A low viscosity hyperbranched epoxy resin, its preparation method and application

Abstract

This invention discloses a low-viscosity hyperbranched epoxy resin, its preparation method, and its application, belonging to the field of plugging agent technology. The preparation method includes the following steps: 4,4'-dihydroxydiphenylmethane is vacuum dried, then mixed with trimethylolpropane triglycidyl ether. Under nitrogen protection, a first heating is performed. After the first heating is completed, a first catalyst, triphenylphosphine, is added, and the mixture is kept at the same temperature for the first reaction. A second heating is then performed. After the second heating is completed, a second catalyst is added, and the mixture is kept at the same temperature for the second reaction, yielding a low-viscosity hyperbranched epoxy resin. This invention addresses the problem of existing plugging agents failing due to their high brittleness, high shrinkage, and poor adhesion to the formation.

Description

Technical Field

[0001] This invention belongs to the field of sealing agent technology, specifically relating to a low-viscosity hyperbranched epoxy resin, its preparation method, and its application. Background Technology

[0002] As oil and gas exploration and development progresses into more complex geological formations, traditional plugging agent systems face severe challenges. During the production process, oil and gas wells may develop severe fractures or pores, leading not only to wellbore collapse or leakage but also to resource waste and reduced oil and gas production. Ordinary cement-based plugging agents, due to their high brittleness, high shrinkage rate, and poor adhesion to the formation, are prone to plugging failure.

[0003] Existing plugging agent preparation technologies mainly rely on bisphenol A. Although it can achieve the purpose of preparing hyperbranched epoxy resin, it has high environmental toxicity and is difficult to meet environmental protection requirements. In addition, bisphenol A has relatively low reactivity, which affects the plugging work in oil and gas field development. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention aims to provide a low-viscosity hyperbranched epoxy resin, its preparation method, and its application. The hyperbranched molecular structure of the prepared hyperbranched epoxy resin HBP can provide a large number of active reaction sites, increase the crosslinking density, and form a high-strength, high-toughness three-dimensional crosslinked network structure through reaction with isocyanate groups. It can be applied in the field of plugging agents to solve the problem of plugging failure caused by the high brittleness, high shrinkage rate, and poor adhesion to the formation of existing plugging agents.

[0005] To achieve the above objectives, the present invention employs the following technical solution: This invention provides a method for preparing a low-viscosity hyperbranched epoxy resin, comprising the following steps: 4,4'-dihydroxydiphenylmethane was vacuum dried and then mixed with trimethylolpropane triglycidyl ether. Under nitrogen protection, the mixture was heated for the first time. After the first heating was completed, the first catalyst, triphenylphosphine, was added and the mixture was kept at the temperature for the first reaction. Then, the mixture was heated for the second time. After the second heating was completed, the second catalyst was added and the mixture was kept at the temperature for the second reaction, thus obtaining a low-viscosity hyperbranched epoxy resin.

[0006] In one embodiment, the vacuum drying temperature is 40°C and the time is 12-24 hours.

[0007] In one embodiment, the mass ratio of 4,4'-dihydroxydiphenylmethane to trimethylolpropane triglycidyl ether is 1:2.5.

[0008] In one embodiment, the stirring speed is 200 rpm; the nitrogen flow rate is 100 mL / min.

[0009] In one embodiment, the heating rate of the first heating is 5°C / min, and the target temperature of the first heating is 100°C.

[0010] In one embodiment, the heating rate of the second heating is 5°C / min, and the target temperature of the second heating is 120°C.

[0011] In one embodiment, the amount of the first catalyst triphenylphosphine added is 0.1%-1% of the total mass of monomers 4,4'-dihydroxydiphenylmethane and trimethylolpropane triglycidyl ether.

[0012] In one embodiment, the second catalyst is ethyltriphenylphosphine bromide, and the amount of the second catalyst added is 0.2%-0.5% of the total mass of monomers 4,4'-dihydroxydiphenylmethane and trimethylolpropane triglycidyl ether.

[0013] In one embodiment, the first reaction takes 3 hours and the second reaction takes 2 hours.

[0014] The present invention also provides a method for preparing a low-viscosity hyperbranched epoxy resin, which yields a low-viscosity hyperbranched epoxy resin.

