Anti-fouling oil well pump

Abstract

The utility model discloses a kind of anti-fouling oil well pump, it is related to oil production equipment technical field.Pump barrel and reciprocating plunger assembly inside are included, and the extension pipe with anti-fouling coating is connected in the upper and lower ends of pump barrel through thread sleeve.The plunger runs two ends out of pump barrel, realize the anti-fouling of outer wall and pump barrel full length contact abrasion.Free floating block with overflow hole is provided in plunger barrel inner cavity, when lower stroke, upward well fluid thrust makes floating block relative plunger up scraping;When upper stroke, plunger both ends valve closes liquid flow static, floating block is under gravity and inertia relative plunger down scraping.The utility model realizes the full length physical scraping of pump barrel inner wall and plunger internal self-driven reciprocating scraping.Extension pipe is detachable, maintenance cost is low, and it is extremely suitable for salt-containing easy-fouling oil well.

Description

Technical Field

[0001] This utility model relates to the field of oilfield production equipment technology, and more specifically, to an oil pump that prevents scaling in saline oil wells. Background Technology

[0002] During oilfield development, conventional pumping units are highly susceptible to scaling in saline wells. Scaling typically occurs in locations where saline crude oil flows through, where there is no mechanical friction, and where the flow rate is slow. The main scaling points include the upper and lower ends of the pump barrel, as well as the inner wall of the plunger barrel. Currently, the industry commonly employs a design where the plunger length is greater than the pump barrel length, allowing the plunger to extend beyond both ends of the pump barrel during the up and down strokes, thus eliminating scaling dead zones at the pump barrel ends; and an anti-scaling coating is sprayed inside the extension pipes at both ends of the pump barrel.

[0003] However, there is no effective way to address the scaling problem inside the plunger barrel; the only option is disassembly and descaling. The plunger assembly contains complex components, and once scaling occurs inside the plunger barrel, disassembly is cumbersome, making on-site cleaning and maintenance extremely difficult, severely impacting oil production efficiency and significantly increasing operating costs.

[0004] Because the plunger cylinder is quite long, spraying an anti-scaling coating on the entire inner wall is costly and technically challenging. Therefore, how to achieve anti-scaling inside the plunger has become a technical problem that needs to be solved by existing technologies. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides an anti-scaling oil pump that achieves physical anti-scaling on the inner wall of the pump barrel and the inner wall of the plunger, and has good maintainability.

[0006] The technical solution of this utility model is: An anti-scaling oil pump includes a pump barrel and a plunger assembly that reciprocates within the pump barrel. The upper and lower ends of the pump barrel are connected to an upper extension pipe and a lower extension pipe via an upper connecting sleeve and a lower connecting sleeve, respectively. The inner walls of the upper and lower extension pipes are coated with an anti-scaling coating. The plunger assembly includes a plunger cylinder, and an axially movable floating block is disposed in the inner cavity of the plunger cylinder. The floating block has several through-holes on its body, and the outer wall of the floating block contacts the inner wall of the plunger cylinder and forms a clearance fit.

[0007] When the pump is operating at the top dead center of the upstroke and the bottom dead center of the downstroke, the upper and lower ends of the plunger assembly extend out of the pump barrel and enter the upper and lower extension pipes, respectively, so that the plunger assembly achieves full-length contact friction with the inner wall of the pump barrel. Additionally, during the downstroke, the upward thrust of the well fluid causes the floating block to scrape upwards relative to the plunger; during the upstroke, the valves at both ends of the plunger are closed and the fluid flow is still, and the floating block scrapes downwards relative to the plunger under its own weight and inertia.

[0008] Preferably, an upper limit ring is provided above the inner cavity of the plunger cylinder, and a lower limit ring is provided below it. The floating block is disposed between the upper limit ring and the lower limit ring to limit the axial travel of the floating block.

[0009] The density of the floating block is greater than the density of the pumped well fluid.

