阅读说明：本技术 一种甲基丙烯酸酯类降凝剂及其制备方法 (Methacrylate pour point depressant and preparation method thereof ) 是由 修宗明 崔仕章 王黎明 宋新旺 高瑞美 侯云福 吕志凤 于 2020-12-16 设计创作，主要内容包括：本申请公开了一种甲基丙烯酸酯类降凝剂及其制备方法,属于油田化学品技术领域。该甲基丙烯酸酯类降凝剂,包括聚甲基丙烯酸混合酯和聚甲基丙烯酸十六酯-丙烯酰胺/二氧化硅纳米复合材料。该甲基丙烯酸类降凝剂,可快速分散于原油中,加入原油中时不需要过多的预热时间,能够显著降低原油的凝点,增强原油的流动性。(The application discloses a methacrylate pour point depressant and a preparation method thereof, and belongs to the technical field of oilfield chemicals. The methacrylate pour point depressant comprises mixed polymethacrylate and hexadecimal polymethacrylate-acrylamide/silicon dioxide nano composite materials. The methacrylic acid pour point depressant can be rapidly dispersed in crude oil, does not need excessive preheating time when added into the crude oil, can obviously reduce the condensation point of the crude oil, and enhances the fluidity of the crude oil.)

1. The methacrylate pour point depressant is characterized by comprising mixed polymethacrylate and hexadecyl polymethacrylate-acrylamide/silicon dioxide nanocomposite.

2. The methacrylic pour point depressant according to claim 1, wherein the methacrylic pour point depressant is composed of mixed polymethacrylate and hexadecyl polymethacrylate-acrylamide/silica nanocomposite, and the weight ratio of the mixed polymethacrylate to the hexadecyl polymethacrylate-acrylamide/silica nanocomposite is (4-1): 1.

3. the methacrylic pour point depressant according to claim 2, wherein the weight ratio of the mixed polymethacrylate to the hexadecimal polymethacrylate-acrylamide/silica nanocomposite is (3-2): 1.

4. the methacrylic pour point depressant according to claim 1, wherein the mixed polymethacrylate is selected from at least two of the group consisting of polylauryl methacrylate, myristyl methacrylate, cetyl polymethacrylate, stearyl polymethacrylate.

5. The methacrylic pour point depressant according to claim 4, wherein the mixed polymethacrylate is composed of lauryl polymethacrylate, myristyl polymethacrylate, cetyl polymethacrylate, stearyl polymethacrylate.

6. The methacrylic pour point depressant according to claim 5, wherein the weight ratio of the lauryl methacrylate to the myristyl methacrylate to the cetyl methacrylate to the stearyl methacrylate is (1-3) to (2-4) to (1-3).

7. A method for producing a methacrylic pour point depressant according to any one of claims 1 to 6 comprising the steps of:

and weighing the methacrylic acid mixed ester and the polyhexadecyl methacrylate-acrylamide/silicon dioxide nano composite material, mixing, and performing ultrasonic dispersion to obtain the methacrylic acid pour point depressant.

8. The method for preparing a methacrylic pour point depressant according to claim 7, wherein the time of ultrasonic dispersion is 15 to 20min, and the temperature during ultrasonic dispersion is 20 to 35 ℃.

9. The method for preparing a methacrylic pour point depressant according to claim 7, wherein the polyhexadecyl methacrylate-acrylamide/silica nanocomposite comprises the following preparation steps:

modifying the nano silicon dioxide by using a silane coupling agent containing double bonds to obtain pre-modified silicon dioxide;

and mixing a hexadecyl methacrylate monomer and an acrylamide monomer with the pre-modified silicon dioxide for grafting reaction to prepare the hexadecyl methacrylate-acrylamide/silicon dioxide nano composite material.

10. Use of a methacrylic pour point depressant according to any one of claims 1 to 6 or prepared by the preparation method according to any one of claims 7 to 9 in waxy crude oil.

Technical Field

The application relates to a methacrylate pour point depressant and a preparation method thereof, belonging to the technical field of oilfield chemicals.

Background

Pour point depressants are a common oil additive, and can reduce the freezing point or cold filter plugging point of oil products, so that the fluidity of the oil products can be maintained when the oil products are stored, transported and used at low temperature and used as vehicle fuels, and the pour point depressants are also called low-temperature flow improvers or wax crystal modifiers.

The common characteristics of the high-wax crude oil are high wax content and high solidification point, which cause great difficulty in the exploitation and transportation of the crude oil. At present, crude oil is generally conveyed at home and abroad by methods such as a heating method, a microbiological method, a chemical additive and the like. The addition of the chemical pour point depressant into the crude oil has the advantages of simple operation, no difficulty in post-treatment and the like. However, due to the complex composition of crude oil, a single type of pour point depressant has limited pour point depressing effect on crude oil.

