A drill string shock absorber having multiple stages of shock absorbing functionality and a method of shock absorbing

Abstract

The application discloses a drill tool shock absorber with a multi-stage damping function and a damping method, which comprises an upper joint and a lower joint; an oil cylinder outer cylinder and an oil cylinder inner cylinder are arranged at the connecting part of the upper joint and the lower joint; one end of the oil cylinder inner cylinder is connected with the lower joint, and the other end of the oil cylinder inner cylinder is connected with an inner cylinder extension piece arranged on the inner wall of the upper joint; one end of the oil cylinder outer cylinder is connected with the upper joint, and the other end of the oil cylinder outer cylinder is connected with an outer cylinder extension piece arranged on the inner wall of the lower joint; a pressing plate, a limiting tube, a pre-tightening nut, a spring, a damping flow channel and a lower oil cylinder are sequentially arranged between the oil cylinder outer cylinder and the oil cylinder inner cylinder from top to bottom; the annular space between the pressing plate and the limiting tube forms an upper oil cylinder, one end of the spring is fixed on the oil cylinder inner cylinder, and the other end of the spring is fixedly connected with the pre-tightening nut; the hydraulic oil in the upper oil cylinder flows downward to the lower oil cylinder through the mud-blocking flow channel; and the hydraulic oil in the upper oil cylinder suspends a pressure-resistant balloon.

Description

Technical Field

[0001] This invention belongs to the field of vibration damping mechanical components, specifically to a drill bit vibration damper and vibration damping method with multi-level vibration damping function. Background Technology

[0002] When a drill string is in service downhole, it is subjected to fluctuating loads such as tension, compression, and torsion due to the uneven cutting of rock by the drill bit at the bottom of the well. The vibration load caused by the uneven cutting of rock, in particular, is a major cause of drill string fatigue damage, especially fatigue damage to threaded connections. Therefore, to reduce the damage to the drill string from impact and vibration loads, shock absorbers are often added to the drill string assembly to absorb the vibration energy, reduce the damage caused by vibration loads, and minimize the occurrence of failure accidents. Conventional shock absorption methods include mechanical shock absorption, such as shock absorption using the compressibility of springs, shock absorption using the compressibility and flow damping of liquids, and shock absorption using compressible gases, etc. These shock absorption structures often only have a single-stage shock absorption function. While gas-type shock absorbers are sensitive, they require extremely high cylinder sealing, making the seals prone to damage and resulting in a short service life. Mechanical shock absorbers, represented by springs, require high-quality spring materials, and the springs are prone to fatigue damage and breakage, leading to a relatively short lifespan. Liquid-type shock absorbers, due to the poor compressibility of liquids, have low sensitivity in the return of the shock absorber mechanism, especially under low loads and high-frequency vibrations, resulting in poor shock absorption. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the present invention provides a drill bit shock absorber and shock absorption method with multi-level shock absorption function, so as to overcome the shortcomings of gas shock absorption, liquid shock absorption and mechanical shock absorption structures in the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A drill bit damper with multi-stage damping function includes an upper connector and a lower connector;

[0006] The upper connector and the lower connector are connected by threads, and the connection part of the upper connector and the lower connector is provided with an outer cylinder and an inner cylinder.

[0007] One end of the cylinder inner tube is connected to the lower connector, and the other end of the cylinder inner tube is connected to the inner tube extension. The inner tube extension is disposed on the inner wall of the upper connector.

[0008] One end of the outer cylinder is connected to the upper connector, and the other end of the inner cylinder is connected to the outer cylinder extension. The outer cylinder extension is located on the inner wall of the lower connector.

[0009] From top to bottom, a pressure plate, a limiting tube, a preload nut, a spring, a damping flow channel, and a lower cylinder are arranged between the outer cylinder and the inner cylinder of the hydraulic cylinder.

[0010] The annular space between the pressure plate and the limiting tube forms the upper oil cylinder. One end of the spring is fixed to the inner cylinder, and the other end of the spring is fixedly connected to the preload nut. The hydraulic oil in the upper oil cylinder flows down to the lower oil cylinder through the mud-blocking flow channel.

[0011] The hydraulic oil in the upper cylinder contains a pressure-resistant balloon suspended in it.

[0012] Preferably, the density of the pressure-resistant balloon is in the range of 1.07–1.09 mg / mm³ compared to the density of the hydraulic oil. 3 .

[0013] Preferably, the shell material of the pressure-resistant balloon is a composite of an oil-resistant high-strength fiber layer and a rubber layer.

[0014] Preferably, one or more of the pressure-resistant balloons are placed inside the lower oil cylinder.

[0015] Preferably, the axial length of the limiting tube is less than the axial length of the lower cylinder.

[0016] Preferably, the spring is a helical spring, and the spring is sleeved on the inner cylinder of the oil cylinder.

