PE fully-coated sucker rod

Abstract

The utility model relates to the technical field of sucker rods, and discloses a PE (polyethylene) fully-coated sucker rod which comprises a sucker rod body, connecting ends are fixedly mounted at the left end and the right end of the sucker rod body respectively, a protective sleeve is sleeved on the outer side of the sucker rod body, and end sleeves are sleeved at the left end and the right end of the sucker rod body respectively. According to the PE fully-coated sucker rod, the outer side of the sucker rod body is coated with the protective sleeve made of the improved ultra-high molecular weight polyethylene material, so that the PE fully-coated sucker rod can better adapt to a well section of 1800-2000 m, and meanwhile, the PE fully-coated sucker rod has better wear resistance; the two ends of the sucker rod body are wrapped and sleeved with the end sleeves made of engineering plastic alloy materials, so that the sucker rod body has better high temperature resistance, friction resistance and corrosion resistance, the end sleeves located at the ends of the sucker rod body are extruded through cooperation of the limiting rings, the inner threaded sleeves, the outer threaded sleeves and the circular-truncated-cone-shaped ring sleeves, and therefore the sucker rod body is prevented from being damaged. And the connection between the end part sleeve and the end part of the sucker rod body is tighter.

Description

Technical Field

[0001] The utility model relates to the technical field of sucker rods, in particular to a PE fully-covered sucker rod. Background Art

[0002] The sucker rod is a slender rod used in pumping wells and is one of the important components of the pumping system. It is connected to the sucker rod string through couplings, connected to the pumping unit through a polished rod at the top and to the plunger of the pump at the bottom. Its function is to transmit the reciprocating motion of the donkey head suspension point of the ground pumping unit to the downhole pump. The main body of the sucker rod is a solid rod with a circular cross-section and thickened forging heads at both ends. The forging heads have connecting threads and square sections for wrenches.

[0003] According to a disclosed coated sucker rod (Announcement No.: CN206513312U), before coating the sucker rod in the above application, the coupling, joint and rod body are first firmly connected, and then the entire rod is coated. Since the coating layer integrally wraps the coupling end, the sucker rod body and the joint end, it can effectively prevent the sucker rod from contacting the corrosive medium and reduce the wear of the sucker rod and the oil pipe.

[0004] However, in actual use of the above-mentioned equipment, the outer coating material of the sucker rod is generally made of ultra-high molecular weight polyethylene. Ultra-high molecular weight polyethylene has very excellent comprehensive performance, but its heat deformation temperature is relatively low (85°C), which limits its application in high-temperature environments and affects the applicable environment range of the sucker rod. In view of this, we proposed a PE fully coated sucker rod. Summary of the Invention

[0005] The purpose of the utility model is to provide a PE fully covered sucker rod to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solution: a PE fully-covered sucker rod, comprising a sucker rod body, wherein connecting ends are fixedly installed on both ends of the sucker rod body, a protective sleeve is sleeved on the outer side of the sucker rod body, and the protective sleeve is made of a modified ultra-high molecular polyethylene material, and end sleeves are sleeved on both ends of the sucker rod body, and the end sleeves are made of an engineering plastic alloy material.

[0007] Preferably, one end of the end sleeve close to the protective sleeve is sleeved on the outside of the protective sleeve.

[0008] Preferably, a sealing structure is provided on the outer side of the connecting end, and the sealing structure includes:

[0009] A limiting ring is fixedly mounted on the outside of the connecting end. An internal threaded sleeve is fixedly mounted on the surface of the limiting ring close to the sucker rod body. The external threaded sleeve is threadedly connected to the external threaded sleeve. When the external threaded sleeve rotates, it can perform linear motion in the left and right directions under the limit of the internal threaded sleeve.

[0010] The truncated cone-shaped ring sleeve is fixedly mounted on a side surface of the external threaded sleeve close to the sucker rod body, and the truncated cone-shaped ring sleeve can move synchronously with the external threaded sleeve.

[0011] Preferably, the size of the truncated cone-shaped ring sleeve is adapted to the size of the end of the sucker rod body.

[0012] Preferably, the inner wall of the internal threaded sleeve is fixedly connected to the outer wall surface of the connecting end.

[0013] Preferably, a rubber sealing sleeve is fixedly mounted on the inner wall surface of the truncated cone-shaped ring sleeve.

