Fracturing fluid thickener and preparation method thereof

Abstract

The present application relates to the technical field of thickening agent, and discloses a fracturing fluid thickening agent and a preparation method thereof, which comprises the following steps: adding dehydroabietyl acid into thionyl chloride to prepare dehydroabietyl acid chloride; adding the dehydroabietyl acid chloride into 2-amino terephthalic acid to obtain an intermediate A; reacting the intermediate A to obtain modified acrylamide; dissolving the modified acrylamide, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and dimethyl diallyl ammonium chloride in deionized water, and adding them into an oil phase to obtain a mixed solution; adding acrylic acid into the mixed solution and adjusting the pH of the solution; continuing to pass nitrogen, adding an initiator, and then carrying out a reaction under temperature rising to obtain the fracturing fluid thickening agent. The rigid dehydroabietyl acid phenanthrene ring structure, the multi-functionality amide structure and the double bond structure further strengthen the polymerization of the polymer and the formation of the hydrogen bond in the compound, and further improve the heat resistance and sand carrying capacity of the fracturing fluid thickening agent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thickening agents, in particular to a fracturing fluid thickening agent and a preparation method thereof. BACKGROUND

[0002] Fracturing fluid thickening agent is an important chemical additive used in oil and gas well fracturing operation, which mainly increases the viscosity of fracturing fluid, thereby improving the sand carrying capacity, reducing the filtration loss, and increasing the fracture width, and ultimately achieving the characteristics of oil and gas production and injection. Although the traditional acrylamide fracturing fluid thickening agent has good thickening performance, its heat resistance and salt tolerance are poor, which limits its application in high temperature and high salinity reservoirs. The research direction of fracturing fluid thickening agent mainly focuses on improving the temperature and salt resistance, reducing the residue, and enhancing the environmental protection.

[0003] The patent with publication number CN113214817 A discloses a super-high-temperature fracturing fluid thickening agent and a preparation method thereof, which comprises: taking acrylamide, acrylic acid and rigid monomer, and adding deionized water to obtain a mixed solution; heating the mixed solution to 45-60℃, and adding an initiator to perform a polymerization reaction under insulation, and the reaction time is 6-8h to obtain a solidified copolymer; and the obtained copolymer is cut, dried and crushed to obtain the thickening agent. Although the fracturing fluid thickening agent obtained by the present application has high viscosity and good stability at high temperature, it still uses petroleum-based compounds as the main raw material and does not have environmental friendliness. The patent with publication number CN118146446 A discloses a fracturing fluid thickening agent and a preparation method thereof, which comprises: uniformly stirring white oil and an emulsifier under nitrogen to obtain an oil phase; dissolving α-eleostearic acid in a solvent, adding thionyl chloride to prepare α-eleostearic acid chloride, and passing ammonia gas to obtain α-eleostearic acid amide; adding α-eleostearic acid amide, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and dimethyldiallylammonium chloride to the oil phase to obtain a mixed solution; adding acrylic acid to the mixed solution and adjusting the pH of the solution; continuing to pass nitrogen, adding an initiator, and after heating reaction, obtaining the fracturing fluid thickening agent. Although the present application modifies the temperature resistance and salt tolerance of the fracturing fluid thickening agent by adding the natural modified derivative α-eleostearic acid amide, and has environmental friendliness, the α-eleostearic acid amide belongs to a single functional amide structure, and still has certain limitations in the temperature resistance and sand carrying capacity of the modified fracturing fluid thickening agent. Therefore, it is an urgent problem to be solved to develop a fracturing fluid thickening agent that meets the environmental requirements and can be used at high temperature. SUMMARY

[0004] Therefore, the present application aims to solve the technical problem of overcoming the poor temperature resistance of the fracturing fluid thickening agent in the prior art, thereby providing a fracturing fluid thickening agent and a preparation method thereof, which uses dehydroabietic acid as a raw material, modifies it to obtain modified acrylamide, and obtains the fracturing fluid thickening agent, thereby improving the temperature resistance and sand carrying capacity of the fracturing fluid thickening agent.

