Rotary flushing paraffin removal and descaling tool

Abstract

The utility model discloses a rotary flushing paraffin removal and descaling tool, which comprises an upper joint, a lower joint, a paraffin removal and descaling device, a paraffin removal and descaling device, a paraffin removal and descaling device, a paraffin removal and descaling device and a paraffin removal and descaling device, and is characterized in that the upper end of the upper joint is connected with an upper tubular column; the upper end of the rotating shaft is provided with a rotating shaft upper reducing section, the middle part is a rotating shaft large-diameter section, and the lower end is provided with a rotating shaft lower reducing section and a rotating shaft lower thread section; the rotating shaft shell is positioned on the periphery of the large-diameter section of the rotating shaft, and a reducing rotating shaft shell inner step is arranged at the lower end; female threads at the upper end of the rotating head are connected with the lower threaded section of the rotating shaft, and at least three tangential water holes are symmetrically formed in the periphery of the middle section of a center hole of the rotating head; the lateral nozzles are respectively arranged in the outer ports of the tangential water holes of the rotating head; central holes of the upper joint, the rotating shaft and the rotating head are communicated, the outer wall of the lower part of the rotating head is covered with a plurality of hard alloy layers, and hard alloy milling teeth are embedded in the hard alloy layers. The tool not only can efficiently remove the deposited wax on the inner wall of the tubular column, but also can avoid damage to the tubular column and environmental pollution.

Description

Technical Field

[0001] This utility model relates to a rotary flushing wax removal and descaling tool, belonging to the technical field of downhole descaling tools. Background Technology

[0002] During oilfield extraction, crude oil contains a certain amount of wax. As extraction progresses, this wax gradually precipitates and deposits on the inner wall of the tubing, forming a wax layer. With the continuous development of oilfields, the problem of wax deposition on the inner wall of the tubing has become increasingly prominent, bringing many adverse effects to oilfield extraction:

[0003] 1. Reduced effective tubing diameter: The wax layer gradually occupies the internal space of the tubing, reducing its effective diameter. This not only reduces crude oil transportation efficiency but may also slow down the flow rate of crude oil within the tubing, further exacerbating the wax deposition phenomenon.

[0004] 2. Increased transport resistance: The presence of the wax layer hinders the flow of crude oil within the tubing, increasing resistance during transport. Maintaining normal crude oil transport requires more energy to power the transport equipment, which undoubtedly increases the energy costs of oilfield extraction.

[0005] 3. Production Interruption: When the wax layer accumulates to a certain extent, it may completely block the tubing, preventing the normal transport of crude oil and forcing an interruption of oilfield production. This interruption not only causes economic losses but also disrupts the normal production order of the oilfield, severely impacting oilfield extraction.

[0006] Currently, commonly used methods for removing wax deposits include mechanical scraping, hot washing, and chemical cleaning. Mechanical scraping involves using scraping tools, such as scraper blades or scrapers, to physically scrape away the wax deposits on the inner wall of the tubing. However, this method has several drawbacks: First, the hard contact between the scraping tool and the tubing wall during scraping can easily damage the tubing, affecting its lifespan and potentially causing leaks, further exacerbating safety hazards in oilfield operations. Second, mechanical scraping primarily targets surface wax deposits; it is less effective at removing stubborn or deep-seated wax deposits. Third, the scraping process can generate a large amount of wax residue, which, if not cleaned promptly, may redeposit on the tubing wall, leading to recurring wax buildup.

[0007] Hot washing involves injecting a high-temperature liquid into the tubing string to melt the wax deposits, thus removing them. However, this process has several drawbacks. Firstly, reaching sufficient temperatures to melt the wax requires significant energy consumption to heat the liquid, increasing oilfield extraction costs and placing an environmental burden. This is particularly challenging in remote oilfields where energy supplies may be insufficient. Secondly, uneven temperature distribution within the tubing string can prevent complete melting of some wax deposits. Furthermore, melted wax may re-deposit on the tubing string after cooling, leading to recurring wax buildup. Finally, the hot washing process can also generate thermal stress on the tubing material, potentially affecting its structural strength.

