Crude oil pour point depressant, preparation method and application

Abstract

This application provides a crude oil pour point depressant, its preparation method, and its application. The crude oil pour point depressant includes a first copolymer and a second copolymer. The first copolymer includes vinyl acetate monomer and a comonomer, the comonomer including alkyl acrylate and / or alkyl methacrylate. The second copolymer includes ethylene monomer and a functional olefin monomer. The functional unit of the functional olefin monomer includes at least one of ester, acid, and anhydride groups. The first copolymer and the second copolymer form an interpenetrating network (IPN). Each copolymer contains a long alkyl backbone and polar side chains, which can improve crude oil fluidity. In addition, the two copolymers form an IPN structure, with the polymers directly interpenetrating and intertwining. This allows both copolymers to exert their respective properties and improves their compatibility, solving the problem of phase separation in composite pour point depressants and preventing sedimentation.

Description

Technical Field

[0001] This application relates to the field of crude oil pour point depressants, and more particularly to a crude oil pour point depressant, its preparation method, and its application. Background Technology

[0002] Crude oil pour point depressants, also known as crude oil flowability improvers, are generally oil-soluble polymers, mostly composed of long alkyl backbones and polar side chains. The addition of crude oil pour point depressants can alter the crystallization state of paraffin in the oil, lowering the pour point and viscosity of the crude oil, thereby improving its low-temperature flowability, increasing efficiency in crude oil collection, transportation, and storage, and reducing production costs.

[0003] Polyethylene-vinyl acetate (EVA) copolymers are currently widely used and effective crude oil pour point depressants. Patents with application numbers CN201610105626.8 and CN201510840551.3 disclose crude oil pour point depressants using ethylene and vinyl acetate as raw materials. However, given the diverse types and complex compositions of crude oil, their application scope remains limited. Ethylene-vinyl acetate pour point depressants are often used for modification or in combination with other pour point depressants.

[0004] When EVA-based pour point depressants are mixed with other chemical types of pour point depressants (such as alkyl acrylates / alkyl methacrylates), incompatibility can occur, leading to EVA precipitation and separation in the product. This non-homogeneous product fails to provide the required performance and may cause clogging problems during application or pumping. Therefore, developing a more stable EVA-containing compound pour point depressant is an urgent problem to be solved. Summary of the Invention

[0005] This application provides a crude oil pour point depressant, its preparation method, and its application. This crude oil pour point depressant can improve the stability of two polymer pour point depressants and avoid precipitation due to incompatibility between the two.

[0006] This application provides a method for preparing the above-mentioned crude oil pour point depressant, wherein an interpenetrating network structure is generated between the two polymers, so that the two polymers interpenetrate and intertwine, thereby improving their compatibility.

[0007] This application provides an application of a crude oil pour point depressant, in which the crude oil pour point depressant prepared above is added to crude oil to achieve a pour point depressing effect in crude oil.

[0008] The first aspect of this application provides a crude oil pour point depressant, comprising: a first copolymer and a second copolymer, wherein the first copolymer comprises vinyl acetate monomer and a comonomer, the comonomer comprising alkyl acrylate and / or alkyl methacrylate, the second copolymer comprises ethylene monomer and a functional olefin monomer, the functional unit of the functional olefin monomer comprising at least one of ester group, acid group, and anhydride group, and the first copolymer and the second copolymer form an interpenetrating polymer network (IPN) structure.

[0009] The crude oil pour point depressant as described above, wherein the functional olefin comonomer includes at least one of vinyl acetate, vinyl butyrate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, acrylic acid, and maleic anhydride.

[0010] The crude oil pour point depressant as described above, wherein the alkyl chain length of the alkyl acrylate and / or alkyl methacrylate of the first copolymer is in the range of C12-C30.

[0011] The crude oil pour point depressant as described above, wherein the first copolymer comprises 15-60% by mass in the crude oil pour point depressant.

[0012] The crude oil pour point depressant as described above, wherein the second copolymer comprises 1-20% by mass in the crude oil pour point depressant.

