Internal anti-corrosion hollow sucker rod

Abstract

The utility model discloses an internal anti-corrosion hollow sucker rod, which belongs to the technical field of sucker rods and comprises a hollow sucker rod body, a branch cleaning pipe is connected to the outer wall of the peripheral side of the hollow sucker rod body in a penetrating manner, and a first detachable top cover is detachably arranged at the top end of the branch cleaning pipe. The top end of the branch cleaning pipe is detachably connected with a replaceable cleaning sleeve, the top end of the replaceable cleaning sleeve is in threaded connection with a second detachable top cover, and a lifting inner sleeve capable of being lifted in the replaceable cleaning sleeve is inserted into the second detachable top cover. Two cleaning steel wires are symmetrically and rotationally connected into the lifting inner sleeve, and burr cleaning strips are arranged on the circumferential sides in the directions that the free ends of the two cleaning steel wires extend into the two sides of the hollow sucker rod body from the branch cleaning pipes in a back-to-back mode. The cleaning steel wire drives the burr cleaning strip to stretch out, draw back and rotate in the hollow sucker rod body to clean oil dirt.

Description

Technical Field

[0001] This utility model belongs to the field of sucker rod technology, and in particular to a hollow sucker rod with internal anti-corrosion properties. Background Technology

[0002] Sucker rods are slender rods in oil wells. They connect to the polished rod at the top and the oil pump at the bottom, transmitting power. They are connected one by one inside the tubing with internal threaded clamps and extend to the piston at the underground oil layer. They pump oil through reciprocating motion. When extracting heavy oil, due to its high viscosity, it is difficult to flow. Generally, it is necessary to electrically heat the heavy oil to reduce its viscosity and increase its fluidity. However, existing sucker rods are generally only hollow rods. After long-term use, oil sludge easily accumulates inside the hollow sucker rod. The simple structure and lack of internal oil sludge cleaning structure make the sucker rod prone to reduced service life due to the inability to drain the accumulated oil sludge.

[0003] A search revealed a Chinese patent publication number: CN218206605U, which describes a carbon fiber hollow sucker rod. The sucker rod body includes a base layer, an anti-corrosion layer fixedly connected to the bottom of the base layer, a reinforcing layer fixedly connected to the top of the base layer, a protective layer fixedly connected to the top of the reinforcing layer, a first insulation layer, a second insulation layer fixedly connected to the top of the first insulation layer, and a weather-resistant layer fixedly connected to the top of the protective layer.

[0004] The cited patent documents also have the same problem: after long-term use, oil stains tend to accumulate inside the hollow sucker rod. The sucker rod with a simple structure that lacks a cleaning structure for the internal oil stains is prone to reduced service life because the accumulated oil stains cannot be discharged. Summary of the Invention

[0005] The purpose of this invention is to provide an internally corrosion-resistant hollow sucker rod to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: an internally corrosion-resistant hollow sucker rod, comprising a hollow sucker rod body, with connecting end sleeves threaded to both ends of the hollow sucker rod body, a branch cleaning pipe penetrating the outer periphery of the hollow sucker rod body, a first removable top cover detachably provided at the top of the branch cleaning pipe, a replaceable cleaning sleeve detachably connected to the top of the branch cleaning pipe, a second removable top cover threaded to the top of the replaceable cleaning sleeve, a lifting inner sleeve capable of being lifted and lowered within the replaceable cleaning sleeve inserted into the second removable top cover, two cleaning steel wires symmetrically and rotatably connected within the lifting inner sleeve, the free ends of the two cleaning steel wires extending from the branch cleaning pipe into the periphery of both sides of the hollow sucker rod body, each side being provided with a cleaning burr strip, the cleaning steel wires driving the cleaning burr strips to extend, retract, and rotate within the hollow sucker rod body to clean oil stains.

[0007] Preferably, the top of the replaceable cleaning sleeve is provided with a first longitudinal insertion through hole for inserting the inner sleeve into the lifting and lowering mechanism.

