An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device and its application

Abstract

The invention discloses an ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device and an application thereof. The material is composed of the following components in parts by mass, and the total parts by mass of each component are 100 parts. The specific components include: 80 to 90 parts by mass of ultra-high molecular weight polyethylene, 3.5 to 6.5 parts by mass of polyoxyethylene, 0.01 to 0.8 parts by mass of a nucleating agent, 3 to 8 parts by mass of a photoinitiator, and 3 to 8 parts by mass of a multifunctional monomer; the molecular weight of the ultra-high molecular weight polyethylene is 1.5 million to 9 million; the invention solves the problem that the prior art uses ultraviolet light curing, and for thick-walled products or products that cannot transmit ultraviolet rays, a low degree of crosslinking and poor crosslinking performance will occur. The prepared material is easy to process, has high strength at high temperature, has good wear resistance, can greatly extend the service life of the pipe, and is suitable for manufacturing the inner liner pipe of the oil production device.

Description

Technical Field

[0001] The invention relates to a material for an inner liner pipe in an oil field production device, and in particular to an ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device and application thereof. Background Art

[0002] During the oil production process in the oil field, due to the harsh and complex oil production environment, the presence of oil, water, high temperature and acid, the oil production pipe often suffers from corrosion and eccentric wear during use. Ultra-high molecular weight polyethylene with good corrosion resistance and self-lubricating properties is used as the inner lining of the oil production pipe. The ultra-high molecular weight polyethylene is cross-linked. Since the direct force of the ultra-high molecular weight polyethylene molecular chain segment is replaced by chemical bonds instead of van der Waals force, its mechanical properties and wear resistance at high temperature can be greatly improved, which can greatly increase its service life. However, there are two difficulties: one is that ultra-high molecular weight polyethylene has a very high molecular weight, high viscosity, is difficult to plasticize, and has a high processing temperature. It is very difficult to process at a maximum temperature of 250°C to 290°C (directly adding peroxide cross-linking agents or silane cross-linking agents at 250°C to 290°C will cause the peroxide to decompose prematurely, the viscosity will increase rapidly, and it will be impossible to process and pre-cross-link). Another difficulty is that the thickness of the liner pipe in the oil production device is 3.5 to 5.5 mm, the pipe wall is relatively thick, and it is difficult to obtain a high degree of cross-linking and satisfactory performance for UV and high-energy ray irradiation and low transmittance.

[0003] Ultra-high molecular weight polyethylene generally adopts the method of first forming the product and then cross-linking. There are many ways of cross-linking. Among them, those using high-energy rays include: gamma rays, beta rays, x-rays and accelerated electron beams for cross-linking. Existing document 1 (patent number CN110078950B) uses peroxide cross-linking, document 2 (patent number CN 115746344A) uses silane cross-linking method, document 3 (patent number CN 101463156) uses ultraviolet light for cross-linking, and document 4 (patent numbers CN 109251389 B, CN116769199A) uses high-energy ray irradiation method, but the disadvantages of documents 1 to 4 are that the radiation source and radiation equipment are expensive, the radiation cost is high, and the production site is limited. There are also peroxide and silane cross-linking systems, because peroxide and silane cross-linking systems are easy to decompose at high temperatures, which will cause the molecular weight to increase further and there is no way to process or cross-link in advance during the processing. In order to avoid processing difficulties, the solution infiltration method is generally used. The solution infiltration method is to immerse the ultra-high molecular weight polyethylene product in a solution containing an initiator and a monomer, and then allow the initiator and the monomer to slowly penetrate into the ultra-high molecular weight polyethylene product under low temperature heating, and then cross-link. Document 5 (patent numbers CN11072798B and CN102493168A) both use the solution infiltration method, but the infiltration time is long and the efficiency is low, which is not suitable for the production of liner pipes.

