A self-coated oil polymer drag reducer and preparation method thereof

Abstract

The invention discloses a self-coating oil polymer drag reducer and a preparation method thereof, belonging to the technical field of oilfield chemical drag reducers. A block copolymer with an amphiphilic structure is prepared by introducing a polyammonium salt segment structure into polymethyl acrylate. The copolymer is easy to self-assemble in the oil product to form an assembly particle with a core-shell structure. The particle has a positive charge inside and a lipophilic alkyl part outside. Due to the presence of the internal ammonium salt positive charge, there is a certain electrostatic repulsion between the particles, which effectively avoids the aggregation and precipitation of the polymer drag reducer in a suspension and oil products. The preparation method of the invention is simple, the prepared drag reducer has high shear resistance and drag reduction rate, and has self-coating ability, can reduce the transportation resistance of the oil product in a fluid pipeline, and reduce energy consumption, and has great application value.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield chemical drag reducers, in particular to a self-coated oil polymer drag reducer and a preparation method thereof. Background Art

[0002] During the transportation of crude oil, due to the viscosity of the oil itself and the friction between the oil and the inner wall of the pipeline, severe turbulence will occur in the part close to the pipeline. The generation of turbulence will increase the energy loss of the fluid in the pipeline, because turbulence will cause the fluid to produce additional friction resistance and eddy loss, thereby increasing the transportation energy consumption. It will also cause unstable movement of the fluid in the pipeline, resulting in increased pipeline vibration and noise, which may affect the stability and safety of the pipeline. Therefore, it is often necessary to add oil drag reducers to suppress the generation of turbulence during the pipeline transportation of crude oil.

[0003] The currently commonly used polymer drag reducers for oil products are viscoelastic under normal conditions, so they generally need to be configured into suspensions for use. In order to prevent the drag reducer particles in the suspension and in the oil from aggregating with each other, the current common method is to add a coating material to coat the particles to isolate the direct contact between the particles. However, the additional coating agent not only causes oil pollution, increases the difficulty of crude oil post-processing, and causes a decrease in oil performance such as viscosity, but also has the disadvantages of clogging pipelines and reducing thermal conductivity. Therefore, it is of great significance to develop a new preparation method for oil polymer drag reducers. Summary of the invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a self-coated oil polymer drag reducer and a preparation method thereof.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A self-coated oil polymer drag reducer, the structural formula of which is as follows: Among them, a is 50~200; b is 10~50; c is 50~200.

[0007] The method for preparing the self-coated oil polymer drag reducer comprises the following steps:

[0008] 1) adding allylamine to organic solvent 1, stirring and mixing evenly, then adding titanium tetrachloride and aluminum trichloride, reacting at 50-150° C. for 12-16 hours, then adding methyl acrylate to the obtained reaction solution and continuing to react for 24-48 hours. After the reaction is completed, filtering, washing the obtained filter cake with deionized water for 2-3 times, and obtaining a precursor polymer 1;

[0009] 2) Add the precursor polymer 1 prepared in step 1) into the organic solvent 2, stir and dissolve, then add iodomethane and potassium carbonate, react at 80-150° C. for 12-24 hours, and after the reaction is completed, remove the solvent by distillation under reduced pressure, wash the residue with deionized water 2-3 times, and dry at 90-100° C. to obtain a self-encapsulated oil polymer drag reducer.

[0010] In step 1), the organic solvent 1 is cyclohexane, ethyl acetate, acetonitrile, benzene or toluene.

[0011] The mass ratio of allylamine, organic solvent 1, titanium tetrachloride, aluminum trichloride and methyl acrylate in step 1) is 1:10-20:1.7-6.5:1.2-4.5:3-4.5.

[0012] In step 2), the organic solvent 2 is benzene, toluene or xylene.

[0013] In step 2), the mass ratio of the precursor polymer 1, the organic solvent 2, methyl iodide and potassium carbonate is 1:10-20:5-8:2.5-6.

[0014] The preparation route of the self-coated oil polymer drag reducer of the present invention is: Among them, a is 50~200; b is 10~50; c is 50~200.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] The self-coated oil polymer drag reducer of the present invention is prepared into a block copolymer with an amphiphilic structure by introducing a polyammonium salt chain segment structure into polymethyl acrylate. The copolymer is easy to self-assemble in the oil to form an assembly particle similar to a core-shell structure. The particle has a positive charge inside and a lipophilic alkyl part on the outside. Due to the presence of the internal ammonium salt positive charge, there is a certain electrostatic repulsion between the particles, which effectively avoids the aggregation and precipitation of the polymer drag reducer in the suspension and the oil, and improves the drag reduction performance.