[0008] The top outer wall of the replaceable cleaning sleeve is provided with an external thread that is threaded to the second detachable top cover.

[0009] Preferably, the top surface of the second detachable top cover has a second longitudinal insertion hole at the middle position for inserting the inner sleeve into the lifting mechanism.

[0010] Preferably, the top of the lifting inner sleeve is integrally connected to a top plate, and both outer walls of the top plate are integrally connected to extension ear plates extending outward.

[0011] Each of the extended ear plates has a pull ring fixedly connected to its top surface.

[0012] Preferably, the second longitudinal insertion through hole has matching grooves extending on both sides and on the top surface of the second detachable top cover for fitting the extension ear plate.

[0013] Preferably, the top plate has two symmetrically embedded sealed bearings inside, and the tip of each cleaning wire is interference-fitted with the inner ring of the sealed bearing.

[0014] Preferably, the inner cavity of the lifting and lowering inner sleeve is symmetrically provided with two insertion cavities for inserting two cleaning steel wires respectively;

[0015] The end of the cleaning wire away from the sealed bearing extends in the inner sleeve of the lifting and lowering mechanism.

[0016] Preferably, the hollow sucker rod body comprises, from the outside to the inside, an alloy steel substrate layer, an internal insulation layer, a metal anti-corrosion coating layer, and a composite coating anti-corrosion coating.

[0017] Compared with the prior art, the technical effects and advantages of this utility model are as follows:

[0018] This invention relates to a hollow sucker rod with internal corrosion protection. A branch cleaning pipe is added to the hollow sucker rod body, along with a cleaning assembly consisting of a lifting inner sleeve, cleaning wires, and deburring strips. This enables convenient and efficient cleaning of oil stains inside the sucker rod. The cleaning wires extend and rotate within the sucker rod under the control of the lifting inner sleeve, while the deburring strips effectively scrape away accumulated oil stains, preventing oil buildup from affecting the normal operation and service life of the sucker rod. The cleaning assembly is detachable and replaceable, facilitating maintenance and significantly reducing cleaning difficulty and maintenance costs.

[0019] This invention provides a sucker rod with an inner wall comprising an alloy steel substrate layer, an internal insulation layer, a metal anti-corrosion coating, and a composite anti-corrosion coating. The alloy steel substrate layer provides basic corrosion resistance and mechanical strength; the internal insulation layer helps maintain the internal temperature of the sucker rod and reduces the viscosity of heavy oil; the metal anti-corrosion coating enhances the corrosion resistance of the inner wall; and the composite anti-corrosion coating further improves the corrosion resistance and wear resistance of the inner wall. This multi-layered structural design forms a strong anti-corrosion barrier, effectively resisting the complex corrosive environment downhole and significantly extending the service life of the sucker rod. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] Figure 2 This is a schematic diagram of the branch cleaning pipe and the first detachable top cover of this utility model in a disassembled state.

[0023] Figure 3 This is a schematic diagram showing the connection structure of the hollow sucker rod body and the replaceable cleaning sleeve of this utility model.

[0024] Figure 4 This is a schematic diagram showing the disassembled state of the replaceable cleaning sleeve and the second detachable top cover of this utility model.

[0025] Figure 5 This is a schematic diagram of the disassembled structure of the second detachable top cover and the lifting inner sleeve of this utility model.

[0026] Figure 6 This is a schematic diagram of the connection structure between the cleaning wire and the deburring strip of this utility model.

[0027] Figure 7 This is a cross-sectional view of the hollow sucker rod body of this utility model.

