Gas lift underground buffer device
By designing a cylinder, movable rod, buffer plate, and buffer assembly, combined with the buffering form of springs and airbags, the problem of easy failure of buffer pads in traditional buffer devices is solved, achieving multiple buffering effects and device durability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- YANCHENG HUARUITONG MASCH CO LTD
- Filing Date
- 2025-02-21
- Publication Date
- 2026-05-01
AI Technical Summary
The buffer pads of traditional gas lift downhole buffer devices are prone to failure or breakage after repeated impacts, resulting in poor buffering effect.
The design incorporates a cylinder, movable rod, buffer plate, pressure plate, and buffer assembly, combined with the buffering methods of springs and airbags. The springs provide initial deceleration, the airbags extend the plunger's descent time during compression, and a one-way valve controls the flow of gas and liquid to achieve multiple buffering.
It effectively slows down the plunger's descent speed, improves the buffering effect, extends the service life of the device, and reduces the probability of corrosion of the spring by the downhole environment.
Smart Images
Figure CN224187536U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of oilfield development technology, specifically relating to a gas lift downhole buffer device. Background Technology
[0002] The gas lift downhole buffer device is a supporting tool used in the gas lift process for oil wells. Its function is to provide an upward buffering force when the plunger falls to the position of the locking device, so as to slow down the plunger's descent speed and protect the locking device and tubing.
[0003] Traditional buffer devices often use springs in conjunction with rubber pads or buffer pads for cushioning. Since the plunger usually falls at a relatively high speed, the impact on the buffer pad is relatively large. After repeated use, the density of the buffer pad will be compressed, resulting in buffer failure or cracking and deformation.
[0004] Therefore, a gas lift downhole buffer device is designed to overcome the aforementioned technical defects. Utility Model Content
[0005] (1) Technical problems to be solved
[0006] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a gas lift downhole buffer device, which aims to solve the technical problem that the buffer pad will fail or break and deform after being subjected to multiple impacts by the plunger in the existing technology.
[0007] (2) Technical solution
[0008] To solve the above-mentioned technical problems, this utility model provides a gas lift downhole buffer device, including a cylinder. Movable rods are movably connected to the upper and lower ends of the cylinder, respectively. One end of each movable rod penetrates the cylinder and is fixedly connected to a buffer plate. A spring is fitted inside the cylinder's inner cavity on the side wall of the movable rod. Both ends of the spring are fixedly connected to the side walls of the cylinder and the buffer plate, respectively. A pressure plate is fixedly connected to the other end of the movable rod. Two rows of through holes are opened near the middle of the cylinder's side wall. A first one-way valve is installed in each of the through holes, with the first one-way valves in the two rows of through holes facing opposite directions. A buffer assembly is provided inside the cylinder's inner cavity.
[0009] Furthermore, the buffer assembly includes a first airbag disposed in the inner cavity of the cylinder. The two ends of the first airbag are fixedly connected to the two side buffer plates respectively. A second airbag is fixedly connected to the side wall of the buffer plate near the spring. The second airbag is annular. The side wall of the buffer plate is provided with four equidistant air holes. A second one-way valve is installed in each air hole. The first airbag communicates with the second airbag through the air holes.
[0010] Furthermore, each of the buffer plates is equipped with two sealing rings on its sidewalls, and the sealing rings are in contact with the inner wall of the cylinder.
[0011] Furthermore, several rubber blocks are fixedly connected to the side wall of the pressure plate away from the cylinder, and the end face of the rubber blocks is arc-shaped.
[0012] Furthermore, a bellows is fitted inside the cylinder along the side wall of the movable rod, with both ends of the bellows fixedly connected to the side walls of the cylinder and the buffer plate, respectively, and the spring is located inside the bellows.
[0013] Furthermore, the second one-way valves within the two vents are configured in opposite directions.
