Sucker rod centralizer and its preparation method

Abstract

This invention discloses a sucker rod centralizer and its manufacturing method, relating to the field of oilfield production tools. The sucker rod centralizer includes a sucker rod, a centralizing block, and a support component. The support component is a steel wire spirally wound around the sucker rod. The centralizing block is molded on the outside of the sucker rod and wraps around the support component. The support component is located in the middle of the centralizing block. Multiple layers of the support component are wound around the sucker rod. A limiting annular groove is provided on the side of the sucker rod, and the centralizing block fills the limiting annular groove. There are multiple limiting annular grooves, located on both sides of the support component. The manufacturing method of the sucker rod centralizer includes the following steps: opening a limiting annular groove on the side of the sucker rod and wrapping the steel wire around the side of the sucker rod; molding the centralizing block on the outside of the sucker rod by injection molding, so that the centralizing block wraps around the support component, the limiting annular groove is located in the injection molding cavity, and the centralizing block fills the limiting annular groove. Compared with the prior art, this invention can prevent the coating on the inner wall of the pipeline from peeling off, extending the service life of the pipeline.

Description

Technical Field

[0001] This invention relates to the field of oilfield production tools, and in particular to a sucker rod centralizer and its preparation method. Background Technology

[0002] In recent years, with the application of various technologies, especially chemical flooding, oilfield pipelines have suffered severe corrosion from electrochemical processes, bacteria, well fluids with high mineral content, polymer flooding, ternary flooding produced fluids, and thermal washing. Corrosion causes thick oxide layers to form on the pipeline surface, and the rough surface is prone to scaling and wax buildup, leading to increased return oil pressure. Further erosion and washing thins the pipe wall, potentially causing perforation and leakage, ultimately resulting in decreased production. While new technologies such as fluorocarbon coatings for internal corrosion protection have improved the service life of sucker rods, the fluorocarbon coating is susceptible to scratches from the sucker rod metal, leading to coating peeling and limiting the application of these new technologies. Summary of the Invention

[0003] The purpose of this invention is to provide a sucker rod centralizer and its preparation method to solve the problems existing in the above-mentioned related technologies, prevent the coating on the inner wall of the pipeline from peeling off, and extend the service life of the pipeline.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] This invention discloses a sucker rod straightener, comprising a sucker rod, a straightener block, and a support member; the support member is a steel wire spirally wrapped around the sucker rod; the straightener block is molded on the outside of the sucker rod and wraps around the support member;

[0006] The sucker rod has a limiting annular groove on its side, and the straightening block fills the limiting annular groove; there are multiple limiting annular grooves, which are located on both sides of the support member.

[0007] In some examples, the straightening block is made of nylon.

[0008] In some examples, the straightening block is spindle-shaped.

[0009] In some examples, the support is located in the middle of the straightening block.

[0010] In some examples, the sucker rod is wrapped with multiple layers of the support.

[0011] This invention also discloses a method for preparing a sucker rod centralizer, comprising the following steps:

[0012] A limiting annular groove is made on the side of the sucker rod; there are multiple limiting annular grooves, which are located on both sides of the support member;

[0013] Wrap the steel wire around the side of the sucker rod;

[0014] A centralizing block is molded on the outside of the sucker rod by injection molding, so that the centralizing block wraps around the support component; when the centralizing block is injection molded, the limiting ring groove is located in the injection cavity, so that the centralizing block fills the limiting ring groove.