[0004] The advantage of ultraviolet light curing is that during the processing, the photoinitiator will not decompose during the production of special materials and the production of products, and will not affect the processing of ultrahigh molecular weight polyethylene. It can be blended and processed into products for ultraviolet light irradiation crosslinking. The disadvantage of ultraviolet light curing is that it is affected by the UV light transmittance of the product. For thick-walled products or products that cannot transmit ultraviolet rays, there are problems of low crosslinking degree and poor crosslinking performance. Document 6 (patent number CN 109251389B) discloses a method for preparing a light-irradiated crosslinked ultrahigh molecular weight polyethylene injection molding composite material and a light-irradiated crosslinked polyethylene for injection molding by using ultraviolet light curing, wherein a low molecular weight polyolefin material is compounded with benzophenone or xanthone, and the low molecular weight polyolefin after the compounding is compounded with ultrahigh molecular weight polyethylene to prepare a light-crosslinked ultrahigh molecular weight polyethylene injection molding grade composite material, and then combined with ultraviolet irradiation technology in the injection molding stage to realize the preparation of light-crosslinked ultrahigh molecular weight polyethylene injection molding products. However, the disadvantage of document 6 is that the mold manufacturing is very difficult, and the inner wall of the injection mold must be made of quartz glass and a high-pressure mercury lamp must be added inside the mold. Document 7 (patent number CN116769199A) discloses a method for preparing a UV-curable cross-linked polyethylene battery separator, which first forms a battery separator product, and then uses an aqueous co-crosslinking agent and an aqueous photoinitiator to dissolve in water to form an ultraviolet irradiation slurry, which is applied to an ultrahigh molecular weight polyethylene base film, and then a network cross-linking structure is formed by ultraviolet irradiation to increase the film breaking temperature of the ultrahigh molecular weight polyethylene separator, that is, the product is first formed, and then a solution is used to infiltrate components such as a photoinitiator, and then ultraviolet irradiation is performed; however, the preparation effect of this method is low and the cross-linking performance is poor. Summary of the invention

[0005] The purpose of the present invention is to provide an ultra-high molecular weight polyethylene material for preparing inner lining pipes in oil field production equipment and its application, which solves the problem that the existing technology uses ultraviolet light curing, and for thick-walled products or products that cannot penetrate ultraviolet rays, low cross-linking degree and poor cross-linking performance will occur. The prepared material is easy to process, has high strength at high temperatures, and good wear resistance, and can greatly extend the service life of the pipe, and is suitable for manufacturing inner lining pipes of oil production equipment.

[0006] In order to achieve the above object, the present invention provides an ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device, the material is composed of the following components in parts by mass, with the total parts by mass of each component being 100 parts, and the specific components are as follows:

[0007] 80-90 parts by weight of ultra-high molecular weight polyethylene, 3.5-6.5 parts by weight of polyoxyethylene, 0.01-0.8 parts by weight of nucleating agent, 3-8 parts by weight of photoinitiator and 3-8 parts by weight of multifunctional monomer; the molecular weight of the ultra-high molecular weight polyethylene is 1.5 million to 9 million; the molecular weight of the polyoxyethylene is 2000 to 20000; the nucleating agent is Milliken's HPN210M, Milliken's HPN20-E, Chenghe Technology NAP-5, N Any one or more of AE-23 and NA11 of Aidico; the photoinitiator is any one or more of 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester (TPO), (2,4,6-trimethylbenzoyl)di(p-tolyl)phosphine oxide (TMO) and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (819); the multifunctional monomer is any one or more of trimethylolpropane triacrylate (TMTPA) and triallyl isocyanurate (TAIC).

[0008] Multifunctional monomers contain multiple double bond groups, which can participate in the cross-linking reaction initiated by free radicals, help increase the degree of cross-linking, and promote the cross-linking reaction. Polyoxyethylene plasticizes ultra-high molecular weight polyethylene, increases its fluidity, and provides lubricity. The processing performance of polyoxyethylene with too high or too low molecular weight will deteriorate. Nucleating agents are used to increase the crystallinity of ultra-high molecular weight polyethylene and increase the transmittance of 190nm to 400nm ultraviolet light, and increase the strength of ultra-high molecular weight polyethylene at high temperatures.

[0009] Preferably, the molecular weight of the ultra-high molecular weight polyethylene is 3 million to 7 million. The molecular weight of the ultra-high molecular weight polyethylene affects the processing performance. Of course, the higher the molecular weight, the better the mechanical properties. However, when the molecular weight of the ultra-high molecular weight polyethylene exceeds 700, its processing performance decreases.

[0010] Preferably, the mass fraction of the nucleating agent is 0.05 to 0.8 parts. When the mass fraction of the nucleating agent is 0.05 to 0.8 parts, it can make it easier for ultraviolet rays to penetrate during UV irradiation, improve the efficiency of the photoinitiated reaction, and increase the degree of crosslinking. The type and amount of the nucleating agent are very important. In the case of UV non-crosslinking, the nucleating agent can slightly improve the mechanical properties and significantly improve the transmittance to ultraviolet rays; in the case of UV crosslinking, due to the increase in transmittance, the nucleating agent promotes the UV crosslinking reaction, increases the degree of crosslinking, and greatly improves its mechanical properties. However, after the mass fraction of the nucleating agent exceeds 0.8 parts, the increase in ultraviolet light transmittance gradually decreases, and the increase in the degree of crosslinking and performance also gradually decreases.