[0017] Preferably, when the limiting tube contacts the preload nut, the pressure value borne by the lower connector is greater than or equal to the set preload value applied by the preload nut to the spring.

[0018] Preferably, a sealing element is placed on the inner surface of the inner cylinder extension to seal the upper oil cylinder.

[0019] Preferably, a sealing element is placed on the inner surface of the outer cylinder extension to seal and limit the lower cylinder.

[0020] A vibration reduction method for a drill bit vibration damper with multi-stage vibration reduction function includes the following processes:

[0021] When the lower connector is under pressure, it drives the pre-tightening nut to squeeze the hydraulic oil in the upper cylinder. The pressure-resistant balloon reduces its volume under pressure, and the lower connector moves upward. At this time, the pressure-resistant balloon is compressed and damped to form a first-level damping.

[0022] When the pressure on the lower connector increases, the volume of the pressure-resistant balloon decreases further. The lower connector moves upward, and the limiting tube contacts the pre-tightening nut. The spring will be compressed. At this time, the shock absorption method naturally transitions from balloon compression shock absorption to spring compression shock absorption, forming a two-stage shock absorption.

[0023] When the pressure load on the lower joint continues to increase, the spring is further compressed, the hydraulic oil in the upper cylinder flows down to the lower cylinder through the mud-blocking channel, and the lower joint moves up. At this time, hydraulic damping and spring shock absorption are the main components, forming a three-stage shock absorption.

[0024] The compression load borne by the lower joint is automatically matched between each level of vibration damping to achieve multi-level vibration damping without fluctuation.

[0025] Compared with the prior art, the present invention has the following beneficial technical effects:

[0026] This invention discloses a drill bit vibration damper with multi-stage damping function. First-stage damping is achieved through compression damping using an upper hydraulic cylinder and a pressure-resistant balloon. Second-stage damping is achieved through compression damping using a pre-tightening nut and a spring. Third-stage damping is achieved by using a mud-blocking channel to guide the material down to the lower hydraulic cylinder, primarily through hydraulic damping and spring damping. This drill bit vibration damper is highly responsive to external vibrations, reacting instantly to the magnitude of the external vibration energy and automatically activating multi-stage damping. It fully utilizes the advantages of gas damping, liquid damping, and mechanical damping (springs) while effectively avoiding the disadvantages of various damping methods, thus improving the damping effect and increasing the service life of the damping structure. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a drill bit vibration damper with multi-stage vibration reduction function according to the present invention;

[0028] In the attached diagram: 1 is the upper connector; 2 is the lower connector; 3 is the outer cylinder of the hydraulic cylinder; 4 is the inner cylinder of the hydraulic cylinder; 5 is the upper hydraulic cylinder; 6 is the lower hydraulic cylinder; 7 is the spring; 8 is the pressure-resistant balloon; 9 is the limiting tube; 10 is the pre-tightening nut; 11 is the damping flow channel; 12 is the inner cylinder extension; 13 is the outer cylinder extension; 14 is the pressure plate; 15 is the seal; 16 is the hydraulic oil. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] The present invention provides a drill bit shock absorber with multi-stage shock absorption function, including an upper connector 1 and a lower connector 2; the upper connector 1 and the lower connector 2 are connected by threads, and the connection part of the upper connector 1 and the lower connector 2 is provided with an outer cylinder 3 and an inner cylinder 4.

[0033] One end of the inner cylinder 4 is connected to the lower connector 2, and the other end of the inner cylinder 4 is connected to the inner cylinder extension 12, which is located on the inner wall of the upper connector 1; one end of the outer cylinder 3 is connected to the upper connector 1, and the other end of the inner cylinder 4 is connected to the outer cylinder extension 13, which is located on the inner wall of the lower connector 2.

[0034] Between the outer cylinder 3 and the inner cylinder 4, from top to bottom, are arranged a pressure plate 14, a limiting tube 9, a pre-tightening nut 10, a spring 7, a damping flow channel 11, and a lower cylinder 6; the annular space between the pressure plate 14 and the limiting tube 9 forms the upper cylinder 5; one end of the spring 7 is fixed to the inner cylinder 4, and the other end of the spring 7 is fixedly connected to the pre-tightening nut 10; the hydraulic oil 16 of the upper cylinder 5 flows down to the lower cylinder 6 through the damping flow channel 11; the hydraulic oil 16 in the upper cylinder 5 is suspended by a pressure-resistant balloon 8.

[0035] This invention discloses a vibration reduction method for a drill bit vibration damper with multi-stage vibration reduction function, comprising the following processes:

[0036] When the lower connector 2 is under pressure, it drives the pre-tightening nut 10 to squeeze the hydraulic oil 16 in the upper cylinder 5. The pressure-resistant balloon 8 is reduced in volume under pressure, and the lower connector 2 moves upward. At this time, the pressure-resistant balloon 8 is compressed and damped to form a first-level damping.

