Dynamic tuning type underground composite shock absorber and working method thereof

Abstract

The invention belongs to the technical field of petroleum and natural gas drilling, and relates to a dynamic tuning type underground composite shock absorber and a working method thereof. Comprising a mandrel which is used for transmitting power of a drill column. The central spindle is sleeved with a disc spring shell and a torsion shaft shell. A first upper step and a first lower step are arranged on the disc spring shell, a second upper step and a second lower step are arranged on the mandrel, and disc spring assemblies are 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 makes contact with the torsion shaft shell, a torsion balance weight and a torsion power piston are arranged between the mandrel and the torsion shaft shell, the torsion power piston is connected with the torsion balance weight through a plurality of flexible steel wire ropes, the torsion power piston is connected with the mandrel through a spline, and a damping shock absorption structure is arranged between the torsion shaft shell and the torsion power piston. Axial jumping and torsional vibration of the drill bit caused by the rock breaking process can be reduced, an underground drilling tool is protected, and the service life of the drilling tool is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas drilling, and relates to a dynamic tuning downhole composite shock absorber and a working method thereof. Background Art

[0002] In the process of oil and gas drilling, downhole vibration is inevitable due to reasons such as drill bit breaking rock. Severe downhole vibration can easily lead to failure of downhole equipment such as drill pipe, drill collar, LWD, MWD, PTWD, guide drilling tools and drill bits, and even increase the risk of fracture, which directly affects drilling benefits and resource exploration efficiency. According to statistics, the non-operating time (NPT) caused by drill string vibration and impact accounts for 25% of the total NPT each year. Especially in the process of drilling in gravel formations, hard formations, deep wells and ultra-deep wells, downhole vibration is more obvious, resulting in frequent accidents of drill tool fracture and falling into the well, and a surge in drill bit consumption. The technology and supporting equipment to suppress harmful downhole vibration have become essential technologies in the above drilling processes. Among them, the key to suppressing downhole vibration is to effectively control the intensity of the "vibration source" - drill bit vibration, especially the strong downhole vibration when drilling in hard and brittle formations, gravel formations and other formations with serious drilling failures, to ensure the continuous, stable and efficient rock breaking of the drill bit, taking into account the rock breaking efficiency and drill bit life, and thus reducing downhole risks while increasing the drill bit stroke drilling speed. The use of downhole vibration dampers is currently the most common vibration reduction method in drilling operations.

[0003] At present, most conventional shock absorbers are spring damping shock absorbers, which have a more obvious effect on suppressing axial vibration. However, there are many forms of downhole vibration, including complex vibrations such as axial vibration and torsional vibration. Multiple vibrations may also develop in coupling with each other, which will pose a huge threat to the safety of downhole drilling tools. In addition, during the drilling process of PDC drill bits, torsional vibration becomes its main vibration form. Obviously, conventional spring damping shock absorbers have limited vibration suppression effects for complex vibration conditions. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a dynamic tuning downhole composite vibration damper and a working method thereof. The present invention can simultaneously reduce the axial runout and torsional vibration of the drill bit caused by the rock breaking process, thereby suppressing the vibration of the drill string from the main source, protecting the downhole drilling tools, and extending the life of the drilling tools.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The invention discloses a dynamic tuning type downhole composite shock absorber, comprising a core shaft, a disc spring housing and a torsion shaft housing are sleeved on the core shaft, a first upper step and a first lower step are provided on the disc spring housing, a second upper step and a second lower step are provided on the core shaft, and a disc spring assembly is provided 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 housing is in contact with the torsion shaft housing, a torsion counterweight and a torsion power piston are provided between the core shaft and the torsion shaft housing, the torsion power piston is connected to the torsion counterweight through a number of flexible steel wire ropes, the torsion power piston is connected to the core shaft through a spline, and a damping shock absorbing structure is provided between the torsion shaft housing and the torsion power piston.

[0008] Furthermore, the disc spring assembly includes a disc spring group, and disc spring washers are arranged at both ends of the disc spring group.

[0009] Furthermore, a spline shell is sleeved on the core shaft, the spline shell is connected to the core shaft through splines, the spline shell is fixedly connected to the disc spring shell, and a first upper step is provided on the spline shell.

[0010] Furthermore, a damping piston is sleeved on the core shaft, a second lower step is provided on the damping piston, and the damping piston is fixedly sleeved on the core shaft.

[0011] Furthermore, an annular damping flow channel is provided between the core shaft and the disc spring housing, and hydraulic oil is added into the annular damping flow channel.

