Glass fiber and carbon fiber compounded sucker rod and preparation method thereof

Abstract

The invention discloses a glass fiber and carbon fiber compounded sucker rod and a preparation method thereof, and relates to the technical field of sucker rods, the glass fiber and carbon fiber compounded sucker rod comprises 40-60 parts of carbon fibers, 20-40 parts of glass fibers, 20-35 parts of a matrix material, 2-5 parts of a flexibilizer, 5-15 parts of a high temperature resistant filler, 0.5-2 parts of a coupling agent, and 0.1-5 parts of other auxiliary agents; the preparation method comprises the following steps: S1, fiber treatment; s2, preparing resin; s3, dipping and forming; s4, curing is conducted; and S5, post-processing. According to the glass fiber and carbon fiber compounded sucker rod and the preparation method thereof, a high-temperature-resistant resin matrix is selected as a matrix material, the toughness of the matrix is enhanced by adding a toughening agent, the glass fibers and the carbon fibers can form a complex three-dimensional fiber network structure through a three-dimensional weaving technology, interface optimization is matched, and the toughness of the sucker rod is improved. The interface bonding force between the fiber and the matrix is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of sucker rods, in particular to a glass fiber and carbon fiber composite sucker rod and a preparation method thereof. Background Art

[0002] The sucker rod is a key component of a well pumping unit, primarily used to transmit power from the surface pumping unit to the downhole pump, thereby driving the pumping unit to pump oil. It is a slender rod, typically carefully crafted from round steel, with thickened ends and threaded connections, connected by couplings to form a rod string. During the pumping process, the rod string is connected to the pumping unit via a polished rod, which is then connected to the pump's plunger. Power from the surface pumping unit is transmitted through the sucker rod to the downhole pump, driving the piston's reciprocating motion to extract crude oil.

[0003] Sucker rods have the ability to withstand tensile and compressive loads, and are corrosion-resistant and wear-resistant. Different materials also offer unique properties. Currently, commonly used sucker rods include conventional steel, fiberglass, carbon fiber, and hollow rods. Fiberglass and carbon fiber sucker rods are very strong and relatively lightweight. This reduces the energy required for lifting when used in deep or ultra-deep wells, thereby improving extraction efficiency. Their lightweight nature also makes transportation and installation easier, reducing operational complexity and costs. Furthermore, these two types of sucker rods exhibit excellent corrosion resistance, enabling long-term, stable operation in harsh underground environments. Consequently, they are gradually replacing traditional sucker rods and becoming the mainstream product in the market.

[0004] However, fiberglass sucker rods and carbon fiber sucker rods are not completely without flaws. For example, fiberglass sucker rods are more brittle than metal sucker rods; this means that when subjected to large impact or bending forces, fiberglass sucker rods are more likely to break, and their wear resistance is insufficient. During long-term use, fiberglass sucker rods are prone to gradual wear due to friction with the well wall or other downhole components, resulting in performance degradation. More importantly, their thermal stability is limited, and their performance in high-temperature environments will be affected, resulting in problems such as reduced strength or deformation, which limits their application in high-temperature oil wells. Similarly, compared with metal materials, carbon fiber materials are more prone to brittle fracture when subjected to impact or bending. In high-temperature environments, carbon fiber sucker rods may cause the connection parts to loosen or fail due to mismatched thermal expansion coefficients. Summary of the Invention

[0005] The object of the present invention is to provide a glass fiber and carbon fiber composite sucker rod and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In one aspect, a glass fiber and carbon fiber composite sucker rod is provided, comprising the following components in parts by weight: 40-60 parts of carbon fiber, 20-40 parts of glass fiber, 20-35 parts of matrix material, 2-5 parts of toughening agent, 5-15 parts of high temperature resistant filler, 0.5-2 parts of coupling agent, and 0.1-5 parts of other additives;

[0008] The carbon fibers and glass fibers are compounded with a matrix material (resin matrix) in the form of continuous fiber bundles or fiber cloths, and the carbon fibers and glass fibers are surface treated;

