CN116396232B - Fracturing fluid thickening and viscosity increasing agent and preparation method thereof - Google Patents

Abstract

The invention relates to the field of fracturing fluid technology, and discloses a fracturing fluid thickening viscosifier and a preparation method thereof. As a reaction raw material, a new Gemini cationic fracturing fluid thickening viscosifier was prepared, and then compounded with sodium salicylate and potassium chloride to obtain a water-based clean fracturing fluid, which was thickened and viscosified The agent has strong intermolecular force and hydrogen bond network in the fracturing fluid, forming a stable cross-linked network structure, which has the advantages of good high temperature resistance and excellent shear resistance. Under high temperature and high shear conditions, Fracturing fluid still has good fracturing performance.

Description

A fracturing fluid viscosifier and preparation method thereof

technical field

The invention relates to the field of fracturing fluid technology, in particular to a fracturing fluid thickening viscosifier and a preparation method thereof.

Background technique

Hydraulic fracturing technology is widely used in the field of low-permeability reservoir development, so it is of great significance to develop high-performance fracturing fluid. Thickeners in clean fracturing fluids have a large impact on fracturing fluid performance. Fracturing fluids mainly include cellulose-based fracturing fluids, guar gum-based fracturing fluids, water-based fracturing fluids, etc. Among them, water-based clean fracturing fluids are mainly divided into cationic, anionic, zwitterionic, etc.

Cationic clean fracturing fluid has the advantages of simple synthesis, good thickening effect, and low cost. It is a promising fracturing fluid. Dimethyl tertiary amine, disodium ethylenediamine tetraacetate, benzyl chloride, etc. are used as reaction raw materials to prepare a composite thickener for cleaning fracturing fluid; patent CN113621361B uses 1-bromododecane, methylamino alcohol, cyclic Oxychloropropane and others were used as reactants to prepare cationic viscoelastic surfactants for the preparation of fracturing fluids. However, the current clean fracturing fluids have problems such as poor shear resistance and low thermal stability.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a fracturing fluid thickening viscosifier, which solves the problem of poor shear resistance and other performances of the cationic clean fracturing fluid.

A fracturing fluid viscosifier with the following structural formula:

.

Further, the preparation method of the fracturing fluid viscosifier is as follows:

(1) Add melamine, 4-bromobutyryl chloride and pyridine to the acetone solvent in an ice-water bath. After the reaction, the solvent is removed by rotary evaporation, and the product is recrystallized in ethyl acetate to obtain 4-bromobutyrylamide-s-triazine.

(2) Add oleic acid, N-methyldiethanolamine and catalyst p-toluenesulfonic acid to the xylene solvent, remove the solvent by rotary evaporation after reaction, and wash the crude product with n-hexane to obtain N-methyl ethyl dioleate intermediate body.

(3) Add N-methyl dioleic acid ethyl ester intermediate and 4-bromobutanamido-s-triazine to N,N-dimethylformamide, after reaction, vacuum dry to remove the solvent, and wash the crude product with n-hexane , recrystallized in a mixed solvent of ethanol and ethyl acetate with a volume ratio of 2:1 to obtain a thickened viscosifier for fracturing fluid.

Further, the reaction molar ratio of melamine, 4-bromobutyryl chloride and pyridine in step (1) is 1:3.2-4.2:2.8-4.5.

Further, in step (1), the reaction is carried out in an ice-water bath for 30-60 min, and then heated to 30-50 °C for 6-24 h.

Further, the molar ratio of oleic acid, N-methyldiethanolamine and catalyst p-toluenesulfonic acid in step (2) is 1.8-3:1:0.12-0.2.

Further, in step (2), the reaction is refluxed at 90-120 °C for 4-12 h.

Further, in the step (3), the molar ratio of N-methyl ethyl dioleate intermediate to 4-bromobutyrylamide-s-triazine is 2.5-4:1.

Further, in step (3), the reaction is refluxed at 110-130 °C for 48-96 h.

Further, add the fracturing fluid viscosifier, potassium chloride, and sodium salicylate into distilled water, and stir evenly at a high speed to obtain clean fracturing fluid. The mass of the fracturing fluid thickened viscosifier in the fracturing fluid is The fraction is 0.8-2.5%, the mass fraction of potassium chloride is 0.2-0.7%, and the mass fraction of sodium salicylate is 0.3-1%.