[0014] Compared with the existing technology, the utility model provides a PE fully covered sucker rod, which has the following beneficial effects:

[0015] 1. The PE fully covered sucker rod adopts a protective sleeve made of improved ultra-high molecular polyethylene material to cover the outside of the sucker rod body, which can better adapt to the well section of 1800-2000 meters and has better wear resistance. By using end sleeves made of engineering plastic alloy material to cover and sleeve the two ends of the sucker rod body, the sucker rod body can have better resistance to high temperature, friction, corrosion and impact. After the above-mentioned coating of the repaired and reused sucker rod, the oil field's regulations on the performance indicators of the coated sucker rod are improved, and various regulations on transportation and operation are simplified.

[0016] 2. The PE fully covered sucker rod can squeeze the end sleeve at the end of the sucker rod body by setting a limit ring, an internal thread sleeve, an external thread sleeve and a truncated cone ring sleeve, so that the connection between the end sleeve and the end of the sucker rod body is tighter, avoiding the formation of gaps in the connection between the end sleeve and the end of the sucker rod body after long-term use, which may cause oil or water vapor to enter the gap and affect the use effect of the end sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0018] Figure 2 This is a structural diagram of the right end of the sucker rod body of the utility model;

[0019] Figure 3 This is a schematic structural diagram of point A of the present utility model.

[0020] In the figure: 1. Sucker rod body; 2. Connecting end; 3. Protective sleeve; 4. End sleeve; 5. Sealing structure; 501. Limiting ring; 502. Internal thread sleeve; 503. External thread sleeve; 504. Cone-shaped ring sleeve; 505. Rubber sealing sleeve. DETAILED DESCRIPTION

[0021] like Figure 1-Figure 3 As shown, the utility model provides a technical solution: a PE fully covered sucker rod, comprising a sucker rod body 1, with connecting ends 2 fixedly installed at both ends of the sucker rod body 1, and a protective sleeve 3 sleeved on the outer side of the sucker rod body 1. The protective sleeve 3 is made of modified ultra-high molecular weight polyethylene material. Ultra-high molecular weight polyethylene has very excellent comprehensive properties, but its heat deformation temperature is relatively low (85°C), which limits its application in high temperature environments.

[0022] In order to improve the high temperature resistance of ultra-high molecular weight polyethylene without affecting its main properties, the high temperature modification of ultra-high molecular weight polyethylene was studied by filler filling modification method. Kaolin, calcium carbonate, titanium dioxide and glass beads were selected as fillers respectively, which significantly improved the high temperature resistance of ultra-high molecular weight polyethylene. With the increase of filler content, the Vicat softening temperature of the material gradually increased, and the rising trend gradually slowed down. When the mass fraction was 10%, the Vicat softening temperature was all increased to above 100℃, an increase of about 20℃; when the mass fraction was 30%, the Vicat softening temperature was all increased to above 110℃, an increase of about 30℃; among them, the Vicat softening temperature of the titanium dioxide and UHMWPE blend was the lowest, which was 110℃; the Vicat softening temperature of the kaolin and UHMWPE blend was the highest, which was 114℃.

[0023] Furthermore, both left and right ends of the sucker rod body 1 are sleeved with end sleeves 4, and the end of the end sleeve 4 close to the protective sleeve 3 is sleeved on the outside of the protective sleeve 3. The end sleeve 4 is made of engineering plastic alloy material, which has high temperature resistance, high hardness and good wear resistance. Therefore, the engineering plastic alloy is used to cover the two ends of the sucker rod, so that it has better high temperature resistance, friction resistance, corrosion resistance and impact resistance.

[0024] A sealing structure 5 is provided on the outside of the connecting end 2, and the sealing structure 5 includes: a limiting ring 501 and a truncated cone-shaped ring sleeve 504. The limiting ring 501 is fixedly installed on the outside of the connecting end 2. The limiting ring 501 can limit the movable position of the external threaded sleeve 503 to prevent the external threaded sleeve 503 from separating from the internal threaded sleeve 502. The left and right ends of the sucker rod body 1 are both truncated cone-shaped structures. The limiting ring 501 is fixedly installed on the side surface close to the sucker rod body 1 with the internal threaded sleeve 502. The inner wall of the internal threaded sleeve 502 is fixedly connected to the outer wall surface of the connecting end 2. The outer side of the internal threaded sleeve 502 is threadedly connected to the external threaded sleeve 503. When the external threaded sleeve 503 rotates, it can perform linear motion in the left and right directions on the outside of the internal threaded sleeve 502.