[0013] The crude oil pour point depressant as described above, wherein the vinyl acetate monomer in the first copolymer is 0.2-10% by mass.

[0014] The crude oil pour point depressant as described above, wherein the solvent of the crude oil pour point depressant is toluene.

[0015] Secondly, this application provides a method for preparing a crude oil pour point depressant as described in any of the first aspects, the method comprising:

[0016] Alkyl acrylate and / or alkyl methacrylate, vinyl acetate, and a second copolymer are dissolved in a solvent to form a monomer solution; wherein the second copolymer comprises an ethylene monomer and a functional olefin monomer, and the functional unit of the functional olefin monomer comprises at least one of an ester group, an acid group, and an anhydride group;

[0017] Free radical polymerization was carried out by adding a free radical initiator to the monomer solution;

[0018] After the reaction is complete, post-processing is performed to obtain the first copolymer.

[0019] The crude oil pour point depressant as described above, wherein the second copolymer is polyethylene-vinyl acetate (EVA).

[0020] Thirdly, this application provides a method for applying a crude oil pour point depressant, wherein the crude oil pour point depressant as described in any of the first aspects is added to a crude oil sample, wherein the amount of crude oil pour point depressant added is 500-4000 ppm.

[0021] This application provides a crude oil pour point depressant, its preparation method, and its application. The crude oil pour point depressant includes a first copolymer and a second copolymer. The first copolymer includes vinyl acetate monomer and a comonomer, the comonomer including alkyl acrylate and / or alkyl methacrylate. The second copolymer includes ethylene monomer and a functional olefin monomer. The functional unit of the functional olefin monomer includes at least one of ester, acid, and anhydride groups. The first copolymer and the second copolymer form an interpenetrating polymer network (IPN). The interpenetrating network structure between the two copolymers, with direct interpenetration and interweaving of the polymers, can improve their compatibility and stability, and prevent sedimentation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram comparing the stability of different samples provided in this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] When EVA-type pour point depressants are mixed with other chemical types of pour point depressants (such as alkyl acrylate / alkyl methacrylate copolymers), incompatibility can occur, causing EVA to precipitate and separate in the product. This non-homogeneous product cannot provide the required performance and may also cause clogging problems during application or pumping.

[0025] This is mainly because EVA-type pour point depressants are primarily composed of ethylene (-CH2CH2-) and vinyl acetate (-COOCH2CH3) units, which possess a certain degree of polarity (because vinyl acetate contains ester groups). Alkyl acrylate polymer pour point depressants, such as butyl acrylate and methacrylate, contain strongly polar groups (e.g., acidic groups), resulting in higher polarity. Molecules with higher polarity readily form strong hydrogen bonds and polar interactions, but when mixed with low-polarity molecules (such as EVA), the difference in polarity leads to insufficient intermolecular interactions, making it difficult to form a homogeneous mixture. This difference in interaction often results in phase separation.

[0026] Based on this, this application takes into account the problem that the two pour point depressants are prone to phase separation after being blended. An EVA-type pour point depressant is added to the monomer of the alkyl acrylate polymer, that is, the EVA-type pour point depressant is added before the polymerization reaction. As the polymerization reaction occurs, the generated alkyl acrylate polymer will entangle and intertwine with the EVA-type polymer, forming a mixture with an interpenetrating network structure. The interaction force will be strengthened, the solubility of the two will be improved, and the problem of easy phase separation will be solved.

[0027] The solution provided in this application can be used not only to obtain a composite pour point depressant by copolymerizing ethylene and ethyl acetate to obtain a mixture of EVA-type pour point depressant and alkyl acrylate polymer pour point depressant, but also to obtain a composite pour point depressant by copolymerizing ethylene and other functional olefin monomers to obtain a mixture of pour point depressant and alkyl acrylate polymer pour point depressant.

