Anti-corrosion sucker rod and anti-corrosion material thereof

Abstract

According to the anticorrosive sucker rod and the anticorrosive material thereof, graphene of the anticorrosive material comprises the following components in percentage by mass: 3%-8% of diphenylmethane diisocyanate, 20%-35% of an organosilicon polymer, 35%-50% of fluororesin, 3%-10% of sucrose polyether polyol, 0.2%-1.0% of dibutyltin dilaurate, 1%-2% of nano graphene and 1%-3% of nano graphene oxide. 2%-5% of a dispersing agent, 0.5%-1.5% of a flatting agent and 0.2%-1.0% of a defoaming agent; tungsten alloy plating layers are arranged on the outer surfaces of the rod head end and the coupling end of the sucker rod; an anti-corrosion coating is arranged in the middle of the rod body; the tungsten alloy plating layers at the two ends of the rod body are in lap joint with the anti-corrosion coating in the middle of the rod body. The anti-corrosion sucker rod has the beneficial effects that a wrench square plating layer cannot be damaged by a tightening tool in the process of descending the sucker rod into a well, the rod body of the sucker rod is coated with the anti-corrosion coating, and the service life of the sucker rod is greatly prolonged.

Description

Technical Field

[0001] The invention relates to a sucker rod, in particular to an anti-corrosion sucker rod and an anti-corrosion material thereof, belonging to the technical field of oil and gas development. Background Art

[0002] With the continuous deepening of oilfield development and production, the corrosion of downhole tools is becoming more and more serious. The corrosion of tools such as sucker rods and oil pipes not only increases the difficulty and risk of operations, but also increases a large amount of operating costs. In severe cases, it may cause the oil well to be shut down and scrapped. Ordinary sucker rods are affected by corrosive media in the well to produce corrosion pits. Small corrosion pits gradually connect to form larger corrosion pits, which reduce the cross-sectional area of ​​the rod body and generate stress concentration points, which eventually lead to a decrease in the bearing capacity of the rod body, resulting in corrosion fatigue and stress corrosion cracking. The existing anti-corrosion sucker rod technology is mainly process-type anti-corrosion sucker rods, such as tungsten-plated sucker rods, coated sucker rods, coated anti-corrosion sucker rods and spray-welded bare rods, etc., which have certain corrosion resistance and adaptability to the corrosive environment of oil wells, but all have certain disadvantages, such as: coating leakage points, the outer diameter of the rod head coupling is too large after the overall coating treatment of the sucker rod, which reduces the flow area in the oil pipe and cannot be applied to small-diameter oil pipes, etc. At the same time, the coating or anti-corrosion coating at the wrench side of the sucker rod end is easily damaged by the tightening tool when the sucker rod is lowered into the well, resulting in a corrosion point source and further extending to the rod body to cause corrosion of the sucker rod. Summary of the invention

[0003] In order to overcome the above-mentioned deficiencies of the existing anti-corrosion sucker rod, the present invention provides an anti-corrosion sucker rod and an anti-corrosion material thereof.

[0004] The technical solution adopted by the present invention to solve the technical problem is: an anti-corrosion material for an anti-corrosion sucker rod, the anti-corrosion material is graphene, and the components and mass percentages of the graphene material are: 3% to 8% of diphenylmethane diisocyanate, 20% to 35% of organic silicon polymer, 35% to 50% of fluororesin, 3% to 10% of sucrose polyether polyol, 0.2% to 1.0% of dibutyltin dilaurate, 1% to 2% of nanographene, 1% to 3% of nanographene oxide, 2% to 5% of dispersant, 0.5% to 1.5% of leveling agent, and 0.2% to 1.0% of defoaming agent.

[0005] Furthermore, the dispersant is sodium polyphosphate.

[0006] Furthermore, the leveling agent is polydimethylsiloxane.

[0007] Furthermore, the defoaming agent is polydimethylsiloxane.

[0008] An anti-corrosion sucker rod using the anti-corrosion material comprises a rod head, a rod body and a spanner. The rod head, spanner I, rod body and spanner II are arranged in sequence along the axis of the sucker rod. The spanner I and the rod head are transitioned through a push surface shoulder. One end of the spanner II is fixedly connected to a coupling. The spanner II and the coupling are transitioned through a push surface shoulder. The spanner I and the spanner II are transitioned to the rod body through a flange. The outer surfaces of the push surface shoulder, spanner I, flange and the transition section between the flange and the rod body at the rod head end are coated with tungsten alloy. The outer surfaces of the coupling, push surface shoulder, spanner II, flange and the transition section between the flange and the rod body at the coupling end are coated with tungsten alloy. An anti-corrosion coating is provided in the middle part of the rod body. The material of the anti-corrosion coating is graphene or high molecular polyethylene. The tungsten alloy coatings at both ends of the rod body overlap with the anti-corrosion coating in the middle part of the rod body.

[0009] Furthermore, the thickness of the tungsten alloy coating is 0.03-0.08 mm.

