Abrasion and corrosion resistant polyethylene oil pipe liner and method of making same

Abstract

This invention provides a wear-resistant and corrosion-resistant polyethylene tubing liner and its preparation method. The wear-resistant and corrosion-resistant polyethylene tubing liner comprises the following components in parts by weight: 50-60 parts high-density polyethylene, 20-30 parts low-density polyethylene, 8-12 parts modified talc, 0.1-2 parts plasticizer, 0.1-2 parts compatibility toughening agent, 0.1-2 parts antioxidant, and 0.1-2 parts antibacterial agent. The modified talc is a product obtained by copolymerizing KH570 grafted talc with acrylate and isoprene. This invention uses different polyethylene resins and modified talc to effectively improve the compatibility between inorganic components and the polyethylene matrix, enhance film quality, and provide reinforcement. Simultaneously, it strengthens wear-resistant and corrosion-resistant properties, making it suitable for the complex and harsh service environment of oil and gas fields and showing good application prospects.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a wear-resistant and corrosion-resistant polyethylene oil pipe liner and its preparation method. Background Technology

[0002] During oil and gas field development, oil pipes, as the core components for transporting crude oil, natural gas, and associated water, are constantly exposed to complex environments containing acidic media such as H2S and CO2, abrasive particles, and rod-tube wear. Corrosion and wear are prominent issues, severely shortening the service life of oil pipes and increasing oilfield maintenance costs and safety hazards. To address this problem, lining protection technology has become the mainstream solution. Polyethylene, due to its low cost, convenient construction, and excellent corrosion resistance, is widely used in the preparation of oil pipe linings.

[0003] Currently, most existing polyethylene tubing liners are made of single high-density or low-density polyethylene, or simply compounded with inorganic fillers to improve performance, but these methods have significant technical shortcomings. Talc, as a commonly used inorganic filler, can improve the rigidity and wear resistance of polyethylene, but its surface contains hydrophilic groups, which have extremely poor compatibility with the non-polar polyethylene matrix. Direct addition can easily lead to filler agglomeration, which not only fails to provide reinforcement but also reduces the film-forming properties and mechanical properties of the liner, making it prone to cracking, detachment, and other failures.

[0004] In existing technologies, silane and titanate coupling agents are often used to modify talc powder. Although this can improve compatibility to some extent, the modification effect is limited and it is difficult to achieve a synergistic improvement in the lining's wear resistance, corrosion resistance, and film-forming properties. Furthermore, when high-density and low-density polyethylene are blended, the interfacial bonding is weak, lacking an efficient compatibility system, and delamination is prone to occur, further affecting the overall performance and service stability of the lining. This fails to meet the long-term service requirements under conditions of uneven wear and strong corrosion in high-water-content oilfields.

[0005] Therefore, it is necessary to provide a new technical solution to overcome the defects existing in the prior art. Summary of the Invention

[0006] Based on this, the present invention provides an anti-wear and anti-corrosion polyethylene tubing liner and its preparation method. The present invention uses different polyethylene resins and modified talc powder to effectively improve the compatibility of inorganic components with polyethylene matrix, improve film quality, play a reinforcing role, and enhance anti-wear and anti-corrosion performance. It can adapt to the complex and harsh service environment of oil and gas fields and has good application prospects.

[0007] One object of the present invention is to provide an anti-wear and anti-corrosion polyethylene oil pipe liner, wherein the anti-wear and anti-corrosion polyethylene oil pipe liner comprises the following components in parts by weight: 50-60 parts of high-density polyethylene 20-30 parts of low-density polyethylene 8-12 parts modified talc Plasticizer 0.1-2 parts 0.1-2 parts of compatibility toughening agent Antioxidant 0.1-2 parts Antibacterial agent 0.1-2 parts; The modified talc is a product obtained by copolymerizing KH570 grafted talc with acrylate and isoprene.

[0008] Furthermore, the acrylate includes methyl acrylate and dodecyl acrylate.

[0009] Furthermore, the mass ratio of dodecyl acrylate to methyl acrylate is 10:2-3.

[0010] Furthermore, the mass ratio of the KH570 grafted talc, acrylate, and isoprene is 10-20:10-15:0.2-0.5.