[0008] Chemical cleaning involves injecting chemicals into the tubing column to dissolve and remove wax deposits through a chemical reaction. However, this process has several drawbacks: most of the chemicals used are corrosive and toxic. These chemicals can pollute the environment during the cleaning process. Furthermore, the disposal of wastewater after chemical cleaning is a challenge; improper handling could further exacerbate environmental pollution. Secondly, the corrosive nature of the chemicals can damage the tubing material, potentially affecting its lifespan. Additionally, operators handling these chemicals must take strict safety precautions to avoid potential health hazards.

[0009] Chinese invention patent CN108222886B discloses a wax scraping device, comprising: an electric motor, a cable and wire assembly connected to the electric motor, and a rotating assembly coaxially connected to the electric motor and rotatable around an axis; the rotating assembly includes a drive shaft and a wax scraping assembly coaxially connected to the drive shaft with a maximum diameter larger than the drive shaft diameter. This wax scraping device is motor-driven, cannot achieve a circulating cleaning function, and struggles to promptly remove accumulated wax and sand from the tube, resulting in low wax removal efficiency and a tendency to jam. The wax scraping blades wear out quickly under high-intensity operation, making it difficult to guarantee wax removal effectiveness over long-term use. Furthermore, the motor-driven design is complex, inconvenient to operate, and poses safety risks.

[0010] In summary, existing cleaning tools are limited in function, have poor applicability, and are inefficient, failing to simultaneously meet the needs of efficient wax scraping and removal of accumulated wax and sand. With the advancement of cost reduction and efficiency improvement efforts in oil fields and the increasing stringency of related environmental protection requirements, there is an urgent need for a more efficient, environmentally friendly, and widely applicable wax and scale removal tool. Utility Model Content

[0011] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, and such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0012] In view of the problems existing in the above and / or prior art, this utility model is proposed.

[0013] The purpose of this utility model is to overcome the problems of low cleaning efficiency, large damage and poor environmental performance of existing tools, and to provide a rotary flushing wax removal and descaling tool that can be widely used to remove wax buildup on the inner walls of various types of pipe columns. It can not only achieve efficient removal of wax buildup on the inner walls of pipe columns, but also avoid damage to the pipe columns and environmental pollution.

[0014] To solve the above technical problems, this utility model provides a rotary rinsing tool for wax removal and descaling, comprising:

[0015] The upper connector has a tapered internal thread at its upper end for connection with the upper tube column, and an external thread at its lower outer circumference for connection with the rotating shaft housing.

[0016] The rotating shaft has an upper diameter reduction section at its upper end, a large diameter section in the middle, and a lower diameter reduction section and a lower threaded section at its lower end.

[0017] A rotating shaft housing is located on the outer periphery of the large-diameter section of the rotating shaft, and a stepped inner section with a reduced diameter is provided at the lower end of the rotating shaft housing;

[0018] The rotating head has a female thread at its upper end that connects to the lower threaded section of the rotating shaft, and at least three tangential water holes are symmetrically arranged on the outer periphery of the middle section of the central hole of the rotating head.

[0019] Side nozzles are installed in the outer ports of the tangential water holes of the rotating head;

[0020] The upper connector, the rotating shaft, and the central hole of the rotating head are interconnected. The lower outer wall of the rotating head is covered with multiple layers of cemented carbide, and cemented carbide milling teeth are embedded in the cemented carbide layers.

[0021] As an improvement of this utility model, an upper bushing is fitted on the outer periphery of the middle section of the reduced diameter section of the rotating shaft. The top of the upper bushing is supported below the inner step of the first inner step hole of the upper connector, and the bottom abuts against the top inner edge of the upper thrust bearing. A lower bushing is supported on the inner step of the rotating shaft housing. The top of the lower bushing is supported at the bottom of the lower thrust bearing, and the top of the lower thrust bearing abuts against the root shoulder of the reduced diameter section of the rotating shaft.

