the torsion shaft shell 9, the torsion power piston 17 is connected with the torsion counterweight 14 through a plurality of flexible steel wire ropes 16, the torsion power piston 17 is connected with the mandrel 1 through a spline connection, and the damping shock-absorbing structure 24 is arranged between the torsion shaft shell 9 and the torsion power piston 17.

[0059] The damping shock-absorbing structure 24 comprises a low-pressure chamber 25 and a high-pressure chamber 26, the low-pressure chamber 25 and the high-pressure chamber 26 are located between the torsion shaft shell 9 and the torsion power piston 17, a low-pressure damping hole 19 in communication with the low-pressure chamber 25 is formed in the torsion shaft shell 9, and a high-pressure damping hole 20 in communication with the high-pressure chamber 26 is formed in the torsion power piston 17.

[0060] The torsional power piston 17 is fixedly connected to the sliding piston 21, and the sliding piston 21 is sleeved with the piston nozzle 22. The piston nozzle 22 is provided with the nozzle snap spring 23 at the port. The inner hole of the core shaft 1, the high-pressure chamber 26, the high-pressure damping hole 20, the inner hole of the sliding piston 21 and the inner hole of the piston nozzle 22 are communicated.

[0061] When the core shaft 1 encounters torsional vibration, the torsional vibration of the core shaft 1 is converted into the axial vibration of the torsional power piston 17 through the flexible steel wire rope 16. The low-pressure chamber 25 and the high-pressure chamber 26 realize the suppression of the vibration of the torsional power piston 17 by discharging and absorbing liquid, thereby suppressing the torsional vibration of the core shaft 1.

[0062] Embodiment five:

[0063] Referring to Figure 1 , the embodiment discloses a power tuning type downhole composite damper, which comprises a core shaft 1, a spline housing 2, a disc spring assembly 3, a disc spring group 4, a disc spring housing 5, a disc spring washer 6, an annular damping flow channel 7, an upper damping flow channel 7-1, a lower damping flow channel 7-2, a damping piston 8, a torsional shaft housing 9, a bearing upper end cover 10, a bearing group 11, a torsional shaft 12, a bearing lower end cover 13, a torsional weight 14, a steel wire rope buckle 15, a flexible steel wire rope 16, a torsional power piston 17, a tight screw 18, a low-pressure damping hole 19, a high-pressure damping hole 20, a sliding piston 21, a piston nozzle 22, a nozzle snap spring 23, a damping shock absorption structure 24, a low-pressure chamber 25, a high-pressure chamber 26, a first upper step 27, a second upper step 28, a first lower step 29, a second lower step 30 and the damping shock absorption structure 24. The spline housing 2 is threadedly connected with the disc spring housing 5. The spline housing 2 is provided with a spline groove in the inner cylinder. The core shaft 1 transmits the drill string torque by cooperating with the spline groove of the spline housing 2. The damping piston 8 is threadedly connected with the core shaft 1. The upper part of the damping piston 8 is tightly connected with the disc spring assembly 3. When the core shaft 1 moves axially relative to the disc spring housing 5, the damping piston 8 moves synchronously with the core shaft 1 and can compress or release the disc spring group 4. The spline housing 2, the disc spring housing 5 and the damping piston 8 form a sealed chamber. The sealed chamber is filled with hydraulic oil. The annular damping flow channel 7 is formed between the step surface of the damping piston 8 and the disc spring housing 5, fluid damping action is formed, and axial elastic damping damping is realized by cooperating with the disc spring group 4. The torsional shaft 12 can rotate independently of the core shaft 1 by cooperating with the bearing group 11. The bearing upper end cover 10 is threadedly connected with the torsional shaft 12 and tightly presses the bearing group 11 downward. The bearing lower end cover 13 is threadedly connected with the core shaft 1 and tightly presses the bearing group 11 upward. The torsional weight 14 is threadedly connected with the torsional shaft 12 and tightly presses the bearing group 11. The torsional shaft 12 and the torsional weight 14 both have a rotating gap between the torsional shaft housing 9 and the core shaft 1. Figure 6 and Figure 7, flexible steel wire rope 16 is fixed on the torsion weight 14 and the torsion power piston 17 by the set screw 18 and the steel wire rope buckle 15; the torsion shaft shell 9 is processed with the low pressure damping hole 19, and the torsion power piston 17 is processed with the high pressure damping hole 20; the inner cylinder of the torsion power piston 17 is processed with the spline groove and is matched with the spline of the lower end of the mandrel 1 to transmit rotation. The sliding piston 21 is connected with the torsion power piston 17 through the thread, the inside of the sliding piston 21 is matched with the piston nozzle 22, and the piston nozzle 22 is fixed on the sliding piston 21 through the nozzle clamp spring 23.