[0037] When the pressure on the lower connector 2 increases, the volume of the pressure-resistant balloon 8 decreases further. The lower connector 2 moves upward, and the limiting tube 9 contacts the pre-tightening nut 10. The spring 7 will be compressed. At this time, the shock absorption method naturally transitions from balloon compression shock absorption to spring 7 compression shock absorption, forming a two-stage shock absorption.

[0038] When the pressure load on the lower connector 2 continues to increase, the spring 7 is further compressed, the hydraulic oil 16 of the upper cylinder 5 flows down to the lower cylinder 6 through the mud-blocking channel, and the lower connector 2 moves up. At this time, the hydraulic damping and the spring 7 are the main damping forces, forming a three-stage damping system.

[0039] The compression load borne by the lower joint 2 is automatically matched between each level of shock absorption to achieve multi-level shock absorption without fluctuation.

[0040] Example

[0041] The present invention will now be described in further detail with reference to the accompanying drawings:

[0042] See Figure 1 , Figure 1 A drill bit vibration damper with multi-stage vibration reduction function includes an upper connector 1 with internal threads, a lower connector 2 with external threads, an outer cylinder 3, an inner cylinder 4, an upper cylinder 5, a lower cylinder 6, a spring 7, a pressure-resistant balloon 8, a limiting tube 9, a preload nut 10, a damping flow channel 11, an inner cylinder extension 12, an outer cylinder extension 13, a pressure plate 14, a seal 15, and hydraulic oil 16.

[0043] The pressure-resistant balloon 8 is filled with a gas at a certain pressure, preferably nitrogen. The pressure-resistant balloon 8 is suspended in the hydraulic oil 16 inside the upper oil cylinder 5.

[0044] See Figure 1 The density of the pressure-resistant balloon 8 is similar to that of the hydraulic oil 16, with a density value of 1.07–1.09 mg / mm³. 3 In this embodiment, the preferred concentration is 1.07 mg / mm. 3 .

[0045] See Figure 1 The shell of the pressure-resistant balloon 8 is made of a composite material of an oil-resistant, high-strength fiber layer and a rubber layer.

[0046] See Figure 1 One or more pressure-resistant balloons 8 are placed according to the volume of the balloon and the volume of the lower oil cylinder 6.

[0047] See Figure 1 The initial air pressure inside the pressure-resistant balloon 8 is 10-15 bar, and in this embodiment, it is preferably 12 bar.

[0048] See Figure 1 The limiting tube 9 is a circular ring with a wall thickness of 15mm, and a through hole with a diameter of 3mm is machined on its circumference.

[0049] See Figure 1 The axial length of the limiting tube 9 is 5mm less than the axial length of the lower oil cylinder 6.

[0050] See Figure 1Spring 7 is helical and is fitted onto the inner cylinder 4 of the oil cylinder.

[0051] See Figure 1 By adjusting the position of the preload nut 10, a set preload can be applied to the spring 7.

[0052] See Figure 1 When the limiting tube 9 contacts the preload nut 10, the pressure value borne by the lower connector 2 is greater than or equal to the set preload value applied by the preload nut 10 to the spring 7.

[0053] See Figure 1 When the lower connector 2 is under pressure, it drives the pre-tightening nut 10 to squeeze the hydraulic oil 16 of the upper cylinder 5, and the pressure-resistant balloon 8 is reduced in volume under pressure. The lower connector 2 moves upward, and at this time, the pressure-resistant balloon 8 is compressed and damped to form a first-level damping.

[0054] See Figure 1 When the pressure on the lower connector 2 increases, the volume of the pressure-resistant balloon 8 decreases further. The lower connector 2 moves upward, and the limiting tube 9 contacts the pre-tightening nut 10. The spring 7 will be compressed. At this time, the shock absorption method naturally transitions from balloon compression shock absorption to spring 7 compression shock absorption, forming a two-stage shock absorption.

[0055] See Figure 1 When the pressure load on the lower connector 2 continues to increase, the spring 7 is further compressed, the hydraulic oil 16 of the upper cylinder 5 flows down to the lower cylinder 6 through the mud-blocking channel, and the lower connector 2 moves up. At this time, the hydraulic damping and the spring 7 are the main damping forces, forming a three-stage damping system.

[0056] See Figure 1 A sealing element 15 is placed on the inner surface of the inner cylinder extension 12, which serves as a seal for the upper oil cylinder 5.

[0057] See Figure 1 A sealing element 15 is placed on the inner surface of the outer cylinder extension 13 to provide sealing and limiting functions for the lower cylinder 6.