[0012] Furthermore, the annular damping flow channel is located between the damping piston and the disc spring housing, and the annular damping flow channel includes an upper damping flow channel and a lower damping flow channel, both of which are opened on the disc spring housing, and the upper damping flow channel and the lower damping flow channel are connected.

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

[0014] Furthermore, the torsion counterweight is sleeved on the core shaft, the lower end cover of the bearing is between the torsion counterweight and the core shaft, and the torsion counterweight is located above the torsion power piston.

[0015] Furthermore, the damping shock absorbing structure includes a low-pressure chamber and a high-pressure chamber, the low-pressure chamber and the high-pressure chamber are located between the torsion shaft housing and the torsion power piston, the torsion shaft housing is provided with a low-pressure damping hole connected to the low-pressure chamber, and the torsion power piston is provided with a high-pressure damping hole connected to the high-pressure chamber;

[0016] The torsional power piston is fixedly connected to the sliding piston, the inner sleeve of the sliding piston is provided with a piston nozzle, a nozzle retaining spring is provided at the piston nozzle port, and the inner hole of the core shaft, 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 connected.

[0017] The present invention also discloses a working method of a dynamic tuning downhole composite shock absorber, comprising the following steps:

[0018] When the mandrel encounters torsional vibration, the torsional power piston will simultaneously experience torsional vibration under the action of the mandrel's spline, and there will be a speed difference between the torsional counterweight and the torsional power piston, then the flexible steel wire rope will begin to twist and entangle, the axial vertical length of the flexible steel wire rope will shorten and pull the torsional power piston upward, and the torsional power piston will continue to consume torsional vibration energy under the action of the damping and shock absorbing structure, thereby achieving the purpose of suppressing the torsional vibration of the drill string;

[0019] When the core shaft vibrates downward or the torsion shaft housing drives the disc spring housing to jump upward relative to the core shaft, the first lower step pushes the disc spring assembly upward, and the second upper step restricts the disc spring assembly from moving upward. The disc spring assembly is compressed to form a spring damping system, which suppresses the upward vibration of the disc spring housing or the downward vibration of the core shaft.

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

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

[0022] The present invention includes a mandrel, and the mandrel is used to transmit the power of the drill string. A disc spring housing and a torsion shaft housing are sleeved on the mandrel. The disc spring housing is used to isolate the disc spring assembly from the outside world and is used to assist the disc spring assembly in damping the drill string. A first upper step and a first lower step are provided on the disc spring housing, and a second upper step and a second lower step are provided on the mandrel. A disc spring assembly is provided 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 vibrate axially relative to each other, 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 is in contact with the torsion shaft housing, and 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 to isolate the torsion counterweight, the torsion power piston and the damping shock absorbing structure from the outside world. A torsional counterweight and a torsional power piston are provided between the mandrel and the torsional shaft housing. The torsional power piston is connected to the torsional counterweight through a number of flexible steel wire ropes. The torsional power piston is connected to the mandrel through a spline. A damping and shock absorbing structure is provided between the torsional shaft housing and the torsional power piston. When the mandrel vibrates torsionally, the mandrel drives the torsional power piston to vibrate synchronously. A speed difference is generated between the torsional power piston and the torsional counterweight. Then, the flexible steel wire rope begins to twist and entangle. The axial vertical length of the flexible steel wire rope will be shortened and the torsional power piston will be pulled upward. The torsional power piston continuously consumes torsional vibration energy under the action of the damping and shock absorbing structure, thereby achieving the purpose of suppressing torsional vibration of the drill string. The present invention can simultaneously reduce the axial runout and torsional vibration of the drill bit caused by the rock breaking process, thereby suppressing the vibration of the drill string from the main source, protecting the downhole drilling tools, and extending the life of the drilling tools.

