A tubular pump suitable for use in a slim hole well

Abstract

The utility model discloses a kind of pipe type pumps suitable for slim hole well, it includes: pump barrel assembly, its top is communicated with sucker rod, the bottom of the pump barrel assembly is connected with fixed valve assembly;Column valve assembly is adapted to slip into to the pump barrel assembly, and movable valve assembly is installed in the upper and lower both ends of the column valve assembly;Disconnecter lower body is fixedly connected with column valve assembly;And disconnecter upper body can be matched with the disconnecter lower body and is engaged, and the top surface of the disconnecter upper body is fixed with sucker rod.The utility model device adopts modular structure design, so that each component can be flexibly combined according to different working conditions and needs, greatly improve the applicability and maintenance convenience of suction pump.

Description

Technical Field

[0001] This utility model specifically relates to the field of coalbed methane well drainage technology, and specifically to a tubular pump suitable for small-bore wells. Background Technology

[0002] Against the backdrop of continuously growing energy demand, coalbed methane, as a clean and efficient energy source, has attracted much attention for its development and utilization. To effectively improve single-well production and resource utilization, the open-window sidetracking horizontal well technology has been studied, opening a new path for the efficient development of coalbed methane. However, due to the special structure of sidetracked horizontal wells, the load distribution on the suction pump is uneven during operation. Increased friction between the pump barrel and plunger in the horizontal section can easily lead to poor sealing, resulting in reduced pump efficiency and affecting continuous gas well production. Furthermore, during drainage, coal dust and sand particles easily deposit and accumulate in the horizontal section, causing sand jamming, which prevents the extraction equipment from working properly and may even cause the tubing to seize, ultimately necessitating major overhaul operations. This undoubtedly significantly increases extraction costs and operational difficulty. Utility Model Content

[0003] Therefore, this utility model proposes a tubular pump suitable for small-bore wells to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a tubular pump suitable for small-bore wells, comprising:

[0005] A pump barrel assembly, the top of which is connected to an oil suction pipe, and the bottom of which is connected to a fixed valve assembly;

[0006] A column valve assembly is adapted to slide into the pump cylinder assembly, and a floating valve assembly is installed in both the upper and lower ends of the column valve assembly;

[0007] The lower part of the disconnector is fixedly connected to the column valve assembly;

[0008] And a disconnector upper body, which can be matched and engaged with the disconnector lower body, and a sucker rod is fixed on the top surface of the disconnector upper body;

[0009] The traveling valve assembly includes:

[0010] The ball seat is fixed inside the valve assembly using a hollow frame.

[0011] The valve sealing ring is fixed inside the valve assembly and located below the ball seat;

[0012] And a ball seal, which is connected to the ball seat by a compression spring, and the ball seal matches and seals the annular hole of the valve sealing ring under the elastic force of the compression spring.

[0013] Furthermore, as a preferred embodiment, the top of the fixed valve assembly is provided with a groove, and a protrusion fixed to the bottom of the pump assembly is tenon-tenon connected in the groove.

[0014] Furthermore, as a preferred embodiment, a plunger valve cover is provided on the outer wall of the plunger valve assembly.

[0015] Furthermore, as a preferred embodiment, the plunger valve cover is made of 20Cr13 material.

[0016] Furthermore, preferably, the inner diameter of the sucker pipe is smaller than the outer diameter of the column valve assembly.

[0017] Furthermore, as a preferred embodiment, the surface of the ball seal is provided with a rubber layer.

[0018] This utility model adopts the above technology and has the following beneficial effects compared with the existing technology:

[0019] 1. The device of this utility model adopts a modular structural design, which allows the components to be flexibly combined according to different working conditions and needs, greatly improving the applicability and maintenance convenience of the suction pump.

[0020] 2. The traveling valve adopts a spring-forced reset structure. During coalbed methane drainage, the downhole conditions are complex and variable, with frequent fluctuations in pressure and flow. Traditional traveling valves are prone to delayed closure or obstructed opening under complex well conditions, affecting the pump's suction and discharge efficiency. However, the spring-forced reset structure of this invention can push the traveling valve to reset under complex well conditions, ensuring smooth suction and discharge. During suction, when the pressure inside the pump chamber decreases, the spring will immediately open the traveling valve, allowing liquid to quickly enter the pump chamber. During discharge, when the pressure inside the pump chamber increases, the spring can promptly close the traveling valve to prevent backflow of liquid, greatly improving the pump's working efficiency and ensuring the stable operation of the suction pump.

