Nano-coating high-strength anti-thread-gluing anti-eccentric-wear special threaded sleeve treated by special permeation layer

Abstract

The invention discloses a nano-coating high-strength anti-thread-gluing anti-eccentric-wear special threaded sleeve treated by a special seepage layer, and belongs to the technical field of sleeves, the nano-coating high-strength anti-thread-gluing anti-eccentric-wear special threaded sleeve comprises a sleeve and a sleeve coupling, high-performance air-tight seal threads are arranged on the left side and the right side of the sleeve coupling, the sleeve is in threaded connection with the sleeve coupling, a torque shoulder is fixedly connected in the sleeve coupling, and the torque shoulder is fixedly connected with the torque shoulder. An RFID intelligent chip is fixedly connected to the side end of the casing coupling, the RFID intelligent chip is located on the casing, the interior of the casing is coated with an anti-oil-dirt and anti-corrosion coating in a spraying mode, and a tracing two-dimensional code is arranged on the portion, close to the inner end face of the coupling, of the casing. A series of problems of using strength of the sleeve, high-performance sealing requirements of the screwed joint, corrosion resistance of the sleeve and eccentric wear in the pipe are solved.

Description

Technical Field

[0001] The invention relates to the technical field of casing, and more specifically to a special threaded casing with a nano-coating, high-strength, anti-sticking and anti-eccentric wear, and special infiltration layer treatment. Background Art

[0002] Oil casing is a steel pipe used to support the well wall of oil and gas wells to ensure that the drilling process and subsequent oil and gas production process can proceed smoothly. It is a key part of oil drilling equipment and must withstand huge pressure, tension and various complex formation forces.

[0003] There are mainly three technical requirements:

[0004] 1. Strength requirements: Oil casing needs to have sufficient strength to withstand the pressure of the well wall, the collapse pressure of the formation, and the tensile and compressive forces during the drilling process. For example, in deep or ultra-deep wells, the casing must withstand internal pressure and external extrusion pressure of up to tens of megapascals or even hundreds of megapascals, so its mechanical performance indicators such as yield strength and tensile strength must meet the corresponding requirements.

[0005] 2. Anti-corrosion performance: Due to the complex environment of oil and gas wells, oil casing may be exposed to various corrosive media, such as hydrogen sulfide, carbon dioxide, formation water, etc. Hydrogen sulfide can cause sulfide stress corrosion cracking of steel, carbon dioxide can cause carbonic acid corrosion, and formation water may contain various salts, leading to electrochemical corrosion. Therefore, oil casing needs to have good corrosion resistance, which can be achieved by using corrosion-resistant alloy materials or surface treatment.

[0006] 3. Sealing requirements: The connection between casings and the connection between casings and wellhead devices must ensure good sealing. If the sealing is not good, oil and gas will leak, which will not only waste resources, but also bring safety hazards and environmental pollution. Usually, special threaded connection methods are used, such as API standard threads or specially designed airtight threads to ensure the sealing effect.

[0007] API standard threads have the following defects:

[0008] 1. Defects in sealing performance

[0009] 1.1 Thread gap problem: After API standard threads are connected, there are certain gaps due to the characteristics of their thread structure. Under high pressure, such as in deep oil well mining, oil and gas may leak through these gaps. For example, when the internal pressure of the oil well reaches tens of MPa, the risk of such leakage will increase significantly. These gaps are caused by the thread processing accuracy and matching method. The design of API threads focuses more on connection strength and processing convenience, and does not have a very tight sealing design like some special airtight threads.

[0010] 1.2 Insufficient sealing durability: As the use time of oil wells increases, the underground environment becomes complex and changeable, such as temperature fluctuations, stratum movement and other factors, which will cause the sealing performance of API standard threads to gradually decline. For example, in some oil wells in areas with relatively active geological activities, slight movement of the stratum may loosen the threads of the casing connection, thereby destroying the original sealing structure.