[0005] To solve the above technical problems, the present application provides a preparation method of a fracturing fluid thickening agent, comprising the following steps:

[0006] (1) Dissolve dehydroabietic acid in a first solvent, and add thionyl chloride to prepare dehydroabietic acid chloride;

[0007] (2) Dissolve the dehydroabietic acid chloride in a second solvent, and add 2-amino terephthalic acid, and keep the pH value of the reaction at 7.5-9 to obtain an intermediate A;

[0008] (3) Dissolve the intermediate A in a third solvent, and add allylamine and an activator to obtain modified acrylamide after reaction;

[0009] (4) Under the condition of nitrogen, uniformly stir white oil and an emulsifier to obtain an oil phase;

[0010] (5) Dissolve modified acrylamide, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and dimethyldiallylammonium chloride in deionized water, and add them to the oil phase to obtain a mixed solution;

[0011] (6) Add acrylic acid to the mixed solution, and adjust the pH of the solution;

[0012] (7) Continue to pass nitrogen, add an initiator, and obtain the fracturing fluid thickening agent after warming reaction.

[0013] Preferably, the preparation process of the modified acrylamide is as follows:

[0014] .

[0015] Preferably, the first solvent in step (1) is at least one of dichloromethane or tetrahydrofuran, the molar ratio of dehydroabietic acid to thionyl chloride is 1:1-1:2, the reaction temperature is 0-20℃, and the reaction time is 4-8h.

[0016] Preferably, the second solvent in step (2) is at least one of dichloromethane or tetrahydrofuran, the molar ratio of dehydroabietic acid chloride to 2-amino terephthalic acid is 1:1-1:1.2, the reaction temperature is 10-20℃, and the reaction time is 2-4h.

[0017] Preferably, the third solvent in the step (3) is at least one of dichloromethane or N,N-dimethylformamide (DMF), the activating agent is 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC), the molar ratio of the intermediate A to the allylamine is 1:2-1:3, the reaction temperature is 50-100℃, and the reaction time is 4-8h.

[0018] Preferably, the weight ratio of the modified acrylamide, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, dimethyldiallylammonium chloride is 1-5:5-10:1-5:1-3; the weight ratio of the acrylamide to the acrylate is 1:3-1:5; and the pH is 7-8.

[0019] Preferably, the reaction temperature in the step (7) is 50-80℃, and the reaction time is 2-6h.

[0020] Preferably, the emulsifier is at least one of Span 80, polyoxyethylene octyl phenol ether 10 or fatty alcohol polyoxyethylene ether AEO-5.

[0021] Preferably, the initiator comprises ammonium persulfate, sodium bisulfite and azobisisobutyronitrile, and the mass ratio of the ammonium sulfate, sodium bisulfite and azobisisobutyronitrile is 1-2:1-2:1.

[0022] Meanwhile, the application also provides a fracturing fluid thickening agent prepared by the above preparation method.

[0023] The technical scheme of the application has the following advantages:

[0024] The fracturing fluid thickening agent and the preparation method thereof provided by the application use dehydroabietic acid, a natural rosin derivative, as a raw material, modify the dehydroabietic acid to obtain modified acrylamide, and obtain the fracturing fluid thickening agent; the rigid dehydroabietic acid phenanthrene ring structure, the multi-functional amide structure and the double bond structure further strengthen the polymerization of the polymer and the formation of the hydrogen bond in the compound, further improve the heat resistance of the fracturing fluid thickening agent, and make the fracturing fluid thickening agent still have high viscosity at high temperature, increase the intermolecular force, and enhance the sand carrying capacity. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the FT-IR graph of the modified acrylamide. DETAILED DESCRIPTION

[0026] The following examples are provided for better understanding of the application and do not limit the best mode of the application, and do not limit the content and protection scope of the application, and any product same or similar to the application obtained by the inspiration of the application or the combination of the application with other prior art features falls within the protection scope of the application.

