A body equal-diameter coated centralizer wax scraping oil pumping rod

Abstract

This invention discloses a uniform-diameter coated, straightening, and wax-scraping sucker rod, belonging to the field of sucker rod technology. It aims to solve the technical problems of traditional segmented independent wax scrapers being prone to detachment and failure, rod eccentricity and wear, and difficulty in thoroughly cleaning wax buildup on the inner wall of the tubing. The invention includes a coupling, with a lifting rod connected to its bottom. The bottom of the lifting rod is connected to an external threaded joint via a core rod. A rotating cylinder is rotatably fitted onto the outer circumference of the core rod. A coating layer is connected to the outer circumference of the rotating cylinder, and the outer circumference of the coating layer has multiple axially oriented flow grooves. A spiral-shaped wax-scraping ridge is formed between every two adjacent flow grooves. A rotary drive assembly is arranged on the upper end of the rod sidewall of the external threaded joint. This invention features a wax-scraping ridge that radially conforms to the entire inner wall of the tubing, allowing the sucker rod to complete wax scraping of the entire inner wall of the tubing through reciprocating motion. It also has the advantages of continuous centering and straightening, and prevention of eccentric wear.

Description

Technical Field

[0001] This invention relates to the field of sucker rod technology, and more specifically, to a sucker rod with a body of equal diameter, a straightening and wax-scraping structure. Background Technology

[0002] In rod-pumped oilfield systems, the surface pumping unit pulls the sucker rod up and down in a reciprocating motion, causing the sucker rod to move linearly up and down within a fixed tubing hundreds to thousands of meters deep. Under normal operating conditions, there should be a gap between the sucker rod and the tubing to prevent them from contacting each other. However, due to wellbore tilt, the weight of the rod string causing it to sag, and the oscillation of the motion, the sucker rod cannot be centered and will eccentrically press against the inner wall of the tubing, resulting in relative friction. At the same time, under the soaking of the original well fluid, a waxy substance forms on the inner wall of the tubing. If it is not cleaned regularly, the wax will accumulate and thicken, eventually causing blockage and affecting normal oil production.

[0003] Currently, the industry commonly addresses these issues by installing independent straightening and wax-scraping devices in sections on the sucker rod. While these sectioned devices can provide some straightening and wax-scraping, they are prone to detachment and failure, leaving the detached sections of the rod exposed and still experiencing uneven wear. This prevents continuous and stable straightening and wax-scraping, and fails to fundamentally solve the technical problems of rod and tubing wear and wax blockage in the tubing. Therefore, we propose a straightening and wax-scraping sucker rod with a body of equal diameter encapsulation. Summary of the Invention

[0004] The purpose of this invention is to provide a body-wound sucker rod with a uniform diameter to solve the technical problems of traditional segmented independent wax scrapers being prone to detachment and failure, rod body eccentricity and wear, and difficulty in thoroughly cleaning wax buildup on the inner wall of the tubing.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a body-equal-diameter coated straightening wax-scraping sucker rod, including a coupling, a lifting rod connected to the bottom of the coupling, and an external threaded joint connected to the bottom of the lifting rod via a core rod; a rotating cylinder is rotatably sleeved on the outer circumference of the core rod via a bearing, and a coating layer is connected to the outer circumference of the rotating cylinder; the outer circumference of the coating layer is axially formed with multiple flow grooves, each flow groove being a right-hand spiral groove structure with a 30° right-hand rotation from one end to the other, and every two phases... A spiral-shaped wax-scraping ridge is formed between adjacent flow channels. The sidewall of the wax-scraping ridge radially covers the entire circumferential area of ​​the inner wall of the tubing, and is used to perform full-area wax scraping on the inner wall of the tubing during the reciprocating stroke of the sucker rod. The upper end of the external threaded joint is provided with a rotary drive assembly. The rotary drive assembly can drive the rotating cylinder together with the coating layer to rotate around the core rod during the reciprocating stroke of the sucker rod, so that the wax-scraping ridge forms a circumferential self-rotating wax scraping during the up-and-down reciprocating wax scraping process.

[0006] Preferably, the coating layer is made of PE material and is tightly fused to the outer wall of the rotating cylinder by an extrusion molding process to form a seamless integrated coating structure.

[0007] Preferably, a worm gear is connected to the bottom of the rotating drum, and the core rod is clearance-fitted with the inner wall of the worm gear.

[0008] Preferably, the rotary drive assembly includes multiple support plates connected to the side wall of the upper rod of the external threaded joint. Each pair of support plates forms a group, and multiple groups of support plates are arranged in a circular array. The two support plates in each group have a symmetrical structure with linear alignment.