[0011] 2. Defects in connection strength

[0012] 2.1 Stress concentration problem: API standard threads are prone to stress concentration at the root and top. When subjected to large tension or pressure, the stress in these parts may exceed the yield strength of the material, causing thread damage. For example, during the process of drilling, when the casing is subjected to large tensile force, stress concentration at the root of the thread may cause cracks to form and expand, thereby affecting the integrity of the casing connection.

[0013] 2.2 Limited torsion resistance: During the installation process, the casing needs to be connected by threaded rotation. API standard threads have certain limitations in torsion resistance. When excessive torque is applied, thread slippage may occur. For example, if the torque is not precisely controlled during installation, when the torque exceeds a certain limit, the friction between the threads cannot be tolerated, which will cause slippage and make the casing connection fail.

[0014] 3. Defects in processing and quality control

[0015] 3.1 Differences in processing accuracy affect fit: When different processing manufacturers produce API standard threaded casing, due to differences in equipment accuracy, process level and other factors, there may be certain deviations in thread size and shape. This deviation will affect the fit accuracy between casings and reduce the connection quality.

[0016] 3.2 Quality inspection is difficult: Due to the structural characteristics of API standard threads, it is difficult to detect some internal defects, such as micro cracks and internal stress concentration. Traditional inspection methods may not be able to fully detect these potential quality problems. For example, it is difficult to find micro cracks inside the root of the thread using conventional appearance inspections. Advanced non-destructive testing technologies such as ultrasonic testing are required, but these technologies are expensive to apply and complex to operate.

[0017] In summary, we propose a special threaded casing with a nano-coating, high strength, anti-galling and anti-eccentric wear special infiltration layer treatment. Summary of the invention

[0018] Technical issues to be solved

[0019] In view of the problems existing in the prior art, the purpose of the present invention is to provide a special threaded casing with a nano-coating, high-strength, anti-galling and anti-eccentric wear special infiltration layer treatment. The present invention provides a high-performance air-tight threaded casing with a nano-coating, high-strength, anti-galling and anti-eccentric wear special infiltration layer treatment, which solves a series of problems such as the casing's use strength, high-performance sealing requirements for threaded joints, casing corrosion resistance and eccentric wear inside the pipe.

[0020] Technical Solution

[0021] To solve the above problems, the present invention adopts the following technical solutions:

[0022] The special threaded casing with nano coating, high strength, anti-sticking and anti-eccentric wear, special infiltration layer treatment, includes a casing and a casing coupling. The left and right sides of the casing coupling are provided with high-performance airtight sealing threads. The casing and the casing coupling are threadedly connected. The casing coupling is fixedly connected with a torque shoulder. The side end of the casing coupling is fixedly connected with an RFID smart chip, and the RFID smart chip is located on the casing. The casing is sprayed with an anti-oil and anti-corrosion coating, and the inner end face of the casing near the coupling is provided with a traceability QR code.

[0023] As a preferred solution of the present invention, both ends of the inner wall surface of the casing coupling are expanded, and the outer wall surface of the connecting end of the casing and the casing coupling is contracted.

[0024] As a preferred solution of the present invention, the coating includes a tube inner permeation layer thickness and a tube inner wall surface permeation layer thickness, and the tube inner permeation layer thickness is arranged inside the tube inner wall surface permeation layer thickness.

[0025] As a preferred solution of the present invention, a clamping groove is provided on both sides of the left and right sides of the torque shoulder, a groove is provided on the sleeve, a spring is fixedly connected in the groove, a clamping block is fixedly connected to the other end of the spring, the end of the clamping block is semicircular, and the clamping block is clamped in the clamping groove.

[0026] As a preferred solution of the present invention, the threaded connection of the sleeve coupling is provided with an external stopper, a magnet block is embedded in the external stopper, the position of the magnet block corresponds to that of the clamping block, one end of the clamping block close to the clamping slot is made of a magnet, and the ends of the magnet block and the clamping block close to each other are magnets with the same poles.

