Drag reducer for fracturing and preparation method thereof

Abstract

The invention relates to the technical field of fracturing fluids, and discloses a drag reducer for fracturing and a preparation method thereof.15 # white oil, acrylamide, Tween 60, epoxidized triton, quaternized silane polymer and water are added into a stirrer and stirred, and the drag reducer for fracturing is obtained after stirring is finished. In the stirring process, an epoxy group in epoxidized triton and a hydroxyl group in a quaternized silane polymer are subjected to a ring-opening reaction to generate new hydroxyl groups, and the new hydroxyl groups and the quaternized silane polymer are crosslinked to form a compact network, so that the anti-shearing capability is better, meanwhile, the flow resistance of fluid in a shaft is reduced, and a better resistance reducing effect is achieved; a boron element in the quaternized silane polymer and a polymer in the drag reducer are subjected to a cross-linking reaction to form a stable gel, and the gel has excellent fracture forming and sand carrying capacities; wherein the quaternary ammonium salt and the silane also have a relatively good drag reduction effect.

Description

Technical Field

[0001] The invention relates to the technical field of fracturing fluids, in particular to a drag reducer for fracturing and a preparation method thereof. Background Art

[0002] Slickwater fracturing is highly efficient and low-cost. During slickwater fracturing, a large amount of liquid needs to be pumped into the ground. During this process, there is a large friction between the fracturing fluid and the pipeline. The friction resistance of the fluid limits the flow of the fluid in the pipeline and increases its energy loss. Therefore, how to avoid this phenomenon is the key to solving the problem.

[0003] For example, patent CN110129021 discloses a drag reducer for fracturing and its preparation method. The drainage active agent prepared by the invention is a surfactant of ammonium oxide obtained by oxidizing hexadecyl dimethyl tertiary amine with hydrogen peroxide. The invention solves the problems of low drag reduction rate and great damage to formations of current drag reducers, but its anti-shear effect and drag reduction rate need to be improved. Summary of the invention

[0004] 1. Technical issues to be resolved In view of the deficiencies of the prior art, the present invention provides a drag reducing agent for fracturing and a preparation method thereof, which has a good drag reducing effect.

[0005] (II) Technical solution To achieve the above object, the present invention provides the following technical solution: a drag reducer for fracturing, comprising the following weight components: 25-35 weight parts of 15# white oil, 15-20 weight parts of acrylamide, 2-6 weight parts of Tween 60, 4-8 weight parts of epoxidized Triton, 5-12 weight parts of quaternized silane polymer, and 20-30 weight parts of water; The preparation method of the epoxidized Triton is: Step 1: placing the reactor in an ice-water bath, then adding dichloromethane solvent, Triton and acryloyl chloride thereto, stirring and mixing, continuing to add triethylamine catalyst thereto, stirring and reacting at 25-40° C. for 16-24 hours, after which the reaction is completed, suction filtering is performed, and the reaction is washed 2-4 times with 1% by mass dilute hydrochloric acid and 1% by mass sodium carbonate solution in sequence, and the filtrate is rotary evaporated to obtain olefinated Triton; Step 2: Add 3-5 parts by weight of olefinated Triton to a toluene solvent, stir evenly, then add 6-9 parts by weight of an aqueous hydrogen peroxide solution, react at 30-45° C., extract after the reaction, dry the organic phase, and distill under reduced pressure to obtain epoxidized Triton.

[0006] Preferably, in step 1, the mass ratio of Triton, acryloyl chloride and triethylamine catalyst is 1:2.2-2.6:0.01-0.03.

[0007] Preferably, the reaction time in step 2 is 4-6 hours.

[0008] Preferably, the preparation method of the quaternized silane polymer is: S1. Add di(dimethylamino)methylvinylsilane and 3-chloro-1-propanol to N,N-dimethylformamide solvent, stir evenly, react at 65-85° C. for 2-4 hours, and after the reaction, rotary distill to obtain hydroxylated silane; S2. Add 4,4'-biphenyl diboronic acid to toluene solvent, stir and disperse, then add hydroxylated silane thereto, react at 80-95°C for 10-12h, and after the reaction, distill under reduced pressure, filter and dry to obtain olefinated boronic acid; S3. Under a nitrogen atmosphere, add olefinated boric acid, allyl alcohol, and 2-acrylamido-2-methylpropanesulfonic acid into a reactor, stir evenly, continue to add azobisisobutyronitrile catalyst, react at 90-110°C for 12-15h, cool to room temperature after reaction, wash with deionized water, and dry to obtain a quaternized silane polymer.