[0014] (3) Beneficial effects
[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0016] This invention utilizes a design incorporating a cylinder, movable rod, buffer plate, pressure plate, and buffer assembly. It employs a spring-assisted airbag buffer system. Firstly, the spring effectively reduces speed and vibration. Secondly, the airbag, after compression, requires a short time to expel gas, during which the plunger's descent speed is slowed, achieving a buffering effect. Thirdly, during the compression and expansion of the airbag, the downhole fluid entering the buffer cylinder also undergoes a process of discharge and entry, similarly slowing the plunger's descent speed and further enhancing the buffering effect. Attached Figure Description
[0017] Figure 1 This is a perspective view of the present utility model;
[0018] Figure 2 This is a schematic diagram of the structure of this utility model;
[0019] Figure 3 This is a partial perspective view of the present invention;
[0020] Figure 4 This utility model Figure 3 A structural diagram.
[0021] The markings in the attached diagram are as follows: 1. Cylinder; 2. Movable rod; 3. Buffer plate; 4. Spring; 5. Pressure plate; 6. Through hole; 7. First one-way valve; 8. Air hole; 9. Second one-way valve; 10. First airbag; 11. Second airbag; 12. Sealing ring; 13. Rubber block; 14. Bellows. Detailed Implementation
[0022] This specific embodiment is a gas lift downhole buffer device, the structural schematic diagram of which is shown below. Figures 1-4As shown, the device includes a cylinder 1. Movable rods 2 are movably connected to the upper and lower ends of the cylinder 1. One end of each movable rod 2 passes through the cylinder 1 and is fixedly connected to a buffer plate 3. A spring 4 is fitted inside the cylinder 1 on the side wall of the movable rod 2. Both ends of the spring 4 are fixedly connected to the side walls of the cylinder 1 and the buffer plate 3, respectively. A pressure plate 5 is fixedly connected to the other end of the movable rod 2. Two rows of through holes 6 are opened near the middle of the side wall of the cylinder 1. A first one-way valve 7 is installed in each of the through holes 6. The first one-way valves 7 in the two rows of through holes 6 are in opposite directions. A buffer assembly is provided inside the cylinder 1.
[0023] like Figure 2 and Figure 4 As shown, the buffer assembly includes a first airbag 10 disposed inside the cylinder 1. The two ends of the first airbag 10 are fixedly connected to two side buffer plates 3. A second airbag 11 is fixedly connected to the side wall of the buffer plate 3 near the spring 4. The second airbag 11 is annular. Four equidistant air holes 8 are provided on the side wall of each buffer plate 3. A second one-way valve 9 is installed in each air hole 8. The first airbag 10 communicates with the second airbag 11 through the air holes 8. The second one-way valves 9 in two of the air holes 8 are arranged in opposite directions.
[0024] Both the first check valve 7 and the second check valve 9 are pressure-type check valves. Pressure-type check valves, by using a valve core or valve disc, keep the valve closed under normal operating pressure, preventing reverse flow of fluid. When sufficient pressure is applied to the valve core or valve disc, the valve opens, allowing fluid flow.
[0025] Specifically, the opening pressure of the second one-way valve 9 is less than the elastic force of the spring 4. When there is no impact force from the plunger descending on the pressure plate 5, the spring 4 is compressed and reset, allowing the gas in the second airbag 11 to begin entering the first airbag 10 through the second one-way valve 9. This resets the first airbag 10, the second airbag 11, and the spring 4. Since the downhole pressure is high, if there is liquid, the liquid can use the pressure to open the first one-way valve 7 and enter the cylinder 1.
[0026] like Figure 3 and Figure 4 As shown, each side wall of the buffer plate 3 is equipped with two sealing rings 12, and the sealing rings 12 are in contact with the inner wall of the cylinder 1.
[0027] Two annular grooves are provided on the buffer plate 3, and the sealing ring 12 is assembled in the annular groove. During use, the sealing ring 12 is tightly fitted with the inner wall of the cylinder 1 to prevent downhole liquid from entering the spring 4 side of the cylinder 1 and affecting the inflation of the second airbag 11.
[0028] like Figure 1 and Figure 2 As shown, several rubber blocks 13 are fixedly connected to the side wall of the pressure plate 5 away from the cylinder 1, and the end face of the rubber block 13 is arc-shaped.