[0023] The method of the present invention is as follows: when the mandrel encounters torsional vibration, the torsional power piston simultaneously experiences torsional vibration under the action of the spline of the mandrel, a speed difference will occur between the torsional counterweight and the torsional power piston, the axial vertical length of the flexible steel wire rope will be shortened and pull the torsional power piston upward, and the torsional power piston continues to consume torsional vibration energy under the action of the damping and shock absorbing structure, thereby achieving the purpose of suppressing the torsional vibration of the drill string. When the mandrel vibrates downward or the torsional shaft housing drives the disc spring housing to jump upward relative to the mandrel, the first lower step pushes the disc spring assembly upward, the second upper step limits the disc spring assembly upward, the disc spring assembly is compressed, and a spring damping system is formed to suppress the upward vibration of the disc spring housing or the downward vibration of the mandrel. When the mandrel vibrates upward or the disc spring housing jumps downward relative to the mandrel, 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, and a spring damping system is formed to suppress the downward vibration of the disc spring housing or the upward vibration of the mandrel. The method of the present invention can simultaneously reduce the axial runout and torsional vibration of the drill bit caused by the rock breaking process, thereby suppressing the vibration of the drill string from the main source, playing a role in protecting the downhole drilling tools and extending the service life of the drilling tools. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0025] Figure 2 It is a cross-sectional view of the upper section of the composite vibration absorber of the present invention;

[0026] Figure 3 It is a cross-sectional view of the middle section of the composite shock absorber of the present invention;

[0027] Figure 4 It is a cross-sectional view of the lower section of the composite shock absorber of the present invention;

[0028] Figure 5 for Figure 1 and Figure 2 AA section view;

[0029] Figure 6 for Figure 1 and Figure 4 BB cross-section diagram;

[0030] Figure 7 It is a diagram showing the assembly relationship between the torsion power piston and the torsion counterweight of the present invention.

[0031] Among them: 1. core shaft; 2. spline housing; 3. disc spring assembly; 4. disc spring group; 5. disc spring housing; 6. disc spring gasket; 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 group; 12. torsion shaft; 13. bearing lower end cover; 14. torsion counterweight; 15. wire rope buckle; 16. flexible 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 retaining 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 enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0035] See also Figure 1 The present invention discloses a dynamic tuning downhole composite shock absorber, comprising a core shaft 1, the core shaft 1 is used to transmit the power of the drill string. The core shaft 1 is sleeved with a disc spring housing 5 and a torsion shaft housing 9, see Figure 2 The disc spring housing 5 is used to isolate the disc spring assembly 3 from the outside world and to assist the disc spring assembly 3 in reducing the vibration of the drill string. A first upper step 27 and a first lower step 29 are provided on the disc spring housing 5, and a second upper step 28 and a second lower step 30 are provided on the core shaft 1. 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. When the disc spring housing 5 and the core shaft 1 vibrate axially relative to each other, the disc spring assembly 3 can suppress the vibration of the disc spring housing 5 and the core shaft 1. The disc spring housing 5 is in contact with the torsion shaft housing 9, and the axial upward vibration of the torsion shaft housing 9 can be transmitted to the disc spring housing 5, and then the axial vibration is suppressed by the disc spring assembly 3. The torsion shaft housing 9 is used to isolate the torsion counterweight 14, the torsion power piston 17 and the damping shock absorbing structure 24 from the outside world. See Figure 3 and Figure 4A torsion counterweight 14 and a torsion power piston 17 are provided between the mandrel 1 and the torsion shaft housing 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. A damping and shock absorbing structure 24 is provided between the torsion shaft housing 9 and the torsion power piston 17. When the mandrel 1 undergoes torsion vibration, the mandrel 1 drives the torsion power piston 17 to vibrate synchronously. The torsion power piston 17 and the torsion counterweight 14 produce a speed difference, and the flexible steel wire rope 16 begins to twist and entangle. The axial vertical length of the flexible steel wire rope 16 will be shortened and the torsion power piston 17 will be pulled upward, that is, the torsion vibration of the mandrel 1 is converted into the axial movement of the torsion power piston 17. The torsion power piston 17 continues to consume the torsion vibration energy under the action of the damping and shock absorbing structure 24, so as to achieve the purpose of suppressing the torsion vibration of the drill string. The present invention can simultaneously reduce the axial runout and torsion vibration of the drill bit caused by the rock breaking process, thereby suppressing the vibration of the drill string from the main source, playing a role in protecting the downhole drilling tools and extending the life of the drilling tools.

[0036] See also Figure 1 In another feasible embodiment of the present invention, the following is modified adaptively according to the situation. It includes a core shaft 1, on which a disc spring housing 5 and a torsion shaft housing 9 are sleeved, see Figure 2 A disc spring assembly 3 is provided between the disc spring housing 5 and the core shaft 1. A first upper step 27 and a first lower step 29 are provided on the disc spring housing 5. A second upper step 28 and a second lower step 30 are provided on the core shaft 1. 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] See also Figure 3 and Figure 4 The disc spring housing 5 is in contact with the torsion shaft housing 9, a torsion counterweight 14 and a torsion power piston 17 are provided between the core shaft 1 and the torsion shaft housing 9, the torsion power piston 17 is connected to the torsion counterweight 14 through a number of flexible steel wire ropes 16, the torsion power piston 17 is connected to the core shaft 1 through a spline, and a damping shock absorbing structure 24 is provided between the torsion shaft housing 9 and the torsion power piston 17.