[0027] As a preferred solution of the present invention, a plurality of groups of fitting blocks are installed at the end of the external stopper, and the fitting blocks are kept in fit with the outer wall surface of the sleeve.

[0028] As a preferred solution of the present invention, a thread groove is provided at the side end of the casing coupling, a threaded ring is threadedly connected in the thread groove, a rubber ring block is fixedly connected in the center position of the threaded ring, the rubber ring block is wear-resistant and high-temperature resistant rubber, and the cross-section of the rubber ring block is triangular.

[0029] Beneficial Effects

[0030] Compared with the prior art, the advantages of the present invention are:

[0031] (1) In this solution, the casing coupling is flush with the torque shoulder. The casing coupling adopts a high-performance air-tight thread (DSP-T6) structure to increase the contact between the torque shoulder and the pipe end. The main sealing surfaces of the inner and outer joints produce a conical sealing effect (angle of 20 degrees) through interference fit, and the auxiliary sealing surface produces a contact seal (angle of -15 degrees). When the joint is in use, the inner wall of the entire pipe body is completely flush, ensuring that the inner wall of the casing will not be impact-worn when the subsequent oil pipe is lowered and replaced.

[0032] (2) In this solution, when the casing coupling is rotated so that the casing coupling and the casing thread are connected together, the clamping block will move toward the inner side of the groove due to the squeezing force of the inner wall of the casing. When the position of the clamping block corresponds to the slot, the rebound force of the spring will push the clamping block into the inside of the slot, completing the clamping connection between the two and further increasing the stability of the connection between the two.

[0033] (3) In this solution, when the casing is connected to the casing coupling, the external stopper is rotated to move the external stopper to the side close to the casing. At this time, the external stopper will cover the connection between the casing and the casing coupling to protect the connection area between the two. When disassembly is required, the external stopper is rotated to move the magnet block to the area corresponding to the position of the card block. At this time, due to the magnetic force, the two correspond to each other and the card block will be repelled into the inside of the groove, causing the card block and the card slot to lose the card connection state. At this time, the casing and the casing coupling are disassembled for easy disassembly.

[0034] (4) In this scheme, the nano-coating has a high-strength anti-sticking and anti-biased wear special infiltration layer to treat a high-performance airtight threaded casing. When the other end of the casing coupling is connected to the pipeline, the threaded ring can be rotated to adjust the length of the connection end between the casing coupling and the external pipeline, so as to be suitable for different environments. At the same time, a deformable rubber ring block is added. When the external pipeline is connected to the casing coupling, the rubber ring block will remain in contact with the outer wall of the external pipeline, further increasing the sealing between the two. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0036] Figure 2 It is a schematic diagram of the thickness of the infiltration layer inside the casing and the pipe body and the thickness of the infiltration layer on the inner wall of the pipe body of the present invention;

[0037] Figure 3 For the present invention Figure 1 A local enlarged schematic diagram of point A in the figure.

[0038] Description of the numbers in the figure:

[0039] 1. Casing; 2. Casing coupling; 3. Torque shoulder; 4. RFID smart chip; 5. Rubber ring block; 6. Coating; 7. Thickness of the inner infiltration layer of the pipe body; 8. Thickness of the infiltration layer on the surface of the inner wall of the pipe body; 9. External stopper; 10. Magnet block; 11. Groove; 12. Card slot; 13. Spring; 14. Card block; 15. Thread groove; 16. Thread ring; 17. Fitting block. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example:

[0042] See also Figure 1-3 , nano-coating high-strength anti-sticking and anti-eccentric wear special infiltration layer treatment special threaded casing, including casing 1 and casing coupling 2, casing coupling 2 has high-performance airtight threads on both sides, casing 1 and casing coupling 2 are threadedly connected, casing coupling 2 is fixedly connected with a torque shoulder 3, the side end of casing coupling 2 is fixedly connected with an RFID smart chip 4, RFID smart chip 4 is located on casing 1, anti-oil and anti-corrosion coating 6 is sprayed inside casing 1, and a traceability QR code is provided on the inner end face of casing 1 near the coupling.