[0009] Preferably, a worm gear is rotatably connected between each pair of support plates, and the worm gear meshes with the worm wheel. Both ends of the worm gear are connected to rollers with a symmetrical structure. The rollers are mushroom-shaped arcuate structures with an overall convex arcuate outline, and the outer outline of the rollers can conform to the inner wall of the oil pipe. The rollers consist of a base column and multiple crushing cones, and the multiple crushing cones are arranged in a ring array on the outer circumference of the base column. The rollers can roll on the wax layer on the inner wall of the oil pipe through the multiple crushing cones.

[0010] Preferably, the crushing cone has a flat plate-like structure, and the outer edges of the flat plate-like structure are capable of crushing and prying solid or semi-solid sheet-like wax blocks.

[0011] Preferably, the worm gear has a sliding channel in its inner cavity, and a slide rod is connected to the side wall of the base column. The slide rod is slidably arranged in the sliding channel. The inner side wall of the sliding channel has multiple limiting grooves, and the outer circumferential wall of the slide rod has multiple transmission sliders connected to it. The transmission sliders are slidably arranged in the limiting grooves. When the roller rolls on the inner wall of the oil pipe, the synchronous circumferential movement of the transmission sliders drives the worm gear to rotate synchronously. Furthermore, the side wall of the slide rod has a circular groove, and a spring is arranged in the circular groove. Two slide rods are connected by the spring.

[0012] Preferably, the outer walls of the rod structures at both ends of the worm are provided with multiple guide grooves of the same structure, and the rod structures at both ends of the worm are movably fitted with slip rings of the same structure. The inner walls of the slip rings are connected to multiple guide sliders, and the guide sliders slide in cooperation with the guide grooves. When the worm rotates, the guide sliders and the slip rings can be driven to rotate synchronously through the guide grooves. The side walls of the slip rings are connected to multiple push rods, and the push rods are movably arranged between every two of the crushing cones and form a sliding contact with the side wall of the base column.

[0013] Preferably, the support plate has a fixed ring cover connected to its side wall, and the inner circumference of the fixed ring cover has a guide arc groove. The guide arc groove is a closed annular groove structure with its ends connected. The axis of the groove structure is arranged at an inclined angle relative to the central axis of the fixed ring cover. The upper end and lower end of the guide arc groove form a fixed horizontal eccentric distance in the radial direction. The slip ring is movably arranged in the inner cavity of the fixed ring cover, and the outer circumference of the slip ring is connected to a driven guide post. The driven guide post is movably arranged in the guide arc groove.

[0014] Preferably, the push rod end is a wedge-shaped cone structure that is narrow at the front and wide at the back; when the two slide rods move apart under the elastic force of the spring and reach the maximum stroke, the push rod is limited between the two adjacent crushing cones; when the two slide rods move towards each other to the minimum stroke state, the end of the push rod wedge-shaped cone structure is housed in the end region between the two adjacent crushing cones.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention achieves seamless welding and fixation between the coating layer and the rotating drum by extruding an integral coating layer on the outer circumference of the rotating drum, thus eliminating the risk of assembly gaps and the scraping components falling off during downhole reciprocating operations. The scraping ridges formed by the coating layer in a right-hand 30° spiral state are radially attached to the entire inner wall of the tubing. The up-and-down reciprocating motion of the sucker rod can complete the full-area scraping of the inner wall of the tubing, which also has the functions of continuous centering and anti-wear. This solves the problems of easy detachment and failure of traditional segmented independent scrapers, rod eccentricity and wear, and difficulty in completely cleaning and blocking the oil production channel due to wax buildup on the inner wall of the tubing.

[0016] 2. This invention also provides a flow channel with multiple right-handed 30° spiral grooves on the sidewall of the coating layer. The spirally arranged flow channel allows the crude oil well fluid in the tubing to flow smoothly upwards, ensuring normal fluid production in the well and preventing the channel from being blocked by the coating structure. It also carries away the scraped wax residue with the well fluid, while balancing the inter-section hydraulic pressure and reducing the liquid resistance of the sucker rod reciprocating motion. This solves the problem that the straight edges of conventional axial straight grooves only scrape along the fixed vertical line of the tubing, and the wax layer on the pipe wall in the straight groove area cannot be swept away, resulting in the continuous accumulation of residual wax and scaling, which does not achieve the full-area wax scraping effect.

[0017] 3. The present invention also provides a rotary drive assembly arranged on the upper end of the rod side wall of the external threaded joint. When the sucker rod moves up and down in the tubing, the roller rolls against the wax layer on the inner wall of the tubing by means of the crushing cone, which in turn drives the worm to rotate. Then, the worm and the worm wheel mesh and drive the rotating drum and the coating layer to rotate as a whole. This allows the wax scraping ridges to rotate in a circular motion on the basis of linear reciprocating motion, thereby achieving a self-rotating composite all-round scraping of hard wax blocks and improving the removal effect of stubborn wax.