[0027] When the specific experimental steps or conditions are not mentioned in the examples, the operation or conditions can be carried out according to the conventional experimental steps described in the literature in the art. When the reagents or instruments are not mentioned by the manufacturer, they are all conventional reagent products that can be obtained by purchase.

[0028] FT-IR (Fourier Transform Infrared Spectroscopy) was performed by using a Nicolet IS50 infrared spectrometer.

[0029] Example 1:

[0030] A preparation method of a fracturing fluid thickening agent, comprising the following steps:

[0031] (1) 30 g of dehydroabietic acid was dissolved in 300 mL of dichloromethane, 18 g of thionyl chloride was added at 0°C, and dehydroabietic acid chloride was prepared at 10°C for 6 h;

[0032] (2) 32 g of dehydroabietic acid chloride was dissolved in 300 mL of dichloromethane, 18 g of 2-amino terephthalic acid was added, and the pH value was maintained at 7.5-9 during the reaction, and the intermediate A was obtained at 15°C for 3 h;

[0033] (3) 46 g of intermediate A was dissolved in 500 mL of DMF, 12 g of allylamine and 19 g of an activator were added, and the modified acrylamide was obtained after reaction;

[0034] (4) 100 g of white oil and 10 g of Span 80 were stirred uniformly under the condition of nitrogen to obtain an oil phase;

[0035] (5) 50 g of modified acrylamide, 70 g of acrylamide, 10 g of 2-acrylamido-2-methylpropane sulfonic acid, and 5 g of dimethyl diallyl ammonium chloride were dissolved in 200 g of deionized water and added to the oil phase to obtain a mixed solution;

[0036] (6) 20 g of acrylic acid was added to the mixed solution, and the pH of the solution was adjusted to 7;

[0037] (7) Nitrogen was continuously passed, and stirring was continued for 30 min, 0.4 g of ammonium persulfate, 0.2 g of sodium bisulfite, and 0.2 g of azobisisobutyronitrile were added, and the temperature was raised to 60°C for reaction for 4 h to obtain the fracturing fluid thickening agent.

[0038] The FT-IR spectrum of the obtained modified acrylamide is shown in Figure 1 From Figure 1 it can be seen that the characteristic absorption peak of N-H appears at 3267.41 cm -1 , the characteristic absorption peak of terminal =C-H appears at 3080.73 cm -1 , and the characteristic absorption peak of =C-H appears at 1656.53 cm -1characteristic absorption peak of carbonyl group appears at 1623.16 cm -1 characteristic absorption peak of carbon-carbon double bond appears at 1630.48 cm

[0039] Example 2

[0040] A preparation method of a fracturing fluid thickening agent, comprising the following steps:

[0041] (1) 30 g of dehydroabietic acid is dissolved in 300 mL of dichloromethane, 24 g of thionyl chloride is added at 0°C, and dehydroabietic acid chloride is prepared at 20°C for 8 h;

[0042] (2) 32 g of dehydroabietic acid chloride is dissolved in 300 mL of dichloromethane, 21 g of 2-amino terephthalic acid is added, the pH value is kept at 7.5-9 during the reaction, and the intermediate A is obtained at 20°C for 4 h;

[0043] (3) 46 g of intermediate A is dissolved in 500 mL of DMF, 17 g of allylamine and 19 g of an activator are added, and the modified acrylamide is obtained after reaction;

[0044] (4) Under the condition of nitrogen, 100 g of white oil and 10 g of polyoxyethylene octylphenol ether 10 are stirred uniformly to obtain an oil phase;

[0045] (5) 30 g of modified acrylamide, 100 g of acrylamide, 20 g of 2-acrylamido-2-methylpropane sulfonic acid and 5 g of dimethyl diallyl ammonium chloride are dissolved in 200 g of deionized water, and then added to the oil phase to obtain a mixed solution;

[0046] (6) 20 g of acrylic acid is added to the mixed solution, and the pH of the solution is adjusted to 7;

[0047] (7) Continue to pass nitrogen, stir for 30 min, add 0.3 g of ammonium persulfate, 0.3 g of sodium bisulfite and 0.3 g of azobisisobutyronitrile, and then heat to 80°C for 6 h to obtain the fracturing fluid thickening agent.