[0011] Preferably, the photoinitiator is ethyl 2,4,6-trimethylbenzoylphenylphosphonate (TPO). The photoinitiator is TPO, which has a higher reaction efficiency and a high initiation efficiency under low ultraviolet intensity irradiation and is suitable for deep curing.

[0012] The present invention provides an application of the ultra-high molecular weight polyethylene material described above in preparing an inner liner pipe in an oil field production device.

[0013] Preferably, the application comprises the following steps:

[0014] (1) The photoinitiator is dissolved in a multifunctional monomer, and then mixed with polyethylene oxide, a nucleating agent and a portion of ultra-high molecular weight polyethylene to form a masterbatch. The masterbatch is mixed with the remaining ultra-high molecular weight polyethylene to form a special material for the inner lining pipe of the oil production device; the ultra-high molecular weight polyethylene has a high viscosity and the additive is difficult to disperse. The ultra-high molecular weight polyethylene is added separately mainly to ensure the uniform dispersion of the nucleating agent in the ultra-high molecular weight polyethylene.

[0015] The mass of the part of the ultra-high molecular weight polyethylene is 25% of the total mass of the ultra-high molecular weight polyethylene; the mass of the remaining ultra-high molecular weight polyethylene is 75% of the total mass of the ultra-high molecular weight polyethylene;

[0016] (2) The special material is extruded into an inner liner pipe through an extruder;

[0017] (3) irradiating the formed inner liner with ultraviolet light to obtain an inner liner for use in an oil field production device; the ultraviolet light irradiation dose is 800 to 2000 MJ / m 2 .

[0018] The dosage of the ultraviolet light irradiation is 800-2000 MJ / m 2 The irradiation dose is very important. If the irradiation dose is too high, it will cause the degradation of ultra-high molecular weight polyethylene, resulting in a decrease in performance. If the irradiation dose is insufficient, the photoinitiator will not be completely decomposed, the reaction will not be sufficient, the cross-linking degree will be insufficient, and the performance will be very poor.

[0019] More preferably, in step (2), the diameter of the extruder is 75 mm.

[0020] More preferably, in step (2), the temperatures of the six sections of the extruder are 180°C, 200°C, 225°C, 250°C, 265°C and 270°C respectively.

[0021] More preferably, in step (2), the outer diameter of the inner liner is 79 mm and the wall thickness is 4.2 mm. The wall thickness has a relatively large impact. The wall thickness of the inner liner used in the oil field ranges from 3.5 to 4.2 mm and the outer diameter is 60 to 79 mm. If the wall thickness is 2 mm, its light transmittance can reach about 60%, and no nucleating agent is required. By selecting a suitable initiator and a multifunctional monomer, a relatively good cross-linking effect can be achieved, and the cross-linking degree can reach 73%. If the wall thickness is more than 5 mm, there is no good cross-linking effect, and the cross-linking degree is also low.

[0022] More preferably, in step (2), the die temperature of the extruder is 275° C., 275° C., 275° C. and 275° C. The temperatures of the extruder and the die reflect that the processing temperature of ultra-high molecular weight polyethylene is relatively high. If the temperature is lowered, extrusion is difficult and the torque is too high.

[0023] The ultra-high molecular weight polyethylene material for preparing the inner liner pipe in the oil field production device of the present invention and its application solve the problem that the prior art uses ultraviolet light curing, and the low crosslinking degree and poor crosslinking performance will occur for thick-walled products or products that cannot transmit ultraviolet rays, and has the following advantages:

[0024] 1. The ultra-high molecular weight polyethylene material used in the present invention for preparing the inner liner pipe in the oil field production device can be processed at 180-275°C. Compared with the prior art CN 109251389 B, a method for preparing a light-irradiated cross-linked ultra-high molecular weight polyethylene injection molding composite material and a light-irradiated cross-linked polyethylene for injection molding, which requires the use of a mold made of quartz glass, the production of the present invention does not require special molds and equipment, and the process is simple and can be produced continuously.

[0025] 2. The inner liner pipe prepared by the present invention has a high degree of crosslinking, good mechanical properties at 80°C, and significantly improved wear resistance and service life. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention are described clearly and completely below. 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.