[0010] Preferably, both the upper connecting sleeve and the lower connecting sleeve are threaded connections. Preferably, the anti-scaling coating is an epoxy powder coating or a reinforced polytetrafluoroethylene coating.

[0011] Specifically, the upper end of the plunger assembly is provided with an upstream moving valve, which has an upper valve ball inside; the lower end of the plunger assembly is provided with a downstream moving valve, which has a lower valve ball inside; the lower end of the lower extension pipe is connected to an inlet valve through an inlet valve connecting sleeve, which has an inlet valve ball inside.

[0012] The beneficial effects of this utility model are: 1. Self-driving scale prevention on the inner wall: A floating block is installed inside the plunger barrel. During the downstroke, the upward dynamic pressure of the well fluid is used to propel the plunger. During the upstroke, gravity and inertia are used to propel the floating block to automatically scrape the inner wall of the plunger up and down with the movement of the oil pump without an external power source. This achieves scale prevention on the inner wall of the oil pump barrel and the inner wall of the plunger.

[0013] 2. Full-length scale prevention on the outer wall: The structure of appropriately shortening the pump barrel and lengthening the plunger ensures full-length contact friction between the plunger and the inner wall of the pump barrel, eliminating scale dead zones at both ends of the pump barrel; the high-smooth coating on the inner wall of the extended pipe achieves a physical "non-stick" effect.

[0014] 3. Modular and easy to maintain: The upper and lower extension tubes are connected by threaded sleeves. When the coating is worn, the operator can directly disassemble and replace the extension tube on site, which greatly reduces the difficulty of inspection and maintenance and maintenance costs. Attached Figure Description

[0015] Figure 1 This is one of the structural schematic diagrams of this utility model (upper stroke); Figure 2 This is the second structural schematic diagram of this utility model (downstroke).

[0016] In the diagram: 1. Pump barrel; 2. Plunger assembly; 21. Upstream moving valve; 22. Upper valve ball; 23. Upper limit ring; 24. Floating block; 25. Plunger barrel; 26. Lower limit ring; 27. Lower valve ball; 28. Downstream moving valve; 3. Inlet valve; 31. Inlet valve ball; 4. Upper extension pipe; 5. Upper connecting sleeve; 6. Lower extension pipe; 7. Lower connecting sleeve; 8. Inlet valve connecting sleeve; 9. Coupling. Detailed Implementation

[0017] The present invention will be further described below with reference to specific embodiments.

[0018] The description of this utility model is merely a structural or even functional description of the embodiments, and the scope of this utility model is not limited by the embodiments described herein.

[0019] like Figure 1 , Figure 2 As shown, an anti-scaling oil pump includes a pump barrel 1 and a plunger assembly 2 that reciprocates within the pump barrel 1. The pump barrel 1 is shortened so that, during operation, when the plunger assembly 2 reaches the top dead center and bottom dead center, both its upper and lower ends protrude from the pump barrel 1. This ensures that the plunger assembly 2 achieves full-length contact wear against the inner wall of the pump barrel 1, thereby eliminating scaling on the inner wall of the pump barrel 1 through physical mechanical friction.

[0020] To ensure a tight seal during the suction stroke, the upper end of the pump cylinder 1 is threadedly connected to the upper extension pipe 4 via the upper connecting sleeve 5, and the lower end is threadedly connected to the lower extension pipe 6 via the lower connecting sleeve 7. The inner walls of both the upper and lower extension pipes are coated with a high-temperature cured epoxy powder coating. This coating has a smooth surface and significantly lower frictional resistance than ordinary steel pipes, making it difficult for scale to find a firm adhesion point, thus achieving a "non-stick" effect in non-friction areas. When the coating wears down, it can be quickly disassembled and replaced by unscrewing the connecting sleeve.

[0021] The upper end of the plunger assembly 2 is provided with an upstream moving valve 21 and an upper valve ball 22, and the lower end is provided with a downstream moving valve 28 and a lower valve ball 27. The bottom end of the lower extension pipe 6 is connected to the inlet valve 3 and the inlet valve ball 31 through the inlet valve connecting sleeve 8, and the uppermost part of the upper extension pipe 4 is connected to the tubing string through the coupling 9.