[0021] 3. A plunger valve cover has been specially added, and it is made of 20Cr13 material. 20Cr13 material has corrosion resistance and high strength, and can work stably in harsh downhole environments containing sulfur and acid. Its properties can also effectively resist the erosion of solid particles such as coal dust and sand, preventing the valve cover from corroding and breaking in harsh downhole environments.

[0022] 4. The lower end of the pump assembly is carefully designed with protruding claws, while the upper end of the fixed valve has a corresponding groove. This unique tenon-and-mortise connection structure design makes the connection between the plunger pump assembly and the fixed valve more stable and reliable, effectively enhancing the stability of the suction pump during operation. When subjected to high pressure, this connection structure can evenly distribute stress, avoiding loosening or damage to the connection caused by local stress concentration.

[0023] 5. The disconnector features unique docking and release functions. During the well run-in process, the upper and lower bodies of the disconnector can be precisely docked using the weight of the sucker rod itself. This docking method requires no additional power unit and is simple and reliable to operate. During docking, the weight of the sucker rod will cause the upper and lower bodies of the disconnector to gradually approach and dock along a specific guide structure. When it is necessary to separate the sucker rod string from the plunger assembly, simply rotate the sucker rod clockwise to release the disconnector. The operation is simple and efficient. This functional design greatly improves operational efficiency and reduces operation time and costs. Attached Figure Description

[0024] Figure 1 A schematic diagram of the internal structure of a tubular pump suitable for small-bore wells;

[0025] Figure 2 for Figure 1 An enlarged schematic diagram of part A in the middle.

[0026] In the diagram: 1. Pump cylinder assembly; 2. Upper body of disconnector; 3. Column valve assembly; 4. Fixed valve assembly; 5. Column valve sealing ring; 6. Groove; 7. Lower body of disconnector; 8. Ball seal; 9. Compression spring; 10. Ball seat; 11. Hollow frame. Detailed Implementation

[0027] With reference to the accompanying drawings of the embodiments of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below.

[0028] Example: Please refer to the appendix. Figure 1 and 2 This utility model provides a technical solution: a tubular pump suitable for small-bore wells, comprising:

[0029] Pump assembly 1 has an oil suction pipe connected to its top, providing a channel for liquid delivery, and the bottom of pump assembly 1 is connected to fixed valve assembly 4.

[0030] The column valve assembly 3 is adapted to slide into the pump cylinder assembly 1, and a floating valve assembly is installed in both the upper and lower ends of the column valve assembly 3;

[0031] Specifically, the lower side of the column valve assembly 3 is tightly connected to the fixed valve assembly 4. This connection method adopts a special sealing and fastening process to ensure that there will be no loosening or leakage in the high-pressure and highly corrosive downhole environment.

[0032] The lower body 7 of the disconnector is fixedly connected to the column valve assembly 3;

[0033] And the upper body 2 of the disconnector, which can be matched and engaged with the lower body 7 of the disconnector, and a sucker rod is fixed on the top surface of the upper body 2 of the disconnector.

[0034] Specifically, the upper part of the disconnector is connected to the sucker rod and is lowered into the well along with the sucker rod to provide power transmission for subsequent drainage.

[0035] The traveling valve assembly includes:

[0036] The ball seat 10 is fixed inside the column valve assembly 3 by a hollow frame 11;

[0037] The valve sealing ring 5 is fixed inside the valve assembly 3 and located below the ball seat 10;

[0038] And ball seal 8, which is connected to ball seat 10 by compression spring 9, and under the elastic force of compression spring 9, ball seal 8 matches and seals the annular hole of column valve sealing ring 5.

[0039] In this embodiment, a groove 6 is provided on the top of the fixed valve assembly 4, and a protrusion fixed to the bottom of the pump cylinder assembly 1 is tenon-tenon connected in the groove 6.