The present invention uses cheap and easy-to-obtain melamine, 4-bromobutyryl chloride, oleic acid, N-methyldiethanolamine, etc. as reaction raw materials to prepare a novel Gemini cationic fracturing fluid thickening viscosifier, which has a preparation method The advantages of simplicity, mild reaction conditions and no pollution provide a new and efficient synthesis method for the preparation of cationic fracturing fluid viscosifiers; compound fracturing fluid viscosifiers with sodium salicylate and potassium chloride , to obtain water-based clean fracturing fluid, the fracturing fluid thickening viscosifier has strong intermolecular force and hydrogen bond network in the fracturing fluid, forming a stable cross-linked network structure, with good high temperature resistance, With the advantage of excellent shear performance, the fracturing fluid still has good fracturing performance under high temperature and high shear conditions.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the implementation manners in the present invention, all other implementation manners obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

Example 1

(1) Add 5 mmol of melamine, 18 mmol of 4-bromobutyryl chloride and 17.5 mmol of pyridine to 400 mL of acetone solvent in an ice-water bath for 40 min under an ice-water bath, then heat to 35 °C, After reacting for 18 h, the solvent was removed by rotary evaporation after the reaction, and the product was recrystallized in ethyl acetate to obtain 4-bromobutyrylamide-s-triazine;

(2) Add 18 mmol of oleic acid, 10 mmol of N-methyldiethanolamine and 1.2 mmol of catalyst p-toluenesulfonic acid to 150 mL of xylene solvent, reflux at 120 °C for 4 h, remove by rotary evaporation after reaction Solvent, the crude product is washed with n-hexane to obtain N-methyl ethyl dioleate intermediate;

(3) Add 40 mmol of N-methyl dioleic acid ethyl ester intermediate and 10 mmol of 4-bromobutyrylamide-s-triazine to 600 mL of N,N-dimethylformamide, at 110 °C Reflux for 96 h, vacuum dry to remove the solvent after the reaction, wash the crude product with n-hexane, and recrystallize in a mixed solvent of ethanol and ethyl acetate with a volume ratio of 2:1 to obtain a fracturing fluid viscosifier with the structural formula: :

;

(4) Add fracturing fluid viscosifier, potassium chloride, and sodium salicylate into distilled water, stir evenly at high speed to obtain clean fracturing fluid, and the mass of fracturing fluid thickened viscosifier in fracturing fluid The fraction is 0.8%, the mass fraction of potassium chloride is 0.5%, and the mass fraction of sodium salicylate is 1%.

Example 2

(1) Add 5 mmol of melamine, 16 mmol of 4-bromobutyryl chloride and 15.8 mmol of pyridine to 300 mL of acetone solvent in an ice-water bath, firstly in an ice-water bath for 60 min, and then heat to 40 °C, After reacting for 6 h, the solvent was removed by rotary evaporation after the reaction, and the product was recrystallized in ethyl acetate to obtain 4-bromobutyrylamide-s-triazine;

(2) Add 20 mmol of oleic acid, 10 mmol of N-methyldiethanolamine and 1.5 mmol of catalyst p-toluenesulfonic acid to 250 mL of xylene solvent, reflux at 120 °C for 4 h, remove by rotary evaporation after reaction Solvent, the crude product is washed with n-hexane to obtain N-methyl ethyl dioleate intermediate;

(3) Add 25 mmol of N-methyl dioleic acid ethyl ester intermediate and 10 mmol of 4-bromobutyrylamide-s-triazine to 300 mL of N,N-dimethylformamide, at 120 °C Reflux for 72 h, vacuum dry to remove the solvent after reaction, wash the crude product with n-hexane, and recrystallize in a mixed solvent of ethanol and ethyl acetate with a volume ratio of 2:1 to obtain a fracturing fluid thickened viscosifier;

(4) Add fracturing fluid viscosifier, potassium chloride, and sodium salicylate into distilled water, stir evenly at high speed to obtain clean fracturing fluid, and the mass of fracturing fluid thickened viscosifier in fracturing fluid The fraction is 1.2%, the mass fraction of potassium chloride is 0.7%, and the mass fraction of sodium salicylate is 0.8%.