[0017] The self-coating oil polymer drag reducer of the present invention has a polyethylene main chain with high tensile strength and toughness, is not easy to break even in a high shear environment, and has excellent shear resistance. The preparation method of the present invention is simple, and the prepared drag reducer has high shear resistance and drag reduction rate, and has self-coating ability, which can reduce the transportation resistance of oil products in fluid pipelines and reduce energy consumption, and has great application value. DETAILED DESCRIPTION

[0018] In order to better understand the technical solution of the present invention, the above content of the present invention is further described in detail below through specific implementation methods in the form of embodiments, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples. All technologies realized based on the above content of the present invention belong to the scope of the present invention. Example 1

[0019] 0.5 kg of allylamine was added to 5 kg of cyclohexane, and the mixture was stirred and mixed evenly. Then, 0.85 kg of titanium tetrachloride and 0.6 kg of aluminum trichloride were added, and the mixture was reacted at 50° C. for 16 hours. Then, 1.5 kg of methyl acrylate was added to the obtained reaction solution, and the reaction was continued for 24 hours. After the reaction was completed, the mixture was filtered, and the obtained filter cake was washed twice with deionized water to obtain a precursor polymer 1.

[0020] 0.5 kg of precursor polymer 1 was added to 5 kg of benzene, stirred and dissolved, and then 2.5 kg of iodomethane and 1.25 kg of potassium carbonate were added. The reaction was carried out at 80°C for 24 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure. The residue was washed twice with deionized water and dried at 90°C to obtain a self-encapsulated oil polymer drag reducer. Example 2

[0021] 0.5 kg of allylamine was added to 6 kg of acetonitrile, and the mixture was stirred and mixed evenly. Then, 1.25 kg of titanium tetrachloride and 0.9 kg of aluminum trichloride were added, and the mixture was reacted at 80° C. for 15 h. Subsequently, 1.75 kg of methyl acrylate was added to the obtained reaction solution, and the reaction was continued for 28 h. After the reaction was completed, the mixture was filtered, and the obtained filter cake was washed twice with deionized water to obtain a precursor polymer 1.

[0022] 0.5 kg of precursor polymer 1 was added to 6 kg of xylene, stirred and dissolved, and then 2.8 kg of methyl iodide and 1.6 kg of potassium carbonate were added. The reaction was carried out at 100 ° C for 22 hours. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed with deionized water for 3 times and dried at 95 ° C to obtain a self-encapsulated oil polymer drag reducer. Example 3

[0023] 0.5 kg of allylamine was added to 7.5 kg of ethyl acetate, and the mixture was stirred and mixed evenly. Then, 1.8 kg of titanium tetrachloride and 1.2 kg of aluminum trichloride were added, and the mixture was reacted at 100° C. for 14 h. Subsequently, 1.95 kg of methyl acrylate was added to the obtained reaction solution, and the reaction was continued for 35 h. After the reaction was completed, the mixture was filtered, and the obtained filter cake was washed 3 times with deionized water to obtain a precursor polymer 1.

[0024] 0.5 kg of precursor polymer 1 was added to 7 kg of toluene, stirred and dissolved, and then 3 kg of iodomethane and 2.1 kg of potassium carbonate were added. The reaction was carried out at 110°C for 20 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure. The residue was washed with deionized water for 3 times and dried at 95°C to obtain a self-encapsulated oil polymer drag reducer. Example 4

[0025] 0.5 kg of allylamine was added to 8 kg of toluene, and the mixture was stirred and mixed evenly. Then, 2.2 kg of titanium tetrachloride and 1.6 kg of aluminum trichloride were added, and the mixture was reacted at 120° C. for 14 h. Subsequently, 2 kg of methyl acrylate was added to the obtained reaction solution, and the reaction was continued for 40 h. After the reaction was completed, the mixture was filtered, and the obtained filter cake was washed 3 times with deionized water to obtain a precursor polymer 1.

[0026] 0.5 kg of precursor polymer 1 was added to 8.5 kg of toluene, stirred and dissolved, and then 3.2 kg of methyl iodide and 2.4 kg of potassium carbonate were added. The reaction was carried out at 120°C for 18 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure. The residue was washed with deionized water for 3 times and dried at 95°C to obtain a self-encapsulated oil polymer drag reducer. Example 5

[0027] 0.5 kg of allylamine was added to 9 kg of benzene, and the mixture was stirred and mixed evenly. Then, 2.8 kg of titanium tetrachloride and 1.9 kg of aluminum trichloride were added, and the mixture was reacted at 140° C. for 13 h. Subsequently, 2.1 kg of methyl acrylate was added to the obtained reaction solution, and the reaction was continued for 44 h. After the reaction was completed, the mixture was filtered, and the obtained filter cake was washed 3 times with deionized water to obtain a precursor polymer 1.