[0040] In this embodiment, a plunger valve cover is provided on the outer wall of the plunger valve assembly 3.

[0041] In this embodiment, the plunger valve cover is made of 20Cr13 material.

[0042] In this embodiment, the inner diameter of the sucker pipe is smaller than the outer diameter of the column valve assembly 3;

[0043] Specifically, since the inner diameter of the 23 / 8NU oil pipe is smaller than the outer diameter of the pump plunger (50.8mm), the pump structure with the coupling has a maximum outer diameter of 48mm.

[0044] In this embodiment, a rubber layer is provided on the surface of the ball seal 8.

[0045] To meet the needs of oil wells with a large inclination, the pump's traveling valve and fixed valve are equipped with a spring-driven forced reset structure, which can be used in oil wells with an inclination of 60 degrees. In specific implementation, the pump barrel assembly 1 and the fixed valve assembly 4 are connected together and tightened. The string valve assembly 3 and the lower body of the disconnector are connected together and placed inside the pump barrel and lowered into the well along with the tubing. The tubing is connected to the top of the pump barrel assembly 1, and the fixed valve is connected to the bottom of the pump barrel assembly 1. The upper body of the disconnector is connected to the corresponding size sucker rod and lowered into the well along with the sucker rod string.

[0046] Subsequently, lower the sucker rod to bring the upper and lower parts of the disconnector into contact. The sucker rod's own weight will achieve docking. After docking, lift the sucker rod, and the weight indicator reading will increase significantly. If docking fails, lift and rotate the sucker rod to re-dock. Lower the pump assembly 1 to the bottom, connecting it to the plunger assembly. At this point, the weight indicator will show zero. Slowly lift the sucker rod until the weight indicator reading is slightly less than the weight of the sucker rod string (approximately 1 / 2 to 3 / 4 of the rod weight). Then, rotate the sucker rod clockwise, causing the upper and lower parts of the disconnector to rotate 90° relative to each other (on the ground, the number of rotations can be calculated as one rotation per 100 meters; add one more rotation for distances exceeding 1000 meters, and adjust the number of rotations according to the rotational torque during operation). Finally, after the sucker rod is rotated to the correct position, hold it and slowly lift it to release the disconnector, disengaging the sucker rod string from the valve assembly 3.

[0047] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A tubular pump suitable for small-bore wells, characterized in that, It includes: The pump barrel assembly (1) has an oil suction pipe connected to its top, and the bottom of the pump barrel assembly (1) is connected to the fixed valve assembly (4). The column valve assembly (3) is adapted to slide into the pump cylinder assembly (1), and a floating valve assembly is installed in both the upper and lower ends of the column valve assembly (3); The lower body of the disconnector (7) is fixedly connected to the column valve assembly (3); And the upper body (2) of the disconnector, which can be matched and engaged with the lower body (7) of the disconnector, and a sucker rod is fixed on the top surface of the upper body (2); The traveling valve assembly includes: The ball seat (10) is fixed inside the column valve assembly (3) by means of a hollow frame (11); The valve sealing ring (5) is fixed inside the valve assembly (3) and located below the ball seat (10); And a ball seal (8), which is connected to the ball seat (10) by a compression spring (9), and the ball seal (8) matches and seals the annular hole of the valve sealing ring (5) under the elastic force of the compression spring (9).

2. A tubular pump suitable for small-bore wells according to claim 1, characterized in that: The top of the fixed valve assembly (4) is provided with a groove (6), and the groove (6) is tenon-mortised with a protrusion fixed to the bottom of the pump cylinder assembly (1).

3. A tubular pump suitable for small-bore wells according to claim 1, characterized in that: A plunger valve cover is provided on the outer wall of the plunger valve assembly (3).

4. A tubular pump suitable for small-bore wells according to claim 3, characterized in that: The plunger valve cover is made of 20Cr13 material.

5. A tubular pump suitable for small-bore wells according to claim 1, characterized in that: The inner diameter of the oil extraction pipe is smaller than the outer diameter of the column valve assembly (3).

6. A tubular pump suitable for small-bore wells according to claim 1, characterized in that: The surface of the ball seal (8) is provided with a rubber layer.

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