Example 3

(1) Add 5 mmol of melamine, 16 mmol of 4-bromobutyryl chloride and 14 mmol of pyridine to 200 mL of acetone solvent in an ice-water bath for 60 min under an ice-water bath, then heat to 50 °C, After reacting for 6 h, the solvent was removed by rotary evaporation after the reaction, and the product was recrystallized in ethyl acetate to obtain 4-bromobutyrylamide-s-triazine;

(2) Add 22 mmol of oleic acid, 10 mmol of N-methyldiethanolamine and 1.5 mmol of catalyst p-toluenesulfonic acid to 200 mL of xylene solvent, reflux at 90 °C for 12 h, remove by rotary evaporation after reaction Solvent, the crude product is washed with n-hexane to obtain N-methyl ethyl dioleate intermediate;

(3) Add 28 mmol of N-methyl dioleic acid ethyl ester intermediate and 10 mmol of 4-bromobutyrylamide-s-triazine to 500 mL of N,N-dimethylformamide, at 130 °C Reflux for 48 hours, vacuum dry to remove the solvent after reaction, wash the crude product with n-hexane, and recrystallize in a mixed solvent of ethanol and ethyl acetate with a volume ratio of 2:1 to obtain a thickened viscosifier for fracturing fluid;

(4) Add fracturing fluid viscosifier, potassium chloride, and sodium salicylate into distilled water, stir evenly at high speed to obtain clean fracturing fluid, and the mass of fracturing fluid thickened viscosifier in fracturing fluid The fraction is 1.8%, the mass fraction of potassium chloride is 0.4%, and the mass fraction of sodium salicylate is 0.6%.

Example 4

(1) Add 5 mmol of melamine, 21 mmol of 4-bromobutyryl chloride and 22.5 mmol of pyridine to 500 mL of acetone solvent in an ice-water bath, firstly in an ice-water bath for 30 min, and then heat to 30 °C, After reacting for 24 h, the solvent was removed by rotary evaporation after the reaction, and the product was recrystallized in ethyl acetate to obtain 4-bromobutyrylamide-s-triazine;

(2) Add 30 mmol of oleic acid, 10 mmol of N-methyldiethanolamine and 1.8 mmol of catalyst p-toluenesulfonic acid to 200 mL of xylene solvent, reflux at 90 °C for 10 h, remove by rotary evaporation after reaction Solvent, the crude product is washed with n-hexane to obtain N-methyl ethyl dioleate intermediate;

(3) Add 35 mmol of N-methyl dioleic acid ethyl ester intermediate and 10 mmol of 4-bromobutyrylamide-s-triazine to 600 mL of N,N-dimethylformamide, at 130 °C Reflux for 72 h, vacuum dry to remove the solvent after reaction, wash the crude product with n-hexane, and recrystallize in a mixed solvent of ethanol and ethyl acetate with a volume ratio of 2:1 to obtain a fracturing fluid thickened viscosifier;

(4) Add fracturing fluid viscosifier, potassium chloride, and sodium salicylate into distilled water, stir evenly at high speed to obtain clean fracturing fluid, and the mass of fracturing fluid thickened viscosifier in fracturing fluid The fraction is 2%, the mass fraction of potassium chloride is 0.5%, and the mass fraction of sodium salicylate is 0.5%.

Example 5

(1) Add 5 mmol of melamine, 18 mmol of 4-bromobutyryl chloride and 14 mmol of pyridine to 300 mL of acetone solvent in an ice-water bath for 60 min under an ice-water bath, then heat to 35 °C, After reacting for 18 h, the solvent was removed by rotary evaporation after the reaction, and the product was recrystallized in ethyl acetate to obtain 4-bromobutyrylamide-s-triazine;

(2) Add 30 mmol of oleic acid, 10 mmol of N-methyldiethanolamine and 2 mmol of catalyst p-toluenesulfonic acid to 300 mL of xylene solvent, reflux at 110 °C for 7 h, and remove the solvent by rotary evaporation after reaction , the crude product was washed with n-hexane to obtain N-methyl ethyl dioleate intermediate;

(3) Add 32 mmol of N-methyl dioleic acid ethyl ester intermediate and 10 mmol of 4-bromobutyrylamide-s-triazine to 400 mL of N,N-dimethylformamide, at 120 °C Reflux for 96 h, vacuum dry to remove the solvent after reaction, wash the crude product with n-hexane, and recrystallize in a mixed solvent of ethanol and ethyl acetate with a volume ratio of 2:1 to obtain a fracturing fluid thickened viscosifier;

(4) Add fracturing fluid viscosifier, potassium chloride, and sodium salicylate into distilled water, stir evenly at high speed to obtain clean fracturing fluid, and the mass of fracturing fluid thickened viscosifier in fracturing fluid The fraction is 2.5%, the mass fraction of potassium chloride is 0.2%, and the mass fraction of sodium salicylate is 0.3%.