[0038] The mandrel 1 is used to transmit the power of the drill string. The disc spring housing 5 is used to isolate the disc spring assembly 3 from the outside world and to assist the disc spring assembly 3 in damping the drill string. The torsion shaft housing 9 can transmit the axial upward vibration to the disc spring housing 5, thereby suppressing the axial vibration through the disc spring assembly 3. The torsion shaft housing 9 is used to isolate the torsion counterweight 14, the torsion power piston 17 and the damping shock absorbing structure 24 from the outside world.

[0039] In specific operation, when the disc spring housing 5 and the mandrel 1 bounce relative to each other, the disc spring housing 5 and the mandrel 1 squeeze 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, and the disc spring assembly 3 is compressed to form a spring damping system, thereby suppressing the relative vibration between the disc spring housing 5 and the mandrel 1. When the mandrel 1 encounters torsional vibration, the torsional power piston 17 simultaneously vibrates torsionally under the action of the spline of the mandrel 1. At this time, there will be a speed difference between the torsional counterweight 14 and the torsional power piston 17, and 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 will continue to consume torsional vibration energy under the action of the damping structure 24, so as to achieve the purpose of suppressing the torsional vibration of the drill string.

[0040] Embodiment 1:

[0041] See also Figure 1 The present embodiment discloses a dynamic tuning downhole composite shock absorber, including a core shaft 1, a disc spring housing 5 and a torsion shaft housing 9 are sleeved on the core shaft 1, a first upper step 27 and a first lower step 29 are formed on the disc spring housing 5, a second upper step 28 and a second lower step 30 are formed on the core shaft 1, and 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;

[0042] The disc spring housing 5 is in contact with the torsion shaft housing 9, and a torsion counterweight 14 and a torsion power piston 17 are provided between the core shaft 1 and the torsion shaft housing 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 core shaft 1 through a spline, and a damping shock absorbing structure 24 is provided between the torsion shaft housing 9 and the torsion power piston 17.

[0043] 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. The disc spring group 4 is pressed by the disc spring washers 6 through the first upper step 27, the first lower step 29, the second upper step 28 and the second lower step 30.

[0044] Embodiment 2:

[0045] See also Figure 1 The present embodiment discloses a dynamic tuning downhole composite shock absorber, including a core shaft 1, a disc spring housing 5 and a torsion shaft housing 9 are sleeved on the core shaft 1, a first upper step 27 and a first lower step 29 are formed on the disc spring housing 5, a second upper step 28 and a second lower step 30 are formed on the core shaft 1, and 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;

[0046] The disc spring housing 5 is in contact with the torsion shaft housing 9, and a torsion counterweight 14 and a torsion power piston 17 are provided between the core shaft 1 and the torsion shaft housing 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 core shaft 1 through a spline, and a damping shock absorbing structure 24 is provided between the torsion shaft housing 9 and the torsion power piston 17.

[0047] See also Figure 5 A spline housing 2 is sleeved on the core shaft 1, the spline housing 2 is connected to the core shaft 1 through a spline, the spline housing 2 is fixedly connected to the disc spring housing 5, and a first upper step 27 is provided on the spline housing 2.

[0048] The mandrel 1 is sleeved with a damping piston 8, and the damping piston 8 is provided with a second lower step 30. The damping piston 8 is fixedly sleeved on the mandrel 1. The mandrel 1 supports the disc spring assembly 3 and the disc spring housing 5 through the damping piston 8.

[0049] An annular damping flow channel 7 is provided between the core shaft 1 and the disc spring housing 5, and hydraulic oil is added into the annular damping flow channel 7.

[0050] 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. The upper damping channel 7-1 and the lower damping channel 7-2 are both opened on the disc spring housing 5. The upper damping channel 7-1 is connected to the lower damping channel 7-2. Since the disc spring housing 5 is sleeved on the damping piston 8, the upper damping channel 7-1 and the surface of the damping piston 8 form an upper damping chamber, and the lower damping channel 7-2 and the surface of the damping piston 8 form a lower damping chamber, and the upper damping channel 7-1 and the lower damping channel 7-2 are connected, that is, the upper damping chamber is connected to the lower damping chamber. When the disc spring housing 5 and the core shaft 1 are relatively bouncing, the hydraulic oil flows between the upper damping chamber and the lower damping chamber, and at the same time suppresses the relative vibration between the disc spring housing 5 and the core shaft 1.