[0015] The present invention also provides a method for preparing low-viscosity hyperbranched epoxy resin and the application of the low-viscosity hyperbranched epoxy resin in the sealing of old fractures in the development of deep oil and gas reservoirs.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for preparing a low-viscosity hyperbranched epoxy resin. The hyperbranched epoxy resin molecule has a highly branched structure, and its abundant terminal active groups can react with multiple reaction sites in cement-based sealants to form a high-strength, high-toughness three-dimensional cross-linked network structure. This network can both provide a supporting effect for the cement system and improve its adhesion performance to the rock interface. At the same time, the hyperbranched epoxy resin molecular chain has a low degree of entanglement and low viscosity. Even with a high molecular weight, its viscosity is significantly lower than that of ordinary linear polymers under the same conditions, which is beneficial for smooth resin injection. This method targets areas deep within the formation, rather than near the wellbore, effectively sealing high-permeability zones or fractures. Furthermore, the resin possesses excellent water resistance, salt resistance, and low permeability, effectively blocking seepage channels within a cement matrix. Even under high temperatures exceeding 120°C and high mineralization conditions deep within the formation, the composite sealant maintains structural integrity, achieving a long-lasting and stable irreversible sealing effect. This invention uses non-toxic raw materials such as bisphenol F, avoiding formation pollution. The preparation process is simple, and the raw materials are readily available, reducing preparation steps and operational risks, resulting in good economic feasibility and environmental benefits.

[0017] Hyperbranched polymerization reactions are prone to vigorous initial reactions, rapidly forming high-molecular-weight products and causing gelation, which affects product quality. Triphenylphosphine, however, exhibits relatively mild reactivity compared to other catalysts. During catalysis, it primarily guides the reaction between epoxy groups and the hydroxyl groups in 4,4'-dihydroxydiphenylmethane, initiating polymer chain growth and preferentially forming low-viscosity oligomers that are easily processed, thus avoiding premature formation of highly cross-linked structures that lead to gelation. Therefore, this invention employs a two-stage catalysis, selecting triphenylphosphine as the catalyst in the first stage. This allows the reactants to form linear and low-branched oligomers in the early stages of the reaction, significantly reducing the risk of gelation. Subsequently, in the second stage, ethyltriphenylphosphine bromide is selected as the catalyst to increase the reaction intensity and promote the formation of highly branched products. This strategy not only effectively suppresses gelation and improves reaction efficiency but also reduces byproducts, thereby obtaining a higher purity target product. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the synthesis principle of the hyperbranched epoxy resin of the present invention. Figure 2 The Fourier transform infrared spectrum of hyperbranched epoxy resin. Detailed Implementation

[0019] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0020] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0021] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0022] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0023] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0024] This invention provides a low-viscosity hyperbranched epoxy resin, its preparation method, and its applications. In geological environments, this composite material can synergistically work with cement-based sealing agents to provide support to the cement system and further improve its adhesion to the rock interface. The low-viscosity hyperbranched epoxy resin is used as a sealing agent to seal severe fractures and pores.

[0025] The low-viscosity hyperbranched epoxy resin provided by this invention can solve the problems of high brittleness, high shrinkage rate, and poor adhesion to the formation of existing ordinary cement-based sealing agents, which lead to sealing failure.

[0026] The aforementioned low-viscosity hyperbranched epoxy resin exhibits environmental adaptability and adhesion under formation conditions. In oilfield plugging operations, it can match formation fractures and synergistically work with cement-based plugging agents to achieve high plugging pressure. Furthermore, the product's raw materials are environmentally friendly and non-toxic, indicating that it can reduce damage to the formation during construction.

[0027] like Figure 1 As shown, this invention provides a method for preparing a low-viscosity hyperbranched epoxy resin, comprising the following steps: Bisphenol F (A2) was pre-dried under vacuum at 40°C for 12-24 hours. The dried bisphenol F (A2) and trimethylolpropane triglycidyl ether (B3) were added to a four-necked flask at a mass ratio of 1:2.5. Under nitrogen protection, the mixture was heated to 100°C at a rate of 5°C / min. Then, 0.1%-1% of triphenylphosphine by mass of the total monomers was added and kept at this temperature for 3 hours. The temperature was then increased to 120°C at a rate of 5°C / min. Finally, 0.2%-0.5% ethyltriphenylphosphine bromide was added and kept at this temperature for 2 hours. The mixture was then cooled to 25°C to obtain the hyperbranched epoxy resin.