[0043] In this embodiment, when the casing 1 is connected to the casing coupling 2, the casing coupling 2 is flush with the torque shoulder 3. The casing coupling 2 adopts a high-performance gas seal (DSP-T6) structure to increase the contact between the torque shoulder 3 and the pipe end to generate contact pressure for sealing. When the joint is used, the inner wall of the entire pipe body is completely flush. During the reciprocating motion of the sucker rod production operation, the rod pipe does not suffer from impact wear.

[0044] Specifically, both ends of the inner wall surface of the casing coupling 2 are expanded, and the outer wall surface of the connecting end of the casing 1 and the casing coupling 2 is contracted.

[0045] In this embodiment, both ends of the inner wall surface of the casing coupling 2 are expanded, and the outer wall surface of the connecting end of the casing 1 and the casing coupling 2 is contracted.

[0046] Specifically, the coating 6 includes a tube body inner permeation layer thickness 7 and a tube body inner wall surface permeation layer thickness 8 , and the tube body inner permeation layer thickness 7 is arranged on the inner side of the tube body inner wall surface permeation layer thickness 8 .

[0047] In this embodiment, the coating 6 includes a tube body internal permeation layer thickness 7 and a tube body inner wall surface permeation layer thickness 8 , and the tube body internal permeation layer thickness 7 is arranged inside the tube body inner wall surface permeation layer thickness 8 .

[0048] Specifically, a slot 12 is provided on both sides of the torque shoulder 3, a groove 11 is provided on the sleeve 1, a spring 13 is fixedly connected in the groove 11, and a block 14 is fixedly connected to the other end of the spring 13. The end of the block 14 is semicircular, and the block 14 is engaged with the slot 12.

[0049] In this embodiment, due to the squeezing pressure of the inner wall of the sleeve 1, the block 14 will move toward the inner side close to the groove 11. When the position of the block 14 corresponds to the slot 12, due to the rebound force of the spring 13, the block 14 will be pushed into the inside of the slot 12 to complete the clamping connection between the two, thereby further increasing the stability of the connection between the two.

[0050] Specifically, the threaded connection of the sleeve coupling 2 is provided with an external stopper 9, in which a magnet block 10 is embedded. The position of the magnet block 10 corresponds to that of the clamping block 14. The end of the clamping block 14 close to the clamping groove 12 is made of a magnet, and the ends of the magnet block 10 and the clamping block 14 close to each other are magnets with the same poles.

[0051] In this embodiment, when the sleeve 1 is connected to the sleeve coupling 2, the external stopper 9 is rotated so that the external stopper 9 moves to the side close to the sleeve 1. At this time, the external stopper 9 will block the connection between the sleeve 1 and the sleeve coupling 2 to protect the connection area between the two. When disassembly is required, the external stopper 9 is rotated so that the magnet block 10 moves to the area corresponding to the position of the block 14. At this time, due to the magnetic force, the two correspond and the block 14 will be repelled into the inside of the groove 11, so that the block 14 and the slot 12 lose the clamping state. At this time, the sleeve 1 and the sleeve coupling 2 are disassembled.

[0052] Specifically, a plurality of groups of fitting blocks 17 are installed at the end of the external stopper 9 , and the fitting blocks 17 are fitted to the outer wall surface of the sleeve 1 .

[0053] In this embodiment, a plurality of groups of fitting blocks 17 are installed at the end of the external stopper 9 , and the fitting blocks 17 are kept in contact with the outer wall surface of the sleeve 1 .