[0028] 0.5 kg of precursor polymer 1 was added to 9 kg of benzene, stirred and dissolved, and then 3.6 kg of iodomethane and 2.8 kg of potassium carbonate were added. The reaction was carried out at 140°C for 14 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure. The residue was washed with deionized water for 3 times and dried at 95°C to obtain a self-encapsulated oil polymer drag reducer. Example 6

[0029] 0.5 kg of allylamine was added to 10 kg of cyclohexane, and the mixture was stirred and mixed evenly. Then, 3.25 kg of titanium tetrachloride and 2.25 kg of aluminum trichloride were added, and the mixture was reacted at 150° C. for 12 hours. Subsequently, 2.25 kg of methyl acrylate was added to the obtained reaction solution, and the reaction was continued for 48 hours. After the reaction was completed, the mixture was filtered, and the obtained filter cake was washed 3 times with deionized water to obtain a precursor polymer 1.

[0030] 0.5 kg of precursor polymer 1 was added to 10 kg of toluene, stirred and dissolved, and then 4 kg of iodomethane and 3 kg of potassium carbonate were added. The reaction was carried out at 150°C for 12 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure. The residue was washed with deionized water for 3 times and dried at 100°C to obtain a self-encapsulated oil polymer drag reducer.

[0031] The self-coated oil polymer drag reducers prepared in Examples 1 to 6 were tested for drag reduction rate. The specific test method is as follows: the self-coated oil polymer drag reducers prepared in Examples 1 to 6 were prepared into a solution with a concentration of 20 mg / L using crude oil. The test device used a rotating disc test device. At 30° C., the device speed was set to 1000 / min, 1200r / min, 1300r / min and 1500r / min, respectively, to test the drag reduction rate of the self-coated oil polymer drag reducer. The test results are shown in Table 1.

[0032] Table 1 Performance evaluation results of the products prepared in Examples 1 to 6:

[0033]

[0034] It can be seen from the results in Table 1 that the self-coated oil polymer drag reducer prepared by the present invention has a high drag reduction rate. At the same time, when the rotation speed increases, that is, the Reynolds number increases, the drag reduction rate does not change much, which means that the polymer chain of the self-coated oil polymer drag reducer prepared by the present invention is not easy to break, has excellent shear resistance, can reduce the transportation resistance of oil in fluid pipelines, reduce energy consumption, and has great application value.

[0035] Although the above describes the specific implementation methods of the present invention, it does not limit the scope of protection of the present invention. Based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present invention.

Claims

1. A self-coated oil polymer drag reducer, characterized in that: Its structural formula is as follows: Among them, a is 50~200; b is 10~50; c is 50~200.

2. The method for preparing the self-coated oil polymer drag reducer according to claim 1, characterized in that: The following steps are involved: 1) adding allylamine to organic solvent 1, stirring and mixing evenly, then adding titanium tetrachloride and aluminum trichloride, reacting at 50-150° C. for 12-16 hours, then adding methyl acrylate to the obtained reaction solution and continuing to react for 24-48 hours. After the reaction is completed, filtering, washing the obtained filter cake with deionized water for 2-3 times, and obtaining a precursor polymer 1; 2) Add the precursor polymer 1 prepared in step 1) into the organic solvent 2, stir and dissolve, then add iodomethane and potassium carbonate, react at 80-150° C. for 12-24 hours, and after the reaction is completed, remove the solvent by distillation under reduced pressure, wash the residue with deionized water 2-3 times, and dry at 90-100° C. to obtain a self-encapsulated oil polymer drag reducer.

3. The method for preparing the self-coated oil polymer drag reducer according to claim 2, characterized in that: In step 1), the organic solvent 1 is cyclohexane, ethyl acetate, acetonitrile, benzene or toluene.

4. The method for preparing the self-coated oil polymer drag reducer according to claim 2, characterized in that: The mass ratio of allylamine, organic solvent 1, titanium tetrachloride, aluminum trichloride and methyl acrylate in step 1) is 1:10-20:1.7-6.5:1.2-4.5:3-4.

5.

5. The method for preparing the self-coated oil polymer drag reducer according to claim 2, characterized in that: In step 2), the organic solvent 2 is benzene, toluene or xylene.

6. The method for preparing the self-coated oil polymer drag reducer according to claim 2, characterized in that: In step 2), the mass ratio of the precursor polymer 1, the organic solvent 2, methyl iodide and potassium carbonate is 1:10-20:5-8:2.5-6.

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