[0028] The first aspect of this application provides a crude oil pour point depressant, comprising: a first copolymer and a second copolymer, wherein the first copolymer comprises vinyl acetate monomer and a comonomer, the comonomer comprising alkyl acrylate and / or alkyl methacrylate, the second copolymer comprises ethylene monomer and a functional olefin monomer, the functional unit of the functional olefin monomer comprising at least one of ester group, acid group, and anhydride group, and the first copolymer and the second copolymer form an interpenetrating network structure.

[0029] This crude oil pour point depressant is a composite type, comprising two categories: one type polymerized from ethylene monomers and functional olefin monomers, and the other from vinyl acetate and alkyl acrylate monomers. Each type consists of a long alkyl backbone and polar side chains, thus enabling it to function as a crude oil pour point depressant and improve crude oil flowability. To enhance the compatibility of the two types of pour point depressants, a second copolymer is added to the monomer solution of the first polymer during the preparation of the first copolymer. During the formation of the first polymer, the second copolymer interpenetrates and intertwines in a spatial network structure, forming an interpenetrating polymer network (IPN) without forming covalent bonds. Thus, the two polymer networks within the IPN structure possess different chemical properties (e.g., polarity, hydrophilic / hydrophobicity, rigidity / flexibility). This interweaving allows both polymers to exert their respective properties and improves their solubility, addressing the issue of phase separation common in composite pour point depressants. This interpenetrating network structure formed during the chemical preparation process cannot be achieved through physical blending, thus resulting in better solubility than blending two pour point depressants.

[0030] In one specific implementation, the first copolymer is obtained from vinyl acetate monomer and alkyl acrylate.

[0031] In one specific implementation, the first copolymer is obtained from vinyl acetate monomer and alkyl methacrylate.

[0032] In one specific implementation, the first copolymer is obtained by polymerizing a combination of two monomers, alkyl methacrylate and alkyl methacrylate, with vinyl acetate monomer.

[0033] Furthermore, the functional olefin comonomers include at least one of vinyl acetate, vinyl butyrate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, acrylic acid, and maleic anhydride.

[0034] Furthermore, the alkyl chain length of the alkyl acrylate and / or alkyl methacrylate of the first copolymer is in the range of C12-C30. Exemplarily, the alkyl chain length can be C12, C14, C18, C20, C22, C25, C26, C28, C30, or any combination of two of the above alkyl chain lengths. In one specific implementation, the alkyl acrylate is octadecyl acrylate.

[0035] The long alkyl chain (C12-C30) increases the hydrophobicity of the copolymer, making it easier for it to interact with petroleum substances such as crude oil. This helps to enhance the affinity of the pour point depressant with the oil phase during oil and gas extraction, oil transportation, and storage, thereby more effectively dispersing and stabilizing solid particles in the oil and preventing the formation of condensates.

[0036] Furthermore, the crude oil pour point depressant includes a solvent, a first copolymer, and a second copolymer, wherein the first copolymer comprises 15-60% by mass in the crude oil pour point depressant. For example, the first copolymer comprises 15%, 20%, 30%, 35%, 40%, 45%, 50%, 60% by mass in the crude oil pour point depressant, or any range consisting of any two of the above mass percentages.

[0037] Furthermore, the second copolymer constitutes 1-20% of the crude oil pour point depressant by mass. For example, the second copolymer constitutes 1%, 5%, 10%, 12%, 15%, 45%, 18%, 20% of the crude oil pour point depressant by mass, or any range consisting of two of the above mass percentages.

[0038] Furthermore, the first copolymer includes vinyl acetate monomer and comonomer, wherein the vinyl acetate monomer comprises 0.2-10% by mass in the first copolymer. For example, the mass percentage is 0.2%, 0.5%, 1%, 3%, 5%, 7%, 8%, 10%, or any range of two of the above mass percentages.

[0039] Furthermore, the total mass percentage of the first copolymer and the second copolymer in the crude oil pour point depressant is 16-80%. For example, the mass percentage is 16%, 20%, 30%, 40%, 50%, 70%, 75%, 80%, or any range of two of the above mass percentages.