[0051] Embodiment three:

[0052] See also Figure 1 The present embodiment discloses a dynamic tuning downhole composite shock absorber, including a core shaft 1, a disc spring housing 5 and a torsion shaft housing 9 are sleeved on the core shaft 1, a first upper step 27 and a first lower step 29 are formed on the disc spring housing 5, a second upper step 28 and a second lower step 30 are formed on the core shaft 1, and 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;

[0053] The disc spring housing 5 is in contact with the torsion shaft housing 9, and a torsion counterweight 14 and a torsion power piston 17 are provided between the core shaft 1 and the torsion shaft housing 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 core shaft 1 through a spline, and a damping shock absorbing structure 24 is provided between the torsion shaft housing 9 and the torsion power piston 17.

[0054] The mandrel 1 is sleeved with a bearing upper end cover 10 and a bearing lower end cover 13, and the bearing lower end cover 13 supports the bearing upper end cover 10, the torsion shaft 12 and the torsion counterweight 14 through the bearing group 11. The bearing lower end cover 13 is fixedly connected to the mandrel 1, the bearing upper end cover 10 is fixedly connected to 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 to the torsion shaft 12, the torsion shaft 12 is connected to 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 housing 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 core shaft 1 , and a bearing lower end cover 13 is disposed between the torsion counterweight 14 and the core shaft 1 . The torsion counterweight 14 is located above the torsion power piston 17 .

[0056] Embodiment 4:

[0057] See also Figure 1 The present embodiment discloses a dynamic tuning downhole composite shock absorber, including a core shaft 1, a disc spring housing 5 and a torsion shaft housing 9 are sleeved on the core shaft 1, a first upper step 27 and a first lower step 29 are formed on the disc spring housing 5, a second upper step 28 and a second lower step 30 are formed on the core shaft 1, and 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;

[0058] The disc spring housing 5 is in contact with the torsion shaft housing 9, and a torsion counterweight 14 and a torsion power piston 17 are provided between the core shaft 1 and the torsion shaft housing 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 core shaft 1 through a spline, and a damping shock absorbing structure 24 is provided between the torsion shaft housing 9 and the torsion power piston 17.

[0059] The damping shock absorbing 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;

[0060] The torsional power piston 17 is fixedly connected to the sliding piston 21. The sliding piston 21 is provided with a piston nozzle 22. A nozzle retaining spring 23 is provided at the port of the piston nozzle 22. 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 connected.

[0061] When the core shaft 1 encounters torsional vibration, the torsional vibration of the core shaft 1 is converted into axial vibration of the torsional power piston 17 through the flexible steel wire rope 16, and the low-pressure chamber 25 and the high-pressure chamber 26 suppress 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] See also Figure 1 The present embodiment discloses a dynamically tuned downhole composite shock absorber, comprising 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 torsion shaft housing 9, a bearing upper end cover 10, a bearing group 11, a torsion shaft 12, a bearing lower end cover 13, a torsion counterweight 14, a wire rope buckle 15, a flexible wire rope 16, a torsion power piston 17, a set screw 18, a low-pressure damping hole 19, a high-pressure damping hole 20, a sliding piston 21, a piston nozzle 22, a nozzle retaining spring 23, a damping shock absorbing 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 a damping shock absorbing structure 24. Among them, the spline housing 2 is connected to the disc spring housing 5 by threads, the inner tube of the spline housing 2 is processed with a spline groove, and 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 connected to the core shaft 1 by threads, and the upper part of the damping piston 8 is pressed against the disc spring assembly 3. When the core shaft 1 and the disc spring housing 5 undergo axial relative movement, the damping piston 8 moves synchronously with the core shaft 1, and can compress or release the disc spring assembly 4. The spline housing 2, the disc spring housing 5 and the damping piston 8 form a sealed chamber, and hydraulic oil is added to the sealed chamber. There is an annular damping flow channel 7 between the step surface of the damping piston 8 and the disc spring housing 5, which forms a fluid damping effect, and cooperates with the disc spring assembly 4 to achieve axial elastic damping vibration reduction. The torsion shaft 12 and the core shaft 1 cooperate through the bearing group 11, and can achieve independent rotation. The upper end cover 10 of the bearing is connected to the torsion shaft 12 by threads, and the bearing group 11 is pressed downwardly. The lower end cover 13 of the bearing is connected to the core shaft 1 by threads, and the bearing group 11 is pressed upwardly. The torsion counterweight 14 is connected to the torsion shaft 12 by threads, and the bearing group 11 is pressed upwardly. There is a rotation gap between the torsion shaft 12 and the torsion counterweight 14 and the torsion shaft housing 9 and the core shaft 1. Figure 6 and Figure 7The flexible steel wire rope 16 is fixed to the torsion counterweight 14 and the torsion power piston 17 through the set screw 18 and the steel wire rope buckle 15; the torsion shaft housing 9 is processed with a low-pressure damping hole 19, and the torsion power piston 17 is processed with a high-pressure damping hole 20; the inner cylinder of the torsion power piston 17 is processed with a spline groove to cooperate with the spline at the lower end of the core shaft 1 to transmit rotation. The sliding piston 21 is connected to the torsion power piston 17 through threads, and the interior of the sliding piston 21 cooperates with the piston nozzle 22, and the piston nozzle 22 is fixed to the sliding piston 21 through the nozzle retaining spring 23.