[0009] The matrix material is a high-temperature resistant resin matrix, specifically one or more of polyimide (PI), polyphenylene sulfide (PPS) or epoxy resin (after high-temperature modification), so as to fully impregnate the fiber and form a good interface bond;

[0010] The toughening agent is selected from rubber particles or thermoplastic elastomers (such as TPU, TPA, TPE, etc.), which is used to improve the toughness of the composite material. By adding it to the resin matrix, the toughness and impact resistance of the sucker rod are improved;

[0011] The high temperature resistant filler is obtained by mixing graphite and silicon dioxide in a ratio of (20-35): (5-20), and is used to improve the thermal stability and wear resistance of the composite material;

[0012] The coupling agent is a silane coupling agent, which is used to improve the interfacial bonding between the fiber and the matrix and improve the overall performance of the composite material. The silane coupling agent reacts with hydroxyl groups and other groups on the surface of the glass fiber and carbon fiber to form a chemical bond, and at the same time reacts chemically with the resin matrix or produces hydrogen bonds, thereby improving the bonding strength between the fiber and the resin;

[0013] The other additives include catalysts, antioxidants, flame retardants, lubricants, etc., which are used to improve the comprehensive performance of the composite material.

[0014] Furthermore, the carbon fiber (as the main reinforcing material, providing high strength and rigidity while reducing weight) is selected from medium modulus carbon fiber, and the fiber diameter of the carbon fiber is 7 microns, the fiber length is controlled at 30 to 50 centimeters, and the carbon fiber is arranged in a woven arrangement to improve the toughness and impact resistance of the sucker rod.

[0015] Furthermore, the glass fiber (used to increase toughness and reduce costs, and together with the carbon fiber form the skeleton of the composite material) is selected from continuous glass fiber or untwisted roving, and the fiber diameter of the glass fiber is 13 to 23 microns, the fiber length is 50±2 mm, and the glass fiber is arranged in a winding arrangement, which helps to achieve uniform distribution and tight bonding of the fibers on the sucker rod.

[0016] Furthermore, the resin matrix is ​​supplied in a granular form, and a vibration screening machine is used to screen the particle size of the resin matrix, and the particle size of the resin matrix after screening is 1 to 3 μm.

[0017] Furthermore, the toughening agent is preferably rubber particles, and the glass transition temperature (Tg) of the rubber particles must be below -40°C to ensure that they can effectively play a toughening role at room temperature. For different base materials, the particle size of the rubber particles is different, as follows:

[0018] For polyimide, the rubber particles have a particle size of 1 to 10 μm;

[0019] For polyphenylene sulfide, the average particle size of the rubber particles is controlled within the range of 0.01 to 1 μm, and the optimal size is 0.05 to 0.5 μm;

[0020] For epoxy resin, the particle size of rubber particles is 100nm to 50μm.

[0021] In one aspect, a method for preparing a glass fiber and carbon fiber composite sucker rod is provided, which is applied to the glass fiber and carbon fiber composite sucker rod as described above, and comprises the following steps:

[0022] S1. Fiber treatment: Surface treatment is performed on the glass fiber and carbon fiber to improve the compatibility between the fiber and the matrix, thereby enhancing the interfacial bonding force, to obtain modified glass fiber and modified carbon fiber. The modified fiber bundles are woven into a spatial mesh structure using three-dimensional weaving technology. The yarns are continuous and straight in the woven structure. This structure allows the fibers to interweave in space, forming a continuous network structure, thereby improving the overall performance of the material, such as tensile strength and impact resistance.

[0023] S2. Resin preparation: Mix the high temperature resistant resin, toughening agent, filler and other additives in a uniform ratio, and heat to dissolve the resin and additives;

[0024] S3, impregnation and molding: impregnate the pretreated fiber with a resin solution to ensure that the fiber is fully impregnated, and then use a pultrusion process to prepare it into the shape of a sucker rod;

[0025] S4. Curing: Curing the formed sucker rod at high temperature to completely cure the resin matrix and form a stable composite material structure. The curing process is carried out in a heating furnace or a curing furnace.