[0054] Specifically, a thread groove 15 is formed at the side end of the casing coupling 2, a threaded ring 16 is threadedly connected to the threaded groove 15, a rubber ring block 5 is fixedly connected to the threaded ring 16 at the center position, the rubber ring block 5 is wear-resistant and high-temperature resistant rubber, and the cross-section of the rubber ring block 5 is triangular.

[0055] In this embodiment, when the other end of the casing coupling 2 is exposed to the pipeline, the threaded ring 16 can be rotated to cover and adjust the length of the connection end between the casing coupling 2 and the external pipeline, so as to be suitable for different environments. At the same time, a deformable rubber ring block 5 is added. When the external pipeline is connected to the casing coupling 2, the rubber ring block 5 will keep in contact with the outer wall surface of the external pipeline, further increasing the sealing between the two.

[0056] This solution provides DSP-T6 casing dimensions and tolerances according to requirements:

[0057]

[0058] Table 1

[0059] The threaded connection, thread type, size and limit deviation of the threaded casing shall comply with the requirements of API Spec5B.DSP-T6 high performance gas-sealing thread inspection standard;

[0060] Mechanical properties of casing: The outer surface of the casing needs to be surface hardened as a whole. The outer surface of the casing is heated to Ac3 (hypoeutectoid steel) or Ac1 (hypereutectoid steel) or above by a special heating method, and then cooled quickly. The surface of the casing undergoes a martensitic phase transformation to form a hardened layer. The fatigue strength of the tube body is significantly improved, its notch sensitivity is reduced, and its deformation resistance, compression resistance, bending resistance, creep resistance and strength are greatly improved;

[0061] Its mechanical properties, flattening force and casing surface hardening layer should meet the requirements of Table 2 below.

[0062]

[0063] Table 2

[0064] Casing anti-sticking treatment: Casing couplings are surface treated with nano-polymers to improve the anti-sticking ability of threads and ensure that the casing threads can withstand 5 times of make-up and make-down without sticking. The make-up and make-down test method is carried out in accordance with API 5C5.

[0065] The mechanical properties of the coupling shall meet the requirements of the following table:

[0066]

[0067] Table 3 RFID radio frequency chip 4 performance indicators:

[0068]

[0069] Table 4

[0070] The main function of the smart chip is to store and preserve the production information, numbering and warehousing management of each casing, realize the production, storage, use, recycling, scrapping and logistics management of the casing, and facilitate classification management.

[0071] Each user's warehouse logistics management center is equipped with six sets of handheld RFID readers, whose functions include the following parts:

[0072] 1. After the casing is produced, the information on the casing smart chip can be written through the radio frequency reader, including: product ID, all traceable information of each production process.

[0073] 2. When purchasing and storing, the warehouse staff can use the reader to read all the logistics information of the casing in, out or in use, and classify and manage and use it according to the storage information of the casing.

[0074] 3. The handheld RF reader / writer system is mainly composed of a microprocessor, a memory, a RF reading / writing module, a power amplifier and an antenna; the handheld RF reader / writer is used in conjunction with the smart chip at the coupling end of the casing, and the information inside the RF smart chip can be read, written and operated through the principle of radio frequency work.

[0075] Supporting management software:

[0076] Each user's logistics and warehousing management center is equipped with a set of management software, developed using Microsoft language. Each management terminal has management software, using Microsoft Access or SQL Server database, which is simple and easy to operate, and convenient for users to store and manage the information of the casing of the logistics and warehousing under their jurisdiction. The software is modularly designed, fully considering user usability, and has the characteristics of simple operation, practical functions, and friendly human-computer interface.

[0077] The inner wall of the casing 1 is subjected to the zinc / boronizing / PIP process;

[0078] The sherardizing process is a process in which the sherardizing agent and the casing 1 are placed in a sherardizing furnace, heated to 400 degrees, and active zinc atoms penetrate into the casing from the surface to the inside.