[0018] 4. The present invention also designs the roller head as a mushroom-shaped arc-shaped structure with an overall convex arc shape, so that the outer contour of the roller head can fit the inner wall of the oil pipe. With multiple crushing cones contacting the inner wall of the oil pipe, when the sucker rod moves up and down in the oil pipe, the multiple crushing cones not only embed into the wax layer of the pipe wall, increasing the frictional resistance of the contact surface and driving the roller head to rotate, thereby providing a stable driving force for the worm gear transmission, but also use the edges of the crushing cones to cut and pry open solid and semi-solid stubborn wax blocks, pre-breaking the hardened wax body, so that the subsequent wax scraping protrusions can quickly remove the residual wax.

[0019] 5. The present invention also connects the two slide rods with a spring. The spring force of the spring makes the two slide rods always maintain a tendency to move in opposite directions. When the wax layer on the inner wall of the oil pipe is uneven in thickness, with local protrusions or depressions, the protruding wax block squeezes the roller head. The slide rods on both sides are compressed and retracted, and the spring spring inside the compression groove retracts inward, so that the roller head can fit against the protruding wax block. The depressed wax block provides space for the roller head to extend, so that the spring spring pushes the slide rods on both sides outward. The slide rods slide outward along the sliding channel in the inner cavity of the worm gear, ensuring that the roller head continuously fits against the surface of the wax layer on the inner wall of the oil pipe. It can adapt to the changes in the protrusion of the wax layer, fit and roll, and crush and pry the hard wax block.

[0020] 6. This invention also incorporates push rods designed between every two crushing cones. When the worm rotates, it synchronously drives the slip ring to rotate. During the rotation of the slip ring, the driven guide post on its outer wall slides circumferentially along the guide arc groove eccentrically arranged on the inner wall of the fixed ring cover. Constrained by the eccentric trajectory of the guide arc groove, the slip ring follows the rotation of the worm and reciprocates along the worm axis. This drives multiple push rods on the side wall of the slip ring to reciprocate between adjacent crushing cones and on the surface of the base column. The reciprocating pushing action of the push rods clears the wax debris stuck between every two crushing cones, preventing wax slag accumulation and blockage between the two crushing cones, which would affect the crushing and wax breaking and friction transmission performance. This ensures smooth rolling transmission of the roller head and achieves automatic slag removal during the rolling process. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the core rod structure of the present invention; Figure 3 This is a schematic diagram of the coating layer and rotating cylinder structure of the present invention; Figure 4 This is a cross-sectional structural diagram of the rotating drum of the present invention; Figure 5 This is a schematic diagram of the rotary drive assembly structure of the present invention; Figure 6 This is a schematic diagram showing one usage state of the roller head of the present invention in the inner cavity of an oil pipe; Figure 7 This is a schematic diagram of the roller head and worm gear structure of the present invention; Figure 8 This is a schematic diagram of the crushing cone structure of the present invention; Figure 9 This is a schematic diagram of the worm gear and slip ring structure of the present invention; Figure 10 This is a cross-sectional schematic diagram of the worm gear and slide bar of the present invention; Figure 11 This is a schematic diagram of the cross-sectional structure of the fixing ring cover of the present invention; Figure 12 This is a schematic diagram of the disassembled structure of the slip ring and the fixing ring cover of the present invention; Figure 13 This is a cross-sectional schematic diagram of the maximum stroke of the two slide bars of the present invention.

[0022] Explanation of the labels in the diagram: 1. Coupling; 2. Lifting rod; 3. Core rod; 4. External threaded joint; 5. Bearing; 6. Rotary drum; 7. Coating layer; 8. Oil pipe; 9. Rotary drive assembly; 601. Worm gear; 701. Flow groove; 702. Wax scraping protrusion; 901. Support plate; 902. Worm gear; 903. Roller head; 904. Base column; 905. Crushing cone; 906. Sliding channel; 907. Slide rod; 908. Limiting groove; 909. Transmission slider; 910. Circular groove; 911. Elastic spring; 912. Guide groove; 913. Slip ring; 914. Guide slider; 915. Push rod; 916. Fixing ring cover; 917. Guide arc groove; 918. Driven guide post. Detailed Implementation

[0023] like Figures 1 to 13 As shown, the present invention relates to a type of sucker rod with a body of equal diameter, a straightening and wax-scraping structure, comprising a coupling 1, a lifting rod 2 connected to the bottom of the coupling 1, and an external threaded joint 4 connected to the bottom of the lifting rod 2 via a core rod 3; the coupling 1 is a sucker rod connecting and mating component, used to thread-lock and splice with the external threaded joint 4 of the adjacent sucker rod above, realizing the series connection of multiple sucker rods end to end; the lifting rod 2 is used as the lifting and hanging force-bearing section during wellbore operation, and the lifting equipment grabs the lifting rod 2 to lift the entire sucker rod and lower it into the tubing.