[0040] Furthermore, the solvent for the crude oil pour point depressant is toluene. Toluene can effectively dissolve and disperse the polymer in the pour point depressant, ensuring its stability and effectiveness.

[0041] Secondly, this application provides a method for preparing a crude oil pour point depressant, the method comprising:

[0042] 1) Dissolve alkyl acrylate and / or alkyl methacrylate, vinyl acetate, and a second copolymer in a solvent to form a monomer solution; wherein the second copolymer comprises ethylene monomer and functional olefin monomer, and the functional unit of the functional olefin monomer comprises at least one of ester group, acid group, and anhydride group;

[0043] 2) Add a free radical initiator to the monomer solution to carry out free radical polymerization;

[0044] 3) After the reaction is complete, post-treatment is performed to obtain the first copolymer.

[0045] In this way, the first copolymer is interwoven into the network structure of the second copolymer, resulting in an interpenetrating network polymer.

[0046] Furthermore, the second copolymer is polyethylene-vinyl acetate (EVA).

[0047] Thirdly, this application provides a method for applying a crude oil pour point depressant, wherein the crude oil pour point depressant as described in the first aspect is added to a crude oil sample, and the amount of crude oil pour point depressant added is 500-4000 ppm. For example, the added amount is 500 ppm, 1000 ppm, 1500 ppm, 2000 ppm, 3000 ppm, or 4000 ppm.

[0048] This application proposes adding a composite pour point depressant with an interpenetrating network structure to crude oil. Adding a small amount of pour point depressant can prevent the crude oil pour point depressant from undergoing phase separation and sedimentation.

[0049] The present application will be further described below through specific embodiments.

[0050] In the following embodiments and comparative examples, the EVA used includes:

[0051] EVA1: 28% vinyl acetate by weight, melt index = 41

[0052] EVA2: 28% vinyl acetate by weight, melt index = 6

[0053] EVA3: 28% vinyl acetate by weight, melt index = 400

[0054] EVA4: 32% vinyl acetate by weight, melt index = 21

[0055] EVA5: 32% vinyl acetate by weight, melt index = 2.5.

[0056] Example 1

[0057] The preparation method of the crude oil pour point depressant in this embodiment includes the following steps:

[0058] 1) Synthesis of octadecyl acrylate: 108 g of acrylic acid, 338 g of octadecyl alcohol, 3.35 g of p-toluenesulfonic acid, 2.54 g of hydroquinone, and 260 g of toluene were added to a 1000 mL three-necked flask equipped with a thermometer, magnetic induction, spherical condenser, and water separator. The mixture was reacted at 125 °C for 4 hours, and then the reaction was stopped. The reaction mixture was poured into a round-bottom flask and evaporated using a rotary evaporator to remove the solvent toluene and excess acrylic acid. The crude ester solution was then poured into a separatory funnel and washed with 5% sodium hydroxide solution until the aqueous layer was colorless to remove the catalyst and polymerization inhibitor. The solution was then repeatedly washed with deionized water until neutral and dried under vacuum to obtain 385 g of a waxy solid product, with a yield of 95%.

[0059] 2) Add 177.4g of octadecyl acrylate, 22.6g of vinyl acetate, 6.67g of EVA5 and 206.67g of toluene to a three-necked flask. Heat the reaction flask to 110℃ and stir for 45 minutes to fully melt EVA5. Then cool to 90℃ and add 6.2g of benzoyl peroxide (BPO) as an initiator to the system. Control the temperature within the range of 85-100℃ and react for 2 hours. Stop the reaction and add 253.3g of toluene to the reaction solution to obtain the crude oil pour point depressant (OAVA1-EVA5).

[0060] The crude oil pour point depressant formulation in Example 1 includes 30% by weight of octadecyl acrylate-vinyl acetate copolymer, 1% by weight of EVA5, and 69% by weight of toluene; in the octadecyl acrylate-vinyl acetate copolymer, the mass ratio of octadecyl acrylate to vinyl acetate is 88.7:11.3.