[0048] Example 3

[0049] A preparation method of a fracturing fluid thickening agent, comprising the following steps:

[0050] (1) 30 g of dehydroabietic acid is dissolved in 300 mL of dichloromethane, 24 g of thionyl chloride is added at 0°C, and dehydroabietic acid chloride is prepared at 20°C for 8 h;

[0051] (2) 32 g of dehydroabietic acid chloride is dissolved in 300 mL of dichloromethane, 21 g of 2-amino terephthalic acid is added, the pH value is kept at 7.5-9 during the reaction, and the intermediate A is obtained at 20°C for 4 h;

[0052] (3) 46 g of the intermediate A is dissolved in 500 mL of DMF, 12 g of allylamine and 19 g of an activator are added, and a modified acrylamide is obtained after reaction;

[0053] (4) 100 g of white oil and 10 g of fatty alcohol polyoxyethylene ether AEO-5 are stirred uniformly under the condition of nitrogen to obtain an oil phase;

[0054] (5) 10 g of the modified acrylamide, 50 g of acrylamide, 10 g of 2-acrylamido-2-methylpropane sulfonic acid and 10 g of dimethyldiallylammonium chloride are dissolved in 200 g of deionized water, and then added to the oil phase to obtain a mixed solution;

[0055] (6) 17 g of acrylic acid is added to the mixed solution, and the pH of the solution is adjusted to 8;

[0056] (7) Nitrogen is continuously passed, and stirring is continued for 30 min, 0.2 g of ammonium persulfate, 0.4 g of sodium bisulfite and 0.2 g of azobisisobutyronitrile are added, the temperature is raised to 50 °C, and reaction is carried out for 2 h to obtain a fracturing fluid thickening agent.

[0057] Example 4:

[0058] A preparation method of a fracturing fluid thickening agent comprises the following steps:

[0059] (1) 30 g of dehydroabietic acid is dissolved in 300 mL of dichloromethane, 18 g of thionyl chloride is added at 0 °C, and dehydroabietic acid chloride is prepared by maintaining the temperature at 10 °C for 6 h;

[0060] (2) 32 g of dehydroabietic acid chloride is dissolved in 300 mL of dichloromethane, 18 g of 2-amino terephthalic acid is added, the pH value is maintained at 7.5-9 during the reaction process, and the intermediate A is obtained by maintaining the temperature at 15 °C for 3 h;

[0061] (3) 46 g of the intermediate A is dissolved in 500 mL of DMF, 12 g of allylamine and 19 g of an activator are added, and a modified acrylamide is obtained after reaction;

[0062] (4) 100 g of white oil and 10 g of Span 80 are stirred uniformly under the condition of nitrogen to obtain an oil phase;

[0063] (5) 10 g of the modified acrylamide, 70 g of acrylamide, 10 g of 2-acrylamido-2-methylpropane sulfonic acid and 5 g of dimethyldiallylammonium chloride are dissolved in 200 g of deionized water, and then added to the oil phase to obtain a mixed solution;

[0064] (6) 20 g of acrylic acid is added to the mixed solution, and the pH of the solution is adjusted to 7;

[0065] (7) continue to pass nitrogen, stirring for 30 min, adding 0.4g ammonium persulfate, 0.2g sodium bisulfite, 0.2g azobisisobutyronitrile, heating to 60℃ for 4h, to obtain the fracturing fluid thickening agent.