[0024] The core rod 3 has a rotating cylinder 6 rotatably connected to its outer circumference via a bearing 5. The outer circumference of the rotating cylinder 6 is connected to a coating layer 7. The coating layer 7 is made of PE material and is tightly fused to the outer wall of the rotating cylinder 6 through an extrusion molding process to form a gapless integrated coating structure. The outer circumference of the coating layer 7 has multiple flow grooves 701 axially formed. The flow grooves 701 can form crude oil flow channels to ensure smooth return of well fluid. The flow grooves 701 are spiral groove structures with a right-hand rotation of 30° from one end to the other. A spiral wax scraping ridge 702 is formed between every two adjacent flow grooves 701. The sidewall of the wax scraping ridge 702 radially covers the entire circumferential area of ​​the inner wall of the tubing 8 and is used to perform full-area wax scraping on the inner wall of the tubing 8 during the reciprocating stroke of the sucker rod.

[0025] This invention achieves seamless welding and fixation between the coating layer and the rotating drum by extruding an integral coating layer 7 on the outer circumference of the rotating drum 6, thus eliminating the traditional split-set straightening and wax scraping sleeve structure. This avoids the risk of assembly gaps and the wax scraping components falling off during downhole reciprocating operations. The wax scraping protrusion 702 formed by the coating layer 7 in a right-handed 30° spiral state is radially attached to the entire inner wall of the tubing. The up-and-down reciprocating motion of the sucker rod can complete the full-area wax scraping of the inner wall of the tubing, which also has the functions of continuous centering and straightening and preventing uneven wear. This solves the problems of easy detachment and failure of traditional segmented independent wax scrapers, rod eccentricity and uneven wear, and difficulty in completely cleaning and blocking the oil production channel due to wax buildup on the inner wall of the tubing 8.

[0026] The present invention also provides a flow channel 701 with multiple right-handed 30° spiral grooves on the sidewall of the coating layer 7. The spirally arranged flow channel 701 allows the crude oil well fluid in the tubing 8 to flow smoothly upward, ensuring normal fluid production of the well and preventing the channel from being blocked by the coating structure. It can also carry away the scraped wax residue with the well fluid, while balancing the inter-section hydraulic pressure and reducing the liquid resistance of the reciprocating motion of the sucker rod. This solves the problem that the straight edges of the conventional axial straight channel only scrape along the fixed vertical line of the tubing 8, and the wax layer on the pipe wall in the straight channel area cannot be swept, resulting in the continuous accumulation of residual wax and scaling, which does not achieve the full-area wax scraping effect.

[0027] In an embodiment of the present invention, a rotary drive assembly 9 is arranged on the upper end rod side wall of the external threaded connector 4. The rotary drive assembly 9 can drive the rotating drum 6 together with the coating layer 7 to rotate around the core rod 3 during the reciprocating stroke of the sucker rod, so that the wax scraping ridge 702 forms a circumferential self-rotating wax scraping during the up-and-down reciprocating wax scraping process.

[0028] Specifically, a worm gear 601 is connected to the bottom of the rotating drum 6, and the core rod 3 is clearance-fitted with the inner wall of the worm gear 601; the rotary drive assembly 9 includes multiple support plates 901 connected to the side wall of the upper rod of the external threaded joint 4, with each pair of support plates 901 forming a group, and multiple groups of support plates 901 arranged in a circular array, with the two support plates 901 in each group having a linearly aligned symmetrical structure; a worm 902 is rotatably connected between the two support plates 901 in each group, and the worm 902 meshes with the worm gear 601. The worm gear 902 is connected to two ends with symmetrical roller heads 903. The roller head 903 is a mushroom-shaped arc-shaped structure with an overall convex arc shape. The outer contour of the roller head 903 can fit against the inner wall of the oil pipe 8. The roller head 903 is composed of a base column 904 and multiple crushing cones 905. The multiple crushing cones 905 are arranged in a ring array on the outer circumference of the base column 904. The roller head 903 can roll on the wax layer on the inner wall of the oil pipe 8 through the multiple crushing cones 905.