[0027] Manufacturers, models and specifications of the raw materials involved in the following examples:

[0028] Ultra-high molecular weight polyethylene was purchased from Yanshan Petrochemical, with molecular weights of 1.5 million, 4 million, 7 million and 9 million;

[0029] Polyoxyethylene was purchased from Jilin Chemical Group's Xingyun Chemical, with molecular weights of 500,000, 2,000, 6,000 and 20,000;

[0030] The photoinitiator TMO was purchased from Lai Ting Technology; the photoinitiators TPO and 819 were both purchased from IGM.

[0031] Example 1

[0032] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device, the material is composed of the following components in parts by mass, with the total parts by mass of each component being 100 parts, and the specific components are as follows:

[0033] 90 parts by mass of ultra-high molecular weight polyethylene (molecular weight 4 million), 5.95 parts by mass of polyoxyethylene (molecular weight 6000), 0.05 parts by mass of nucleating agent (Milliken HPN20-E), 1 part by mass of photoinitiator TPO and 3 parts by mass of multifunctional monomer TMPTA.

[0034] The method for preparing the liner pipe of the oil field production device from the ultra-high molecular weight polyethylene material used for preparing the liner pipe of the oil field production device comprises:

[0035] (1) The photoinitiator is dissolved in a multifunctional monomer, and then mixed with polyoxyethylene PEG, a nucleating agent and a portion of ultra-high molecular weight polyethylene (the portion of the ultra-high molecular weight polyethylene accounts for 25% of the total mass of the ultra-high molecular weight polyethylene), and a masterbatch is formed on a twin-screw extruder. The masterbatch and the remaining ultra-high molecular weight polyethylene (the remaining ultra-high molecular weight polyethylene accounts for 75% of the total mass of the ultra-high molecular weight polyethylene) are mixed and granulated on a twin-screw extruder to form a special material for the inner lining pipe of the oil production device.

[0036] (2) The special material is extruded into an inner liner tube through a single screw extruder with a diameter of 75 mm; the six-stage temperatures of the extruder are 180°C, 200°C, 225°C, 250°C, 265°C and 270°C, and the mold temperatures are 275°C, 275°C, 275°C and 275°C; the outer diameter of the inner liner tube is 79 mm and the wall thickness is 4.2 mm.

[0037] (3) The inner liner is irradiated with ultraviolet light at a dose of 1500 mJ / m 2 , and obtain the inner liner pipe used in the oil field production device.

[0038] Example 2

[0039] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0040] The mass fraction of ultra-high molecular weight polyethylene is 84 parts, the mass fraction of photoinitiator TPO is 5 parts, and the mass fraction of multifunctional monomer is 5 parts.

[0041] The method for preparing the inner liner pipe in the oil field production device from the ultra-high molecular weight polyethylene material is the same as that in Example 1.

[0042] Example 3

[0043] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0044] The mass fraction of ultra-high molecular weight polyethylene is 84.5 parts, the mass fraction of polyoxyethylene is 5 parts, the mass fraction of nucleating agent (Milliken HPN20-E) is 0.5 parts, the mass fraction of photoinitiator TPO is 5 parts and the mass fraction of multifunctional monomer TMPTA is 5 parts.

[0045] The method for preparing the inner liner pipe in the oil field production device from the ultra-high molecular weight polyethylene material is the same as that in Example 1.

[0046] Example 4

[0047] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0048] The mass fraction of ultra-high molecular weight polyethylene is 84.2 parts, the mass fraction of polyoxyethylene is 5 parts, the mass fraction of nucleating agent (Milliken HPN20-E) is 0.3 parts, the mass fraction of nucleating agent (Milliken HPN210M) is 0.5 parts, the mass fraction of photoinitiator TPO is 5 parts and the mass fraction of multifunctional monomer TMPTA is 5 parts.

[0049] The method for preparing the inner liner pipe in the oil field production device from the ultra-high molecular weight polyethylene material is the same as that in Example 1.

[0050] Example 5

[0051] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0052] The mass fraction of ultra-high molecular weight polyethylene is 80 parts, the mass fraction of polyoxyethylene is 6 parts, the mass fraction of nucleating agent (Milliken HPN210M) is 1 part, the mass fraction of photoinitiator TPO is 5 parts and the mass fraction of multifunctional monomer TMPTA is 8 parts.

[0053] The method for preparing the inner liner pipe in the oil field production device from the ultra-high molecular weight polyethylene material is the same as that in Example 1.