[0064] The high pressure chamber is formed by the high pressure damping hole 20 of the torsion power piston 17 and the sliding piston 21, the low pressure damping hole 19 of the torsion shaft shell 9 exists and forms the low pressure chamber 25 with the torsion power piston 17, therefore the torsion power piston 17 and the sliding piston 21 descend under the action of the pressure difference of the high and low pressure chambers. The inner surface of the torsion power piston 17 is processed with the spline matched with the mandrel, the drill string rotation drives the mandrel 1 to rotate, and the mandrel 1 drives the torsion power piston 17 to rotate synchronously. The torsion weight 14 and the torsion shaft 12 are fixed together to form the torsion body through the thread connection, the torsion shaft 12 is matched with the mandrel 1 through the bearing set 11, and the torsion shaft 12 and the mandrel 1 can realize relatively independent rotation while limiting the axial movement. The upper end of the torsion power piston 17 is connected with the torsion weight 14 through the flexible steel wire rope 16, and the flexible steel wire rope 16 transmits the rotation of the torsion power piston 17 to the torsion weight 14 in the tension state. The spline shell 2, the disc spring shell 5 and the damping piston 8 form the sealed chamber, and the hydraulic oil is added, and the annular damping flow channel 7 exists between the step surface of the damping piston and the disc spring shell.

[0065] When the drill string rotates at a normal uniform speed, the mandrel 1 drives the torsion power piston 17 and the sliding piston 21 to rotate synchronously, and the torsion power piston 17 drives the torsion weight 14 and the torsion shaft 12 to rotate through the flexible steel wire rope 16 in tension. When the drill string encounters torsional vibration, the torsion power piston 17 appears torsional vibration under the action of the spline of the mandrel 1, at this time, the torsion shaft 12 and the torsion weight 14 still maintain the initial rotation speed due to the torsional inertia, so that the rotation speed difference between the torsion weight 14 and the torsion power piston 17 appears, the lower flexible steel wire rope starts to twist and wind, the axial vertical length of the flexible steel wire rope is shortened, at this time, the flexible steel wire rope pulls the torsion power piston 17 upwards, and the torsion power piston 17 repeatedly resists the pulling due to the damping and the pressure difference, thereby continuously consuming the torsional vibration energy, so as to achieve the purpose of inhibiting the torsional vibration of the drill string.

[0066] When the drill string encounters axial vibration, the torsion shaft shell 9 drives the disc spring shell 5 and the spline shell 2 to jump upwards, at this time, due to the inertia effect, the mandrel can be considered to be in an axial stationary state, so that the first lower step 29 at the lower end of the disc spring shell pushes the lower disc spring washer to go up, the mandrel limits the upper disc spring washer through the second upper step 28, and the disc spring set 4 is compressed under the limitation of the upper and lower disc spring washers 6, meanwhile, the annular damping flow channel 7 of the disc spring shell 5 and the damping piston 8 form a low-pressure damping cavity, hydraulic damping cooperates with the disc spring set to form a spring damping system, and the upward vibration of the disc spring shell is inhibited. When the disc spring shell 5 vibrates downward, the disc spring shell 5 drives the spline shell 2 to go down, the spline shell pushes the disc spring assembly 3 and the disc spring set 4 downward, since the mandrel 1 and the damping piston 8 are connected together through threads, and the damping piston 8 limits the lower disc spring washer 6 and the disc spring set 4 at the upper end, at this time, the disc spring set 4 is also compressed, meanwhile, the annular damping flow channel 7 of the disc spring shell 5 and the damping piston 8 form a high-pressure damping cavity and a low-pressure damping cavity, hydraulic damping is formed, hydraulic damping cooperates with the disc spring set to form a spring damping system, and the downward vibration of the disc spring shell is inhibited.

[0067] The present application can simultaneously achieve the purpose of reducing axial vibration and torsional vibration of the drill string. By using a flexible steel wire rope to connect the torsional body and the torsional power piston, the purpose of axial damping to inhibit torsional vibration is achieved. Compared with the prior art, the tool has simple principle, compact and reliable structure, small influence on drilling parameters and drilling tool structure when used, and can adjust and install nozzles of different diameters to control the tension of the flexible steel wire rope and damping according to different operating environments, so that the adaptability is strong and the tool is easy to popularize and apply on site.