[0064] The high-pressure damping hole 20 of the torsion power piston 17 and the sliding piston 21 form a high-pressure chamber, and the low-pressure damping hole 19 of the torsion shaft housing 9 forms a low-pressure chamber 25 with the torsion power piston 17, so the torsion power piston 17 and the sliding piston 21 move downward at the same time under the pressure difference between the high and low pressure chambers. The inner surface of the torsion power piston 17 is processed with a spline that matches the mandrel. The rotation of the drill string drives the mandrel 1 to rotate, and the mandrel 1 drives the torsion power piston 17 to rotate synchronously. The torsion counterweight 14 and the torsion shaft 12 are fixedly connected together by threaded connection to form a torsion body. The torsion shaft 12 and the mandrel 1 are matched by the bearing group 11. The torsion shaft 12 and the mandrel 1 can achieve relatively independent rotation while limiting their axial movement. The upper end of the torsion power piston 17 is connected to the torsion counterweight 14 through a flexible steel wire rope 16, and the flexible steel wire rope 16 transmits the rotation of the torsion power piston 17 to the torsion counterweight 14 under tension. The spline housing 2, the disc spring housing 5, and the damping piston 8 form a sealed chamber, and hydraulic oil is added therein. An annular damping flow channel 7 exists between the step surface of the damping piston and the disc spring housing.

[0065] When the drill string rotates normally at a 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 counterweight 14 and the torsion shaft 12 to rotate through the tensioned flexible steel wire rope 16. When the drill string encounters torsional vibration, the torsion power piston 17 simultaneously vibrates torsionally under the action of the spline of the mandrel 1. At this time, the torsion shaft 12 and the torsion counterweight 14 still maintain the initial rotation speed due to the torsional inertia, so that there will be a speed difference between the torsion counterweight 14 and the torsion power piston 17. The torsion counterweight continues to rotate, and the lower flexible steel wire rope begins to twist and entangle, and the axial vertical length of the flexible steel wire rope will be shortened. At this time, the flexible steel wire rope will pull the torsion power piston 17 upward, and the torsion power piston 17 repeatedly resists the pulling due to the damping and pressure difference, thereby continuously consuming the torsion vibration energy, achieving the purpose of suppressing the torsion vibration of the drill string.

[0066] When the drill string encounters axial vibration, the torsion shaft housing 9 drives the disc spring housing 5 and the spline housing 2 to jump upward. At this time, due to the effect of inertia, the core shaft can be considered to be in an axial static state, so that the first lower step 29 at the lower end of the disc spring housing pushes the lower disc spring washer upward, and the core shaft limits the upper disc spring washer through the second upper step 28. The disc spring group 4 is compressed under the restriction of the upper and lower disc spring washers 6. At the same time, the annular damping flow channel 7 of the disc spring housing 5 and the damping piston 8 form a low-pressure damping chamber, and the hydraulic damping cooperates with the disc spring group to form a spring damping system to suppress the upward vibration of the disc spring housing. When the disc spring housing 5 vibrates downward, the disc spring housing 5 drives the spline housing 2 downward, and the spline housing will push the disc spring assembly 3 and the disc spring group 4 downward. Since the core shaft 1 is connected to the damping piston 8 by threads, and the upper end of the damping piston 8 limits the lower disc spring washer 6 and the disc spring group 4, the disc spring group 4 is also compressed at this time. At the same time, the annular damping flow channel 7 of the disc spring housing 5 and the damping piston 8 form a high-pressure damping chamber and a low-pressure damping chamber to form hydraulic damping. The hydraulic damping cooperates with the disc spring group to form a spring damping system to suppress the downward vibration of the disc spring housing.