[0015] In some examples, a positioning disc is used when winding the steel wire; the positioning disc has radially arranged grooves and radially arranged threaded holes, as well as through holes parallel to its own axis; both the grooves and threaded holes extend to the center of the positioning disc and are interconnected, and the central angle corresponding to the area between the groove and the threaded hole is an acute angle; the axis of the positioning disc is parallel to the axis of the sucker rod, the sucker rod is slid along the groove to the center of the positioning disc, and then the positioning screw is screwed into the threaded hole so that the positioning screw abuts against or holds the sucker rod. Leave a gap; partially insert the positioning screw into the groove to prevent the sucker rod from sliding out of the positioning disc along the groove; pass one end of the steel wire wound on the drum through the through hole from the first side of the positioning disc to the second side of the positioning disc and fix it to the sucker rod; as the sucker rod rotates, the positioning disc moves to its second side and the drum rotates, the steel wire is wound into a spiral shape on the sucker rod, and then the steel wire is cut to complete the winding of one layer of steel wire; when there are multiple layers of steel wire, continue to complete the winding of subsequent steel wires in the above manner;

[0016] When creating the limiting ring groove, the axis of the grinding wheel is parallel to the axis of the sucker rod. After the grinding wheel starts to rotate, it is gradually brought closer to the sucker rod until the grinding wheel contacts the sucker rod, thus creating the limiting ring groove on the sucker rod. When the limiting ring groove is a complete ring, the rotation angle of the sucker rod is not less than 360 degrees when the grinding wheel is grooved; when the limiting ring groove is an incomplete ring, the rotation angle of the sucker rod is less than 360 degrees when the grinding wheel is grooved.

[0017] Compared with related technologies, the present invention achieves the following technical effects:

[0018] When the centralizing block contacts the inner wall of the pipe, it is subjected to the squeezing force of the sucker rod on its inner side and the pipe on its outer side, causing the centralizing block to increase in length. When the squeezing force is too great, the centralizing block is easily cracked or even crushed. In this invention, since the support member surrounds the sucker rod and the centralizing block wraps around the support member, when the centralizing block elongates under the squeezing force from both the inner and outer sides, it causes the support member inside to elongate as well. Due to its own elasticity, the support member will exert an elastic force on the centralizing block that resists its elongation, acting like a spring, thereby limiting the axial deformation of the centralizing block and preventing it from being cracked or crushed.

[0019] In a preferred embodiment of the invention, the centralizing block is spindle-shaped. This spindle-shaped outer contour reduces the resistance encountered by crude oil flowing through the centralizing block, thereby improving extraction efficiency.

[0020] In a preferred embodiment of the present invention, a limiting annular groove is provided on the side of the sucker rod, and a straightening block fills the limiting annular groove. The axis of the limiting annular groove is the same as the axis of the sucker rod. Since the straightening block fills the limiting annular groove, the limiting annular groove can restrict the movement of the straightening block along the axial direction of the sucker rod, thereby limiting the straightening block. When there are multiple limiting annular grooves, and they are located on both sides of the support member, the limiting grooves on both sides can limit the axial length of the support member and the section of the straightening block (the section between the limiting grooves on both sides) by axially limiting the straightening block filled therein, thus limiting the elongation of the straightening block when it is compressed.

[0021] In a preferred embodiment of the present invention, multiple layers of support members are wound around the sucker rod. Considering that the elastic resistance provided by a single layer of winding is limited, the support members in this embodiment are arranged in a multi-layered winding manner, with the winding axis of each layer being the axis of the sucker rod. From the inner layer of the support member to the outer layer of the support member, the axial length of the support member gradually decreases. This arrangement ensures that the number of support member layers gradually decreases from the middle to both ends of the straightening block, matching the spindle-shaped outer contour of the straightening block and avoiding excessively small spacing between the support member and the outer surface of the straightening block. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of how the straightening block is obtained through injection molding;

[0024] Figure 2 A schematic diagram showing how a support is created by wrapping around the sucker rod;

[0025] Figure 3 A schematic diagram for machining a limiting annular groove on a sucker rod;

[0026] Figure 4 This is a schematic diagram of a sucker rod centralizer of the present invention (with a limiting annular groove).

[0027] Figure 5 This is another schematic diagram of the sucker rod centralizer of the present invention (without a positioning annular groove).

[0028] Figure 6 This is a schematic diagram of the sucker rod centralizer in a pipeline (with a limiting annular groove) in some examples of the present invention.

[0029] Figure 7 for Figure 2A cross-sectional view along the AA direction;

[0030] Figure 8 This is a schematic diagram of a multi-layered support structure wound around a sucker rod.

