Multi-section anticorrosion coating and plating layer of oil pumping polished rod

Abstract

The utility model discloses a multi -section anticorrosion coating plating layer pumping light rod, including upsetting end, pole body and not upsetting end, pole body includes base body section, first nickel plating layer section, corrosion -resistant alloy coating section and second nickel plating layer section in proper order, first nickel plating layer section and corrosion -resistant alloy coating section junction are equipped with first transition section, and second nickel plating layer section and corrosion -resistant alloy coating section junction are equipped with second transition section, base body section surface coats rust -resistant paint, the utility model discloses a coating and plating layer are combined, and the convenient preparation process of nickel plating layer is used at both ends to solve the difficulty of nickel -based alloy coating thermal spraying -remelting complex preparation process, through being located at the different position of pumping light rod base body surface, using different coating process and plating process preparation different coating and plating layer, to better improve the wear -resistant corrosion -resistant performance of pole body whole.

Description

Technical Field

[0001] This utility model belongs to the field of artificial oil extraction equipment, specifically relating to a multi-section anti-corrosion coated sucker rod. Background Technology

[0002] Artificial oil recovery is the primary method of oilfield production, and the service life of the oil recovery components directly affects the normal production of the oil well. In artificial oil recovery, the sucker rod is a key component connecting the pumping unit and the pumping pump. The polished sucker rod, the first sucker rod, is typically 7-10 meters long. During oil recovery, the polished sucker rod is subjected to the combined effects of its own weight, the weight of the well fluid, and localized bending caused by external factors, making its mechanical properties crucial. In particular, the corrosive nature of the well fluid makes corrosion resistance another important performance characteristic of the polished sucker rod.

[0003] Among existing sucker rod products, steel is the most widely used material. To improve the wear and corrosion problems on the surface of sucker rods, a nickel-based alloy coating is typically prepared by thermal spraying and remelting on the surface of low-alloy steel or other steel sucker rod blanks. The excellent corrosion resistance of the nickel-based alloy coating itself can effectively improve the corrosion performance of the sucker rod, while the high surface hardness of the nickel-based alloy coating can significantly improve the wear resistance of the sucker rod. The process of preparing the nickel-based alloy coating on the surface of the sucker rod blank involves a high-temperature process of thermal spraying and remelting, which is equivalent to heat-treating the sucker rod substrate. On the one hand, since both the upset and un-upset ends of the sucker rod substrate are threaded, heat treatment of the threaded surfaces during coating preparation can cause deformation. On the other hand, the outer diameter of the rod near the upset end is significantly larger than that of the middle section. During the thermal spraying and remelting of the alloy coating, due to limitations in heating uniformity and the diameter of the induction heating coil, the nickel-based alloy coating cannot actually cover all sections of the rod near the upset end. Therefore, in existing alloy-coated sucker rods, there are areas adjacent to the upset and un-upset ends that are not covered by the alloy coating. This prevents effective improvement in the wear and corrosion resistance of both the head and tail sections of the sucker rod. Therefore, the overall wear and corrosion resistance of the sucker rod needs further improvement, and novel sucker rods require further development. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art by providing a multi-segment anti-corrosion coated sucker rod that combines alloy coating and plating. By employing different coating and plating processes at different locations on the sucker rod substrate surface to prepare different coatings and platings, the wear and corrosion resistance of the sucker rod can be further improved.

[0005] The present invention relates to a multi-segment anti-corrosion coated oil sucker rod, which adopts the following main technical solutions: The rod includes an upset end, a body, and an un-upset end. From the un-upset end to the upset end, the body sequentially includes a base section, a first nickel-plated section, a corrosion-resistant alloy coating section, and a second nickel-plated section. A first transition section with a length not exceeding 10 mm is provided at the junction of the first nickel-plated section and the corrosion-resistant alloy coating section, and a second transition section with a length not exceeding 10 mm is provided at the junction of the second nickel-plated section and the corrosion-resistant alloy coating section. The nickel plating in the first transition section is located on the surface of the corrosion-resistant alloy coating, and the nickel plating in the second transition section is located on the surface of the corrosion-resistant alloy coating. The surface of the base section is coated with anti-rust paint, and the anti-rust paint covers the first nickel-plated section with a length not exceeding 10 mm at the junction with the first nickel-plated section.

[0006] Furthermore, the coating thickness of the corrosion-resistant alloy coating section is 0.2-0.5 mm.

[0007] Furthermore, the surface roughness of the corrosion-resistant alloy coating segment is 0.2-0.8 micrometers.

[0008] Furthermore, the length of the base segment is 0.5 to 1 meter.

[0009] Furthermore, the length of the first nickel-plated section does not exceed 0.5 meters.