[0026] S5. Post-processing: Cut, polish and inspect the cured sucker rod to ensure it meets the use requirements.

[0027] Furthermore, in step S1, the surface treatment of the carbon fiber specifically includes:

[0028] Oxidation: Use hot air, oxygen (O2), carbon dioxide (CO2), ozone (O3) and other gases as media to oxidize carbon fibers. After treatment, the specific surface area and surface roughness of the carbon fibers increase, and the types and quantities of oxygen-containing functional groups on the surface also increase, thereby improving the comprehensive mechanical properties of carbon fiber reinforced composites.

[0029] Coating: The carbon fiber is placed in an active monomer atmosphere. Under the action of an initiator, the monomer reacts with the active groups or edge carbon atoms on the fiber, thereby improving the compatibility of the carbon fiber with the matrix.

[0030] The surface treatment of the glass fiber includes physical deposition modification, specifically including:

[0031] Physical deposition modification of organic compounds: organic compounds are wrapped on the surface of glass fibers and used as bridges to achieve better interface bonding between glass fibers and resin matrix;

[0032] Physical deposition modification of inorganic compounds: By coating the surface of glass fiber with inorganic materials of a certain structure or inorganic materials rich in functional groups, its surface roughness and chemical activity are improved, and the mechanical interlocking and interface bonding between the fiber and the resin are enhanced.

[0033] Furthermore, in step S2, a high-speed mixer is selected for the mixing operation, the rotation speed is controlled between 500 and 800 rpm, the mixing temperature is controlled between 80 and 120° C., and the stirring time is ≥20 min.

[0034] Furthermore, the specific operation of step S3 is as follows: glass fiber and carbon fiber are drawn out from the creel, and the fibers are placed in a resin glue tank and impregnated with resin glue. The purpose of impregnation is to allow the resin to fully infiltrate the fibers and ensure a good bond between the fibers and the resin. The impregnated fibers then enter a pultrusion mold. In the mold, the fibers are subjected to pressure and temperature and gradually solidify (the resin volume shrinks during the curing process, and the carbon fiber / resin separates from the mold) and form a continuous sucker rod shape.

[0035] Furthermore, in step S4, the temperature of the curing process is controlled at 140-160°C, the heating rate is in the range of 5°C / min to 20°C / min, and the heating time is 6-12 hours.

[0036] The present invention provides a glass fiber and carbon fiber composite sucker rod and a preparation method thereof, which have the following beneficial effects:

[0037] The sucker rod of the present invention uses a high-temperature resistant resin matrix as its base material, and enhances its toughness by adding toughening agents. These toughening agents absorb energy when the sucker rod is subjected to external forces, thereby improving its toughness. Furthermore, during its preparation, three-dimensional weaving technology is used to form a complex three-dimensional fiber network structure with glass fibers and carbon fibers, thereby enhancing the material's toughness and impact resistance. Combined with interface optimization, the interfacial bonding between the fibers and the matrix is ​​further improved. Specifically, by treating the fiber surface (oxidation, coating, etc.), its compatibility with the matrix is ​​improved, thereby enhancing interfacial bonding and improving the toughness of the sucker rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention is a schematic flow chart of the steps of a glass fiber and carbon fiber composite sucker rod and a preparation method thereof. DETAILED DESCRIPTION

[0039] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0040] A glass fiber and carbon fiber composite sucker rod, comprising the following components by mass: 50 parts carbon fiber, 30 parts glass fiber, 30 parts matrix material, 2 parts toughening agent, 10 parts high temperature resistant filler, 1 part coupling agent, and 1 part other additives;

[0041] The carbon fibers and glass fibers are compounded with a matrix material (resin matrix) in the form of continuous fiber bundles or fiber cloth, and the carbon fibers and glass fibers are surface treated.