[0022] As a further improvement of this utility model, a central nozzle is installed at the lower end of the central hole of the rotating head, with the nozzle opening facing downwards.

[0023] As a further improvement of this utility model, the lower outer periphery of the rotating head is provided with a guide cone that is wider at the top and narrower at the bottom, and the lower ends of each of the hard alloy layers extend to the lower outer periphery of the guide cone.

[0024] As a further improvement of this utility model, the upper end of the central hole of the rotating shaft is provided with a hexagonal hole, and the lower part of the hexagonal hole is provided with a tool relief groove.

[0025] As a further improvement of this utility model, the side nozzles and tangential water holes are provided in three symmetrical configurations with the axis of the rotating head as the center.

[0026] As a further improvement of this utility model, the outer circumference of the large-diameter section of the rotating shaft is provided with helical blades, and the upper circumference of the central hole of the rotating shaft is provided with multiple diversion holes that communicate with the upper space of the helical blades; the lower space of the helical blades communicates with the central hole of the rotating shaft through multiple converging holes.

[0027] As a further improvement of this utility model, each of the diversion holes extends obliquely outward and downward and is evenly distributed along the same positive conical surface, and each of the confluence holes extends radially, or extends obliquely inward and downward and is evenly distributed along the same inverted conical surface.

[0028] As a further improvement of this utility model, the diversion holes and the confluence holes are each evenly distributed in 3-6 portions.

[0029] As a further improvement of this utility model, the helix angle of the helical blade is 15°-25°, and the height of the helical blade is 1 / 5-1 / 3 of the diameter of the large diameter section of the rotating shaft.

[0030] As a further improvement of this utility model, the lower outer periphery of the rotating head is symmetrically provided with three cutting planes, and the cemented carbide layer covers the arc surface between the cutting planes; the outlet of each of the tangential water holes is located on the corresponding cutting plane.

[0031] Compared with the prior art, the present invention has achieved the following beneficial effects: 1. Cleaning function: It combines mechanical wax scraping and spray washing sand removal functions. By reasonably arranging the nozzle position and water jet direction, it can efficiently remove the wax and sand in the tube column, ensuring that the tube column remains unobstructed during the wax scraping operation.

[0032] 2. Automatic rotation: The rotating head is driven to rotate automatically by the reaction force of the fluid, which does not require an additional power source, reduces energy consumption, and has the characteristics of simple structure, high efficiency and high reliability.

[0033] 3. Reduced damage: The rotating head is coated with hard alloy and scrapes the wax by rotating, minimizing damage to the inner wall of the tubing during the wax removal process.

[0034] 4. High Applicability: The modular design facilitates disassembly, replacement, and maintenance, making it suitable for cleaning different specifications of tubing strings. Operation is simple, maintenance is convenient, and safety and reliability are guaranteed. The scientifically designed structure effectively removes wax buildup and impurities from inside the tubing strings, making it suitable for various scenarios requiring pipeline cleaning, including oil and gas field development.

[0035] 5. Green and environmentally friendly: It does not use electric power or chemical agents, and has little impact on the environment. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are provided for reference and illustration only and are not intended to limit this utility model. Wherein:

[0037] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0038] Figure 2 for Figure 1 A bottom view;

[0039] Figure 3 for Figure 1 A cross-sectional view of the nozzle section;

[0040] Figure 4 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0041] In the diagram: 1. Upper connector;

[0042] 2. Rotating shaft; 2a. Hexagonal hole; 2b. Diverter hole; 2c. Helical blade; 2d. Manifold hole;

[0043] 3. Rotating shaft housing; 4. Upper shaft sleeve; 5. Upper thrust bearing; 6. Lower shaft sleeve; 7. Lower thrust bearing;

[0044] 8. Rotating head; 8a. Tangential water hole; 8b. Guide cone; 8c. Hard alloy layer;

[0045] 9. Side nozzle; 10. Center nozzle; Detailed Implementation

[0046] In the following description of this utility model, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not mean that the device must have a specific orientation.