[0031] In the diagram: 1. Sucker rod stabilizer; 11. Sucker rod; 12. Stabilizer block; 13. Support component; 14. Limiting ring groove; 15. Pipe; 2. Steel wire; 3. Motor; 4. Support roller; 5. Positioning disc; 51. Slide groove; 52. Threaded hole; 53. Positioning screw; 54. Through hole; 6. Drum; 7. Grinding wheel; 8. Upper mold; 9. Lower mold; 10. Injection cavity; 101. Semi-circular groove; 102. Hopper; 103. Injection molding machine. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The purpose of this invention is to provide a sucker rod centralizer and its preparation method to solve the problems existing in the above-mentioned related technologies, prevent the coating on the inner wall of the pipeline from peeling off, and extend the service life of the pipeline.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Reference Figures 1-8 This embodiment provides a sucker rod centralizer 1, including a sucker rod 11, a centralizer 12, and a support member 13. The support member 13 is a steel wire 2 spirally wrapped around the sucker rod 11. The centralizer 12 is molded on the outside of the sucker rod 11 and wraps around the support member 13.

[0036] The sucker rod 11 has a limiting annular groove 14 on its side, and the straightening block 12 fills the limiting annular groove 14; there are multiple limiting annular grooves 14, which are located on both sides of the support member 13.

[0037] The working principle of the sucker rod centralizer 1 in this embodiment is as follows:

[0038] In this embodiment, the centralizing block 12 is used to contact the inner wall of the pipe 15, separating the pipe 15 from the sucker rod 11. This prevents direct friction between the sucker rod 11 and the anti-corrosion coating on the inner wall of the pipe 15, thereby preventing the coating on the inner wall of the pipe 15 from peeling off and extending the service life of the pipe 15. Furthermore, the greater the thickness of the centralizing block 12, the closer the diameter of the sucker rod centralizer 1 is to the inner diameter of the pipe 15, and the closer the axis of the sucker rod 11 is to the axis of the pipe 15. Thus, by setting the centralizing block 12, the sucker rod 11 is centralized and aligned, ensuring the stable operation of the oil extraction system.

[0039] When the straightening block 12 contacts the inner wall of the pipe 15, it is subjected to the squeezing force of the sucker rod 11 on its inner side and the pipe 15 on its outer side, causing the length of the straightening block 12 to increase. When the squeezing force is too large, the straightening block 12 is easily cracked or even crushed. In this embodiment, since the support member 13 surrounds the sucker rod 11 and the straightening block 12 wraps around the support member 13, when the straightening block 12 elongates under the squeezing force from both the inner and outer sides, it causes the support member 13 inside it to elongate as well. Due to its own elasticity, the support member 13 will apply an elastic force to the straightening block 12 to resist its elongation, which is equivalent to a spring, thereby limiting the axial deformation of the straightening block 12 and preventing the straightening block 12 from being cracked or crushed.

[0040] The axis of the limiting annular groove 14 and the axis of the sucker rod 11. Since the centralizing block 12 fills the limiting annular groove 14, the limiting annular groove 14 can restrict the movement of the centralizing block 12 along the axial direction of the sucker rod 11, thereby playing the role of limiting the centralizing block 12.

[0041] It should be noted that if the straightening blocks 12 are not axially limited, after a period of use, the straightening blocks 12 on the sucker rod 11 will slide downward to the lower end of the sucker rod 11 under the action of gravity, so that the upper end of the sucker rod 11 cannot be straightened, and the upper end of the sucker rod 11 will easily come into contact with the inner wall of the pipe 15, causing the coating on the inner wall of the pipe 15 to peel off.

[0042] This embodiment solves this problem by creating a limiting annular groove 14 on the sucker rod 11 and filling the limiting annular groove 14 with the straightening block 12.

[0043] Furthermore, the limiting ring groove 14 can be a complete ring or an incomplete ring. When the limiting ring groove 14 is a complete ring, it does not restrict the rotation of the straightening block 12. When the limiting ring groove 14 is an incomplete ring, it can restrict the rotation of the straightening block 12.