[0011] Furthermore, the compatibility toughening agent is an ethylene-acrylate copolymer.

[0012] Another object of the present invention is to provide a method for preparing the above-mentioned wear-resistant and corrosion-resistant polyethylene oil pipe liner, wherein the method for preparing the wear-resistant and corrosion-resistant polyethylene oil pipe liner includes the following steps: S1. KH570 and hydroxylated talc are mixed and heated to react, resulting in KH570 grafted talc. S2. The KH570 grafted talc powder is mixed with acrylate, isoprene and initiator, and heated and stirred under inert gas protection to obtain modified talc powder. S3. Mix the modified talc powder and the remaining components evenly, add them to a twin-screw extruder, and extrude and granulate to obtain a wear-resistant and corrosion-resistant polyethylene oil pipe liner.

[0013] Furthermore, in step S1, the heating reaction is carried out at a temperature of 50-100°C for 2-12 hours.

[0014] Furthermore, in step S2, the heating temperature is 60-120℃ and the heating time is 1-6 h.

[0015] Furthermore, in step S3, the temperature of the extrusion granulation is 150-250℃.

[0016] The present invention has the following beneficial effects: This invention discloses a wear-resistant and corrosion-resistant polyethylene oil pipe liner. Through the compounding of high-density polyethylene and low-density polyethylene, it combines good strength with solvent and chemical resistance, and improves extrusion processing performance. Simultaneously, this invention uses methyl acrylate, dodecyl acrylate, and isoprene to react with talc grafted with double bonds. This improves the dispersion and compatibility of talc in the organic polymer. Furthermore, the introduced polyacrylate units have flexible, large-branched structures, promoting film formation and improving toughness. A small amount of methyl acrylate breaks the polymer regularity, making the molecular chain stacking looser, further regulating processing rheological properties and improving toughness. This invention also uses isoprene as a crosslinking agent, which promotes mild crosslinking between acrylates, forming a network structure, further enhancing the product's wear and corrosion resistance. In addition, this invention uses EMA and other substances as additives, which have good affinity with the main polyethylene and modified talc, playing a compatibilizing role and improving interfacial bonding. This allows multiple components to bind tightly and synergistically strengthen the system, improving its stability and strength. Detailed Implementation

[0017] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0018] The terms "preferred," "more preferably," and "more suitable" used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0019] It should be understood that, except in any operational instance or otherwise indicated, all figures representing the amounts of ingredients used, for example, in the specification and claims, should be understood to be modified in all cases by the term "about". Therefore, unless otherwise stated, the numerical parameters set forth in the following specification and appended claims are approximations varying with the desired performance to be obtained according to the invention.

[0020] The raw material components in this embodiment of the invention are as follows: The high-density polyethylene is DGDB2480H.

[0021] The low-density polyethylene is DFDA-7042.

[0022] The plasticizer is POE 1850G.

[0023] The compatibility toughening agent is ethylene-acrylate copolymer (EMA 1126AC).

[0024] The antioxidant is antioxidant 1010.

[0025] The antibacterial agent is nano-copper oxide.

[0026] In the embodiments of this invention, "parts" refers to parts by mass. Example 1

[0027] A wear-resistant and corrosion-resistant polyethylene oil pipe liner, wherein the wear-resistant and corrosion-resistant polyethylene oil pipe liner comprises the following components in parts by weight: 50 parts of high-density polyethylene 20 parts of low-density polyethylene 8 parts modified talc 1 part plasticizer 1 part compatibility toughening agent 1 part antioxidant 0.2 parts of antibacterial agent; The preparation method of the wear-resistant and corrosion-resistant polyethylene oil pipe liner includes the following steps: S1. Talc powder was soaked in an excess sodium hydroxide solution (concentration 30 wt%), stirred at 90℃ for 6 h, cooled, washed, centrifuged and dried to obtain hydroxylated talc powder. Using an ethanol and water mixture with a volume ratio of 8:1 as a solvent, the pH was adjusted to 5.0 with glacial acetic acid. Then, the hydroxylated talc powder and KH570 were mixed with each other in a mass ratio of 5:1 and refluxed and stirred in an 85°C water bath for 6 h. After cooling to room temperature, the mixture was centrifuged, washed, and dried to obtain KH570 grafted talc powder. S2. Using water as a solvent, KH570 grafted talc powder, dodecyl acrylate, methyl acrylate, isoprene, sodium dodecyl sulfate emulsifier and potassium persulfate initiator were mixed in a mass ratio of 20:10:2:0.5:0.2:0.16. The mixture was reacted at 70°C for 6 h under nitrogen protection. After cooling, the mixture was centrifuged and dried to obtain modified talc powder. S3. Mix the modified talc powder and the remaining components evenly according to the above mass proportions, add them to a twin-screw extruder, and extrude and granulate at 180-200℃ to obtain wear-resistant and corrosion-resistant polyethylene oil pipe lining material. Example 2