[0061] Example 2

[0062] The method for preparing OAVA1-EVA5 in Example 1 differs from that in Example 1 in that the crude oil pour point depressant formulation includes 25% by weight of octadecyl acrylate-vinyl acetate copolymer, 2% by weight of EVA5, and 73% by weight of toluene. In the octadecyl acrylate-vinyl acetate copolymer, the mass ratio of octadecyl acrylate to vinyl acetate is 88.7:11.3.

[0063] Example 3

[0064] The method for preparing OAVA1-EVA5 in Example 1 differs from that in Example 1 in that the crude oil pour point depressant formulation includes 25% by weight of octadecyl acrylate-vinyl acetate copolymer, 2% by weight of EVA5, and 73% by weight of toluene. In the octadecyl acrylate-vinyl acetate copolymer, the mass ratio of octadecyl acrylate to vinyl acetate is 89.0:11.0.

[0065] Example 4

[0066] The preparation method of the example differs from that of Example 1 in that the vinyl acetate in Example 1 is replaced with butyl acrylate to obtain octadecyl acrylate-butyl acrylate copolymer (OABUA1-EVA5).

[0067] The formulation of the crude oil pour point depressant contains 95.8% octadecyl acrylate to butyl acrylate copolymer by weight, with EVA5 added before the reaction. The product formulation consists of 25% octadecyl acrylate to butyl acrylate copolymer by weight, 2% EVA5 by weight, and 73% toluene by weight. The mass ratio of octadecyl acrylate to butyl acrylate is 95.8% : 4.2.

[0068] Comparative Example 1

[0069] Formulation of crude oil pour point depressant: In this comparative example, EVA is not added before the polymerization of vinyl acetate-octadecyl acrylate (OA1). Instead, after polymerization, it is stirred and blended with EVA1 (28% by weight vinyl acetate, melt index 41) in a toluene solution system. The mass ratio of octadecyl acrylate polymer to EVA1 is 30%:4%.

[0070] Comparative Example 2

[0071] Using the preparation method of Comparative Example 1, the mass ratio of octadecyl acrylate polymer to EVA1 was 30%:2%.

[0072] Comparative Example 3

[0073] Using the preparation method of Comparative Example 1, the mass ratio of octadecyl acrylate polymer to EVA1 was 25%:1%.

[0074] Comparative Example 4

[0075] Using the preparation method of Comparative Example 1, the mass ratio of octadecyl acrylate polymer to EVA1 was 25%:0.5%.

[0076] Comparative Example 5

[0077] Using the preparation method of Comparative Example 1, the mass ratio of octadecyl acrylate polymer to EVA1 was 20%:2%.

[0078] Comparative Example 6

[0079] Using the preparation method of Comparative Example 1, the mass ratio of octadecyl acrylate polymer to EVA1 was 20%:1%.

[0080] Comparative Example 7

[0081] Using the preparation method of Comparative Example 1, the mass ratio of octadecyl acrylate polymer to EVA1 was 18%:4%.

[0082] Comparative Example 8

[0083] Using the preparation method of Comparative Example 1, the mass ratio of octadecyl acrylate polymer to EVA1 was 16%:4%.

[0084] Comparative Example 9

[0085] The preparation method of Comparative Example 1 was adopted, except that EVA2 was used instead of EVA1. In the crude oil pour point depressant, the mass ratio of octadecyl acrylate polymer to EVA2 was 25%:3%.

[0086] Comparative Example 10

[0087] The preparation method of Comparative Example 1 was adopted, except that EVA3 was used instead of EVA1. In the crude oil pour point depressant, the mass ratio of octadecyl acrylate polymer to EVA2 was 25%:3%.

[0088] Comparative Example 11

[0089] The preparation method of Comparative Example 1 was adopted, except that EVA4 was used instead of EVA1. In the crude oil pour point depressant, the mass ratio of octadecyl acrylate polymer to EVA2 was 25%:3%.