[0047] To make the technical means, creative features, achieved objectives and effects of this utility model easier to understand, the present utility model will be further described below with reference to specific illustrations. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Example

[0049] like Figures 1 to 3 As shown, the rotary flushing wax removal and descaling tool of this utility model includes an upper connector 1, a rotating shaft 2, a rotating shaft housing 3, a rotating head 8, a side nozzle 9, and a central nozzle 10. The upper end of the upper connector 1 is provided with a tapered internal thread that connects to the upper tubing, and the lower end connects to the cleaning equipment, providing the necessary fluid power to the cleaning equipment. The lower end of the upper connector 1 is provided with an external thread that connects to and seals with the upper end of the rotating shaft housing 3. The lower end of the central hole of the upper connector 1 is provided with a first inner stepped hole and a second inner stepped hole of the upper connector that are successively reduced in diameter.

[0050] The middle section of the rotating shaft 2 is the large-diameter section, located within the inner cavity of the rotating shaft housing 3. The upper end of the rotating shaft 2 has a reduced-diameter section, the upper part of which is inserted into the second inner step hole of the upper connector with a clearance fit. An upper bushing 4 is fitted around the outer periphery of the middle section of the reduced-diameter section. The upper bushing 4 is located in the first inner step hole of the upper connector, with its top supported below the inner step of the first inner step hole. The bottom of the upper bushing 4 abuts against the top inner edge of the upper thrust bearing 5, achieving axial positioning of the upper part of the rotating shaft 2. The top outer edge of the upper thrust bearing 5 is located below the upper connector 1, and its bottom is supported on the shoulder of the reduced-diameter section of the rotating shaft 2.

[0051] The lower end of the rotating shaft 2 is provided with a reduced diameter section, and below the reduced diameter section is a threaded section. The lower end of the rotating shaft housing 3 is provided with a reduced diameter inner step. The reduced diameter section of the rotating shaft passes through the central hole of the inner step. A lower bushing 6 is supported on the inner step. The top of the lower bushing 6 is supported on the bottom of the lower thrust bearing 7. The top of the lower thrust bearing 7 abuts against the root shoulder of the reduced diameter section, thereby achieving axial positioning of the lower part of the rotating shaft 2 and enabling it to rotate relative to the upper connector 1 and the rotating shaft housing 3.

[0052] The lower threaded section of the rotating shaft is connected to the female thread at the upper end of the rotating head 8 and they are mutually sealed, resulting in a stable structure, convenient installation, and effective prevention of liquid leakage. A guide cone 8b is provided on the lower outer periphery of the rotating head 8 to facilitate tool downward movement. Multiple layers of cemented carbide 8c are clad on the lower outer wall of the rotating head 8. These cemented carbide layers 8c are evenly distributed around the outer periphery of the rotating head 8 and extend downward to the outer wall of the guide cone 8b. Carbide milling teeth are embedded within the cemented carbide layers 8c.

[0053] The outer periphery of the central hole of the rotating head 8 is connected to three tangential water holes 8a. The three tangential water holes 8a are open to the outside, and each of them has a side nozzle 9 with an outward-facing nozzle port. The jets from the three side nozzles 9 are ejected along the tangential direction of the nozzle. The rotating head 8 is driven to rotate at high speed by the fluid reaction force. The carbide milling teeth on the outer wall of the rotating head 8 efficiently mill and remove wax and impurities from the inner wall of the tubing.

[0054] The lower outer periphery of the rotating head 8 is symmetrically provided with three cutting planes, and a cemented carbide layer covers the arc surface between the cutting planes; the outlets of each tangential water hole and the side nozzle 9 are located on the corresponding cutting plane.

[0055] The upper connector 1, the rotating shaft 2 and the central hole of the rotating head 8 are connected. A central nozzle 10 is installed at the lower end of the central hole of the rotating head 8. The central nozzle 10 jets downwards, which facilitates the rise of the accumulated sand and wax residue below, which are then returned to the wellhead with the well fluid, thereby being cleaned and preventing the wax residue from being deposited again on the inner wall of the tubing string.