[0029] The present invention also includes a rotary drive assembly 9 arranged on the upper end of the rod side wall of the external threaded joint 4. When the sucker rod moves up and down in the tubing 8, the roller head 903 rolls against the wax layer on the inner wall of the tubing by the crushing cone 905, thereby driving the worm gear 902 to rotate. Then, the worm gear 902 meshes with the worm wheel 601 to drive the rotating drum 6 and the coating layer 7 to rotate as a whole. This allows the wax scraping ridge 702 to rotate in a circular motion on the basis of linear reciprocating motion, thereby achieving a self-rotating composite all-round scraping of hard wax blocks and improving the removal effect of stubborn wax.

[0030] As another embodiment of the present invention, the crushing cone 905 is a flat plate structure. Because the wax on the inner wall of the tubing 8 is normally solid, semi-solid, or viscous paste at room temperature in the well, it is firmly stuck to the tubing wall. When it is solid or semi-solid, it is harder and has stronger adhesion. Therefore, the crushing cone 905 is designed as a flat plate structure. Because the outer edge of the flat plate structure has a smaller contact area with the wax layer, the pressure increases under constant pressure, which allows the outer edge of the flat plate structure to crush and pry the solid or semi-solid sheet-like wax blocks.

[0031] This invention also designs the roller head 903 as a mushroom-shaped, arc-shaped structure, with an overall outer contour that is convex and curved, such as... Figure 6 As shown, the outer contour of the roller head 903 can fit against the inner wall of the oil pipe 8, and the roller head 903 contacts the inner wall of the oil pipe 8 through multiple crushing cones 905. When the sucker rod moves up and down in the oil pipe 8, the multiple crushing cones 905 not only embed into the wax layer of the pipe wall, increasing the frictional resistance of the contact surface, but also drive the roller head 903 to rotate, thereby providing a stable driving force for the worm gear transmission. The edges of the crushing cones 905 can also be used to cut and pry solid and semi-solid stubborn wax blocks, pre-breaking the hardened wax body, so that the subsequent wax scraping ridge 702 can quickly remove the residual wax.

[0032] In an embodiment of the present invention, a sliding channel 906 is provided in the inner cavity of the worm gear 902, and a slide rod 907 is connected to the side wall of the base column 904. The slide rod 907 is slidably arranged in the sliding channel 906. The inner side wall of the sliding channel 906 is provided with a plurality of limiting grooves 908, and a plurality of transmission sliders 909 are connected to the outer circumferential wall of the slide rod 907. The transmission sliders 909 are slidably arranged in the limiting grooves 908. When the roller head 903 rolls on the inner wall of the oil pipe 8, the worm gear 902 can be driven to rotate synchronously through the synchronous circumferential movement of the transmission sliders 909. Furthermore, a circular groove 910 is provided in the side wall of the slide rod 907, and a spring spring 911 is arranged in the circular groove 910. Two slide rods 907 are connected by the spring spring 911.

[0033] In this process, the sucker rod reciprocates up and down, and the roller head 903 rotates due to friction from the wax layer on the pipe wall, which drives the slide rod 907 to rotate circumferentially. The transmission slider 909 on the outer wall of the slide rod 907 is locked in the limiting slide groove 908 on the inner wall of the sliding channel 906 and rotates synchronously, thereby driving the worm gear 902 to rotate together.

[0034] This invention connects two slide rods 907 via a spring 911. Utilizing the elastic force of the spring 911, the two slide rods 907 maintain a constant opposing motion trend. When the wax layer on the inner wall of the oil pipe 8 has uneven thickness, with local protrusions or depressions, the protruding wax block squeezes the roller head 903. The slide rods 907 on both sides are compressed and retract, compressing the spring 911 inside the circular groove 910 to retract inward, allowing the roller head 903 to adhere to the protruding wax block. The depressed wax block provides space for the roller head 903 to extend, allowing the spring 911 to push the slide rods 907 outward. The slide rods 907 slide outward along the sliding channel 906 inside the worm gear 902, ensuring that the roller head 903 continuously adheres to the surface of the wax layer on the inner wall of the oil pipe 8. It can adapt to changes in the wax layer protrusion, adhere and roll, and crush and pry open hard wax blocks.

[0035] In an embodiment of the present invention, multiple guide grooves 912 of the same structure are provided on the outer side walls of the rod structures at both ends of the worm 902. Slip rings 913 of the same structure are movably sleeved on the rod structures at both ends of the worm 902. Multiple guide sliders 914 are connected to the inner circumference of the slip rings 913. The guide sliders 914 slide in cooperation with the guide grooves 912. When the worm 902 rotates, the guide sliders 914 and the slip rings 913 can be driven to rotate synchronously through the guide grooves 912. Multiple push rods 915 are connected to the side wall of the slip rings 913. The push rods 915 are movably arranged between every two breaking cones 905 and form a sliding contact with the side wall of the base column 904.