[0044] Since there are multiple limiting ring grooves 14, and they are located on both sides of the support member 13, the limiting slide grooves 51 on both sides can limit the axial length of the support member 13 and the section of the supporting member 13 and the supporting block 12 (the section between the limiting slide grooves 51 on both sides) by limiting the axial length of the straightening block 12 filled therein, thus limiting the elongation of the straightening block 12 when it is squeezed.

[0045] In some examples, the straightening block 12 is made of nylon.

[0046] Nylon is characterized by wear resistance, corrosion resistance, and low friction, which can meet the working environment of frequent friction and chemical corrosion in pipeline 15 and reduce the moving resistance of the oil tubing.

[0047] It is understood that those skilled in the art may also choose other materials for the straightening block 12, such as PEEK, carbon fiber reinforced plastic, polytetrafluoroethylene, etc.

[0048] In some examples, the straightening block 12 is spindle-shaped.

[0049] This spindle-shaped outer contour can reduce the resistance encountered by crude oil when it flows through the centralizing block 12, thereby improving extraction efficiency.

[0050] In some examples, the support 13 is located in the middle of the straightening block 12.

[0051] Because the straightening block 12 is spindle-shaped, its thickness in the middle is greater than that at both ends. Therefore, the middle part of the straightening block 12 is the position that contacts the inner wall of the pipe 15, i.e., the position that is squeezed by the pipe 15, and is the main deformation area of ​​the straightening block 12. By placing the support member 13 in the middle of the straightening block 12, i.e., in the main deformation area, the elongation of the straightening block 12 when squeezed can be better limited.

[0052] In some examples, the sucker rod 11 is wrapped with multiple layers of support members 13.

[0053] Considering that the elastic resistance provided by a single layer of winding is limited, in this embodiment the support member 13 adopts a multi-layer winding method, and the winding axis of each layer is the axis of the sucker rod 11.

[0054] For example, the axial length of the support member 13 gradually decreases from the inner support member 13 to the outer support member 13.

[0055] This arrangement allows the number of layers of the support member 13 to gradually decrease from the middle of the straightening block 12 to both ends of the straightening block 12, in order to match the spindle-shaped outer contour of the straightening block 12 and avoid the distance between the support member 13 and the outer surface of the straightening block 12 being too small.

[0056] In some examples, the material of steel wire 2 can be carbon spring steel, alloy spring steel, etc.

[0057] This embodiment also provides a method for preparing a sucker rod centralizer, used to obtain the above-mentioned sucker rod centralizer 1, comprising the following steps:

[0058] A limiting annular groove 14 is formed on the side of the sucker rod 11. There are multiple limiting annular grooves 14, which are located on both sides of the support member 13.

[0059] Wrap the steel wire 2 around the side of the sucker rod 11.

[0060] A straightening block 12 is molded on the outside of the sucker rod 11 by injection molding, so that the straightening block 12 wraps around the support member 13. When the straightening block 12 is injection molded, the limiting annular groove 14 is located in the injection cavity, so that the straightening block 12 fills the limiting annular groove 14.

[0061] Since this preparation method is used to prepare the sucker rod centralizer 1, it also has the same advantages as the sucker rod centralizer 1, which will not be elaborated here.

[0062] Since the centralizing block 12 fills the limiting annular groove 14, the limiting annular groove 14 can restrict the movement of the centralizing block 12 along the axial direction of the sucker rod 11, thereby playing the role of limiting the centralizing block 12.

[0063] In some examples, when the wire 2 is wound around the oil rod 2 and the limiting annular groove 14 is opened, the sucker rod 11 is connected to the motor 3 and rotates under the drive of the motor 3. Support rollers 4 are arranged on both sides below the sucker rod 11. When the sucker rod 11 rotates, the support rollers 4 on both sides provide rolling support for the sucker rod 11.