[0010] Furthermore, the thickness of the anti-corrosion coating on the outer surface of the rod body is 0.15 to 0.25 mm.

[0011] Furthermore, the overlap length of the tungsten alloy coating of the rod body and the anti-corrosion coating is ≥20 mm.

[0012] The beneficial effect of the present invention is that by tungsten plating the sucker rod head and the coupling end, the tungsten alloy plating has a high hardness, ensuring that the tightening tool during the sucker rod lowering process will not damage the wrench plating, so that both ends of the rod body have corrosion resistance; the sucker rod body part is coated with graphene anti-corrosion coating or polymer polyethylene coating, which solves the problem of damage to the anti-corrosion layer of the sucker rod during the lowering process, and greatly improves the service life of the sucker rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the anti-corrosion sucker rod of the present invention.

[0014] In the figure: 1. rod head, 2. rod body, 3. coupling, 4-1. wrench square I, 4-2. wrench square II, 5. thrust surface shoulder, 6. flange, 7. tungsten alloy plating, 8. anti-corrosion coating. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, those skilled in the art should be aware that the present invention is not limited to the specific embodiments listed, and all embodiments should be included in the protection scope of the present invention as long as they conform to the spirit of the present invention.

[0016] In the description of the present invention, it should be noted that the terms "vertical", "up", "down", "left", "right", "horizontal", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing or simplifying the description of the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0017] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connection", and "seal" should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection, a direct connection, an indirect connection, or an integral connection; it can be a mechanical connection, an indirect connection through an intermediate medium, or a communication between the two components. The seal can be an oil seal, a packing seal, or other forms of seals. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] The invention discloses an anti-corrosion material for an anti-corrosion sucker rod. The anti-corrosion material is graphene. The components of the graphene material and their mass percentages are: 3%-8% of diphenylmethane diisocyanate, 20%-35% of organic silicon polymer, 35%-50% of fluororesin, 3%-10% of sucrose polyether polyol, 0.2%-1.0% of dibutyltin dilaurate, 1%-2% of nanographene, 1%-3% of nanographene oxide, 2%-5% of dispersant, 0.5%-1.5% of leveling agent and 0.2%-1.0% of defoaming agent.

[0019] Furthermore, the dispersant is sodium polyphosphate, which has two relative properties, lipophilicity and hydrophilicity, in the molecule, and can evenly disperse the solid and liquid particles of inorganic and organic pigments that are difficult to dissolve in liquids, and can also prevent the sedimentation and aggregation of particles, thereby forming an amphiphilic agent required for a stable suspension.

[0020] Furthermore, the leveling agent is polydimethylsiloxane. Polydimethylsiloxane can promote the coating to form a flat, smooth and uniform coating film during the drying film-forming process, reduce the surface tension of the coating liquid, increase the coverage, and make the film formation uniform and natural.

[0021] Furthermore, the defoaming agent is polydimethylsiloxane, which is used to prevent the generation of bubbles and foam, thereby improving the quality of the product.

[0022] Furthermore, the main components of the organic silicon polymer, silicone oil and silicone resin, have good heat resistance and thermal stability, and play a role in improving the performance of the coating.

[0023] Graphene is used as the anti-corrosion material for sucker rods. Graphene is tough, has good plasticity, good anti-corrosion performance, and stable chemical properties. It is transparent but not airtight under visible light and has good barrier properties. The graphene fracture strength is 130GPa. The above properties make graphene have excellent anti-corrosion and mechanical properties.

[0024] See attached Figure 1 The present invention discloses an anti-corrosion sucker rod using the anti-corrosion material, comprising a rod head 1, a rod body 2, and a wrench square 4. The rod head 1, wrench square I 4-1, the rod body 2, and wrench square II 4-2 are sequentially arranged along the axis of the sucker rod, and the wrench square I 4-1 and the rod head 1 are transitioned through a push surface shoulder 5; one end of the wrench square II 4-2 is fixedly connected to the coupling 3, and the wrench square II 4-2 and the coupling 3 are transitioned through the push surface shoulder 5, and the wrench square I 4-1 and the wrench square II 4-2 are transitioned to the rod body 2 through a flange 6.

[0025] The outer surfaces of the thrust shoulder 5, wrench square I 4-1, flange 6, and the transition section between flange 6 and rod body 2 at the end of the rod head 1 are coated with tungsten alloy 7. The outer surfaces of the coupling 3, thrust shoulder 5, wrench square II 4-2, flange 6, and the transition section between flange 6 and rod body 2 at the end of the coupling 3 are coated with tungsten alloy 7.

[0026] An anti-corrosion coating 8 is provided in the middle portion of the rod body 2 , and the material of the anti-corrosion coating 8 is graphene or high molecular polyethylene.

[0027] The tungsten alloy coatings 7 at both ends of the rod body 2 overlap with the anti-corrosion coating 8 in the middle of the rod body 2 .

[0028] Furthermore, the thickness of the tungsten alloy coating 7 is 0.03-0.08 mm; preferably, the thickness of the tungsten alloy coating 7 is 0.05 mm.