[0056] The upper end of the center hole of the rotating shaft 2 is provided with a hexagonal hole 2a, which facilitates the insertion of tools to tighten the rotating shaft 2. The lower end of the hexagonal hole 2a is provided with a tool relief groove.

[0057] The actual working steps of this rotary flushing wax and scale removal tool are as follows:

[0058] 1. Attach the rotary flushing wax removal and descaling tool to the bottom of the tubing column and lower it into the tubing that needs to be dewaxed.

[0059] 2. Once the fluid reaches a certain depth, the pump is turned on for circulation. The fluid enters the rotating head 8 through the central channel of the upper connector 1 and the rotating shaft 2. A portion of the fluid is ejected from each side nozzle 9. The water jet from the side nozzles 9 generates a reaction force that drives the rotating head 8 to rotate at high speed. The carbide milling teeth on the outer periphery of the rotating head 8 scrape the wax. While scraping the wax and removing the scale, the head is lowered to perform continuous wax removal operations. The high-pressure fluid ejected from the central nozzle 10 can simultaneously remove the accumulated sand and wax residue below.

[0060] 3. After cleaning, remove the tools and check their condition. If necessary, repeat the above steps. Example

[0061] The rest is the same as in Embodiment 1. A spiral blade 2c, integrally connected to the outer circumference of the large-diameter section of the rotating shaft 2, is provided. Multiple obliquely outward and downward-reaching diversion holes 2b are provided on the upper circumference of the central hole of the rotating shaft 2, communicating with the upper space of the spiral blade 2c. The lower space of the spiral blade 2c communicates with the central hole of the rotating shaft 2 through multiple radially extending or obliquely inward and downward-reaching diversion holes 2d. Three to six diversion holes 2b and diversion holes 2d are evenly distributed.

[0062] Part of the water flows downward along the central hole of the rotating shaft 2, while the other part enters the space where the helical blade 2c is located through the various branch holes 2b. When it reaches below the helical blade 2c, it returns to the central hole of the rotating shaft 2 through the various confluence holes 2d to continue flowing downward. Under the action of the water flow, the helical blade 2c drives the rotating shaft 2 to rotate in the same direction as the rotation of the rotating head 8 driven by the side nozzles 9. This creates a superposition, which together increases the rotational kinetic energy and speed of the rotating head 8, thereby further improving the wax scraping effect of the carbide grinding and milling teeth.

[0063] The helix angle of the helical blade 2c is 15°-25°, and the height of the helical blade 2c is 1 / 5-1 / 3 of the diameter of the large diameter section of the rotating shaft.

[0064] This rotary flushing wax and scale removal tool features a modular design and can be widely used for removing wax buildup on the inner walls of various production tubing sizes in oilfields. It effectively reduces maintenance costs while significantly improving scraping efficiency, achieving both economic and environmental benefits. Furthermore, this tool can also be applied to other areas requiring tubing cleaning, such as natural gas and geothermal wells. Its safety, efficiency, and reliability make it crucial for cleaning and maintaining various tubing inner walls and for unconventional resource development.