[0066] Example 5:

[0067] A preparation method of a fracturing fluid thickening agent, comprising the following steps:

[0068] (1) 30g dehydroabietic acid is dissolved in 300mL dichloromethane, 24g thionyl chloride is added at 0℃, and dehydroabietic acid chloride is prepared at 20℃ for 8h;

[0069] (2) 32g dehydroabietic acid chloride is dissolved in 300mL dichloromethane, 21g 2-amino terephthalic acid is added, and the pH value is kept at 7.5~9 during the reaction, to obtain intermediate A at 20℃ for 4h;

[0070] (3) 46g intermediate A is dissolved in 500mL DMF, 17g allylamine and 19g activator are added, and modified acrylamide is obtained after reaction;

[0071] (4) 100g white oil, 10g polyoxyethylene octyl phenol ether 10 are stirred uniformly under the condition of nitrogen to obtain an oil phase;

[0072] (5) 10g modified acrylamide, 100g acrylamide, 20g 2-acrylamido-2-methylpropane sulfonic acid, 5g dimethyldiallylammonium chloride are dissolved in 200g deionized water, and added to the oil phase to obtain a mixed solution;

[0073] (6) 20g acrylic acid is added to the mixed solution, and the pH of the solution is adjusted to 7;

[0074] (7) continue to pass nitrogen, stirring for 30 min, adding 0.3g ammonium persulfate, 0.3g sodium bisulfite, 0.3g azobisisobutyronitrile, heating to 80℃ for 6h, to obtain the fracturing fluid thickening agent.

[0075] Comparative Example 1:

[0076] A preparation method of a fracturing fluid thickening agent, comprising the following steps:

[0077] (1) 100g white oil, 10g Span 80 are stirred uniformly under the condition of nitrogen to obtain an oil phase;

[0078] (2) 70g acrylamide, 10g 2-acrylamido-2-methylpropane sulfonic acid, 5g dimethyldiallylammonium chloride are dissolved in 50g deionized water, and added to the oil phase to obtain a mixed solution;

[0079] (3) 20 g of acrylic acid was added to the mixed solution, and the pH of the solution was adjusted to 7;

[0080] (4) Nitrogen was continuously passed, stirring for 30 min, 0.4 g of ammonium persulfate, 0.2 g of sodium bisulfite, and 0.2 g of azobisisobutyronitrile were added, and the temperature was raised to 60°C for 4 h to obtain the fracturing fluid thickening agent.

[0081] Comparative Example 2:

[0082] The fracturing fluid thickening agent was prepared according to the preparation method of the fracturing fluid thickening agent and the preparation method thereof disclosed in the patent publication CN118146446 A.

[0083] The fracturing fluid thickening agents prepared in Examples 1-5 and Comparative Examples 1 and 2 were respectively dissolved in tap water at a concentration of 0.6%, and the viscosity was tested at different temperatures under a shear rate of 170 S -1 for 2 h. The test results are shown in Table 1.

[0084] Table 1 Viscosity of fracturing fluid thickening agents obtained from different examples and comparative examples in tap water at different temperatures

[0085]

[0086] The fracturing fluid thickening agents prepared in Examples 1-5 and Comparative Examples 1 and 2 were respectively dissolved in 8.5 million salinity brine at a concentration of 1.4%, and the viscosity was tested at 120°C under a shear rate of 170 S -1 for 2 h. The test results are shown in Table 2.

[0087] Table 2 Viscosity of fracturing fluid thickening agents obtained from different examples and comparative examples in 8.5 million salinity brine

[0088]

[0089] 100 g of the sample after the viscosity test of the fracturing fluid thickening agents prepared in Examples 1-5 and Comparative Examples 1 and 2 was dissolved in tap water at a concentration of 0.6% at 60°C under a shear rate of 170 S -1 for 2 h, 25 g of quartz sand (particle size of 40-70 mesh) was added, stirred uniformly, and then poured into a measuring cylinder. The settling velocity of the sand in the fracturing fluid was measured by the static suspension method to evaluate the sand carrying performance.