[0054] Example 6

[0055] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0056] The mass fraction of ultra-high molecular weight polyethylene is 80 parts, the mass fraction of polyoxyethylene is 3.5 parts, the mass fraction of nucleating agent (Milliken HPN20-E) is 0.3 parts, the mass fraction of nucleating agent (Milliken HPN210M) is 0.2 parts, the mass fraction of photoinitiator TPO is 8 parts and the mass fraction of multifunctional monomer TMPTA is 8 parts.

[0057] The method for preparing the inner liner pipe in the oil field production device from the ultra-high molecular weight polyethylene material is the same as that in Example 1.

[0058] Example 7

[0059] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0060] The mass fraction of ultra-high molecular weight polyethylene is 80 parts, the mass fraction of polyoxyethylene is 6.5 parts, the mass fraction of nucleating agent (NAE-23 of Chenghe Technology) is 0.3 parts, the mass fraction of nucleating agent (NAP-5 of Chenghe Technology) is 0.2 parts, the mass fraction of photoinitiator TPO is 5 parts and the mass fraction of multifunctional monomer TMPTA is 8 parts.

[0061] The method for preparing the inner liner pipe in the oil field production device from the ultra-high molecular weight polyethylene material is the same as that in Example 1.

[0062] Example 8

[0063] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0064] The mass fraction of ultra-high molecular weight polyethylene is 80 parts (molecular weight 1.5 million), the mass fraction of polyoxyethylene is 6.5 parts, the mass fraction of nucleating agent (Aidico NA-11) is 0.5 parts, the mass fraction of photoinitiator TPO is 5 parts and the mass fraction of multifunctional monomer TMPTA is 8 parts.

[0065] The method for preparing the inner liner pipe in the oil field production device from the ultra-high molecular weight polyethylene material is the same as that in Example 1.

[0066] Example 9

[0067] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0068] The mass fraction of ultra-high molecular weight polyethylene is 80 parts (molecular weight 7 million), the mass fraction of polyoxyethylene is 3.5 parts, the mass fraction of nucleating agent (Milliken HPN20-E) is 0.3 parts, the mass fraction of nucleating agent (Milliken HPN210M) is 0.2 parts, the mass fraction of photoinitiator TPO is 4 parts, the mass fraction of photoinitiator 819 is 4 parts and the mass fraction of multifunctional monomer TAIC is 8 parts.

[0069] The method for preparing the inner liner pipe in the oil field production device from the ultra-high molecular weight polyethylene material is the same as that in Example 1.

[0070] Example 10

[0071] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0072] The mass fraction of ultra-high molecular weight polyethylene (molecular weight 9 million) is 80 parts, the mass fraction of polyoxyethylene is 6.5 parts, the mass fraction of nucleating agent (Milliken HPN20-E) is 0.3 parts, the mass fraction of nucleating agent (Milliken HPN210M) is 0.2 parts, the mass fraction of photoinitiator TMO is 5 parts and the mass fraction of multifunctional monomer TMPTA is 8 parts.

[0073] The method for preparing the inner liner pipe in the oil field production device from the ultra-high molecular weight polyethylene material is the same as that in Example 1.

[0074] Embodiment 11

[0075] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is basically the same as Example 1, except that: the mass fraction of is 84.5 parts, the mass fraction of polyoxyethylene is 5 parts, the mass fraction of a nucleating agent (Milliken HPN20-E) is 0.5 parts, the mass fraction of a photoinitiator TPO is 5 parts, and the mass fraction of a multifunctional monomer TMPTA is 5 parts.

[0076] The method for preparing the inner liner pipe in the oil field production device from the ultra-high molecular weight polyethylene material is the same as that in Example 1.

[0077] The method for preparing the inner liner pipe of the oil field production device from the ultra-high molecular weight polyethylene material is basically the same as that in Example 1, except that:

[0078] In step (3), the irradiation intensity is 800 mJ / cm 2 .

[0079] Example 12

[0080] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0081] The mass fraction of ultra-high molecular weight polyethylene is 84.5 parts, the mass fraction of polyoxyethylene is 5 parts, the mass fraction of nucleating agent (Milliken HPN20-E) is 0.5 parts, the mass fraction of photoinitiator TPO is 5 parts and the mass fraction of multifunctional monomer TMPTA is 5 parts.