[0022] To address the issues of cumbersome disassembly and easy scaling inside the plunger assembly 2, a floating block 24 is installed inside the cavity of the plunger cylinder 25 of the plunger assembly 2. The floating block 24 has a certain mass and a density greater than that of the well fluid. Its body has several axial flow holes, and its outer wall rubs against the inner wall of the plunger. An upper limit ring 23 and a lower limit ring 26 are provided inside the plunger cylinder 25 to limit the stroke of the floating block 24 and prevent it from touching the traveling valve.

[0023] The working principle of this utility model: During the downstroke (such as) Figure 2 As the plunger assembly 2 moves downward, the inlet valve 3 closes, and the upstream moving valve 21 and downstream moving valve 28 open. The oil inside the plunger cylinder 25 flows upward at relatively high speed, and the strong fluid thrust overcomes the weight of the floating block 24, pushing it upward to the upper limit ring 23. During this process, the floating block 24 scrapes the inner wall of the plunger cylinder 25 from bottom to top.

[0024] During the upstroke (such as) Figure 1As the plunger assembly 2 moves upward, the inlet valve 3 opens, and the upstream moving valve 21 and downstream moving valve 28 close. The oil inside the plunger cylinder 25 remains relatively stationary. At this time, under the action of its own weight and the downward inertial force generated by its upward acceleration relative to the plunger cylinder 25, the floating block 24 slowly sinks relative to the lower limit ring 26 in the liquid. During this process, the floating block 24 scrapes the inner wall of the plunger cylinder 25 from top to bottom.

[0025] Of course, the above description is only a preferred embodiment of this utility model and should not be considered as limiting the scope of the embodiments of this utility model. This utility model is not limited to the above examples, and all equivalent changes and improvements made by those skilled in the art within the scope of this utility model should be included in the patent coverage of this utility model.

Claims

1. An anti-scaling oil pump, comprising a pump barrel (1) and a plunger assembly (2) reciprocating within the pump barrel (1), wherein the upper end and lower end of the pump barrel (1) are respectively connected to an upper extension pipe (4) and a lower extension pipe (6) via an upper connecting sleeve (5) and a lower connecting sleeve (7); the inner walls of the upper extension pipe (4) and the lower extension pipe (6) are provided with an anti-scaling coating; Its features are: The plunger assembly (2) includes a plunger cylinder (25), and an axially movable floating block (24) is provided in the inner cavity of the plunger cylinder (25). The floating block (24) has several through-holes on its body. The outer wall of the floating block (24) contacts the inner wall of the plunger cylinder (25) and forms a clearance fit.

2. The anti-scaling oil pump according to claim 1, characterized in that: The upper limit ring (23) is provided above the inner cavity of the plunger cylinder (25), and the lower limit ring (26) is provided below. The floating block (24) is located between the upper limit ring (23) and the lower limit ring (26) to limit the axial travel of the floating block (24).

3. The anti-scaling oil pump according to claim 1 or 2, characterized in that: The material density of the floating block (24) is greater than the density of the pumped well fluid.

4. The anti-scaling oil pump according to claim 1, characterized in that: Both the upper connecting sleeve (5) and the lower connecting sleeve (7) are threaded connections.

5. The anti-scaling oil pump according to claim 1, characterized in that: The anti-scaling coating is an epoxy powder coating or a reinforced polytetrafluoroethylene coating.

6. The anti-scaling oil pump according to claim 1, characterized in that: The upper end of the plunger assembly (2) is provided with an upstream moving valve (21), and the inside is provided with an upper valve ball (22); the lower end of the plunger assembly (2) is provided with a downstream moving valve (28), and the inside is provided with a lower valve ball (27); the lower end of the lower extension pipe (6) is connected to an oil inlet valve (3) through an oil inlet valve connecting sleeve (8), and the inside is provided with an oil inlet valve ball (31).

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