[0068] Based on the above structure, the present application further discloses a working method of the power tuning type downhole composite damper, which comprises the following steps:

[0069] When the mandrel 1 encounters torsional vibration, the torsional power piston 17 simultaneously appears torsional vibration under the action of the spline of the mandrel 1, at this time, the torsional weight 14 still maintains the initial rotating speed due to the torsional inertia effect, a rotating speed difference appears between the torsional weight 14 and the torsional power piston 17, then the flexible steel wire rope 16 starts to twist and wind, the axial vertical length of the flexible steel wire rope 16 is shortened and the torsional power piston 17 is pulled upwards, and the torsional power piston 17 continuously consumes torsional vibration energy under the action of the damping shock-absorbing structure 24, so as to achieve the purpose of inhibiting the torsional vibration of the drill string.

[0070] When the mandrel 1 vibrates downward or the torsional shaft shell 9 drives the disc spring shell 5 to jump upwards relative to the mandrel 1, the first lower step 29 pushes the disc spring assembly 3 to go up, the second upper step 28 limits the upward movement of the disc spring assembly 3, the disc spring assembly 3 is compressed, a spring damping system is formed, and the upward vibration of the disc spring shell 5 or the downward vibration of the mandrel 1 is inhibited.

[0071] When the core shaft 1 vibrates upward or the disc spring shell 5 jumps downward relative to the core shaft 1, the first upper step 27 pushes the disc spring assembly 3 downward, the second lower step 30 limits the downward movement of the disc spring assembly 3, the disc spring assembly 3 is compressed, a spring damping system is formed, and the downward vibration of the disc spring shell 5 or the upward vibration of the core shaft 1 is inhibited.

[0072] Referring to Figure 1 In another possible embodiment of the present application, the following is adaptively modified according to the situation. When the core shaft 1 encounters torsional vibration, the torsional power piston 17 simultaneously appears torsional vibration under the action of the spline of the core shaft 1, at this time, the torsional weight 14 still maintains the initial rotational speed due to the torsional inertia effect, a rotational speed difference will appear between the torsional weight 14 and the torsional power piston 17, the flexible steel wire rope 16 starts to twist and wind, the axial vertical length of the flexible steel wire rope 16 will be shortened and pull the torsional power piston 17 upward, and the torsional power piston 17 continuously consumes torsional vibration energy under the action of the damping shock-absorbing structure 24, so as to achieve the purpose of inhibiting the torsional vibration of the drill string. When the core shaft 1 vibrates downward or the disc spring shell 5 jumps upward relative to the core shaft 1, the first lower step 29 pushes the disc spring assembly 3 upward, the second upper step 28 limits the upward movement of the disc spring assembly 3, the disc spring assembly 3 is compressed, a spring damping system is formed, and the upward vibration of the disc spring shell 5 or the downward vibration of the core shaft 1 is inhibited. When the core shaft 1 vibrates upward or the disc spring shell 5 jumps downward relative to the core shaft 1, the first upper step 27 pushes the disc spring assembly 3 downward, the second lower step 30 limits the downward movement of the disc spring assembly 3, the disc spring assembly 3 is compressed, a spring damping system is formed, and the downward vibration of the disc spring shell 5 or the upward vibration of the core shaft 1 is inhibited. The method of the present application can simultaneously reduce the axial jump and torsional vibration of the drill bit caused by the rock breaking process, thereby inhibiting the drill string vibration from the main source, protecting the downhole drilling tool, and prolonging the service life of the drilling tool.

[0073] The above is only to illustrate the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical scheme falls within the protection scope of the claims of the present application.