[0009] Preferably, the mass ratio of di(dimethylamino)methylvinylsilane to 3-chloro-1-propanol in S1 is 1:1.4-1.8.

[0010] Preferably, the mass ratio of 4,4'-biphenyldiboronic acid to hydroxylated silane in S2 is 0.4-0.6:1.

[0011] Preferably, the mass ratio of olefinated boronic acid, acryl alcohol, 2-acrylamido-2-methylpropanesulfonic acid and azobisisobutyronitrile catalyst in S3 is 1.2-1.3:1:0.8-1.1:0.01-0.02.

[0012] Preferably, the preparation method of the drag reducer for fracturing is: add 15# white oil, acrylamide, Tween 60, epoxidized Triton, quaternized silane polymer and water into a stirrer, stir for 10-15 minutes, and obtain the drag reducer for fracturing after stirring.

[0013] 3. Beneficial technical effects The invention provides a fracturing drag reducer by adding 15# white oil, acrylamide, Tween 60, epoxidized Triton, quaternized silane polymer and water into a stirrer and stirring the mixture.

[0014] During the stirring process, the epoxy groups in the epoxidized triton react with the hydroxyl groups in the quaternized silane polymer to form a ring-opening reaction, generating new hydroxyl groups, which cross-link with each other to form a tight network, making it more resistant to shearing and helping to reduce the flow resistance of the fluid in the wellbore, thus having a better drag reduction effect; the boron element in the quaternized silane polymer cross-links with the polymer in the drag reducer to form a stable gel, which has excellent seam-making and sand-carrying capabilities; the quaternary ammonium salt molecular structure contains hydrophilic and hydrophobic parts, which enables the quaternary ammonium salt to form micelles in the aqueous solution, thereby reducing the surface tension and interfacial tension of the liquid, reducing the resistance of the fluid flow, and achieving a drag reduction effect; the silane also has a good drag reduction effect. 4,4'-biphenyl diboronic acid reacts with hydroxylated silane to obtain olefinated boric acid, which increases the degree of substitution of the quaternary ammonium salt group and silane, further improving its drag reduction effect. DETAILED DESCRIPTION Example 1

[0015] (1) placing a reactor in an ice-water bath, then adding dichloromethane solvent, Triton and acryloyl chloride thereto, stirring and mixing, and continuing to add triethylamine catalyst thereto, wherein the mass ratio of Triton, acryloyl chloride and triethylamine catalyst is 1:2.2:0.01, stirring and reacting at 25°C for 16 hours, after which the reaction is filtered, and washed twice with 1% by mass dilute hydrochloric acid and 1% by mass sodium carbonate solution in sequence, and the filtrate is rotary evaporated to obtain olefinated Triton; (2) Add 3 parts by weight of olefinated Triaton to a toluene solvent, stir evenly, then add 6 parts by weight of an aqueous hydrogen peroxide solution, react at 30° C. for 4 hours, extract after the reaction, dry the organic phase, and distill under reduced pressure to obtain epoxidized Triaton; (3) Add di(dimethylamino)methylvinylsilane and 3-chloro-1-propanol to N,N-dimethylformamide solvent, wherein the mass ratio of di(dimethylamino)methylvinylsilane to 3-chloro-1-propanol is 1:1.4, stir evenly, react at 65°C for 2h, and after the reaction, rotary distill to obtain hydroxylated silane; (4) adding 4,4'-biphenyl diboronic acid to toluene solvent, stirring and dispersing, and then adding hydroxylated silane thereto, wherein the mass ratio of 4,4'-biphenyl diboronic acid to hydroxylated silane is 0.4:1, reacting at 80°C for 10 hours, and after the reaction is completed, distilling under reduced pressure, filtering and drying to obtain olefinated boronic acid; (5) Under a nitrogen atmosphere, olefinated boronic acid, acryl alcohol, and 2-acrylamide-2-methylpropanesulfonic acid are added to a reactor, stirred evenly, and azobisisobutyronitrile catalyst is added thereto, wherein the mass ratio of olefinated boronic acid, acryl alcohol, 2-acrylamide-2-methylpropanesulfonic acid, and azobisisobutyronitrile catalyst is 1.2:1:0.8:0.01, reacted at 90°C for 12h, cooled to room temperature after reaction, washed with deionized water, and dried to obtain a quaternary ammonium silane polymer; (6) Add 25 parts by weight of 15# white oil, 15 parts by weight of acrylamide, 2 parts by weight of Tween 60, 4 parts by weight of epoxidized Triton, 5 parts by weight of quaternized silane polymer, and 20 parts by weight of water into a stirrer and stir for 10 minutes to obtain a drag reducer for fracturing. Example 2