[0025] When the outer threaded sleeve 503 is moved, the truncated cone-shaped ring sleeve 504 can be driven to move synchronously. The size of the truncated cone-shaped ring sleeve 504 is adapted to the size of the end of the sucker rod body 1. When the truncated cone-shaped ring sleeve 504 moves toward the end of the sucker rod body 1, it can squeeze the end sleeve 4 at the end of the sucker rod body 1, making the connection between the end sleeve 4 and the end of the sucker rod body 1 tighter. After long-term use, the connection between the end sleeve 4 and the end of the sucker rod body 1 will not cause oil or water vapor to enter the gap, affecting the use effect of the end sleeve 4. A rubber sealing sleeve 505 is fixedly installed on the inner wall surface of the truncated cone-shaped ring sleeve 504. The rubber sealing sleeve 505 can protect the outer side of the end sleeve 4 when the truncated cone-shaped ring sleeve 504 squeezes and seals the end sleeve 4, avoiding excessive squeezing and damage to the end sleeve 4 affecting its use.

[0026] In the present invention, when in use, the oil and gas molecules that penetrate into the secondary used sucker rod body 1 are first expelled to prevent bubbles from forming in the coated sucker rod body 1, and when encountering high temperature in the well, the protective sleeve 3 and the end sleeve 4 are prevented from rupturing due to gas explosion. The improved ultra-high molecular polyethylene used in the protective sleeve 3 can withstand high temperatures of 100 degrees and can better adapt to the well section of 1800-2000 meters. At the same time, it has better wear resistance. Since the engineering plastic alloy has high temperature resistance, high hardness and good wear resistance, when the end sleeve 4 covers the two ends of the sucker rod body 1, it can have better high temperature resistance, friction resistance, corrosion resistance and impact resistance. After the protective sleeve 3 and the end sleeve 4 are covered, the external threaded sleeves 503 on both sides are rotated to tighten the internal threaded sleeves 503. When the threaded sleeve 502 cooperates with the truncated cone-shaped ring sleeve 504 to move toward the end of the sucker rod body 1, the end sleeve 4 located at the end of the sucker rod body 1 can be squeezed, so that the connection between the end sleeve 4 and the end of the sucker rod body 1 is tighter. The rubber sealing sleeve 505 can be provided to protect the outer side of the end sleeve 4 when the truncated cone-shaped ring sleeve 504 squeezes and seals the end sleeve 4. After the above-mentioned coating, the repaired and reused sucker rods improve the oil field's regulations on the performance indicators of the coated sucker rods, simplify various regulations on transportation, operation, etc., greatly improve operating efficiency, extend the pump inspection cycle, and reduce various costs. It has broad application prospects in the field of oil production for the treatment of chemical corrosion, electrostatic corrosion, and eccentric wear of pipes and rods.

[0027] The above generally describes the present invention in detail. However, it is obvious to those skilled in the art that modifications or improvements may be made to the present invention. Therefore, modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A PE fully covered sucker rod, comprising a sucker rod body (1), wherein both left and right ends of the sucker rod body (1) are fixedly mounted with connecting ends (2), characterized in that: The outer side of the sucker rod body (1) is sleeved with a protective sleeve (3), and the left and right ends of the sucker rod body (1) are sleeved with end sleeves (4); A sealing structure (5) is provided on the outer side of the connection end (2), and the sealing structure (5) comprises: A limiting ring (501), the limiting ring (501) being fixedly mounted on the outside of the connecting end (2), an internal thread sleeve (502) being fixedly mounted on a surface of a side of the limiting ring (501) close to the sucker rod body (1), and an external thread sleeve (503) being threadedly connected to the outside of the internal thread sleeve (502); A truncated cone-shaped ring sleeve (504), wherein the truncated cone-shaped ring sleeve (504) is fixedly mounted on a surface of one side of the external threaded sleeve (503) close to the sucker rod body (1); The size of the truncated cone-shaped ring sleeve (504) is adapted to the size of the end of the sucker rod body (1); The inner wall of the internal threaded sleeve (502) is fixedly connected to the outer wall surface of the connecting end (2).

2. The PE fully covered sucker rod according to claim 1, characterized in that: One end of the end sleeve (4) close to the protective sleeve (3) is sleeved on the outside of the protective sleeve (3).

3. The PE fully covered sucker rod according to claim 2, characterized in that: A rubber sealing sleeve (505) is fixedly mounted on the inner wall surface of the truncated cone-shaped ring sleeve (504).

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