[0028] Explanation of reference numerals in the attached figures:

[0029] In the diagram: 1. Hollow sucker rod body; 2. Connecting end sleeve; 3. Branch cleaning pipe; 4. First removable top cover; 5. Replaceable cleaning sleeve; 6. Second removable top cover; 7. External threaded passage; 8. First longitudinal insertion through hole; 9. Lifting inner sleeve; 10. Cleaning wire; 11. Pull ring; 12. Second longitudinal insertion through hole; 13. Matching groove; 14. Extension ear plate; 15. Sealed bearing; 16. Top plate; 17. Deburring strip; 18. Alloy steel substrate layer; 19. Built-in insulation layer; 20. Metal anti-corrosion coating; 21. Composite coating anti-corrosion coating. Detailed Implementation

[0030] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0031] Unless otherwise defined, the directions mentioned herein, such as up, down, left, right, front, back, inside, and outside, are based on the directions shown in the figures of this utility model, and are explained here together.

[0032] This embodiment discloses, as follows: Figures 1 to 7 The diagram shows an internally corrosion-resistant hollow sucker rod, comprising a hollow sucker rod body 1, with connecting end sleeves 2 threaded to both ends of the hollow sucker rod body 1. Depending on the actual usage requirements of the sucker rod, a polished rod is connected at the top and a sucker pump at the bottom. A branch cleaning pipe 3 is connected through the outer periphery of the hollow sucker rod body 1. A first removable top cover 4 is detachably provided at the top of the branch cleaning pipe 3. The branch cleaning pipe 3 and the first removable top cover 4 are connected by threads, facilitating installation and disassembly.

[0033] Specifically, a replaceable cleaning sleeve 5 is detachably connected to the top of the branch cleaning pipe 3. A second detachable top cover 6 is threadedly connected to the top of the replaceable cleaning sleeve 5. A lifting inner sleeve 9 that can be lifted and lowered in the replaceable cleaning sleeve 5 is inserted into the second detachable top cover 6. Two cleaning steel wires 10 are symmetrically rotatably connected in the lifting inner sleeve 9. The free ends of the two cleaning steel wires 10 extend from the branch cleaning pipe 3 into the hollow sucker rod body 1. Both sides are provided with cleaning burr strips 17. The cleaning steel wires 10 drive the cleaning burr strips 17 to extend, retract and rotate in the hollow sucker rod body 1 to clean oil stains.

[0034] Specifically, the lifting inner sleeve 9 serves as the load-bearing and driving component for the cleaning wire 10. Its up-and-down movement controls the extension and retraction of the cleaning wire 10 within the sucker rod, thereby driving the deburring strip 17 to scrape away oil. The lifting inner sleeve 9 is connected to the second detachable top cover 6 via the second longitudinal insertion through-hole 12. Its top pull ring 11 facilitates manual lifting by the operator or mechanical up-and-down movement. The inner sleeve has an insertion cavity that connects to the cleaning wire 10, enabling control of the wire's rotation and extension.

[0035] Specifically, two cleaning wires 10 directly contact the inner wall of the sucker rod, and the cleaning deburring strips 17 on them scrape away oil stains, achieving effective cleaning of the internal oil stains. The cleaning wires 10 are connected to the sealed bearings 15 inside the lifting inner sleeve 9 through their top ends, ensuring smooth rotation and extension under the control of the inner sleeve. The two ends of the wires are fixed inside the lifting inner sleeve 9 and the hollow sucker rod body 1, respectively. Through the up-and-down movement and rotation of the inner sleeve, the cleaning deburring strips 17 are driven to scrape away oil stains.

[0036] Specifically, the cleaning deburring strip 17 extends, retracts, and rotates together with the cleaning wire 10. Its sharp edges effectively scrape away oil stains from the inner wall of the sucker rod, keeping the inner wall clean. The combined design of the deburring strip and the wire makes the cleaning operation more comprehensive and thorough, effectively dealing with the complex oil stains inside the sucker rod.

[0037] Specifically, the top of the replaceable cleaning sleeve 5 has a first longitudinal insertion through hole 8 for inserting the lifting inner sleeve 9, and the top outer wall of the replaceable cleaning sleeve 5 has an external thread 7 that is threaded to the second detachable top cover 6. The top surface of the second detachable top cover 6 has a second longitudinal insertion through hole 12 for inserting the lifting inner sleeve 9.