[0016] (1) placing a reactor in an ice-water bath, then adding dichloromethane solvent, Triton and acryloyl chloride, stirring and mixing, and continuing to add triethylamine catalyst, wherein the mass ratio of Triton, acryloyl chloride and triethylamine catalyst is 1:2.6:0.03, stirring and reacting at 40°C for 24 hours, after which the reaction is filtered, and washed four times with 1% by mass dilute hydrochloric acid and 1% by mass sodium carbonate solution in sequence, and the filtrate is rotary evaporated to obtain olefinated Triton; (2) adding 5 parts by weight of olefinated Triton to a toluene solvent, stirring evenly, and then adding 9 parts by weight of an aqueous hydrogen peroxide solution thereto, reacting at 45° C. for 6 hours. After the reaction is completed, extracting, drying the organic phase, and distilling under reduced pressure to obtain epoxidized Triton; (3) Add di(dimethylamino)methylvinylsilane and 3-chloro-1-propanol to N,N-dimethylformamide solvent, wherein the mass ratio of di(dimethylamino)methylvinylsilane to 3-chloro-1-propanol is 1:1.8, stir evenly, react at 85°C for 4 hours, and after the reaction, rotary distill to obtain hydroxylated silane; (4) adding 4,4'-biphenyl diboronic acid to toluene solvent, stirring and dispersing, and then adding hydroxylated silane thereto, wherein the mass ratio of 4,4'-biphenyl diboronic acid to hydroxylated silane is 0.6:1, reacting at 95°C for 12 hours, and after the reaction is completed, distilling under reduced pressure, filtering and drying to obtain olefinated boronic acid; (5) Under a nitrogen atmosphere, olefinated boronic acid, acryl alcohol, and 2-acrylamide-2-methylpropanesulfonic acid are added to a reactor, stirred evenly, and azobisisobutyronitrile catalyst is continuously added thereto, wherein the mass ratio of olefinated boronic acid, acryl alcohol, 2-acrylamide-2-methylpropanesulfonic acid, and azobisisobutyronitrile catalyst is 1.3:1:1.1:0.02, reacted at 110° C. for 15 h, cooled to room temperature after reaction, washed with deionized water, and dried to obtain a quaternary ammonium silane polymer; (6) Add 35 parts by weight of 15# white oil, 20 parts by weight of acrylamide, 6 parts by weight of Tween 60, 8 parts by weight of epoxidized Triton, 12 parts by weight of quaternized silane polymer, and 30 parts by weight of water into a stirrer and stir for 15 minutes to obtain a drag reducer for fracturing. Example 3

[0017] (1) placing the reactor in an ice-water bath, then adding dichloromethane solvent, Triton and acryloyl chloride thereto, stirring and mixing, and continuing to add triethylamine catalyst thereto, wherein the mass ratio of Triton, acryloyl chloride and triethylamine catalyst is 1:2.4:0.02, stirring and reacting at 30°C for 22 hours, after which the reaction is filtered, and washed three times with 1% by mass dilute hydrochloric acid and 1% by mass sodium carbonate solution in sequence, and the filtrate is rotary evaporated to obtain olefinated Triton; (2) adding 4 parts by weight of olefinated Triton to a toluene solvent, stirring evenly, and then adding 7 parts by weight of an aqueous hydrogen peroxide solution thereto, reacting at 42° C. for 5 hours. After the reaction is completed, extracting, drying the organic phase, and distilling under reduced pressure to obtain epoxidized Triton; (3) Add di(dimethylamino)methylvinylsilane and 3-chloro-1-propanol to N,N-dimethylformamide solvent, wherein the mass ratio of di(dimethylamino)methylvinylsilane to 3-chloro-1-propanol is 1:1.6, stir evenly, react at 75°C for 3h, and after the reaction, rotary distill to obtain hydroxylated silane; (4) adding 4,4'-biphenyl diboronic acid to toluene solvent, stirring and dispersing, and then adding hydroxylated silane thereto, wherein the mass ratio of 4,4'-biphenyl diboronic acid to hydroxylated silane is 0.5:1, reacting at 90°C for 11 hours, and after the reaction is completed, distilling under reduced pressure, filtering and drying to obtain olefinated boronic acid; (5) Under a nitrogen atmosphere, olefinated boronic acid, acryl alcohol, and 2-acrylamide-2-methylpropanesulfonic acid are added to a reactor, stirred evenly, and azobisisobutyronitrile catalyst is added thereto, wherein the mass ratio of olefinated boronic acid, acryl alcohol, 2-acrylamide-2-methylpropanesulfonic acid, and azobisisobutyronitrile catalyst is 1.2:1:0.9:0.015, and the reaction is carried out at 100° C. for 14 h. After the reaction is completed, the reaction is cooled to room temperature, washed with deionized water, and dried to obtain a quaternary ammonium silane polymer; (6) Add 30 parts by weight of 15# white oil, 22 parts by weight of acrylamide, 4 parts by weight of Tween 60, 6 parts by weight of epoxidized Triton, 10 parts by weight of quaternized silane polymer, and 25 parts by weight of water into a stirrer and stir for 12 minutes to obtain a drag reducer for fracturing. Example 4