[0042] In this embodiment, the carbon fiber (as the main reinforcement material, providing high strength and rigidity while reducing weight) is selected from medium modulus carbon fiber, which has a good balance between strength and rigidity, and the fiber diameter of the carbon fiber is 7 microns. The finer fiber diameter helps to improve the specific strength (strength to weight ratio) of the carbon fiber, and is also beneficial to the impregnation of the resin and the overall performance of the composite material. The fiber length is controlled between 30 and 50 centimeters. Longer carbon fibers can provide better mechanical properties and fatigue resistance, and also help to reduce the risk of fiber breakage in the composite material. The carbon fibers are arranged in a woven arrangement to improve the toughness and impact resistance of the sucker rod.

[0043] Glass fiber (used to increase toughness and reduce costs, and together with carbon fiber forms the skeleton of the composite material) selects continuous glass fiber or roving. Continuous glass fiber provides good mechanical properties and processability, while roving is easier to wet and mix. The fiber diameter of the glass fiber is 13 to 23 microns to balance the mechanical properties and processability. The fiber length is 50±2 mm, which is easy to handle and mix. It is suitable for applications that require fast processing and lower costs. The glass fiber is arranged in a winding arrangement, which helps to achieve uniform distribution and tight bonding of the fibers on the sucker rod.

[0044] The matrix material is a high-temperature resistant resin matrix, specifically one or more of polyimide (PI), polyphenylene sulfide (PPS), or epoxy resin (modified for high temperature resistance), to fully impregnate the fibers and form a good interfacial bond. The resin matrix is ​​supplied in granular form and is sieved using a vibrating screen to a particle size of 1 to 3 μm.

[0045] The toughening agent is rubber particles. Rubber particles can control the development of silver cracks (micro cracks in the resin matrix) and stop them in time, thereby preventing them from developing into destructive cracks. At the same time, they can initiate and branch silver cracks, increase the number of silver cracks and energy absorption, and improve the toughness of the material. The glass transition temperature (Tg) of the rubber particles must be below -40°C to ensure that they can effectively play a toughening role at room temperature. For different matrix materials, the particle size of the rubber particles is different, as follows:

[0046] For polyimide, the rubber particles have a particle size of 1 to 10 μm;

[0047] For polyphenylene sulfide, the average particle size of the rubber particles is controlled within the range of 0.01 to 1 μm, and the optimal size is 0.05 to 0.5 μm;

[0048] For epoxy resin, the particle size of rubber particles is 100nm to 50μm.

[0049] The high-temperature resistant filler is obtained by mixing graphite and silicon dioxide in a ratio of 5:3, and is used to improve the thermal stability and wear resistance of the composite material.

[0050] Silane coupling agents are used to improve the interfacial bonding between the fiber and the matrix, enhancing the overall performance of the composite material. Silane coupling agents react with hydroxyl groups and other groups on the surface of glass and carbon fibers to form chemical bonds. They also react chemically with the resin matrix or produce hydrogen bonds, thereby increasing the bond strength between the fiber and the resin.

[0051] Other additives include catalysts (used to control the curing rate of the resin to ensure that the composite material can be fully cured during the processing, thereby improving the mechanical properties and heat resistance of the material), antioxidants (which can prevent the material from degrading due to oxidation during processing and use, extending the service life of the material), flame retardants (which reduce the flammability of the sucker rod and make it less likely to burn), lubricants (which can improve the processing fluidity of the material, reduce energy consumption and mold wear during processing, and improve the surface quality of the product), etc., which are used to improve the comprehensive performance of the composite material.

[0052] like Figure 1 As shown, a method for preparing a glass fiber and carbon fiber composite sucker rod is applied to the glass fiber and carbon fiber composite sucker rod as mentioned above, comprising the following steps:.

[0053] S1. Fiber treatment: Surface treatment is performed on the glass fiber and carbon fiber to improve the compatibility between the fiber and the matrix, thereby enhancing the interfacial bonding force to obtain modified glass fiber and modified carbon fiber. The modified fiber bundles are woven into a spatial network structure using three-dimensional weaving technology. The yarns are continuous and uninterrupted in the woven structure and have a high degree of straightness. This structure allows the fibers to interweave with each other in space to form a continuous network structure, thereby improving the overall performance of the material, such as tensile strength and impact resistance.