[0082] The method for preparing the inner liner pipe of the oil field production device from the ultra-high molecular weight polyethylene material is basically the same as that in Example 1, except that:

[0083] In step (3), the irradiation intensity is 2000mJ / cm 2 .

[0084] Embodiment 13

[0085] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0086] The mass fraction of ultra-high molecular weight polyethylene is 84.5 parts, the mass fraction of polyoxyethylene (molecular weight 2000) is 5 parts, the mass fraction of nucleating agent (Milliken HPN20-E) is 0.5 parts, the mass fraction of photoinitiator TPO is 5 parts and the mass fraction of multifunctional monomer TMPTA is 5 parts.

[0087] The method for preparing the inner liner pipe of the oil field production device from the ultra-high molecular weight polyethylene material is basically the same as that in Example 1, except that:

[0088] In step (3), the irradiation intensity is 1500mJ / cm 2 .

[0089] Embodiment 14

[0090] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0091] The mass fraction of ultra-high molecular weight polyethylene is 84.5 parts, the mass fraction of polyoxyethylene (molecular weight 20,000) is 5 parts, the mass fraction of nucleating agent (Milliken HPN20-E) is 0.5 parts, the mass fraction of photoinitiator TPO is 5 parts and the mass fraction of multifunctional monomer TMPTA is 5 parts.

[0092] The method for preparing the inner liner pipe of the oil field production device from the ultra-high molecular weight polyethylene material is basically the same as that in Example 1, except that:

[0093] In step (3), the irradiation intensity is 1500mJ / cm 2 .

[0094] Comparative Example 1

[0095] A pure ultra-high molecular weight polyethylene for an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0096] The component is only ultra-high molecular weight polyethylene, and the mass fraction of the ultra-high molecular weight polyethylene is 100 parts.

[0097] The method for preparing the polyethylene material for preparing the inner liner pipe in the oil field production device is basically the same as that in Example 1, except that:

[0098] In step (1), 100 parts by mass of ultra-high molecular weight polyethylene is granulated on a twin-screw extruder to form a special material for the inner lining pipe of the oil production device.

[0099] Comparative Example 2

[0100] A polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0101] The mass fraction of ultra-high molecular weight polyethylene is 94 parts, the mass fraction of polyoxyethylene is 5 parts, and the mass fraction of nucleating agent (Milliken HPN210M) is 1 part.

[0102] The method for preparing the polyethylene material for preparing the inner liner pipe in the oil field production device is basically the same as that in Example 1, except that:

[0103] In step (1), no initiator and multifunctional monomer TMPTA were added.

[0104] Comparative Example 3

[0105] A polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0106] Without adding a nucleating agent, the mass fraction of ultra-high molecular weight polyethylene is 82 parts, the mass fraction of polyethylene oxide is 5 parts, the mass fraction of photoinitiator TPO is 5 parts, and the mass fraction of multifunctional monomer TMPTA is 8 parts.

[0107] The method for preparing the polyethylene material for preparing the inner liner pipe in the oil field production device is basically the same as that in Example 1, except that:

[0108] In step (1), no nucleating agent is added.

[0109] Comparative Example 4

[0110] A polyethylene material for preparing an inner liner pipe in an oil field production device (the corresponding patent number of each component is the formula of the corresponding embodiment 4 in CN109251389B) is basically the same as that of embodiment 1, except that:

[0111] The mass fraction of ultra-high molecular weight polyethylene is 80 parts, the mass fraction of low molecular weight polyolefin is 19 parts, the mass fraction of photoinitiator (benzophenone) is 0.8 parts, and the mass fraction of photoinitiator ITX (anthrone initiator) is 0.2 parts.

[0112] The method for preparing the polyethylene material for preparing the inner liner pipe in the oil field production device is the same as that in Example 1.

[0113] Comparative Example 5

[0114] A polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0115] The mass fraction of ultra-high molecular weight polyethylene is 85 parts, the mass fraction of polyoxyethylene (molecular weight 6000) is 5 parts, the mass fraction of photoinitiator (benzophenone) is 4 parts, the mass fraction of photoinitiator ITX (anthrone initiator) is 1 part and the mass fraction of multifunctional monomer TMPTA is 5 parts.

[0116] The method for preparing the polyethylene material for preparing the inner liner pipe in the oil field production device is the same as that in Example 1.

[0117] Comparative Example 6

[0118] A polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0119] The mass fraction of ultra-high molecular weight polyethylene is 84.5 parts, the mass fraction of polyoxyethylene is 5 parts, the mass fraction of nucleating agent (Milliken HPN20-E) is 0.5 parts, the mass fraction of photoinitiator (benzophenone) is 5 parts and the mass fraction of multifunctional monomer TMPTA is 5 parts.