[0010] Furthermore, the nickel plating of the second nickel plating section extends to the unthreaded area of ​​the upset end.

[0011] Furthermore, the coating thickness of the first nickel plating section and the second nickel plating section is 10-50 micrometers.

[0012] Furthermore, the alloy coating of the corrosion-resistant alloy coating section has a microhardness of 300-500 HV when tested under a 200 g load.

[0013] Furthermore, the outer diameters of the substrate section, the first nickel plating section, the corrosion-resistant alloy coating section, and the second nickel plating section are the same.

[0014] Furthermore, the first nickel plating section and the second nickel plating section are uniformly deposited on the outer surface of the bare rod through chemical nickel plating, and the corrosion-resistant alloy coating section is uniformly welded to the outer surface of the rod through thermal spraying and remelting.

[0015] Compared with the prior art, the multi-segment anti-corrosion coated oil sucker rod of this utility model application has the following advantages: First, this utility model combines coating and plating, and adopts a multi-segment novel structure for different positions of the sucker rod. It makes full use of the advantages of nickel plating and nickel-based alloy coating in terms of performance and preparation process. The alloy coating in the middle of the rod is prepared by thermal spraying-remelting process at high temperature, while the nickel plating is obtained by chemical plating treatment at no more than 100°C at both ends of the rod. The combination of the two achieves effective coverage of the coating on the surface of the sucker rod substrate, which effectively improves the wear and corrosion resistance of the sucker rod.

[0016] Secondly, this invention employs a structure combining an uncoated substrate section and a coated section on the rod body near the un-upset end of the sucker rod, replacing the existing hard alloy coating. This avoids premature fatigue failure of the hard alloy coating during the rod clamping process. Therefore, this invention improves the fatigue performance near the rod clamp while maximizing the improvement of the rod's wear and corrosion resistance.

[0017] Third, this utility model has a transition section specially provided at the junction of the alloy coating and the nickel plating on both ends of the sucker rod. In particular, the alloy coating is covered by the nickel plating in the transition section, so that the edge of the alloy coating is further effectively connected, avoiding the exposure of the substrate, thereby significantly improving the wear and corrosion resistance of the sucker rod. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the oil extraction rod of this utility model.

[0019] Figure 2 This utility model presents schematic diagrams of the base structure at different positions of the oil sucker rod. Detailed Implementation

[0020] See Figure 1 and Figure 2This utility model discloses a multi-segment anti-corrosion coated oil extraction rod 1, comprising an upset end 10, a rod body, and an un-upset end 11. From the un-upset end 11 to the upset end 10, the rod body sequentially includes a base segment 12, a first nickel-plated segment 13, a corrosion-resistant alloy coating segment 14, and a second nickel-plated segment 15. The boundary between the second nickel-plated segment 15 and the upset end 10 is a cross-section with an increasing diameter, meaning the outer diameter of the second nickel-plated segment 15 is uniform and consistent with the outer diameter of the corrosion-resistant alloy coating segment 14. A first transition segment 131 with a length not exceeding 10 mm is provided at the junction of the first nickel-plated segment 13 and the corrosion-resistant alloy coating segment 14, and a first transition segment 131 with a length not exceeding 10 mm is provided at the junction of the second nickel-plated segment 15 and the corrosion-resistant alloy coating segment 14. The second transition section 151 is mm in diameter. The nickel plating in the first transition section 131 is located on the surface of the corrosion-resistant alloy coating. The substrate section 12 is coated with anti-rust paint, and the anti-rust paint covers a nickel plating layer with a length not exceeding 10 mm at the junction with the first nickel plating section. The above technical solution of the present invention adopts a multi-segment novel structure for different positions of the sucker rod, making full use of the advantages of nickel plating and nickel-based alloy coating in terms of performance and preparation process. The alloy coating in the middle of the rod is prepared at high temperature by thermal spraying-remelting process, while the nickel plating is obtained at both ends of the rod by chemical plating. The combination of the two achieves effective coverage of the coating on the surface of the sucker rod substrate, thereby improving its wear and corrosion resistance.

[0021] Furthermore, the coating thickness of the corrosion-resistant alloy coating section 14 is 0.2-0.5 mm.

[0022] Furthermore, the surface roughness of the corrosion-resistant alloy coating segment 14 is 0.2-0.8 micrometers.

[0023] Furthermore, the base section 12 is 0.5 to 1 meter long, leaving space for the mounting of the bare rod clip.

[0024] Furthermore, the length of the first nickel-plated section 13 does not exceed 0.5 meters. This design takes into account both the wear and corrosion resistance of the bare rod body and provides a new position for the possible mounting of the bare rod clip.