Comparative example 1

Add the fracturing fluid viscosifier prepared in Example 1, potassium chloride, and sodium salicylate into distilled water, and stir evenly at a high speed to obtain a clean fracturing fluid, and the fracturing fluid thickened viscosifier in the fracturing fluid The mass fraction of potassium chloride is 0.5%, the mass fraction of potassium chloride is 0.5%, and the mass fraction of sodium salicylate is 1%.

Comparative example 2

Add the fracturing fluid viscosifier prepared in Example 1, potassium chloride, and sodium salicylate into distilled water, and stir evenly at a high speed to obtain a clean fracturing fluid, and the fracturing fluid thickened viscosifier in the fracturing fluid The mass fraction of potassium chloride is 3%, the mass fraction of potassium chloride is 0.5%, and the mass fraction of sodium salicylate is 1%.

The performance of clean fracturing fluid is tested with reference to SY/T 6376-2008 "General Specifications for Fracturing Fluids" and SY/T 5107-2005 "Methods for Performance Evaluation of Water-based Fracturing Fluids".

Table 1 When the shear rate is 200/s, the viscosity of clean fracturing fluid at different temperatures

When the shear rate is 200/s and the temperature is 50°C, the viscosity of the fracturing fluid reaches 122.4-170.9 when the fracturing fluid thickening agent in the fracturing fluid prepared in Examples 1-5 is 0.8-2.5%. mPa s.

Table 2 When the temperature is 30 ℃, the viscosity of clean fracturing fluid at different shear rates

The above descriptions of the embodiments are for those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative efforts. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (10)

1. A fracturing fluid thickening viscosifier, characterized in that: the structural formula of the fracturing fluid thickening viscosifier is as follows: . 2. a preparation method of the fracturing fluid thickening viscosifier according to claim 1, characterized in that: the preparation method is: (1) Add melamine, 4-bromobutyryl chloride and pyridine to the acetone solvent in an ice-water bath, remove the solvent after the reaction, and recrystallize to obtain 4-bromobutyrylamide-s-triazine; (2) Add oleic acid, N-methyldiethanolamine and catalyst p-toluenesulfonic acid to the xylene solvent, remove the solvent after the reaction, and wash to obtain the N-methyl dioleic acid ethyl ester intermediate; (3) Add N-methyl dioleate intermediate and 4-bromobutyrylamide-s-triazine to N,N-dimethylformamide, remove the solvent after reaction, wash and recrystallize to obtain fracturing Liquid thickener. 3. the preparation method of fracturing fluid viscosifying agent according to claim 2, is characterized in that: in step (1), the reaction molar ratio of melamine, 4-bromobutyryl chloride and pyridine is 1:3.2-4.2: 2.8-4.5. 4. The preparation method of fracturing fluid thickened viscosifier according to claim 2, characterized in that: in step (1), the reaction is first carried out in an ice-water bath for 30-60 min, and then heated to 30-50 °C , react for 6-24 h. 5. The preparation method of fracturing fluid thickening viscosifier according to claim 2, characterized in that: in step (2), the molar ratio of oleic acid, N-methyldiethanolamine and catalyst p-toluenesulfonic acid is 1.8- 3:1:0.12-0.2. 6. The preparation method of the fracturing fluid viscosifier according to claim 2, characterized in that: in step (2), the reaction is refluxed at 90-120°C for 4-12 hours. 7. The preparation method of fracturing fluid thickening viscosifier according to claim 2, characterized in that: in step (3), N-methyl dioleate intermediate and 4-bromobutyramide s-3 The molar ratio of oxazine is 2.5-4:1. 8. The preparation method of the fracturing fluid viscosifier according to claim 2, characterized in that: in step (3), the reaction is refluxed at 110-130 °C for 48-96 h. 9. The application of the fracturing fluid viscosifying agent described in any one of claims 1-8 in clean fracturing fluid, characterized in that: the fracturing fluid viscosifying agent, potassium chloride, Sodium salicylate is added to distilled water and stirred evenly at high speed to obtain clean fracturing fluid. 10. The application of the fracturing fluid viscosifying agent in clean fracturing fluid according to claim 9, characterized in that: the mass fraction of the fracturing fluid viscosifying agent in the fracturing fluid is 0.8-2.5% , the mass fraction of potassium chloride is 0.2-0.7%, and the mass fraction of sodium salicylate is 0.3-1%.