[0120] The method for preparing the polyethylene material for preparing the inner liner pipe in the oil field production device is the same as that in Example 1.

[0121] Comparative Example 7

[0122] A polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0123] The mass fraction of ultra-high molecular weight polyethylene is 84.5 parts, the mass fraction of polyoxyethylene (molecular weight 500,000) is 5 parts, the mass fraction of nucleating agent (Milliken HPN20-E) is 0.5 parts, the mass fraction of photoinitiator (benzophenone) TPO is 5 parts and the mass fraction of multifunctional monomer TMPTA is 5 parts.

[0124] The method for preparing the polyethylene material for preparing the inner liner pipe in the oil field production device is the same as that in Example 1.

[0125] Comparative Example 8

[0126] An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device is substantially the same as that in Example 1, except that:

[0127] The mass fraction of ultra-high molecular weight polyethylene is 88 parts, the mass fraction of polyoxyethylene is 6 parts, the mass fraction of nucleating agent (Milliken HPN210M) is 1 part, and the mass fraction of photoinitiator TPO is 5 parts

[0128] The method for preparing the inner liner pipe in the oil field production device from the ultra-high molecular weight polyethylene material is the same as that in Example 1.

[0129] Experimental Example 1 Performance Test

[0130] Samples of the same size were cut from the liner pipes prepared in Examples 1 to 14 and Comparative Examples 1 to 7 for testing, wherein the mass wear test was conducted in accordance with GB / T3960, the tensile yield strength was tested in accordance with GB / T1040, the crosslinking degree was tested in accordance with the GB / T8474 test method, and the transmittance was tested in accordance with GB / T2410. The specific test results are detailed in Table 1.

[0131] Table 1 Performance of Examples and Comparative Examples

[0132]

[0133]

[0134] It can be seen from the data in Table 1 that compared with the pure ultra-high molecular weight polyethylene of Comparative Example 1, the tensile strength of the ultra-wear-resistant ultra-high molecular weight polyethylene materials prepared by Examples 3 to 12 of the present invention at 80°C is greatly increased, the wear amount is greatly reduced, and the wear resistance is significantly improved. Compared with Comparative Example 2 (without cross-linking and with nucleating agent) and Comparative Example 1 (without cross-linking and without nucleating agent), Examples 1-5 of the present invention show that when there is no nucleating agent or the content of the nucleating agent is low (Example 1, the content of the nucleating agent is 0.05%), the ultraviolet transmittance is low, the cross-linking degree of the material is low, and the performance improvement is not large, which shows that the nucleating agent slightly improves the tensile strength and wear resistance at high temperature. When the content of the nucleating agent is high, (Examples 3 to 5) the ultraviolet transmittance is high, the cross-linking degree is high, and the performance is greatly improved after cross-linking. Different types of nucleating agents are used in Examples 6, 7 and 8. It can be seen that the effects of Milliken HPN20-E and Milliken HPN210M are better than Chenghe Technology NAE-23, Chenghe Technology NAP-5 and Aidico NA-11. The test data of Examples 2 to 5 of the present invention show that as the amount of nucleating agent added gradually increases, the transmittance of ultraviolet light also gradually increases, the degree of crosslinking increases significantly, and the performance is greatly improved. However, after the mass fraction of the nucleating agent exceeds 0.8 parts, the increase in ultraviolet light transmittance gradually decreases, and the increase in crosslinking degree and performance also gradually decreases. Compared with Comparative Example 4, Example 3 of the present invention is the formula of Example 4 corresponding to the patent number CN 109251389 B. It can be seen from the test results that the strength of Example 3 is much higher than that of Comparative Example 4. Compared with Comparative Example 6, Example 3, Example 9 and Example 10 of the present invention use TPO as a photoinitiator, Example 9 uses TPO and 819 as photoinitiators, and Example 10 uses TMO as a photoinitiator. The crosslinking degrees of Example 3, Example 9 and Example 10 are between 67% and 73%, and the crosslinking degree of Comparative Example 6 is 35%. The performance of Examples 3, 9 and 10 is much better than that of the Comparative Example. It shows that the initiation effect of TPO, 819 and TMO is better than that of benzophenone and ITX. These initiators can still have a high reaction efficiency under low ultraviolet intensity irradiation, and the initiation efficiency is high, which is suitable for deep curing. Compared with Comparative Example 8, Example 5 does not have a multifunctional monomer in Comparative Example 8. The crosslinking degree of Example 5 is 77%, and the crosslinking degree of Comparative Example 8 is 61%, which shows that the addition of multifunctional monomers increases the crosslinking degree and improves the strength. Compared with Example 1 and Example 2, the amount of photoinitiator and multifunctional monomer in Example 1 is too small, and its crosslinking degree and strength are both low. The molecular weights of the ultra-high molecular weight polyethylene used in Examples 8, 9 and 10 are 1.5 million, 7 million and 9 million respectively, and their processing properties are excellent, medium and poor respectively. The irradiation doses of Examples 11 and 12 of the present invention are different. The irradiation dose of Example 11 is 800 mJ / m 2 Example 12: irradiation dose 2000 mJ / m 2The crosslinking degree of Example 11 is 54%, and the crosslinking degree of Example 12 is 75%, indicating that the irradiation dose has a greater effect on the strength. Compared with Comparative Example 7, Examples 13 and 14 of the present invention use polyoxyethylene with a molecular weight of 2000, Example 14 uses polyoxyethylene with a molecular weight of 20,000, and Comparative Example 7 uses polyoxyethylene with a molecular weight of 500,000, indicating that the processing performance will deteriorate if polyoxyethylene with too high or too low molecular weight is used.