[0067] The present invention can simultaneously achieve the purpose of reducing the axial vibration and torsional vibration of the drill string. By using a flexible steel wire rope to connect the torsion body and the torsional power piston, the purpose of axial damping to suppress torsional vibration is achieved. Compared with the prior art, the tool of the present invention is simple in principle, compact and reliable in structure, directly connected to the drill string when in use, with little effect on drilling parameters and drilling tool structure, and can adjust and install nozzles of different diameters according to different operating environments to control the tension and damping of the flexible steel wire rope, with strong adaptability and easy on-site promotion and application.

[0068] Based on the above structure, the present invention also discloses a working method of a dynamic tuning downhole composite shock absorber, comprising the following steps:

[0069] When the mandrel 1 encounters torsional vibration, the torsional power piston 17 simultaneously experiences torsional vibration under the action of the spline of the mandrel 1. At this time, the torsional counterweight 14 still maintains the initial rotation speed due to the torsional inertia, and there will be a speed difference between the torsional counterweight 14 and the torsional power piston 17. Then, the flexible steel wire rope 16 begins to twist and wrap, and the axial vertical length of the flexible steel wire rope 16 will shorten and pull the torsional power piston 17 upward. The torsional power piston 17 continues to consume torsional vibration energy under the action of the damping and shock absorbing structure 24, thereby achieving the purpose of suppressing the torsional vibration of the drill string.

[0070] When the core shaft 1 vibrates downward or the torsion shaft housing 9 drives the disc spring housing 5 to jump upward relative to the core shaft 1, the first lower step 29 pushes the disc spring assembly 3 upward, and the second upper step 28 limits the upward movement of the disc spring assembly 3. 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 core shaft 1.

[0071] When the core shaft 1 vibrates upward or the disc spring housing 5 jumps downward relative to the core shaft 1, the first upper step 27 pushes the disc spring assembly 3 downward, and the second lower step 30 limits 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 core shaft 1.

[0072] See also Figure 1 In another feasible embodiment of the present invention, the following is adaptively modified according to the situation. When the mandrel 1 encounters torsional vibration, the torsional power piston 17 simultaneously experiences torsional vibration under the action of the spline of the mandrel 1. At this time, the torsional counterweight 14 still maintains the initial rotation speed due to the torsional inertia, and there will be a speed difference between the torsional counterweight 14 and the torsional power piston 17, then the flexible steel wire rope 16 begins to twist and wind, and 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 continues to consume torsional vibration energy under the action of the damping and shock absorbing structure 24, so as to achieve the purpose of suppressing the torsional vibration of the drill string. When the mandrel 1 vibrates downward or the torsional shaft housing 9 drives the disc spring housing 5 to jump upward relative to the mandrel 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 to suppress the upward vibration of the disc spring housing 5 or the downward vibration of the mandrel 1. When the mandrel 1 vibrates upward or the disc spring housing 5 jumps downward relative to the mandrel 1, the first upper step 27 pushes the disc spring assembly 3 downward, and the second lower step 30 limits the downward movement of the disc spring assembly 3. The disc spring assembly 3 is compressed to form a spring damping system to suppress the downward vibration of the disc spring housing 5 or the upward vibration of the mandrel 1. The method of the present invention can simultaneously reduce the axial runout and torsional vibration of the drill bit caused by the rock breaking process, thereby suppressing the vibration of the drill string from the main source, protecting the downhole drilling tools, and extending the life of the drilling tools.

[0073] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A dynamic tuned downhole composite shock absorber, characterized in that: The invention comprises a core shaft (1), a disc spring housing (5) and a torsion shaft housing (9) are sleeved on the core shaft (1), a first upper step (27) and a first lower step (29) are provided on the disc spring housing (5), a second upper step (28) and a second lower step (30) are provided on the core shaft (1), and 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) is in contact with the torsion shaft housing (9), a torsion counterweight (14) and a torsion power piston (17) are provided between the core shaft (1) and the torsion shaft housing (9), the torsion power piston (17) is connected to the torsion counterweight (14) via a plurality of flexible steel wire ropes (16), the torsion power piston (17) and the core shaft (1) are connected via a spline, and a damping shock absorbing structure (24) is provided between the torsion shaft housing (9) and the torsion power piston (17).