[0018] (1) placing a reactor in an ice-water bath, then adding dichloromethane solvent, Triton and acryloyl chloride thereto, stirring and mixing, and continuing to add triethylamine catalyst thereto, wherein the mass ratio of Triton, acryloyl chloride and triethylamine catalyst is 1:2.2:0.01, stirring and reacting at 25°C for 16 hours, after which the reaction is filtered, and washed twice with 1% by mass dilute hydrochloric acid and 1% by mass sodium carbonate solution in sequence, and the filtrate is rotary evaporated to obtain olefinated Triton; (2) Add 3 parts by weight of olefinated Triaton to a toluene solvent, stir evenly, then add 6 parts by weight of an aqueous hydrogen peroxide solution, react at 30° C. for 4 hours, extract after the reaction, dry the organic phase, and distill under reduced pressure to obtain epoxidized Triaton; (3) Add di(dimethylamino)methylvinylsilane and 3-chloro-1-propanol to N,N-dimethylformamide solvent, wherein the mass ratio of di(dimethylamino)methylvinylsilane to 3-chloro-1-propanol is 1:1.8, stir evenly, react at 85°C for 4 hours, and after the reaction, rotary distill to obtain hydroxylated silane; (4) adding 4,4'-biphenyl diboronic acid to toluene solvent, stirring and dispersing, and then adding hydroxylated silane thereto, wherein the mass ratio of 4,4'-biphenyl diboronic acid to hydroxylated silane is 0.6:1, reacting at 95°C for 12 hours, and after the reaction is completed, distilling under reduced pressure, filtering and drying to obtain olefinated boronic acid; (5) Under a nitrogen atmosphere, olefinated boronic acid, acryl alcohol, and 2-acrylamide-2-methylpropanesulfonic acid are added to a reactor, stirred evenly, and azobisisobutyronitrile catalyst is added thereto, wherein the mass ratio of olefinated boronic acid, acryl alcohol, 2-acrylamide-2-methylpropanesulfonic acid, and azobisisobutyronitrile catalyst is 1.2:1:0.9:0.015, and the reaction is carried out at 100° C. for 14 h. After the reaction is completed, the reaction is cooled to room temperature, washed with deionized water, and dried to obtain a quaternary ammonium silane polymer; (6) Add 30 parts by weight of 15# white oil, 22 parts by weight of acrylamide, 4 parts by weight of Tween 60, 6 parts by weight of epoxidized Triton, 10 parts by weight of quaternized silane polymer, and 25 parts by weight of water into a stirrer and stir for 12 minutes to obtain a drag reducer for fracturing.

[0019] Comparative Example 1 Compared with Example 4, this comparative example is different in that no Triton epoxide is added.

[0020] Comparative Example 2 Compared with Example 4, this comparative example is different in that no quaternary ammonium silane polymer is added.

[0021] The drag reducers prepared in Examples 1-4 and Comparative Examples 1-2 were prepared into 0.05 wt% aqueous solutions at 25°C and added to a dissolution tank. The solutions were pumped out and entered the test section through a rotor flowmeter. The flow rate was measured by a rotor flowmeter, and the flow rate was controlled by a frequency converter to measure the pressure drop of the solution through the test section. The diameter of the test circular tube was 0.635 cm, the length of the test tube section was 3 meters, and the diameter was 10 mm. The drag reduction rate was measured at flow rates of 5 m / s, 10 m / s, 15 m / s and 20 m / s. The test results are shown in Table 1.