[0025] Furthermore, the nickel plating of the second nickel plating segment 15 extends to the unthreaded area of ​​the upset end, thereby improving the wear and corrosion resistance of the upset end.

[0026] Furthermore, the coating thickness of the first nickel plating segment 13 and the second nickel plating segment 15 is 10-50 micrometers.

[0027] Furthermore, the alloy coating of the corrosion-resistant alloy coating section 14 has a microhardness of 300-500 HV when tested under a 200 g load.

[0028] Furthermore, the outer diameters of the substrate section 12, the first nickel-plated section 13, the corrosion-resistant alloy coating section 14, and the second nickel-plated section 15 are the same. The first nickel-plated section 13 is provided between the substrate section 12 and the corrosion-resistant alloy coating section 14. This first nickel-plated section replaces the hard alloy coating at the corresponding position in the prior art, ensuring timely clamping of the guide rod at this position. It also prevents premature fatigue failure of the hard alloy coating during guide rod clamping, improving fatigue performance near the guide rod clamp.

[0029] To better illustrate the technical solution of this utility model, the following description uses a 25.4 mm diameter 30CrMo steel-based sucker rod commonly found in oil fields as an example.

[0030] The first and second nickel-plated sections of the sucker rod are uniformly deposited on the outer surface of the rod body through chemical plating, with nickel as the main component. The corrosion-resistant alloy coating section is uniformly welded to the outer surface of the rod body through thermal spraying and remelting. The powder composition of the corrosion-resistant alloy coating is NiCrBSi self-fluxing alloy powder, with the following composition by mass percentage: C: 0%~0.40%, Si: 2.0%~3.0%, B: 2.0%~3.0%, Cr: 7.0~10.0%, Cu: 7.0%~12.0%, Fe≤5.0%, and the balance being nickel.

[0031] A corrosion-resistant alloy coating is prepared using a mature thermal spraying-remelting production line for the alloy coating of the sucker rod. The first and second nickel plating sections are prepared using a chemical plating process. In this embodiment, the nickel plating is a partially phosphorus-containing nickel plating with better wear and corrosion resistance, and a mature Ni-P chemical plating process is employed. The processing steps include: (1) The oil sucker rod substrate blank is subjected to surface chemical degreasing treatment, and is thoroughly brushed and degreased multiple times using high-temperature alkaline solution at 70℃~80℃. (2) The base of the sucker rod is sanded at different locations as needed. During the sanding process, the base of the sucker rod is rotated on a fixed axis to ensure that its outer diameter reaches the required size. See [reference needed]. Figure 2This results in the outer diameters of the substrate segment 12, the first nickel-plated substrate segment 130, and the corrosion-resistant alloy coating substrate segment 140 decreasing sequentially. The outer diameters of the first nickel-plated substrate segment 130 and the second nickel-plated substrate segment 150 are the same. The transition 1310 between the first nickel-plated substrate segment 130 and the corrosion-resistant alloy coating substrate segment 140 is treated with a gradual diameter change using an arc transition. Similarly, the transition 1510 between the second nickel-plated substrate segment 150 and the corrosion-resistant alloy coating substrate segment 140 is treated with a gradual diameter change using an arc transition. The specific outer diameter of the substrate at different locations is determined based on the thickness of the nickel plating and the corrosion-resistant alloy coating. This ensures that after subsequent steps to prepare nickel plating with a thickness of 10-50 micrometers and corrosion-resistant alloy coating with a thickness of 0.2-0.5 mm, the outer diameter of the entire sucker rod remains consistent at different locations. (3) The sucker rod is kept rotating at a low speed around the axis. The corrosion-resistant alloy coating section in the middle of the sucker rod substrate is preheated with a medium frequency induction heating coil of 200℃~300℃. After adjusting the gas pressure of oxygen, acetylene, compressed air and argon in the thermal spraying equipment, the nickel-based alloy powder is melted at high temperature and then the nickel-based alloy coating is thermally sprayed at the corresponding position of the corrosion-resistant alloy coating section. (4) The hot sprayed alloy coating on the surface of the sucker rod is remelted using a medium frequency induction heating coil. The remelting temperature is 930℃~980℃. During the remelting process, the sucker rod is in a rotating state, and the alloy coating surface is made to show a mirror effect. (5) Polish the cooled alloy-coated sucker rod to obtain an alloy coating with a thickness of 0.2-0.5 mm and a surface roughness of 0.2-0.8 micrometers; considering that polishing in this step will reduce the outer diameter of the rod corresponding to the alloy coating, an appropriate allowance can be left in the preparation of the alloy coating. (6) The first nickel plating layer substrate 130 and the second nickel plating layer substrate 150 at both ends of the sucker rod are subjected to nickel-phosphorus plating process by chemical plating. The process involves degreasing, water washing, activation, chemical plating, water washing and drying. The sucker rod substrate parts corresponding to the first nickel plating layer and the second nickel plating layer are placed in the corresponding sealing tank after being sealed in sections. The nickel plating solution is placed in the sealing tank so that the sucker rod substrate is immersed in it. During this process, the alloy coating section 14 and the substrate 12 prepared in the previous step are isolated outside the sealing tank. The plating solution and process in the sealed tank are determined with reference to conventional parameters in existing technologies. The plating solution composition includes: 24~26 g / L nickel sulfate, 28~30 g / L sodium hypophosphite, 22~24 g / L complexing agent, 3~5 g / L suspending agent, 2~3 ppm stabilizer, pH value 4~6, temperature 70~90℃, and chemical plating time of 2~3 hours, ultimately obtaining a nickel plating layer with a thickness of 10~50 micrometers; a first transition section 131 with a length of 6 mm is provided at the junction of the first nickel plating layer section 13 and the corrosion-resistant alloy coating section 14, and a second transition section 131 with a length of 6 mm is provided at the junction of the second nickel plating layer section 15 and the corrosion-resistant alloy coating section 14. The second transition section 151 is mm in diameter. The nickel plating layer in the first transition section 131 is located on the surface of the corrosion-resistant alloy coating. The nickel plating layer in the second transition section 151 is located on the surface of the corrosion-resistant alloy coating. The method of covering the alloy coating with nickel plating layer in the transition section makes the edge of the alloy coating more effectively connected, avoids the exposure of the substrate, and thus significantly improves the wear and corrosion resistance of the sucker rod. (7) The surface of the substrate segment 12 is coated with a commercially available anti-rust paint, and the anti-rust paint covers a nickel plating layer with a length of about 7 mm at the junction with the first nickel plating segment 13; (8) Finally, a multi-segment anti-corrosion coated oil sucker rod is obtained. Starting from the un-upset end and moving towards the upset end, it consists of a 0.9-meter-long base segment 12, a 0.4-meter-long first nickel-plated segment 13, a corrosion-resistant alloy coating segment 14, and a 0.3-meter-long second nickel-plated segment 15. The nickel plating of the second nickel-plated segment extends to the unthreaded area of ​​the upset end, which improves the corrosion resistance of the upset end.