[0064] In some examples, a positioning disc 5 is used when winding the steel wire 2. The positioning disc 5 has a radially arranged groove 51 and a radially arranged threaded hole 52. Both the groove 51 and the threaded hole 52 extend to the center of the positioning disc 5 and are interconnected. The central angle corresponding to the area between the groove 51 and the threaded hole 52 is an acute angle. With the axis of the positioning disc 5 parallel to the axis of the sucker rod 11, the sucker rod 11 is slid along the groove 51 to the center of the positioning disc 5. Then, the positioning screw 53 is screwed into the threaded hole 52, so that the positioning screw 53 abuts against or maintains a slight gap with the sucker rod 11. A portion of the positioning screw 53 extends into the groove 51, thereby preventing the sucker rod 11 from sliding out of the positioning disc 5 along the groove 51. One end of the positioning screw 53 extending into the threaded hole 52 can be used to fix a gasket, such as a rubber gasket, by adhesive or other fixing methods, thereby reducing damage to the sucker rod 11. The positioning disc 5 is also provided with a through hole 54 parallel to its own axis. One end of the steel wire 2 wound on the drum 6 passes through the through hole 54 from the first side of the positioning disc 5 to the second side of the positioning disc 5 and is fixed to the sucker rod 11. When the sucker rod 11 rotates, a linear drive device moves the positioning disc 5 along its axis to its second side, and the drum 6 also rotates actively or passively. After passing through the through hole 54, the steel wire 2 extends in a straight line along the second side of the positioning disc 5 (i.e., in a direction perpendicular to the axis of the through hole 54) to the edge of the positioning disc 5, and then extends in a straight line in a direction inclined towards the first side of the positioning disc 5 to the sucker rod 11. With the rotation of the sucker rod 11, the translation of the positioning disc 5, and the rotation of the drum 6, the steel wire 2 is wound into a spiral shape on the sucker rod 11, and then the steel wire 2 is cut, thus completing the winding of one layer of steel wire 2. When there are multiple layers of steel wire 2, the winding of subsequent steel wire 2 is completed in the same way.

[0065] For example, there are various ways to fix one end of the steel wire 2 to the sucker rod 11, such as binding, welding, or bonding. When binding is used, it must be tied tightly so that the steel wire 2 will not slip when the sucker rod 11 rotates (i.e., the steel wire 2 will not slide relative to the sucker rod 11).

[0066] In some examples, when creating the limiting annular groove 14, the axis of the grinding wheel 7 is parallel to the axis of the sucker rod 11. After the grinding wheel 7 begins to rotate, it is gradually brought closer to the sucker rod 11 until it contacts the sucker rod 11, thus creating the limiting annular groove 14 on the sucker rod 11. When the limiting annular groove 14 is a complete ring, the rotation angle of the sucker rod 11 should be no less than 360 degrees when the grinding wheel 7 creates the groove. When the limiting annular groove 14 is an incomplete ring, the rotation angle of the sucker rod 11 should be less than 360 degrees when the grinding wheel 7 creates the groove.

[0067] In some examples, when injection molding the straightening block 12, the upper mold 8 and the lower mold 9 are closed, so that the injection cavity 10 surrounds the preset shaft section of the sucker rod 11. The discharge port of the injection molding machine 103 is aligned with the feed port of the upper mold 8, the injection molding machine 103 is started, and the injection molding material is added to the feed port of the injection molding machine 103 through the hopper 102, thus obtaining the straightening block 12 in the injection cavity 10. Both ends of the upper mold 8 and the lower mold 9 have semi-circular grooves 101 with the same radius as the sucker rod 11, so that after the upper mold 8 and the lower mold 9 are closed, the two semi-circular grooves 101 just form a circular hole for the sucker rod 11 to pass through. This circular hole is in sealed contact with the sucker rod 11 to prevent the injection molding material from leaking out of the cavity.

[0068] The injection molding process should be carried out after the steel wire 2 is wrapped and the limiting annular groove 14 is opened (for example of opening the limiting annular groove 14), so that the molded straightening block 12 not only wraps the support 13, but also fills the limiting annular groove 14 (for example of opening the limiting annular groove 14).