[0058] See Figure 1 After the pressure load disappears, the lower connector 2 moves downward due to the rebound of the spring 7 and the pressure-resistant balloon 8, and the hydraulic oil 16 of the lower cylinder 6 flows back to the upper cylinder 5.

[0059] See Figure 1 Spring 7 can also be designed as a disc spring or other spring assembly.

[0060] See Figure 1 The pressure-resistant balloon 8 can also be designed as an airbag.

[0061] See Figure 1 The compression load borne by each level of shock absorber is automatically matched through the lower joint 2, so as to achieve multi-level shock absorber without fluctuation.

[0062] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A drill bit vibration damper with multi-stage vibration reduction function, characterized in that, Includes an upper connector (1) and a lower connector (2); The upper connector (1) and the lower connector (2) are connected by threads, and the connection part of the upper connector (1) and the lower connector (2) is provided with an outer cylinder (3) and an inner cylinder (4). One end of the cylinder inner tube (4) is connected to the lower connector (2), and the other end of the cylinder inner tube (4) is connected to the inner tube extension (12). The inner tube extension (12) is set on the inner wall of the upper connector (1). One end of the outer cylinder (3) of the oil cylinder is connected to the upper connector (1), and the other end of the inner cylinder (4) of the oil cylinder is connected to the outer cylinder extension (13). The outer cylinder extension (13) is set on the inner wall of the lower connector (2). The cylinder outer cylinder (3) and cylinder inner cylinder (4) are arranged from top to bottom as follows: pressure plate (14), limit tube (9), pre-tightening nut (10), spring (7), damping flow channel (11) and lower cylinder (6). The annular space between the pressure plate (14) and the limiting tube (9) forms the upper cylinder (5). One end of the spring (7) is fixed on the inner cylinder (4), and the other end of the spring (7) is fixedly connected to the pre-tightening nut (10). The hydraulic oil (16) of the upper cylinder (5) flows down to the lower cylinder (6) through the mud-blocking channel (11). The hydraulic oil (16) in the upper cylinder (5) has a pressure-resistant balloon (8) suspended in it. When the limiting tube (9) contacts the pre-tightening nut (10), the pressure value borne by the lower connector (2) is greater than or equal to the set pre-pressure value applied by the pre-tightening nut (10) to the spring (7); When the lower connector (2) is under pressure, the lower connector (2) drives the pre-tightening nut (10) to squeeze the hydraulic oil (16) in the upper cylinder (5), the pressure-resistant balloon (8) reduces its volume under pressure, and the lower connector (2) moves upward. At this time, the pressure-resistant balloon (8) is compressed and damped to form a first-level damping. When the pressure on the lower connector (2) increases, the volume of the pressure-resistant balloon (8) decreases further. The lower connector (2) moves upward, and the limiting tube (9) contacts the pre-tightening nut (10). The spring (7) will be compressed. At this time, the shock absorption method naturally transitions from balloon compression shock absorption to spring (7) compression shock absorption, forming a secondary shock absorption. When the pressure load on the lower connector (2) continues to increase, the spring (7) is further compressed, the hydraulic oil (16) of the upper cylinder (5) flows down to the lower cylinder (6) through the mud-blocking channel, and the lower connector (2) moves up. At this time, the hydraulic damping and the spring (7) are the main damping, forming a three-stage damping. The compression load borne by each level of vibration damping is automatically matched through the lower joint (2) to achieve multi-level vibration damping without fluctuation.

2. A drill bit vibration damper with multi-stage vibration reduction function according to claim 1, characterized in that, The density of the pressure-resistant balloon (8) and the density of the hydraulic oil (16) are in the range of 1.07~1.09 mg / mm³. 3 .

3. A drill bit vibration damper with multi-stage vibration reduction function according to claim 1, characterized in that, The shell material of the pressure-resistant balloon (8) is a composite of an oil-resistant high-strength fiber layer and a rubber layer.

4. A drill bit vibration damper with multi-stage vibration reduction function according to claim 1, characterized in that, One or more of the pressure-resistant balloons (8) are placed inside the lower oil cylinder (6).

5. A drill bit vibration damper with multi-stage vibration reduction function according to claim 1, characterized in that, The axial length of the limiting tube (9) is less than the axial length of the lower oil cylinder (6).

6. A drill bit vibration damper with multi-stage vibration reduction function according to claim 1, characterized in that, The spring (7) is a helical spring, and the spring (7) is sleeved on the inner cylinder (4).

7. A drill bit vibration damper with multi-stage vibration reduction function according to claim 1, characterized in that, A sealing element (15) is placed on the inner surface of the inner cylinder extension (12) to seal the upper oil cylinder (5).

8. A drill bit vibration damper with multi-stage vibration reduction function according to claim 1, characterized in that, A sealing element (15) is placed on the inner surface of the outer cylinder extension (13) to seal and limit the lower cylinder (6).

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