[0135] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. An ultra-high molecular weight polyethylene material for preparing an inner liner pipe in an oil field production device by ultraviolet curing, characterized in that: When the material is cured by UV light, the UV radiation dose is 800~2000MJ / m 2 The material contains the following components in parts by mass, with the total parts by mass of each component being 100 parts. The specific components are as follows: 80-90 parts by weight of ultra-high molecular weight polyethylene, 3.5-6.5 parts by weight of polyoxyethylene, 0.5-0.8 parts by weight of a nucleating agent, 3-8 parts by weight of a photoinitiator, and 3-8 parts by weight of a multifunctional monomer; The molecular weight of the ultra-high molecular weight polyethylene is 1.5 million to 9 million; The molecular weight of the polyoxyethylene is 2000-20000; The nucleating agent is any one or more of Milliken's HPN210M, Milliken's HPN20-E, Chenghe Technology's NAP-50, NAE-23 and Aidico's NA11; The photoinitiator is any one or more of 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, (2,4,6-trimethylbenzoyl)di(p-tolyl)phosphine oxide and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; The multifunctional monomer is any one or both of trimethylolpropane triacrylate and triallyl isocyanurate.

2. The ultra-high molecular weight polyethylene material according to claim 1, characterized in that: The molecular weight of the ultra-high molecular weight polyethylene is 3 million to 7 million.

3. The ultra-high molecular weight polyethylene material according to claim 1, characterized in that: The photoinitiator is ethyl 2,4,6-trimethylbenzoylphenylphosphonate.

4. Use of the ultra-high molecular weight polyethylene material according to any one of claims 1 to 3 in preparing an inner liner pipe in an oil field production device.

5. The use according to claim 4, characterized in that: The application consists of the following steps: (1) dissolving the photoinitiator in the multifunctional monomer, and then mixing it with the polyoxyethylene, the nucleating agent and part of the ultra-high molecular weight polyethylene to form a masterbatch, and the masterbatch is mixed with the remaining ultra-high molecular weight polyethylene to form a special material for the inner lining pipe of the oil production device; The mass of the part of the ultra-high molecular weight polyethylene is 25% of the total mass of the ultra-high molecular weight polyethylene; the mass of the remaining ultra-high molecular weight polyethylene is 75% of the total mass of the ultra-high molecular weight polyethylene; (2) The special material is extruded into an inner liner pipe through an extruder; (3) irradiating the formed inner liner with ultraviolet light to obtain an inner liner for use in an oil field production device; the ultraviolet light irradiation dose is 800-2000 MJ / m 2 .

6. The use according to claim 5, characterized in that: The extruder had a diameter of 75 mm.

7. The use according to claim 5, characterized in that: The six temperature zones of the extruder are 180°C, 200°C, 225°C, 250°C, 265°C and 270°C respectively.

8. The use according to claim 7, characterized in that: The outer diameter of the inner liner pipe is 79 mm and the wall thickness is 4.2 mm.

9. The use according to claim 7, characterized in that: The die temperatures of the extruder were 275°C, 275°C, 275°C, and 275°C.

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