[0090] Comparative Example 12

[0091] Octadecyl acrylate homopolymer OA1 is obtained by polymerizing octadecyl acrylate via free radical polymerization.

[0092] The crude oil pour point depressant was obtained by blending OA1:EVA1 in a toluene solution at a mass ratio of 25%:3%.

[0093] Comparative Example 13

[0094] An octadecyl acrylate-butyl acrylate copolymer (OABUA1) was prepared, wherein the mass ratio of octadecyl acrylate to butyl acrylate was 95.8%:4.2%.

[0095] The crude oil pour point depressant was obtained by stirring and mixing OABUA1:EVA1 in a toluene solution at a mass ratio of 25%:3%.

[0096] Comparative Example 14

[0097] An octadecyl acrylate-vinyl acetate copolymer (OAVA1) was prepared, wherein the mass ratio of octadecyl acrylate to vinyl acetate was 88.7%:11.3%.

[0098] The crude oil pour point depressant was obtained by stirring and mixing the OAVA1:EVA1 in a toluene solution at a mass ratio of 25%:3%.

[0099] Comparative Example 15

[0100] An octadecyl acrylate-octadecyl methacrylate copolymer (OAOSA1) was prepared, wherein the mass ratio of octadecyl acrylate to vinyl acetate was 77.4%:25.6%.

[0101] The crude oil pour point depressant was obtained by stirring and mixing OAOSA1:EVA1 in a toluene solution at a mass ratio of 25%:3%.

[0102] Test case

[0103] The above examples and comparative examples were placed at room temperature (23°C) for 1 day, 3 days, and 10 days, and the state of the solution was observed.

[0104] The specific results are shown in Table 1.

[0105]

[0106]

[0107] "2-phase" refers to a large number of particles on the inner wall of the glass bottle; "3-phase" refers to a large number of particles on the inner wall of the glass bottle, while there is a solid precipitate at the bottom of the liquid phase.

[0108] The test results above show that, in Examples 1-4, adding an EVA-type pour point depressant to the monomer solution before the polymerization reaction resulted in a pour point depressant that remained essentially transparent after 3 days. Compared to the blending results of the comparative examples, this significantly improved the compatibility and stability of the two. Examples 1, 2, and 4 also maintained good stability after ten days.

[0109] In the comparative examples, neither changing the proportions nor altering the percentage of monomer fragments in the EVA-type pour point depressant could achieve the effects described in the examples. This is because such interpenetrating network polymers cannot be prepared solely through blending.

[0110] Figure 1 This is a schematic diagram comparing the stability of different samples provided in this application, as shown below. Figure 1 As shown, from left to right, the crude oil pour point depressants of Comparative Example 1, Comparative Example 12, Comparative Example 13, and Example 1 are actual images of their effects after ten days. As can be seen from the images, the Comparative Example 12 exhibits a three-phase state, Comparative Example 12 exhibits a turbid state, Comparative Example 13 exhibits a two-phase state, while Example 1 exhibits a clear state.

[0111] The comparison of effects shown in the figure also proves that adding EVA-type pour point depressant during the synthesis of acrylate copolymers results in a composite pour point depressant with better stability than the composite pour point depressant obtained by blending, and can solve the sedimentation problem between the two.

[0112] Pour Depression Effect Test

[0113] Using a pour point test standard similar to ASTM 5853, crude oil samples from the Asia-Pacific region were heated to approximately 80°C, with 2000 ppm of pour point depressant added. After standing at room temperature for 24 hours, the temperature was raised to 45°C, and then allowed to cool naturally to 30°C before testing. Flowability was observed by slightly tilting the sample, checking its flowability every 3°C. When the temperature dropped below 24°C, the flowability was checked every 1°C. When the sample remained unflowed for 5 seconds while horizontal, it was considered gelled, and the pour point was defined as 1°C higher than the temperature at which it gelled. The sample in this example is:

[0114] Blank control, without the addition of pour point depressant.