[0036] Furthermore, a fixed ring cover 916 is connected to the side wall of the support plate 901. A guide arc groove 917 is provided on the inner circumference of the fixed ring cover 916. The guide arc groove 917 is a closed annular groove structure with its ends connected. The axis of its groove structure is arranged at an inclined angle relative to the central axis of the fixed ring cover 916. The upper end of the guide arc groove 917 and the lower end of the groove form a fixed horizontal eccentric distance in the radial direction. A slip ring 913 is movably arranged in the inner cavity of the fixed ring cover 916. A driven guide post 918 is connected to the outer circumference of the slip ring 913. The driven guide post 918 is movably arranged in the guide arc groove 917.

[0037] During downhole operations, as the device moves down or up with the sucker rod, the roller 903 continuously adheres to the surface of the wax layer on the inner wall of the tubing 8. Relying on its own radial adjustment structure, it adapts to the uneven shape of the wax layer to complete the rolling and contact. Simultaneously, the rolling and cutting action uses a squeezing force to break up the hardened wax blocks solidified on the tubing wall. The broken wax blocks and the remaining viscous, paste-like wax layer may be compressed and accumulated between each pair of breaking cones 905. This invention, by designing a push rod 915 between each pair of breaking cones 905, allows the slip ring 913 to rotate synchronously when the worm gear 902 rotates. During the rotation of the slip ring 913, the driven guide post 918 on its outer wall moves along the inner edge of the fixed ring cover 916. The guide arc groove 917, which is eccentrically arranged with an inclined wall, slides in a circular motion. Constrained by the eccentric trajectory of the guide arc groove 917, the slip ring 913 rotates with the worm gear 902 and reciprocates along the axial direction of the worm gear 902. This drives multiple push rods 915 on the side wall of the slip ring 913 to slide back and forth between adjacent crushing cones 905 and on the surface of the base column 904. The reciprocating pushing action of the push rods 915 clears the wax debris stuck between each pair of crushing cones 905, preventing the accumulation of wax residue and blockage between each pair of crushing cones 905, which would affect its crushing and wax breaking and friction transmission performance. This ensures the smooth rolling transmission of the roller head 903 and achieves the effect of automatic slag removal during the rolling process.

[0038] In another embodiment of the present invention, the end of the push rod 915 is a wedge-shaped cone structure that is narrow at the front and wide at the back; when the two slide rods 907 move apart under the elastic force of the elastic spring 911 and reach the maximum stroke, the push rod 915 is limited between the two adjacent crushing cones 905; when the two slide rods 907 move towards each other to the minimum stroke state, the end of the wedge-shaped cone structure of the push rod 915 is housed in the end region between the two adjacent crushing cones 905.

[0039] Among them, due to the uneven thickness of the wax layer on the inner wall of the oil pipe 8 and the abnormal protrusion of the wax layer in some areas, the two rollers 903 will make radial adaptive fine adjustments to adapt to the pipe wall profile in real time. This directly drives the two sets of slide rods 907 linked with the rollers to produce small-range spacing changes, so that the two slide rods 907 reciprocate slightly within the range of maximum and minimum stroke.

[0040] like Figure 11 The diagram shows the minimum stroke state of the two sliding rods 907 moving towards each other. At this time, relying on the wedge-shaped cone shape of the push rod 915 (narrow at the front and wide at the back), the wedge-shaped cone is always kept within the space between the adjacent crushing cones 905 and fits the shape of the roller head 903. It will not extend outside the roller head 903, which not only ensures the effective slag removal effect of the push rod 915's telescopic movement, but also avoids the push rod 915 directly contacting the wax layer on the inner wall of the oil pipe 8 and affecting the rolling of the roller head 903.

[0041] like Figure 13 The diagram shows the maximum stroke of the two sliding rods 907 moving in opposite directions. At this time, the push rod 915 extends to the limit position of its movement, keeping its wedge-shaped cone head within the space between the adjacent crushing cones 905, so that it can still perform effective slag removal.

[0042] Therefore, regardless of whether the two slide rods 907 are at their minimum stroke or far from their maximum stroke, the wedge-shaped cone of push rod 915 is always confined within the gap between adjacent crushing cones 905. It can continuously clean the wax debris and broken wax residue embedded in the gap throughout the entire process. The problem of push rod 915 disengaging from the gap and failing to clean the residue due to the spacing fluctuation caused by the adaptive roller 903 is not present. This results in a continuous and effective effect of clearing the wax residue falling between the two crushing cones 905.