[0028] A wear-resistant and corrosion-resistant polyethylene oil pipe liner, wherein the wear-resistant and corrosion-resistant polyethylene oil pipe liner comprises the following components in parts by weight: 55 parts of high-density polyethylene 22 parts of low-density polyethylene 9 parts modified talc 1 part plasticizer 1 part compatibility toughening agent 1 part antioxidant 0.2 parts of antibacterial agent; The preparation method of the wear-resistant and corrosion-resistant polyethylene oil pipe liner includes the following steps: S1. Talc powder was soaked in an excess sodium hydroxide solution (concentration 30 wt%), stirred at 90℃ for 6 h, cooled, washed, centrifuged and dried to obtain hydroxylated talc powder. Using an ethanol and water mixture with a volume ratio of 8:1 as a solvent, the pH was adjusted to 5.0 with glacial acetic acid. Then, the hydroxylated talc powder and KH570 were mixed with each other in a mass ratio of 5:1 and refluxed and stirred in an 85°C water bath for 6 h. After cooling to room temperature, the mixture was centrifuged, washed, and dried to obtain KH570 grafted talc powder. S2. Using water as a solvent, KH570 grafted talc powder, dodecyl acrylate, methyl acrylate, isoprene, sodium dodecyl sulfate emulsifier and potassium persulfate initiator were mixed in a mass ratio of 20:10:2:0.5:0.2:0.16. The mixture was reacted at 70°C for 6 h under nitrogen protection. After cooling, the mixture was centrifuged and dried to obtain modified talc powder. S3. Mix the modified talc powder and the remaining components evenly according to the above mass proportions, add them to a twin-screw extruder, and extrude and granulate at 180-200℃ to obtain wear-resistant and corrosion-resistant polyethylene oil pipe lining material. Example 3

[0029] A wear-resistant and corrosion-resistant polyethylene oil pipe liner, wherein the wear-resistant and corrosion-resistant polyethylene oil pipe liner comprises the following components in parts by weight: 60 parts of high-density polyethylene 24 parts of low-density polyethylene 10 parts modified talc 1.2 parts plasticizer 1.2 parts compatibility toughening agent 1 part antioxidant 0.2 parts of antibacterial agent; The preparation method of the wear-resistant and corrosion-resistant polyethylene oil pipe liner includes the following steps: S1. Talc powder was soaked in an excess sodium hydroxide solution (concentration 30 wt%), stirred at 90℃ for 6 h, cooled, washed, centrifuged and dried to obtain hydroxylated talc powder. Using an ethanol and water mixture with a volume ratio of 8:1 as a solvent, the pH was adjusted to 5.0 with glacial acetic acid. Then, the hydroxylated talc powder and KH570 were mixed with each other in a mass ratio of 5:1 and refluxed and stirred in an 85°C water bath for 6 h. After cooling to room temperature, the mixture was centrifuged, washed, and dried to obtain KH570 grafted talc powder. S2. Using water as a solvent, KH570 grafted talc powder, dodecyl acrylate, methyl acrylate, isoprene, sodium dodecyl sulfate emulsifier and potassium persulfate initiator were mixed in a mass ratio of 20:10:2:1:0.2:0.16. The mixture was reacted at 70°C for 6 h under nitrogen protection. After cooling, the mixture was centrifuged and dried to obtain modified talc powder. S3. Mix the modified talc powder and the remaining components evenly according to the above mass proportions, add them to a twin-screw extruder, and extrude and granulate at 180-200℃ to obtain wear-resistant and corrosion-resistant polyethylene oil pipe lining material.