[0054] 1) Surface treatment of carbon fiber specifically includes:

[0055] Oxidation: Use hot air, oxygen (O2), carbon dioxide (CO2), ozone (O3) and other gases as media to oxidize carbon fibers. After treatment, the specific surface area and surface roughness of the carbon fibers increase, and the types and quantities of oxygen-containing functional groups on the surface also increase, thereby improving the comprehensive mechanical properties of carbon fiber reinforced composites.

[0056] Coating: The carbon fiber is placed in an active monomer atmosphere. Under the action of an initiator, the monomer reacts with the active groups or edge carbon atoms on the fiber, thereby improving the compatibility of the carbon fiber with the matrix.

[0057] 2) Surface treatment of glass fiber includes physical deposition modification, specifically including:

[0058] Physical deposition modification of organic compounds: organic compounds are wrapped on the surface of glass fibers and used as bridges to achieve better interface bonding between glass fibers and resin matrix;

[0059] Physical deposition modification of inorganic compounds: By coating the surface of glass fiber with inorganic materials of a certain structure or inorganic materials rich in functional groups, its surface roughness and chemical activity are improved, and the mechanical interlocking and interface bonding between the fiber and the resin are enhanced.

[0060] S2. Resin preparation: Use a high-speed mixer to mix the high-temperature resistant resin, toughening agent, filler and other additives according to the proportion, and heat to dissolve the resin and additives. The speed of the high-speed mixer is controlled between 500 and 800 rpm, the mixing temperature is controlled between 80 and 120°C, and the stirring time is ≥20min.

[0061] S3. Impregnation and Forming: The pretreated fibers are impregnated with a resin solution to ensure they are fully wetted, and then pultrusion is used to prepare them into the shape of a sucker rod. The specific operations of this step are: glass fiber and carbon fiber are drawn from the creel, and the fibers are placed into the resin tank and impregnated with the resin solution. The purpose of impregnation is to fully infiltrate the fibers with the resin, ensuring a good bond between the fibers and the resin. The impregnated fibers then enter the pultrusion mold, where they are subjected to pressure and temperature, gradually solidifying (the resin shrinks during the curing process, and the carbon fiber / resin separates from the mold) and forming a continuous sucker rod shape.

[0062] S4. Curing: The formed sucker rod is cured at high temperature to completely cure the resin matrix and form a stable composite material structure. The curing process is carried out in a heating furnace or a curing furnace. The temperature of the curing process is controlled at 140-160°C, the heating rate range is between 5°C / min and 20°C / min, and the heating time is 6-12h.

[0063] S5. Post-processing: Cut, polish and inspect the cured sucker rod to ensure it meets the use requirements.

[0064] The embodiments of the present invention are presented for purposes of illustration and description and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments are chosen and described in order to better illustrate the principles of the invention and its practical application and to enable those skilled in the art to understand the invention and design various embodiments with various modifications as suited for specific applications.

Claims

1. A glass fiber and carbon fiber composite sucker rod, characterized in that: The invention comprises the following components in parts by weight: 40 to 60 parts of carbon fiber, 20 to 40 parts of glass fiber, 20 to 35 parts of matrix material, 2 to 5 parts of toughening agent, 5 to 15 parts of high temperature resistant filler, 0.5 to 2 parts of coupling agent, and 0.1 to 5 parts of other additives; The carbon fibers and glass fibers are compounded with a matrix material in the form of continuous fiber bundles or fiber cloths, and the carbon fibers and glass fibers are surface treated; The matrix material is a high temperature resistant resin matrix, specifically one or more of polyimide, polyphenylene sulfide or epoxy resin; The toughening agent is selected from rubber particles or thermoplastic elastomer; The high temperature resistant filler is obtained by mixing graphite and silicon dioxide in a ratio of (20-35): (5-20); The coupling agent is a silane coupling agent; The other additives include catalysts, antioxidants, flame retardants, and lubricants.