[0079] The boronizing process mainly adopts the solid boronizing process, and a certain content of B4C (boronizing source) + KBF4 (accelerator) + SiC (diluent) is used to realize the boronizing layer through related processes. The main advantages of the boronizing process are to reduce the processing temperature and shorten the processing time.

[0080] Controlled ion penetration technology uses a composite process to penetrate nitrogen, carbon, oxygen and rare earth elements into the ferrous metal matrix, forming a controllable multi-layer anti-corrosion and wear-resistant layer on the product surface, further improving its corrosion resistance and wear resistance. It is also a new surface modification technology for steel parts with lower processing temperature and more environmentally friendly processing process.

[0081] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and improved concepts of the present invention within the technical scope disclosed by the present invention, and they should be covered by the protection scope of the present invention.

Claims

1. A special threaded casing with a nano-coating, high strength, anti-galling and anti-eccentric wear, and a special infiltration layer treatment, comprising a casing (1) and a casing coupling (2), characterized in that: The left and right sides of the casing coupling (2) are provided with high-performance air-tight threads, the casing (1) and the casing coupling (2) are threadedly connected, a torque shoulder (3) is fixedly connected inside the casing coupling (2), an RFID smart chip (4) is fixedly connected to the side end of the casing coupling (2), the RFID smart chip (4) is located on the casing (1), an anti-oil and anti-corrosion coating (6) is sprayed inside the casing (1), and a traceability QR code is provided on the inner end surface of the casing (1) near the coupling.

2. The nano-coated high-strength anti-galling and anti-eccentric wear special infiltration layer treated special threaded casing according to claim 1, characterized in that: Both ends of the inner wall surface of the casing coupling (2) are in a flared shape, and the outer wall surface of the connecting end of the casing (1) and the casing coupling (2) is in a contracted shape.

3. The nano-coated high-strength anti-galling and anti-eccentric wear special infiltration layer treated special threaded casing according to claim 2, characterized in that: The coating (6) comprises a pipe body internal permeation layer thickness (7) and a pipe body internal wall surface permeation layer thickness (8), wherein the pipe body internal permeation layer thickness (7) is arranged on the inner side of the pipe body internal wall surface permeation layer thickness (8).

4. The nano-coated high-strength anti-galling and anti-eccentric wear special infiltration layer treated special threaded casing according to claim 3, characterized in that: The torque shoulder (3) is provided with a clamping groove (12) on both left and right sides, the sleeve (1) is provided with a groove (11), a spring (13) is fixedly connected in the groove (11), a clamping block (14) is fixedly connected to the other end of the spring (13), the end of the clamping block (14) is semicircular, and the clamping block (14) is clamped with the clamping groove (12).

5. The nano-coated high-strength anti-galling and anti-eccentric wear special infiltration layer treated special threaded casing according to claim 4, characterized in that: The sleeve coupling (2) is threadedly connected to an external stopper (9), a magnet block (10) is embedded in the external stopper (9), the magnet block (10) corresponds to the position of the clamping block (14), one end of the clamping block (14) close to the clamping groove (12) is made of a magnet, and the ends of the magnet block (10) and the clamping block (14) close to each other are magnets with the same pole.

6. The nano-coated high-strength anti-galling and anti-eccentric wear special infiltration layer treated special threaded casing according to claim 5, characterized in that: A plurality of groups of fitting blocks (17) are installed at the end of the external stopper (9), and the fitting blocks (17) are kept in contact with the outer wall surface of the sleeve (1).

7. The nano-coated high-strength anti-galling and anti-eccentric wear special infiltration layer treated special threaded casing according to claim 6, characterized in that: A thread groove (15) is formed at the side end of the casing coupling (2), a thread ring (16) is connected to the inner thread of the thread groove (15), a rubber ring block (5) is fixedly connected to the inner center of the thread ring (16), the rubber ring block (5) is made of wear-resistant and high-temperature resistant rubber, and the cross section of the rubber ring block (5) is triangular.

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