[0090] Table 3 Settling velocity of fracturing fluid thickening agents obtained from different examples and comparative examples

[0091]

[0092] As can be seen from Tables 1-3, by adding the modified acrylamide, the viscosity of the fracturing fluid thickening agent at different temperatures can be significantly improved, the salt tolerance and sand carrying capacity of the fracturing fluid thickening agent can be improved. This is because the rigid dehydroabietic acid phenanthrene ring structure, the multifunctional amide structure and the double bond structure further strengthen the polymerization of the polymer and the formation of hydrogen bonds in the compound, further improve the heat resistance of the fracturing fluid thickening agent, and make it still have high viscosity at high temperature, increase the intermolecular force, and enhance the sand carrying capacity.

[0093] Obviously, the above examples are only examples for clearly illustrating, but not limitation to the embodiments. Other different forms of changes or variations can be made on the basis of the above description for those skilled in the art. Here, all the embodiments need not and cannot be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method of preparing a fracturing fluid viscosifier, characterized in that, The method comprises the following steps: (1) dissolving dehydroabietic acid in a first solvent, and adding thionyl chloride to prepare dehydroabietic acid chloride; (2) dissolving the dehydroabietic acid chloride in a second solvent, and adding 2-amino terephthalic acid, and keeping the pH value of the reaction at 7.5-9 to obtain an intermediate A; (3) dissolving the intermediate A in a third solvent, and adding allylamine and an activating agent to obtain a modified acrylamide after the reaction; (4) stirring white oil and an emulsifier uniformly under the condition of nitrogen to obtain an oil phase; (5) dissolving the modified acrylamide, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and dimethyldiallylammonium chloride in deionized water, and adding them into the oil phase to obtain a mixed solution; (6) adding acrylic acid into the mixed solution, and adjusting the pH value of the solution to 7-8; (7) continuing to pass nitrogen, adding an initiator, and obtaining a fracturing fluid thickening agent after the reaction under heating. The first solvent is at least one of dichloromethane or tetrahydrofuran, the second solvent is at least one of dichloromethane or tetrahydrofuran, the third solvent is at least one of dichloromethane or N,N-dimethylformamide, and the activating agent is 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride. The weight ratio of the modified acrylamide, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and dimethyldiallylammonium chloride is 1-5:5-10:1-5:1-3, and the weight ratio of the acrylic acid to the acrylamide is 1:3-1:

5.

2. The method of claim 1, wherein the crosslinker is prepared by the process comprising the steps of: In the step (1), the molar ratio of the dehydroabietic acid to the thionyl chloride is 1:1-1:2, the reaction temperature is 0-20℃, and the reaction time is 4-8h.

3. The method for preparing a fracturing fluid thickener according to claim 1, wherein: In the step (2), the molar ratio of the dehydroabietic acid chloride to the 2-amino terephthalic acid is 1:1-1:1.2, the reaction temperature is 10-20℃, and the reaction time is 2-4h.

4. The method for preparing a fracturing fluid thickener according to claim 1, wherein: In the step (3), the molar ratio of the intermediate A to the allylamine is 1:2-1:3, the reaction temperature is 50-100℃, and the reaction time is 4-8h.

5. The method for preparing a fracturing fluid thickener according to claim 1, wherein: In the step (7), the reaction temperature is 50-80℃, and the reaction time is 2-6h.

6. The method for preparing a fracturing fluid thickener according to claim 1, wherein: The emulsifier is at least one of Span 80, polyoxyethylene octyl phenol ether 10 or fatty alcohol polyoxyethylene ether AEO-5.

7. The method for preparing a fracturing fluid thickener according to claim 1, wherein: The initiator comprises ammonium persulfate, sodium bisulfite and azobisisobutyronitrile, and the mass ratio of the ammonium persulfate, the sodium bisulfite and the azobisisobutyronitrile is 1-2:1-2:

1.

8. A fracturing fluid viscosifier characterized in that, The fracturing fluid thickening agent is prepared by the preparation method in any one of claims 1-7.

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