2. The glass fiber and carbon fiber composite sucker rod according to claim 1, characterized in that: The carbon fibers are medium modulus carbon fibers, and the fiber diameter of the carbon fibers is 7 microns, the fiber length is controlled to be 30 to 50 centimeters, and the carbon fibers are arranged in a woven arrangement.

3. The glass fiber and carbon fiber composite sucker rod according to claim 1, characterized in that: The glass fibers are continuous glass fibers or rovings, and the fiber diameter of the glass fibers is 13 to 23 microns, the fiber length is 50±2 mm, and the glass fibers are arranged in a winding manner.

4. The glass fiber and carbon fiber composite sucker rod according to claim 1, characterized in that: The resin matrix is ​​supplied in a granular form, and a vibration screening machine is used to screen the particle size of the resin matrix, and the particle size of the resin matrix after screening is 1 to 3 μm.

5. The glass fiber and carbon fiber composite sucker rod according to claim 1, characterized in that: The toughening agent is preferably rubber particles, and the glass transition temperature of the rubber particles must be below -40°C. The particle size of the rubber particles varies depending on the base material, as follows: For polyimide, the rubber particles have a particle size of 1 to 10 μm; For polyphenylene sulfide, the average particle size of the rubber particles is controlled within the range of 0.01 to 1 μm, and the optimal size is 0.05 to 0.5 μm; For epoxy resin, the particle size of rubber particles is 100nm to 50μm.

6. A method for preparing a glass fiber and carbon fiber composite sucker rod, applied to the glass fiber and carbon fiber composite sucker rod according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Fiber treatment: Surface treatment of glass fiber and carbon fiber is performed to obtain modified glass fiber and modified carbon fiber, and the modified fiber bundles are woven into a spatial network structure using three-dimensional weaving technology; S2. Resin preparation: Mix the high temperature resistant resin, toughening agent, filler and other additives in a uniform ratio, and heat to dissolve the resin and additives; S3, impregnation and molding: impregnating the pretreated fiber with a resin solution, and then using a pultrusion process to prepare it into the shape of a sucker rod; S4, curing: curing the formed sucker rod at high temperature, and the curing process is carried out in a heating furnace or a curing furnace; S5. Post-processing: cutting, grinding and inspecting the cured sucker rod.

7. The method for preparing a glass fiber and carbon fiber composite sucker rod according to claim 6, characterized in that: In step S1, the surface treatment of carbon fibers specifically includes: Oxidation: Use hot air, oxygen, carbon dioxide, ozone and other gases as media to oxidize carbon fibers; Coating: The carbon fiber is placed in an active monomer atmosphere. Under the action of an initiator, the monomer reacts with the active groups or edge carbon atoms on the fiber. The surface treatment of the glass fiber includes physical deposition modification, specifically including: Physical deposition modification of organic compounds: organic compounds are wrapped on the surface of glass fibers and used as bridges to achieve better interface bonding between glass fibers and resin matrix; Physical deposition modification of inorganic compounds: by coating the inorganic material on the surface of the glass fiber.

8. The method for preparing a glass fiber and carbon fiber composite sucker rod according to claim 6, characterized in that: In step S2, a high-speed mixer is selected for the mixing operation, the rotation speed is controlled at 500 to 800 rpm, the mixing temperature is controlled at 80 to 120° C., and the stirring time is ≥20 min.

9. The method for preparing a glass fiber and carbon fiber composite sucker rod according to claim 6, characterized in that: The specific operation of step S3 is as follows: glass fiber and carbon fiber are drawn out from the creel, and the fibers are placed into a resin tank to be impregnated with the resin solution. The impregnated fibers then enter a pultrusion mold, where the fibers are subjected to pressure and temperature, gradually solidified, and formed into a continuous sucker rod shape.

10. The method for preparing a glass fiber and carbon fiber composite sucker rod according to claim 6, characterized in that: In step S4, the temperature of the curing process is controlled at 140-160° C., the heating rate is in the range of 5° C. / min to 20° C. / min, and the heating time is 6-12 hours.

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