[0065] The above description is merely a preferred embodiment of the present utility model, showing and describing the basic principles, main features, and advantages of the present utility model. It is not intended to limit the scope of patent protection of the present utility model. Those skilled in the art should understand that the present utility model is not limited to the above embodiments. In addition to the above embodiments, the present utility model may have other implementations without departing from the spirit and scope of the present utility model. Various changes and improvements to the present utility model are also possible. All technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present utility model. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents. Technical features not described in the present utility model can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. A rotary rinsing tool for removing wax and scale, characterized in that, include: The upper connector (1) has a tapered internal thread at its upper end for connection with the upper pipe column, and an external thread at its lower outer circumference for connection with the rotating shaft housing (3); The rotating shaft (2) has an upper diameter reduction section at its upper end, a large diameter section in the middle, and a lower diameter reduction section and a lower threaded section at its lower end. The rotating shaft housing (3) is located on the outer periphery of the large diameter section of the rotating shaft, and the lower end is provided with a reduced diameter inner step of the rotating shaft housing; The rotating head (8) has a female thread at its upper end that connects to the lower thread section of the rotating shaft, and at least three tangential water holes (8a) are symmetrically provided on the outer periphery of the middle section of the central hole of the rotating head. Side nozzles (9) are respectively installed in the outer port of the tangential water hole (8a) of the rotating head (8); The upper connector (1), the rotating shaft (2) and the rotating head (8) are connected by a central hole. The lower outer wall of the rotating head (8) is covered with multiple cemented carbide layers (8c), and cemented carbide milling teeth are embedded in the cemented carbide layers (8c).

2. The rotary rinsing tool for removing wax and scale according to claim 1, characterized in that: An upper bushing (4) is fitted around the outer periphery of the middle section of the reduced diameter section of the rotating shaft. The top of the upper bushing (4) is supported below the inner step of the first inner step hole of the upper connector (1), and the bottom abuts against the top inner edge of the upper thrust bearing (5). A lower bushing (6) is supported on the inner step of the rotating shaft housing (3). The top of the lower bushing (6) is supported at the bottom of the lower thrust bearing (7), and the top of the lower thrust bearing (7) abuts against the root shoulder of the reduced diameter section of the rotating shaft.

3. The rotary rinsing tool for removing wax and scale according to claim 1, characterized in that: A central nozzle (10) is installed at the lower end of the central hole of the rotating head (8), with the nozzle (10) pointing downwards.

4. The rotary rinsing tool for removing wax and scale according to claim 1, characterized in that: The lower outer periphery of the rotating head (8) is provided with a guide cone (8b) that is wider at the top and narrower at the bottom, and the lower ends of each of the hard alloy layers (8c) extend to the lower outer periphery of the guide cone (8b).

5. The rotary rinsing tool for removing wax and scale according to claim 1, characterized in that: The upper end of the central hole of the rotating shaft (2) is provided with a hexagonal hole (2a), and the lower part of the hexagonal hole (2a) is provided with a tool relief groove.

6. The rotary rinsing tool for removing wax and scale according to claim 1, characterized in that: The lateral nozzle (9) and tangential water hole (8a) are provided in three symmetrical configurations with respect to the axis of the rotating head (8).

7. The rotary rinsing tool for removing wax and scale according to claim 1, characterized in that: The outer circumference of the large diameter section of the rotating shaft (2) is provided with a helical blade (2c). The upper circumference of the central hole of the rotating shaft is provided with multiple diversion holes (2b) that communicate with the upper space of the helical blade (2c). The lower space of the helical blade (2c) is connected to the central hole of the rotating shaft through multiple confluence holes (2d).

8. The rotary rinsing tool for removing wax and scale according to claim 7, characterized in that: Each of the diverting holes (2b) extends obliquely outward and downward and is evenly distributed along the same positive conical surface, and each of the converging holes (2d) extends radially or extends obliquely inward and downward and is evenly distributed along the same inverted conical surface.

9. A rotary rinsing tool for removing wax and scale according to claim 7, characterized in that: The diversion hole (2b) and the confluence hole (2d) are each evenly distributed in 3-6 portions.

10. A rotary rinsing tool for removing wax and scale according to claim 7, characterized in that: The helix angle of the helical blade (2c) is 15°-25°, and the height of the helical blade (2c) is 1 / 5-1 / 3 of the diameter of the large diameter section of the rotating shaft.

11. A rotary rinsing tool for removing wax and scale according to any one of claims 1 to 10, characterized in that: The lower outer periphery of the rotating head (8) is symmetrically provided with three cutting planes, and the cemented carbide layer (8c) covers the arc surface between the cutting planes; the outlet of each tangential water hole (8a) is located on the corresponding cutting plane.

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