Disclosure of Invention

In order to solve the problems, the application provides a methacrylate pour point depressant, a preparation method and an application thereof, and the methacrylate pour point depressant can obviously reduce the pour point of the waxy crude oil, reduce the viscosity of the waxy crude oil and effectively improve the fluidity of the crude oil.

According to one aspect of the present application, there is provided a methacrylate pour point depressant comprising mixed polymethacrylates and hexadecimal polymethacrylate-acrylamide/silica nanocomposites.

The mixed polymethacrylate and the hexadecimal polymethacrylate-acrylamide/silicon dioxide nano composite material are compounded, ester groups in the mixed polymethacrylate and amide groups in the hexadecimal polymethacrylate-acrylamide/silicon dioxide nano composite material have synergistic effect, so that the precipitation of wax crystals is effectively inhibited, the shape and the crystallization mode of the wax crystals are changed, the dispersion degree of the wax crystals is more stable, and the pour point depressing effect on crude oil is better.

Preferably, the methacrylic acid pour point depressant is composed of mixed polymethacrylate and hexadecyl polymethacrylate-acrylamide/silicon dioxide nanocomposite, and the weight ratio of the mixed polymethacrylate to the hexadecyl polymethacrylate-acrylamide/silicon dioxide nanocomposite is (4-1): 1.

preferably, the weight ratio of the mixed polymethacrylate to the hexadecimal polymethacrylate-acrylamide/silicon dioxide nanocomposite is (3-2): 1.

preferably, the mixed polymethacrylate is selected from at least two of polylauryl methacrylate, hexadecyl polymethacrylate and octadecanyl polymethacrylate.

Preferably, the mixed polymethacrylate consists of dodecyl polymethacrylate, tetradecyl polymethacrylate, hexadecyl polymethacrylate and octadecyl polymethacrylate.

Preferably, the weight ratio of the dodecyl methacrylate to the tetradecyl methacrylate to the hexadecyl methacrylate to the octadecyl methacrylate is (1-3) to (2-4) to (1-3).

According to another aspect of the present application, there is provided a method for preparing a methacrylic pour point depressant, comprising the steps of:

and weighing the methacrylic acid mixed ester and the polyhexadecyl methacrylate-acrylamide/silicon dioxide nano composite material, mixing, and performing ultrasonic dispersion to obtain the methacrylic acid pour point depressant.

Preferably, the ultrasonic dispersion time is 15-20min, and the temperature during ultrasonic dispersion is 20-35 ℃.

Preferably, the poly hexadecyl methacrylate-acrylamide/silicon dioxide nano composite material comprises the following preparation steps:

modifying the nano silicon dioxide by using a silane coupling agent containing double bonds to obtain pre-modified silicon dioxide;

and mixing a hexadecyl methacrylate monomer and an acrylamide monomer with the pre-modified silicon dioxide for grafting reaction to prepare the hexadecyl methacrylate-acrylamide/silicon dioxide nano composite material.

The hexadecyl methacrylate-acrylamide/silicon dioxide nano composite material is obtained by mixing a hexadecyl methacrylate monomer and an acrylamide monomer with the pre-modified silicon dioxide for grafting reaction, so that the grafting rate is improved, and the surface of the nano silicon dioxide is grafted with a multi-polymer coating layer, so that the complexity of organic components and the complexity of polar groups are increased.

According to a further aspect of the present application, there is provided a use of the above-mentioned methacrylic pour point depressant or the methacrylic pour point depressant prepared by the above-mentioned preparation method in waxy crude oil.

Benefits of the present application include, but are not limited to:

1. the methacrylic acid pour point depressant can be rapidly dispersed in crude oil, does not need excessive preheating time when added into the crude oil, can obviously reduce the condensation point of the crude oil, and enhances the fluidity of the crude oil.

2. The methacrylic acid pour point depressant can form strong hydrogen bonds with colloid and asphaltene molecules, and the structure formed by the colloid and the asphalt through the hydrogen bond fixation is disassembled, so that the adverse effect of the colloid and the asphaltene molecules is inhibited, and the viscosity of crude oil is reduced.

3. The methacrylic acid pour point depressant can be used for properly adjusting the carbon number distribution and polarity, solves the problem of use limitation of a single pour point depressant on different types of crude oil, and properly expands the application range of the pour point depressant.

4. The preparation method of the methacrylic acid pour point depressant is simple in process and beneficial to operation.

Detailed Description

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

The raw materials in the examples of the present application were all purchased commercially, unless otherwise specified.