Claims

1. A dynamically tuned downhole composite vibration damper, characterized in that, Includes a spindle (1), on which a disc spring housing (5) and a torsion shaft housing (9) are fitted. The disc spring housing (5) has a first upper step (27) and a first lower step (29). The spindle (1) has a second upper step (28) and a second lower step (30). A disc spring assembly (3) is provided between the first upper step (27) and the first lower step (29) and between the second upper step (28) and the second lower step (30). The disc spring housing (5) and the torsion shaft housing (9) are in contact. A torsion counterweight (14) and a torsion power piston (17) are provided between the spindle (1) and the torsion shaft housing (9). The torsion power piston (17) is connected to the torsion counterweight (14) through several flexible steel wire ropes (16). The torsion power piston (17) is connected to the spindle (1) through a spline. A damping and shock absorption structure (24) is provided between the torsion shaft housing (9) and the torsion power piston (17). The spindle (1) is fitted with a spline shell (2), the spline shell (2) is connected to the spindle (1) by a spline, the spline shell (2) is fixedly connected to the disc spring shell (5), and the spline shell (2) is provided with a first upper step (27). A damping piston (8) is sleeved on the mandrel (1), and a second lower step (30) is provided on the damping piston (8). The damping piston (8) is fixedly sleeved on the mandrel (1). The damping structure (24) includes a low-pressure chamber (25) and a high-pressure chamber (26). The low-pressure chamber (25) and the high-pressure chamber (26) are located between the torsion shaft housing (9) and the torsion power piston (17). The torsion shaft housing (9) is provided with a low-pressure damping hole (19) communicating with the low-pressure chamber (25), and the torsion power piston (17) is provided with a high-pressure damping hole (20) communicating with the high-pressure chamber (26). The torsional piston (17) is fixedly connected to the sliding piston (21). The sliding piston (21) is fitted with a piston nozzle (22). A nozzle retainer (23) is provided at the port of the piston nozzle (22). The inner hole of the spindle (1), the high pressure chamber (26), the high pressure damping hole (20), the inner hole of the sliding piston (21), and the inner hole of the piston nozzle (22) are connected.

2. The dynamically tuned downhole composite vibration damper as described in claim 1, characterized in that, The disc spring assembly (3) includes a disc spring group (4), and disc spring washers (6) are arranged at both ends of the disc spring group (4).

3. The dynamically tuned downhole composite vibration damper as described in claim 1, characterized in that, An annular damping channel (7) is provided between the spindle (1) and the disc spring housing (5), and hydraulic oil is added to the annular damping channel (7).

4. The dynamically tuned downhole composite vibration damper as described in claim 3, characterized in that, The annular damping channel (7) is located between the damping piston (8) and the disc spring housing (5). The annular damping channel (7) includes an upper damping channel (7-1) and a lower damping channel (7-2). Both the upper damping channel (7-1) and the lower damping channel (7-2) are opened on the disc spring housing (5), and the upper damping channel (7-1) and the lower damping channel (7-2) are connected.

5. A dynamically tuned downhole composite vibration damper as described in claim 1, characterized in that, The mandrel (1) is fitted with an upper bearing cap (10) and a lower bearing cap (13). The lower bearing cap (13) is fixedly connected to the mandrel (1). The upper bearing cap (10) is fixedly connected to the torsion shaft (12). A bearing assembly (11) is arranged between the upper bearing cap (10) and the lower bearing cap (13). The upper bearing cap (10) is fixedly connected to the torsion shaft (12). The torsion shaft (12) is connected to the torsion counterweight (14). The torsion shaft (12), the upper bearing cap (10), and the torsion counterweight (14) are located between the mandrel (1) and the torsion shaft housing (9). The bearing assembly (11) and the lower bearing cap (13) are located between the torsion shaft (12) and the mandrel (1).

6. A dynamically tuned downhole composite vibration damper as described in claim 5, characterized in that, The torsion counterweight (14) is sleeved on the spindle (1), and the lower end cover (13) of the bearing is between the torsion counterweight (14) and the spindle (1). The torsion counterweight (14) is located above the torsion power piston (17).

7. A method for operating the dynamically tuned downhole composite vibration damper as described in claim 1, characterized in that, Includes the following steps: When the mandrel (1) encounters torsional vibration, the torsional power piston (17) will also experience torsional vibration under the action of the spline of the mandrel (1). A speed difference will occur between the torsional counterweight (14) and the torsional power piston (17), and the flexible steel wire rope (16) will begin to twist and wind. The axial vertical length of the flexible steel wire rope (16) will be shortened and pull the torsional power piston (17) upward. Under the action of the damping and shock absorption structure (24), the torsional power piston (17) will continuously consume the torsional vibration energy, thereby achieving the purpose of suppressing the torsional vibration of the drill string. When the spindle (1) vibrates downward or the torsional shaft housing (9) causes the disc spring housing (5) to jump upward relative to the spindle (1), the first lower step (29) pushes the disc spring assembly (3) upward, and the second upper step (28) restricts the disc spring assembly (3) from moving upward. The disc spring assembly (3) is compressed to form a spring damping system, which suppresses the upward vibration of the disc spring housing (5) or the downward vibration of the spindle (1). When the spindle (1) vibrates upward or the disc spring housing (5) jumps downward relative to the spindle (1), the first upper step (27) pushes the disc spring assembly (3) downward, and the second lower step (30) restricts the downward movement of the disc spring assembly (3). The disc spring assembly (3) is compressed to form a spring damping system, which suppresses the downward vibration of the disc spring housing (5) or the upward vibration of the spindle (1).

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