[0029] Furthermore, the thickness of the anti-corrosion coating 8 on the outer surface of the rod body 2 is 0.15-0.25 mm; preferably, the thickness of the anti-corrosion coating 8 is 0.20 mm.

[0030] Furthermore, the overlap length of the tungsten alloy coating 7 and the anti-corrosion coating 8 of the rod body 2 is ≥20 mm.

[0031] The present invention is used to process the sucker rod. First, the surface of the sucker rod is shot blasted. Then, both ends of the sucker rod, including the coupling, the wrench and both ends of the rod body, are plated with tungsten alloy. The length of the tungsten alloy plating is 200-40 mm, so that both ends of the sucker rod have corrosion resistance. After that, the sucker rod body is coated with graphene anti-corrosion material or polymer polyethylene. Attention is paid to the overlap treatment of the joint between the tungsten alloy plating and the graphene anti-corrosion material / polymer polyethylene to ensure that the overlap length is ≥20 mm, so as to achieve full coverage of the anti-corrosion plating and coating on the surface of the sucker rod.

[0032] The present invention performs tungsten plating on both ends of the sucker rod. Since the tungsten alloy plating has a high hardness, tightening the tool during the process of lowering the sucker rod into the well will not damage the plating on the wrench side of the rod body, so that the two ends of the rod body have corrosion resistance. The sucker rod body is coated with graphene anti-corrosion coating or high molecular polyethylene, so that the rod body has the ability to resist well fluid corrosion without increasing the outer diameter of the rod head coupling at the end of the sucker rod.

[0033] The present invention discloses an anti-corrosion sucker rod and its anti-corrosion material. The surface of the sucker rod is treated by two anti-corrosion methods, namely, coating anti-corrosion and tungsten plating anti-corrosion. The sucker rod head and a section of the coupling end are tungsten-plated to ensure that the anti-corrosion layer of the wrench side at both ends of the sucker rod will not be damaged during the process of going down to the well, so that the two ends of the rod body have anti-corrosion ability. The sucker rod body is coated with graphene anti-corrosion coating or high-molecular polyethylene to make the rod body have the ability to resist well fluid corrosion. The anti-corrosion effect of the sucker rod is achieved, and the problem of damage to the anti-corrosion layer during the process of going down to the well is solved, the service life of the anti-corrosion rod is greatly improved, and it is suitable for use with small-diameter oil pipes.

[0034] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the claims of this patent.

Claims

1. An anti-corrosion material for an anti-corrosion sucker rod, characterized by: The anti-corrosion material is graphene, and the components of the graphene material and their mass percentages are: 3% to 8% of diphenylmethane diisocyanate, 20% to 35% of silicone polymer, 35% to 50% of fluororesin, 3% to 10% of sucrose polyether polyol, 0.2% to 1.0% of dibutyltin dilaurate, 1% to 2% of nanographene, 1% to 3% of nanographene oxide, 2% to 5% of dispersant, 0.5% to 1.5% of leveling agent, and 0.2% to 1.0% of defoaming agent.

2. The anti-corrosion material for the anti-corrosion sucker rod according to claim 1, characterized in that: The dispersant is sodium polyphosphate.

3. The anti-corrosion material for the anti-corrosion sucker rod according to claim 1, characterized in that: The leveling agent is polydimethylsiloxane.

4. The anti-corrosion material for the anti-corrosion sucker rod according to claim 1, characterized in that: The defoaming agent is polydimethylsiloxane.

5. An anti-corrosion sucker rod using the anti-corrosion material of claim 1, comprising a rod head, a rod body, and a wrench square, wherein the rod head, wrench square I, the rod body, and wrench square II are sequentially arranged along the axis of the sucker rod, and wrench square I and the rod head are transitioned through a thrust surface shoulder; one end of wrench square II is fixedly connected to a coupling, and wrench square II and the coupling are transitioned through a thrust surface shoulder, and wrench square I and wrench square II are transitioned to the rod body through a flange, wherein: The outer surfaces of the push-bearing surface shoulder, wrench square I, flange, flange and rod body transition section of the rod head end are coated with tungsten alloy; the outer surfaces of the coupling, push-bearing surface shoulder, wrench square II, flange, flange and rod body transition section of the coupling end are coated with tungsten alloy; An anti-corrosion coating is arranged in the middle part of the rod body, and the material of the anti-corrosion coating is graphene or high molecular polyethylene; the tungsten alloy coatings at both ends of the rod body overlap with the anti-corrosion coating in the middle part of the rod body.

6. The anti-corrosion sucker rod according to claim 5 is characterized in that: The thickness of the tungsten alloy coating is 0.03-0.08 mm.

7. The anti-corrosion sucker rod according to claim 5 is characterized in that: The thickness of the anti-corrosion coating on the outer surface of the rod body is 0.15-0.25 mm.

8. The anti-corrosion sucker rod according to claim 5 is characterized in that: The overlap length of the tungsten alloy coating of the rod body and the anti-corrosion coating is ≥20mm.

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