Example 1

The preparation method of the polymethacrylate pour point depressant comprises the following steps:

weighing the methacrylic acid mixed ester and the poly hexadecyl methacrylate-acrylamide/silicon dioxide nano composite material, mixing, and performing ultrasonic dispersion to obtain the methacrylic acid pour point depressant;

wherein the ultrasonic dispersion time is 15-20min, and the ultrasonic dispersion temperature is 20-35 ℃.

(1) Preparation method of polymethacrylic acid mixed ester

The mixed polymethacrylate is at least two selected from the group consisting of lauryl polymethacrylate, myristyl polymethacrylate, cetyl polymethacrylate and stearyl polymethacrylate.

Of these, polylauryl methacrylate, myristyl methacrylate, cetyl methacrylate, and stearyl methacrylate are commercially available.

(2) Preparation of poly (hexadecyl methacrylate) -acrylamide/silicon dioxide nano composite material

Modifying the nano silicon dioxide by using a silane coupling agent containing double bonds to obtain pre-modified silicon dioxide;

mixing a cetyl methacrylate monomer and an acrylamide monomer with pre-modified silicon dioxide for grafting reaction to prepare the hexadecyl methacrylate-acrylamide/silicon dioxide nano composite material.

After the mixed polymethacrylate and the hexadecyl polymethacrylate-acrylamide/silicon dioxide nano composite material are compounded, the mixed polymethacrylate and the hexadecyl polymethacrylate-acrylamide/silicon dioxide nano composite material can be rapidly dispersed in crude oil under the synergistic action, and excessive preheating time is not needed when the mixed polymethacrylate and the hexadecyl polymethacrylate-acrylamide/silicon dioxide nano composite material are added into the crude oil.

The specific implementation conditions are as follows:

TABLE 1 concrete conditions of examples and comparative examples

Example 2

Characterization of

In the embodiment, high-wax-content crude oil is used as experimental oil, the wax content of the experimental oil is 21%, the freezing point is 35 ℃, the content of colloid asphaltene is 4%, the viscosity is 600-1000mPa & s, and the freezing point of the crude oil pour point depressant is detected according to the GB/T510-1983 standard.

Viscosity in this example is a measure of the viscosity of the pour point depressant for crude oil at 60 ℃.

TABLE 2 pour point depressant performance test results

According to the test results in table 2, after the mixed polymethacrylate and the hexadecyl polymethacrylate-acrylamide/silica nanocomposite are compounded, the condensation point of the crude oil can be significantly reduced and the viscosity of the crude oil can be reduced compared with the mixed polymethacrylate or the hexadecyl polymethacrylate-acrylamide/silica nanocomposite.

This is probably because, firstly, when the polymethacrylate mixed ester is dispersed in the crude oil, ester groups are firstly adsorbed on the surface of paraffin molecules with the decrease of temperature, and since alkyl chain parts in the polymethacrylate dodecyl methacrylate, the polymethacrylate tetradecyl methacrylate, the polymethacrylate hexadecyl methacrylate and the polymethacrylate octadecyl methacrylate are similar to the structure of normal paraffin with corresponding length in the crude oil, the paraffin molecules are tightly surrounded by dodecyl chain, tetradecyl chain, hexadecyl chain and octadecyl chain, the molecular acting force among crystals is weakened, the solubility of the crystals is increased, the aggregation and growth of the paraffin crystals and the formation of a three-dimensional network structure are inhibited, and the crystallization behavior of the crystals is changed; secondly, the poly hexadecyl methacrylate-acrylamide/silicon dioxide nano composite material has heterogeneous nucleation effect due to the special surface effect and small-size effect, can be used as a nucleation point to adsorb paraffin crystals to crystallize and separate out on the surface of the paraffin crystals, and provides the nucleation crystallization point for the poly hexadecyl methacrylate-acrylamide/silicon dioxide nano composite material, so that the crystals begin to crystallize around the nucleation point, neat, fine and orderly arranged crystals are generated, further aggregation and growth of the crystals are hindered, the appearance of the crystals is effectively changed, and the low-temperature flow property of crude oil is improved; compared with a single pour point depressant, the polymethacrylate pour point depressant of the present application has the advantages that the sensitivity to crude oil is increased, the use limitation problem of the single pour point depressant to different types of crude oil can be made up, and the application range of the pour point depressant is properly expanded.

Because ester groups and amide groups exist in the polymethacrylic acid pour point depressant, the polymethacrylic acid pour point depressant can form stronger hydrogen bonds with colloid and asphaltene molecules, and a plane overlapping stacking structure formed by the colloid and the asphaltene which are fixed by the hydrogen bonds is disassembled, so that the viscosity of crude oil can be reduced.

The above description is only an example of the present application, and the protection scope of the present application is not limited by these specific examples, but is defined by the claims of the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the technical idea and principle of the present application should be included in the protection scope of the present application.