[0022] Table 1: Drag reduction test.

[0023] project 5m / s drag reduction rate 10m / s drag reduction rate 15m / s drag reduction rate 20m / s drag reduction rate Example 1 74.6 77.1 81.3 83.7 Example 2 76.9 79.6 82.5 84.9 Example 3 75.1 78.4 82.6 83.1 Example 4 74.8 77.5 81.5 84.2 Comparative Example 1 61.2 68.2 72.3 74.8 Comparative Example 2 60.4 67.4 72.5 73.6 It can be seen from Table 1 that Examples 1-4 of the present invention have better drag reduction effects than Comparative Examples 1-2.

[0024] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A drag reducer for fracturing, characterized in that: The invention comprises the following components by weight: 25-35 parts by weight of 15# white oil, 15-20 parts by weight of acrylamide, 2-6 parts by weight of Tween 60, 4-8 parts by weight of epoxidized Triton, 5-12 parts by weight of quaternized silane polymer, and 20-30 parts by weight of water; The preparation method of the epoxidized Triton is: Step 1: placing the reactor in an ice-water bath, then adding dichloromethane solvent, Triton and acryloyl chloride thereto, stirring and mixing, continuing to add triethylamine catalyst thereto, stirring and reacting at 25-40° C. for 16-24 hours, after which the reaction is completed, suction filtering is performed, and the reaction is washed 2-4 times with 1% by mass dilute hydrochloric acid and 1% by mass sodium carbonate solution in sequence, and the filtrate is rotary evaporated to obtain olefinated Triton; Step 2: Add 3-5 parts by weight of olefinated Triton to a toluene solvent, stir evenly, then add 6-9 parts by weight of an aqueous hydrogen peroxide solution, react at 30-45° C., extract after the reaction, dry the organic phase, and distill under reduced pressure to obtain epoxidized Triton.

2. The drag reducer for fracturing according to claim 2, characterized in that: In the step 1, the mass ratio of Triton, acryloyl chloride and triethylamine catalyst is 1:2.2-2.6:0.01-0.

03.

3. The drag reducer for fracturing according to claim 2, characterized in that: The reaction time in step 2 is 4-6 hours.

4. The drag reducer for fracturing according to claim 1, characterized in that: The preparation method of the quaternized silane polymer is: S1. Add di(dimethylamino)methylvinylsilane and 3-chloro-1-propanol to N,N-dimethylformamide solvent, stir evenly, react at 65-85° C. for 2-4 hours, and after the reaction, rotary distill to obtain hydroxylated silane; S2. Add 4,4'-biphenyl diboronic acid to toluene solvent, stir and disperse, then add hydroxylated silane thereto, react at 80-95°C for 10-12h, and after the reaction, distill under reduced pressure, filter and dry to obtain olefinated boronic acid; S3. Under a nitrogen atmosphere, add olefinated boric acid, allyl alcohol, and 2-acrylamido-2-methylpropanesulfonic acid into a reactor, stir evenly, continue to add azobisisobutyronitrile catalyst, react at 90-110°C for 12-15h, cool to room temperature after reaction, wash with deionized water, and dry to obtain a quaternized silane polymer.

5. The drag reducer for fracturing according to claim 3, characterized in that: The mass ratio of di(dimethylamino)methylvinylsilane to 3-chloro-1-propanol in S1 is 1:1.4-1.

8.

6. The drag reducer for fracturing according to claim 3, characterized in that: The mass ratio of 4,4'-biphenyldiboronic acid to hydroxylated silane in S2 is 0.4-0.6:

1.

7. The drag reducer for fracturing according to claim 3, characterized in that: The mass ratio of olefinated boric acid, acryl alcohol, 2-acrylamido-2-methylpropanesulfonic acid and azobisisobutyronitrile catalyst in S3 is 1.2-1.3:1:0.8-1.1:0.01-0.

02.

8. A method for preparing a drag reducer for fracturing according to any one of claims 1 to 7, characterized in that: The preparation method of the drag reducer for fracturing is as follows: 15# white oil, acrylamide, Tween 60, epoxidized Triton, quaternized silane polymer and water are added into a stirrer, and stirred for 10-15 minutes, and then the drag reducer for fracturing is obtained.