[0038] Specifically, the first longitudinal insertion hole 8 is located inside the replaceable cleaning sleeve 5, providing a space channel for vertical movement of the lifting inner sleeve 9. The first longitudinal insertion hole 8 matches the outer dimensions of the lifting inner sleeve 9, ensuring that the lifting inner sleeve 9 slides smoothly up and down inside the cleaning sleeve, thereby achieving extension control of the cleaning wire 10.

[0039] Specifically, the top of the lifting inner sleeve 9 is integrally connected to a top plate 16, and the outer walls on both sides of the top plate 16 are integrally connected to extension ear plates 14. Each extension ear plate 14 is fixedly connected to a pull ring 11 on its top surface. On both sides of the second longitudinal insertion through hole 12 and on the top surface of the second detachable top cover 6, there are mating grooves 13 for the extension ear plates 14 to be installed. The inner cavity of the lifting inner sleeve 9 is symmetrically provided with two insertion cavities for two cleaning wires 10 to be inserted. The end of the cleaning wire 10 away from the sealing bearing 15 extends in the lifting inner sleeve 9.

[0040] Specifically, the pull ring 11 is installed on the top of the lifting inner sleeve 9, providing a convenient gripping point for the operator to manually lift the inner sleeve for cleaning operations. The pull ring 11 is integrally connected with the lifting inner sleeve 9, and its design facilitates the application of external force. By pulling the inner sleeve manually or with auxiliary tools, the extension and rotation of the cleaning wire 10 can be achieved.

[0041] Specifically, the top plate 16 has two symmetrically embedded sealed bearings 15, with the tip of each cleaning wire 10 interference-fitted with the inner ring of the sealed bearing 15. The tight fit between the inner rings of the two sealed bearings 15 and the cleaning wires 10 allows the wires to rotate under the control of the inner sleeve, while the outer rings of the bearings are fixed to the inner wall of the inner sleeve, ensuring stability during rotation. The sealing design of the bearings prevents oil from entering the inner sleeve, protecting the internal structure from contamination.

[0042] Specifically, the hollow sucker rod body 1 comprises, from the outside to the inside, an alloy steel base layer 18, an internal insulation layer 19, a metal anti-corrosion coating 20, and a composite coating anti-corrosion layer 21. The hollow sucker rod body 1 uses alloy steel as the base material, whose excellent mechanical strength and corrosion resistance ensure long-term stable operation in complex downhole environments. The alloy steel base layer 18 uses high-strength, wear-resistant alloy steel as the main material to ensure the basic mechanical properties of the sucker rod. The internal insulation layer 19 is an internal insulation layer, such as fiberglass or aluminum silicate, set inside the base layer. The materials help maintain the internal temperature of the sucker rod, reduce the viscosity of heavy oil, and improve oil production efficiency; Metal anti-corrosion coating 20: Apply a layer of metal anti-corrosion coating, such as zinc, nickel, chromium, etc., outside the built-in insulation layer to enhance the corrosion resistance of the inner wall of the sucker rod and prevent the internal medium from corroding the alloy steel substrate; Composite coating anti-corrosion coating 21: Apply a layer of composite coating anti-corrosion coating outside the metal anti-corrosion coating. This coating is composed of high-performance resin, ceramic micro powder, nano additives, etc., forming a dense anti-corrosion barrier, further improving the corrosion resistance and wear resistance of the inner wall of the sucker rod.