[0069] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method of manufacturing a sucker rod centralizer, characterized by, The method comprises the following steps: A limiting ring groove (14) is formed on the side of the sucker rod (11); the limiting ring groove (14) is in multiple numbers and is located on both sides of the supporting member (13); the supporting member (13) is a steel wire (2) spirally wound around the sucker rod (11); The steel wire (2) is wound around the side of the sucker rod (11); A centralizer (12) is molded on the outer side of the sucker rod (11) by injection molding, so that the centralizer (12) wraps the supporting member (13); when the centralizer (12) is injection molded, the limiting ring groove (14) is located in the injection cavity, so that the centralizer (12) fills the limiting ring groove (14); A positioning disc (5) is used when winding the steel wire (2); the positioning disc (5) is provided with a radial sliding groove (51), a radial threaded hole (52), and a through hole (54) parallel to the axis of the positioning disc (5); the sliding groove (51) and the threaded hole (52) both extend to the center of the positioning disc (5) and are in communication with each other, and the central angle between the sliding groove (51) and the threaded hole (52) is an acute angle; the axis of the positioning disc (5) is parallel to the axis of the sucker rod (11), the sucker rod (11) is slid along the sliding groove (51) to the center of the positioning disc (5), then the positioning screw (53) is screwed into the threaded hole (52), so that the positioning screw (53) abuts against or leaves a gap with the sucker rod (11); part of the positioning screw (53) extends into the sliding groove (51), preventing the sucker rod (11) from sliding out of the positioning disc (5) along the sliding groove (51); one end of the steel wire (2) wound on the winding drum (6) is passed through the through hole (54) from the first side of the positioning disc (5) to the second side of the positioning disc (5) and fixed on the sucker rod (11); with the rotation of the sucker rod (11), the translation of the positioning disc (5) to the second side thereof, and the rotation of the winding drum (6), the steel wire (2) is wound on the sucker rod (11) in a spiral shape, then the steel wire (2) is cut, and the winding of one layer of the steel wire (2) is completed.

2. The preparation method of the sucker rod centralizer according to claim 1, characterized in that: When the steel wire (2) is in multiple layers, the winding of the subsequent steel wire (2) is continued according to the above method; When the limiting ring groove (14) is formed, the axis of the grinding wheel sheet (7) is parallel to the axis of the sucker rod (11), the grinding wheel sheet (7) starts to rotate, and the grinding wheel sheet (7) gradually approaches the sucker rod (11) until the grinding wheel sheet (7) contacts the sucker rod (11), that is, the limiting ring groove (14) is formed on the sucker rod (11); when the limiting ring groove (14) is a complete ring, the rotation angle of the sucker rod (11) when the grinding wheel sheet (7) is grooved is not less than 360 degrees; when the limiting ring groove (14) is an incomplete ring, the rotation angle of the sucker rod (11) when the grinding wheel sheet (7) is grooved is less than 360 degrees.

3. The method of claim 2, wherein: The sucker rod centralizer (1) comprises a sucker rod (11), a centralizing block (12) and a supporting member (13); the supporting member (13) is a steel wire (2) spirally winding around the sucker rod (11); the centralizing block (12) is molded on the outer side of the sucker rod (11) and wraps the supporting member (13); The side surface of the sucker rod (11) is provided with a plurality of limiting ring grooves (14), and the centralizing block (12) fills the limiting ring grooves (14); When the centralizing block (12) is elongated under the extrusion force, the supporting member (13) is elongated together, and the supporting member (13) applies an elastic force to the centralizing block (12) to resist the elongation of the centralizing block (12).

4. The method of claim 3, wherein: The centralizing block (12) is made of nylon.

5. The method of claim 3, wherein: The centralizing block (12) is in the shape of a shuttle.

6. The method of claim 5, wherein: The supporting member (13) is located at the middle part of the centralizing block (12).

7. The method of claim 3, wherein: The sucker rod (11) is wound with multiple layers of the supporting member (13).

Images