[0030] Comparative Example 1 The difference between this comparative example and Example 1 is that step S2 is omitted, and KH570 grafted talc is used as the modified talc; the other components and preparation methods are the same as in Example 1.

[0031] Comparative Example 2 The difference between this comparative example and Example 1 is that step S2 is modified as follows: Using water as a solvent, KH570 grafted talc powder, dodecyl acrylate, sodium dodecyl sulfate emulsifier, and potassium persulfate initiator were mixed in a mass ratio of 20:12.5:0.2:0.16. The mixture was reacted at 70°C for 6 h under nitrogen protection. After cooling, the mixture was centrifuged and dried to obtain modified talc powder. Other components and preparation methods were the same as in Example 1.

[0032] Test case The samples prepared in the examples and comparative examples were subjected to performance tests.

[0033] Test method: Performance tests shall be conducted in accordance with the provisions of standards such as GB / T 1040, GB / T 18743, GB / T 3960, and GB / T 11547.

[0034] The test results are shown in Table 1.

[0035] Table 1 Performance Test Results

[0036] As shown in Table 1, the wear-resistant and corrosion-resistant polyethylene tubing liner prepared in the embodiments of the present invention not only has a large elongation at break and notched impact strength, ensuring toughness, but also excellent wear resistance and corrosion resistance. In particular, the comprehensive performance of Example 1 is the best. In Example 3, the amount of crosslinking agent isoprene was increased, which is beneficial to improving wear resistance, but the toughness decreased. Comparative Example 1 uses talc modified with silane coupling agent as a component, without introducing a polymer structure. Compared with the embodiments, its toughness and wear resistance are significantly reduced. The modified talc of Comparative Example 2 only introduces polydodecyl acrylate, lacking a network structure, and its comprehensive performance is also not ideal.

[0037] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0038] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A wear-resistant and corrosion-resistant polyethylene oil pipe liner, characterized in that, The wear-resistant and corrosion-resistant polyethylene oil pipe liner comprises the following components in parts by weight: 50-60 parts of high-density polyethylene 20-30 parts of low-density polyethylene 8-12 parts modified talc Plasticizer 0.1-2 parts 0.1-2 parts of compatibility toughening agent Antioxidant 0.1-2 parts Antibacterial agent 0.1-2 parts; The modified talc is a product obtained by copolymerizing KH570 grafted talc with acrylate and isoprene.

2. The wear-resistant and corrosion-resistant polyethylene oil pipe liner according to claim 1, characterized in that, The acrylates include methyl acrylate and dodecyl acrylate.

3. The wear-resistant and corrosion-resistant polyethylene oil pipe liner according to claim 2, characterized in that, The mass ratio of dodecyl acrylate to methyl acrylate is 10:2-3.

4. The wear-resistant and corrosion-resistant polyethylene oil pipe liner according to claim 1, characterized in that, The mass ratio of KH570 grafted talc, acrylate, and isoprene is 10-20:10-15:0.2-0.

5.

5. The method for preparing the wear-resistant and corrosion-resistant polyethylene oil pipe liner according to any one of claims 1-4, characterized in that, The preparation method of the wear-resistant and corrosion-resistant polyethylene oil pipe liner includes the following steps: S1. KH570 and hydroxylated talc are mixed and heated to react, resulting in KH570 grafted talc. S2. The KH570 grafted talc powder is mixed with acrylate, isoprene and initiator, and heated and stirred under inert gas protection to obtain modified talc powder. S3. Mix the modified talc powder and the remaining components evenly, add them to a twin-screw extruder, and extrude and granulate to obtain a wear-resistant and corrosion-resistant polyethylene oil pipe liner.

6. The method for preparing the wear-resistant and corrosion-resistant polyethylene oil pipe liner according to claim 5, characterized in that, In step S1, the heating reaction is carried out at a temperature of 50-100℃ for 2-12 hours.

7. The method for preparing the wear-resistant and corrosion-resistant polyethylene oil pipe liner according to claim 5, characterized in that, In step S2, the heating temperature is 60-120℃ and the heating time is 1-6 h.

8. The method for preparing the wear-resistant and corrosion-resistant polyethylene oil pipe liner according to claim 5, characterized in that, In step S3, the temperature of the extrusion granulation is 150-250℃.

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