[0043] Working principle

[0044] When cleaning oil stains inside the hollow sucker rod body 1, the first removable top cover 4 is loosened, and the replaceable cleaning sleeve 5 is installed on the branch cleaning pipe 3. The inner sleeve 9 is then lifted and lowered using the hand-held pull ring 11, thereby raising and lowering both the inner sleeve 9 and the cleaning wires 10. The two cleaning wires 10 extend in opposite directions inside the hollow sucker rod body 1, causing the cleaning burr strip 17 to scrape away oil stains. The cleaning wires 10 are connected at their top ends to the sealed bearing 15 inside the inner sleeve 9, ensuring smooth rotation and extension under the control of the inner sleeve. The two ends of the wires are fixed to the inner sleeve 9 and the sucker rod body 1, respectively. The up-and-down movement and rotation of the inner sleeve cause the cleaning burr strip 17 to scrape away oil stains.

[0045] After cleaning, remove the cleaning wire 10, disassemble the replaceable cleaning sleeve 5, and reset the first removable top cover 4 onto the branch cleaning pipe 3.

[0046] It should be noted that, in this document, relational terms such as "one" and "two" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0047] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hollow sucker rod with internal corrosion protection, comprising a hollow sucker rod body (1), characterized in that: The hollow sucker rod body (1) is threaded with connecting end sleeves (2) at both ends. A branch cleaning pipe (3) is connected through the outer wall of the hollow sucker rod body (1). A first removable top cover (4) is detachably provided at the top of the branch cleaning pipe (3). A replaceable cleaning sleeve (5) is detachably connected at the top of the branch cleaning pipe (3). A second removable top cover (6) is threadedly connected at the top of the replaceable cleaning sleeve (5). The second detachable top cover (6) is inserted with a lifting inner sleeve (9) that can be lifted and lowered in a replaceable cleaning sleeve (5). Two cleaning steel wires (10) are symmetrically rotatably connected in the lifting inner sleeve (9). The free ends of the two cleaning steel wires (10) extend from the branch cleaning pipe (3) into the hollow sucker rod body (1) on both sides. Cleaning burr strips (17) are provided on both sides. The cleaning steel wires (10) drive the cleaning burr strips (17) to extend, retract and rotate in the hollow sucker rod body (1) to clean oil stains.

2. The internally corrosion-resistant hollow sucker rod according to claim 1, characterized in that: The top of the replaceable cleaning sleeve (5) has a first longitudinal insertion through hole (8) for inserting the lifting inner sleeve (9). The top outer wall of the replaceable cleaning sleeve (5) is provided with an external thread (7) that is threaded to the second removable top cover (6).

3. The internally corrosion-resistant hollow sucker rod according to claim 2, characterized in that: The second detachable top cover (6) has a second longitudinal insertion through hole (12) in the middle of the top surface for inserting the lifting inner sleeve (9).

4. The internally corrosion-resistant hollow sucker rod according to claim 3, characterized in that: The top of the lifting inner sleeve (9) is integrally connected to a top plate (16), and the outer walls on both sides of the top plate (16) are integrally connected to an extension ear plate (14). Each of the extended ear plates (14) has a pull ring (11) fixedly connected to its top surface.

5. The internally corrosion-resistant hollow sucker rod according to claim 4, characterized in that: The second longitudinal insertion through hole (12) extends on both sides of the second removable top cover (6) and is provided with matching grooves (13) for the matching installation of the extension ear plate (14).

6. The internally corrosion-resistant hollow sucker rod according to claim 5, characterized in that: The top plate (16) has two symmetrically embedded sealed bearings (15), and the top end of each cleaning wire (10) is interference-fitted with the inner ring of the sealed bearing (15).

7. The internally corrosion-resistant hollow sucker rod according to claim 6, characterized in that: The inner cavity of the lifting inner sleeve (9) is symmetrically provided with two insertion cavities for inserting two cleaning steel wires (10) respectively; The end of the cleaning wire (10) away from the sealing bearing (15) extends in the lifting inner sleeve (9).

8. The internally corrosion-resistant hollow sucker rod according to claim 7, characterized in that: The hollow sucker rod body (1) includes, from the outside to the inside, an alloy steel substrate layer (18), an internal insulation layer (19), a metal anti-corrosion coating layer (20), and a composite coating anti-corrosion coating layer (21).

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