2. A dynamically tuned downhole composite shock absorber as claimed in claim 1, characterized in that: The disc spring assembly (3) comprises a disc spring group (4), and disc spring washers (6) are arranged at both ends of the disc spring group (4).

3. A dynamically tuned downhole composite shock absorber as claimed in claim 1, characterized in that: The core shaft (1) is sleeved with a spline housing (2), the spline housing (2) and the core shaft (1) are connected via splines, the spline housing (2) and the disc spring housing (5) are fixedly connected, and the spline housing (2) is provided with a first upper step (27).

4. A dynamically tuned downhole composite shock absorber as claimed in claim 3, characterized in that: The core shaft (1) is sleeved with a damping piston (8), the damping piston (8) is provided with a second lower step (30), and the damping piston (8) is fixedly sleeved on the core shaft (1).

5. A dynamically tuned downhole composite shock absorber as claimed in claim 4, characterized in that: An annular damping flow channel (7) is provided between the core shaft (1) and the disc spring housing (5), and hydraulic oil is added into the annular damping flow channel (7).

6. A dynamically tuned downhole composite shock absorber as claimed in claim 5, characterized in that: The annular damping flow channel (7) is located between the damping piston (8) and the disc spring housing (5), and the annular damping flow channel (7) comprises an upper damping flow channel (7-1) and a lower damping flow channel (7-2), and both the upper damping flow channel (7-1) and the lower damping flow channel (7-2) are opened on the disc spring housing (5), and the upper damping flow channel (7-1) and the lower damping flow channel (7-2) are connected.

7. A dynamically tuned downhole composite shock absorber as claimed in claim 1, characterized in that: The core shaft (1) is sleeved with a bearing upper end cover (10) and a bearing lower end cover (13); the bearing lower end cover (13) is fixedly connected to the core shaft (1); the bearing upper end cover (10) is fixedly connected to the torsion shaft (12); a 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 to the torsion shaft (12); the torsion shaft (12) is connected to a torsion counterweight (14); the torsion shaft (12), the bearing upper end cover (10) and the torsion counterweight (14) are located between the core shaft (1) and the torsion shaft housing (9); and the bearing group (11) and the bearing lower end cover (13) are located between the torsion shaft (12) and the core shaft (1).

8. A dynamically tuned downhole composite shock absorber as claimed in claim 7, characterized in that: The torsion counterweight (14) is sleeved on the core shaft (1), a bearing lower end cover (13) is located between the torsion counterweight (14) and the core shaft (1), and the torsion counterweight (14) is located above the torsion power piston (17).

9. A dynamically tuned downhole composite shock absorber as claimed in claim 1, characterized in that: The damping shock absorbing structure (24) comprises a low-pressure chamber (25) and a high-pressure chamber (26), wherein 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 torsion power piston (17) is fixedly connected to the sliding piston (21); a piston nozzle (22) is sleeved inside the sliding piston (21); a nozzle retaining spring (23) is arranged at the port of the piston nozzle (22); 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 connected.

10. A method for operating a dynamic tuned downhole composite shock absorber as claimed in claim 1, characterized in that: The following steps are involved: When the mandrel (1) encounters torsional vibration, the torsional power piston (17) simultaneously experiences torsional vibration under the action of the spline of the mandrel (1), and a speed difference occurs between the torsional counterweight (14) and the torsional power piston (17), so that the flexible steel wire rope (16) begins to twist and entangle, and the axial vertical length of the flexible steel wire rope (16) is shortened and pulls the torsional power piston (17) upward, while the torsional power piston (17) continuously consumes torsional vibration energy under the action of the damping and shock absorbing structure (24), thereby achieving the purpose of suppressing torsional vibration of the drill string; When the core shaft (1) vibrates downward or the torsion shaft housing (9) drives the disc spring housing (5) to jump upward relative to the core shaft (1), the first lower step (29) pushes the disc spring assembly (3) upward, and the second upper step (28) limits the upward movement of the disc spring assembly (3). 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 core shaft (1); When the core shaft (1) vibrates upward or the disc spring housing (5) jumps downward relative to the core shaft (1), the first upward step (27) pushes the disc spring assembly (3) downward, and the second downward step (30) limits 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 core shaft (1).

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