[0115] OABUA1-EVA5 = 95.8%: 4.2% by weight of octadecyl acrylate-butyl acrylate copolymer, with EVA5 added before the reaction. Product formulation: 25% by weight of octadecyl acrylate-butyl acrylate copolymer, 2% by weight of EVA5, and 73% by weight of toluene.

[0116] OAVA1-EVA5 = 88.7%: 11.3% by weight of octadecyl acrylate-vinyl acetate copolymer, with EVA5 added before the reaction. Product formulation: 25% by weight of octadecyl acrylate-vinyl acetate copolymer, 2% by weight of EVA5, and 73% by weight of toluene.

[0117] OAVA1-EVA5 = 88.7%: 11.3% by weight of octadecyl acrylate-vinyl acetate copolymer, with EVA5 added before the reaction. Product formulation: 30% by weight of octadecyl acrylate-vinyl acetate copolymer, 1% by weight of EVA5, and 69% by weight of toluene.

[0118] OA1:EVA5 = 26%:4%, with EVA5 added after the reaction. Product formulation: 26% by weight octadecyl acrylate, 4% by weight EVA5, and 70% by weight toluene.

[0119] For detailed results, please refer to Table 2.

[0120]

[0121] As can be seen, after adding the pour point depressant, the pour point decreased significantly compared to the blank control. Adding the EVA-type pour point depressant before the reaction also had a pour point depressing effect. It is worth noting that although the pour point depressing effect is not necessarily better with the blend (OA1:EVA5 = 26%:4%), it has excellent stability.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A crude oil pour point depressant, characterized in that, include: A first copolymer and a second copolymer, wherein the first copolymer comprises vinyl acetate monomer and a comonomer, the comonomer comprising alkyl acrylate and / or alkyl methacrylate, the second copolymer comprises ethylene monomer and a functional olefin monomer, the functional unit of the functional olefin monomer comprising at least one of ester group, acid group, and anhydride group, and the first copolymer and the second copolymer form an interpenetrating network structure IPN.

2. The crude oil pour point depressant according to claim 1, characterized in that, The functional olefin comonomers include at least one of vinyl acetate, vinyl butyrate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, acrylic acid, and maleic anhydride.

3. The crude oil pour point depressant according to claim 1, characterized in that, The alkyl chain length of the alkyl acrylate and / or alkyl methacrylate of the first copolymer is in the range of C12-C30.

4. The crude oil pour point depressant according to any one of claims 1-3, characterized in that, The first copolymer has a mass percentage of 15-60% in the crude oil pour point depressant.

5. The crude oil pour point depressant according to any one of claims 1-3, characterized in that, The second copolymer comprises 1-20% by mass in the crude oil pour point depressant.

6. The crude oil pour point depressant according to any one of claims 1-3, characterized in that, In the first copolymer, the mass percentage of the vinyl acetate monomer is 0.2-10%.

7. The crude oil pour point depressant according to any one of claims 1-3, characterized in that, The solvent for the crude oil pour point depressant is toluene.

8. A method for preparing a crude oil pour point depressant, characterized in that, The preparation method is used to prepare the crude oil pour point depressant according to any one of claims 1-7, and the method includes: Alkyl acrylate and / or alkyl methacrylate, vinyl acetate, and a second copolymer are dissolved in a solvent to form a monomer solution; wherein the second copolymer comprises an ethylene monomer and a functional olefin monomer, and the functional unit of the functional olefin monomer comprises at least one of an ester group, an acid group, and an anhydride group; Free radical polymerization was carried out by adding a free radical initiator to the monomer solution; After the reaction is complete, a crude oil pour point depressant is obtained.

9. The preparation method according to claim 8, characterized in that, The second copolymer is polyethylene-vinyl acetate EVA.

10. A method for applying a crude oil pour point depressant, characterized in that, The crude oil pour point depressant as described in any one of claims 1-6 is added to the crude oil sample, wherein the amount of crude oil pour point depressant added is 500-4000 ppm.

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