[0029] The rubber block 13 can also initially alleviate the impact force generated when the plunger descends, and can also protect the pressure plate 5 and reduce the wear of the pressure plate 5.
[0030] like Figure 2 and Figure 4 As shown, the side wall of the movable rod 2 is fitted with a bellows 14 inside the cylinder 1. The two ends of the bellows 14 are fixedly connected to the side walls of the cylinder 1 and the buffer plate 3, respectively. The spring 4 is located inside the bellows 14.
[0031] Among them, the bellows 14 has good expansion and contraction performance and sealing performance, and can operate in accordance with the stretching or compression of the spring 4, effectively reducing the probability of corrosion of the spring 4 by the downhole environment, thereby extending the service life of the spring 4.
[0032] Working principle: First, the device is placed at a suitable location on the oil well using hoisting equipment. When the plunger descends, the upper pressure plate 5 is stressed first. At this time, the pressure plate 5 drives the buffer plate 3 to move downward through the movable rod 2. At the same time, the spring 4 is stretched for initial buffering. The pressure is transmitted to the lower pressure plate 5 through the cylinder 1, causing the two buffer plates 3 to move relative to each other and compress the first airbag 10. The gas in the first airbag 10 enters the second airbag 11 through the second one-way valve 9, which delays the plunger descent time and achieves secondary buffering. As the internal space of the cylinder 1 becomes smaller, the downhole fluid stored inside is discharged outward through the first one-way valve 7, which prolongs the compression time of the first airbag 10. Thus, the plunger is buffered three times, thereby improving its buffering effect.
[0033] All technical features in this embodiment can be freely combined according to actual needs.
[0034] The above embodiments are preferred implementations of this utility model. In addition, this utility model can also be implemented in other ways. Any obvious substitutions without departing from the concept of this technical solution are within the protection scope of this utility model.
Claims
1. A gas lift downhole cushioning device comprising a cylinder (1), characterized in that: The upper and lower end faces of the cylinder (1) are respectively movably connected to movable rods (2). One end of each movable rod (2) passes through the cylinder (1) and is fixedly connected to a buffer plate (3). The side wall of the movable rod (2) is fitted with a spring (4) in the inner cavity of the cylinder (1). The two ends of the spring (4) are fixedly connected to the side walls of the cylinder (1) and the buffer plate (3) respectively. The other end of the movable rod (2) is fixedly connected to a pressure plate (5). The side wall of the cylinder (1) is provided with two rows of through holes (6) near the middle. Each through hole (6) is equipped with a first one-way valve (7). The first one-way valves (7) in the two rows of through holes (6) are in opposite directions. The inner cavity of the cylinder (1) is provided with a buffer assembly.
2. A gas lift downhole surge device according to claim 1, characterized in that: The buffer assembly includes a first airbag (10) disposed in the inner cavity of the cylinder (1). The two ends of the first airbag (10) are fixedly connected to the two buffer plates (3) on both sides respectively. The buffer plates (3) are fixedly connected to the side wall near the spring (4) with a second airbag (11). The second airbag (11) is annular. The side wall of the buffer plate (3) is provided with four equidistant air holes (8). Each air hole (8) is equipped with a second one-way valve (9). The first airbag (10) communicates with the second airbag (11) through the air holes (8).
3. The gas lift downhole buffer device according to claim 1, characterized in that: The buffer plate (3) is equipped with two sealing rings (12) on its side wall, and the sealing rings (12) are in contact with the inner wall of the cylinder (1).
4. A gas lift downhole surge device according to claim 1, characterized in that: Several rubber blocks (13) are fixedly connected to the side wall of the pressure plate (5) away from the cylinder (1), and the end face of the rubber block (13) is arc-shaped.
5. A gas lift downhole surge device according to claim 1, characterized in that: The movable rod (2) has a bellows (14) fitted inside the cylinder (1) on its side wall. The two ends of the bellows (14) are fixedly connected to the side walls of the cylinder (1) and the buffer plate (3) respectively. The spring (4) is located inside the bellows (14).
6. A gas lift downhole surge device according to claim 2, wherein: The second one-way valves (9) in the two vents (8) are arranged in opposite directions.