[0043] Working principle: This embodiment provides a body-equal diameter wrapped straightening and wax scraping sucker rod. In use, firstly, multiple sucker rods are connected in series to form a rod column by threaded connection between the end coupling 1 and the external threaded joint 4. The entire rod column is then hoisted and lowered into the oil pipe 8 with the help of the hoisting rod 2. The ground pumping unit drives the entire set of sucker rods to make up-down reciprocating linear motion along the axial direction of the oil pipe 8. Secondly, during the up-and-down movement of the sucker rod, the outer diameter of the PE material integrated coating layer 7 is adapted to the inner diameter of the tubing, and the spirally arranged wax scraping protrusions 702 are closely attached to the entire inner wall of the tubing 8. The rod body reciprocates and moves linearly to scrape off the wax adhering to the tubing wall. The spiral flow groove 701 forms a continuous flow channel, and the scraped wax residue is discharged upward along the flow groove 701 to the wellhead with the well fluid. At the same time, the overall coating layer 7 continuously supports the rod column to stay in the center, preventing the sucker rod from being eccentric and rubbing against the tubing 8. Meanwhile, the mushroom-shaped rollers 903 at both ends of the rotary drive assembly 9 are always pushed outward and tightly adhered to the wax layer on the inner wall of the tubing 8 under the action of the elastic spring 911. When the thickness of the wax layer on the downhole tubing is uneven, the rollers 903 are squeezed by the protruding wax blocks, compressing the elastic spring 911 to retract. When the tubing wall is concave, the spring opens the slide rod 907 to extend, achieving radial adaptive fitting. When the rollers 903 move up and down with the rod, the edges of the surface breaking cone 905 crush and pry the solid and semi-solid hardened wax blocks on the tubing wall, breaking up large stubborn wax blocks in advance. The rollers 903 rotate by the friction of the wax layer, and the worm gear 902 rotates synchronously through the transmission slider 909 on the outside of the slide rod 907. Furthermore, the worm gear 902 meshes with the worm wheel 601 to drive the rotating drum 6 and the coating layer 7 to rotate around the core rod 3 by relying on the bearing 5, so that the spiral wax scraping ridge 702 can be superimposed with circumferential rotation on the basis of reciprocating wax scraping, forming a compound all-round wax scraping effect of reciprocating lifting and rotation. Finally, as the worm gear 902 rotates, it drives the slip ring 913 to rotate synchronously through the guide groove 912. The driven guide post 918 on the outer side of the slip ring slides along the inclined and eccentric guide arc groove 917 inside the fixed ring cover 916. Due to the eccentric limitation of the groove, the slip ring 913 slides back and forth along the axial direction of the worm gear 902 during the rotation, driving the side wall wedge push rod 915 to reciprocate and push between adjacent crushing cones 905, clearing the wax debris stuck between every two crushing cones 905.

[0044] The embodiments disclosed in this invention are preferred embodiments, but are not limited thereto. Those skilled in the art can easily understand the spirit of this invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of this invention, they are all within the protection scope of this invention.

Claims

1. A type of constant-diameter coated, straightening, wax-scraping sucker rod, characterized in that, Includes a coupling (1), the bottom of which is connected to a lifting rod (2), and the bottom of the lifting rod (2) is connected to an external threaded joint (4) via a core rod (3); The outer circumference of the core rod (3) is rotatably sleeved with a rotating cylinder (6) through a bearing (5), and the outer circumference of the rotating cylinder (6) is connected with a covering layer (7). The outer circumferential wall of the coating layer (7) is provided with multiple flow grooves (701) in an axial direction. The flow groove (701) is a spiral groove structure with a right-hand rotation of 30° from one end to the other. A spiral wax scraping ridge (702) is formed between every two adjacent flow grooves (701). The side wall of the wax scraping ridge (702) fully covers the entire circumferential area of ​​the inner wall of the tubing (8) in a radial range, and is used to perform full-area wax scraping on the inner wall of the tubing (8) during the reciprocating stroke of the sucker rod. The upper end of the external threaded connector (4) is provided with a rotary drive assembly (9). The rotary drive assembly (9) can drive the rotating drum (6) and the coating layer (7) to rotate around the core rod (3) during the reciprocating stroke of the sucker rod, so that the wax scraping ridge (702) forms a circumferential self-rotating wax scraping during the up-and-down reciprocating wax scraping process.

2. The body-wound, wax-scraping sucker rod with equal diameter coating as described in claim 1, characterized in that, The coating layer (7) is made of PE material and is tightly fused to the outer wall of the rotating cylinder (6) by extrusion molding to form a seamless integrated coating structure.