[0032] This utility model discloses a multi-segment anti-corrosion coated oil sucker rod, which combines coating and plating. Different coatings are prepared at different positions on the surface of the oil sucker rod substrate. The convenient preparation process of nickel plating is used at both ends to solve the difficulty of the complex preparation process of hot spraying and remelting of nickel-based alloy coating. By organically combining the preparation process and performance of both, the overall wear and corrosion resistance of the rod is greatly improved.

Claims

1. A multi-segment anti-corrosion coated oil sucker rod, comprising an upset end, a rod body, and an un-upset end, characterized in that, Starting from the un-upset end and moving towards the upset end, the rod body sequentially includes a base section, a first nickel-plated section, a corrosion-resistant alloy coating section, and a second nickel-plated section. A first transition section with a length not exceeding 10 mm is provided at the junction of the first nickel-plated section and the corrosion-resistant alloy coating section, and a second transition section with a length not exceeding 10 mm is provided at the junction of the second nickel-plated section and the corrosion-resistant alloy coating section. The nickel plating in the first transition section is located on the surface of the corrosion-resistant alloy coating, and the nickel plating in the second transition section is located on the surface of the corrosion-resistant alloy coating. The surface of the base section is coated with anti-rust paint.

2. The sucker rod according to claim 1, characterized in that, The coating thickness of the corrosion-resistant alloy coating section is 0.2-0.5 mm.

3. The sucker rod according to claim 1, characterized in that, The surface roughness of the corrosion-resistant alloy coating section is 0.2-0.8 micrometers.

4. A sucker rod according to claim 1, characterized in that, The length of the base segment is 0.5 to 1 meter.

5. A sucker rod according to claim 1, characterized in that, The length of the first nickel-plated section does not exceed 0.5 meters.

6. A sucker rod according to claim 1, characterized in that, The nickel plating of the second nickel plating section extends to the unthreaded area of ​​the upset end.

7. A sucker rod according to claim 1, characterized in that, The coating thickness of the first and second nickel plating sections is 10-50 micrometers.

8. A sucker rod according to claim 1, characterized in that, The alloy coating of the corrosion-resistant alloy coating section has a microhardness of 300-500 HV when tested under a 200 g load.

9. A sucker rod according to claim 1, characterized in that, The outer diameters of the substrate section, the first nickel plating layer section, the corrosion-resistant alloy coating section, and the second nickel plating layer section are the same.

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