3. The body-wound, equal-diameter coated, straightening, and wax-scraping sucker rod according to claim 2, characterized in that, The bottom of the rotating drum (6) is connected to a worm gear (601), and the core rod (3) is in clearance fit with the inner wall of the worm gear (601).

4. The body-wound, wax-scraping sucker rod with equal diameter coating as described in claim 3, characterized in that, The rotary drive assembly (9) includes multiple support plates (901) connected to the upper end rod sidewall of the external threaded joint (4). Each pair of support plates (901) forms a group, and multiple groups of support plates (901) are arranged in a ring array. The two support plates (901) in each group have a symmetrical structure with linear alignment.

5. A body-worn, straightening, wax-scraping sucker rod according to claim 4, characterized in that, A worm gear (902) is rotatably connected between each pair of support plates (901). The worm gear (902) meshes with the worm wheel (601). Both ends of the worm gear (902) are connected to rollers (903) with a symmetrical structure. The roller head (903) is a mushroom-shaped arc-shaped structure with an overall convex arc-shaped outer contour. The outer contour of the roller head (903) can fit against the inner wall of the oil pipe (8). The roller head (903) is composed of a base column (904) and multiple crushing cones (905). The multiple crushing cones (905) are arranged in a ring array on the outer circumference of the base column (904). The roller head (903) can roll on the wax layer on the inner wall of the oil pipe (8) through the multiple crushing cones (905).

6. A body-worn, straightening, wax-scraping sucker rod according to claim 5, characterized in that, The crushing cone (905) has a flat plate-like structure, and the outer edges of the flat plate-like structure can crush and pry solid and semi-solid sheet-like wax blocks.

7. A body-wound, equal-diameter coated, straightening, and wax-scraping sucker rod according to claim 6, characterized in that, The worm gear (902) has a sliding channel (906) in its inner cavity, and a slide rod (907) is connected to the side wall of the base column (904). The slide rod (907) is slidably arranged in the sliding channel (906). The sliding channel (906) has multiple limiting grooves (908) on its inner sidewall, and the sliding rod (907) has multiple transmission sliders (909) connected to its outer circumference. The transmission sliders (909) are slidably arranged in the limiting grooves (908). When the roller (903) rolls on the inner wall of the oil pipe (8), the synchronous circumferential movement of the transmission sliders (909) can drive the worm (902) to rotate synchronously. Furthermore, a circular groove (910) is provided on the side wall of the slide rod (907), and a spring (911) is arranged in the circular groove (910). The two slide rods (907) are connected by the spring (911).

8. A body-wound, equal-diameter coated, straightening, and wax-scraping sucker rod according to claim 7, characterized in that, Multiple guide grooves (912) of the same structure are provided on the outer side walls of the rod structures at both ends of the worm (902). Slip rings (913) of the same structure are movably sleeved on the rod structures at both ends of the worm (902). Multiple guide sliders (914) are connected to the inner circumference of the slip rings (913). The guide sliders (914) slide in cooperation with the guide grooves (912). When the worm (902) rotates, it can drive the guide slider (914) and the slip ring (913) to rotate synchronously through the guide groove (912); The slip ring (913) has a plurality of push rods (915) connected to its sidewall. The push rods (915) are movably arranged between every two of the crushing cones (905) and are in a sliding contact state with the sidewall of the base column (904).

9. A body-wound, equal-diameter coated, straightening, and wax-scraping sucker rod according to claim 8, characterized in that, The support plate (901) is connected to a fixing ring cover (916) on its side wall. The fixing ring cover (916) has a guide arc groove (917) on its inner circumference. The guide arc groove (917) is a closed annular groove structure with its ends connected. The axis of its groove structure is arranged at an inclined angle relative to the central axis of the fixing ring cover (916). The upper end of the guide arc groove (917) and the lower end of the groove form a fixed horizontal eccentric distance in the radial direction. The slip ring (913) is movably arranged in the inner cavity of the fixed ring cover (916), and the outer circumferential wall of the slip ring (913) is connected to a driven guide post (918), which is movably arranged in the guide arc groove (917).

10. A body-wound, equal-diameter, straightening, wax-scraping sucker rod according to claim 9, characterized in that, The push rod (915) has a wedge-shaped cone head structure that is narrow at the front and wide at the back. When the two slide rods (907) move apart under the elastic force of the spring (911) and reach the maximum stroke, the push rod (915) is limited between the two adjacent crushing cones (905). When the two slide rods (907) move towards each other to the minimum stroke state, the end of the wedge-shaped cone head structure of the push rod (915) is housed in the end area between the two adjacent crushing cones (905).

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