[0028] The nitrogen flow rate is approximately 100 mL / min, and the stirring speed is 200 rpm.

[0029] This invention utilizes the abundant end-group functional groups of the hyperbranched molecules in epoxy resin to provide numerous active reaction sites. Through reaction with isocyanate groups, a high-strength, high-toughness three-dimensional cross-linked network structure can be formed. This network structure not only significantly improves the strength and toughness of the plugging system but also effectively reduces the volume shrinkage of the system during curing. Simultaneously, this composite material can synergistically work with cement-based plugging agents to provide support to the cement system and further improve its adhesion to the rock interface. This composite plugging system can form a long-term effective plugging solution, providing effective technical means and theoretical support for solving the water shut-off problem in high water-cut wells, and laying a solid foundation for the subsequent efficient development of oil and gas fields.

[0030] This invention provides a low-viscosity hyperbranched epoxy resin prepared by the above-described method. The raw materials of the low-viscosity hyperbranched epoxy resin include bisphenol F (A2) and trimethylolpropane triglycidyl ether (B3) in a mass ratio of 1:2.5. The prepared sample was characterized by Fourier transform infrared spectroscopy (FT-IR), and the test results are as follows. Figure 2 As shown.

[0031] Among the above raw materials, 4,4'-dihydroxydiphenylmethane (also commonly known as: bisphenol F, methylene bisphenol); trimethylolpropane triglycidyl ether (abbreviated as: TMPTE / TPEG).

[0032] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0033] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0034] Example 1 This embodiment provides a method for preparing a low-viscosity hyperbranched epoxy resin, comprising the following steps: 10 g of bisphenol F (A2) and 25.00 g of trimethylolpropane triglycidyl ether (B3), which had been vacuum dried at 40 °C for 12 h, were added sequentially to a four-necked flask at room temperature.

[0035] Nitrogen protection was turned on, the flow rate was 100 mL / min, and the mixture was stirred at 200 rpm. The temperature was increased to 100℃ at a programmed rate of 5℃ / min. 0.175 g of triphenylphosphine was added and the mixture was kept at this temperature for 3 h. Then 0.07 g of ethyltriphenylphosphine bromide was added and the mixture was kept at this temperature for another 2 h until the reaction endpoint was reached. After heating was stopped, the product was cooled to room temperature to obtain a low-viscosity hyperbranched epoxy resin.

[0036] Example 2 This embodiment provides a method for preparing a low-viscosity hyperbranched epoxy resin, comprising the following steps: 10 g of bisphenol F (A2) and 25.00 g of trimethylolpropane triglycidyl ether (B3), which had been vacuum dried at 40 °C for 24 h, were added sequentially to a four-necked flask at room temperature.

[0037] Nitrogen protection was turned on, the flow rate was 100 mL / min, and the mixture was stirred at 200 rpm. The temperature was increased to 100℃ at a programmed rate of 5℃ / min. 0.175 g of triphenylphosphine was added and the mixture was kept at this temperature for 3 h. Then 0.07 g of ethyltriphenylphosphine bromide was added and the mixture was kept at this temperature for another 2 h until the reaction endpoint was reached. After heating was stopped, the product was cooled to room temperature to obtain a low-viscosity hyperbranched epoxy resin.

[0038] Example 3 This embodiment provides a method for preparing a low-viscosity hyperbranched epoxy resin, comprising the following steps: 10 g of bisphenol F (A2) and 25.00 g of trimethylolpropane triglycidyl ether (B3), which had been vacuum dried at 40 °C for 12 h, were added sequentially to a four-necked flask at room temperature.

[0039] Nitrogen protection was turned on, the flow rate was 100 mL / min, and the mixture was stirred at 200 rpm. The temperature was increased to 100℃ at a programmed rate of 5℃ / min. 0.35 g of triphenylphosphine was added and the mixture was kept at this temperature for 3 h. Then 0.07 g of ethyltriphenylphosphine bromide was added and the mixture was kept at this temperature for another 2 h until the reaction endpoint was reached. After heating was stopped, the product was cooled to room temperature to obtain a low-viscosity hyperbranched epoxy resin.

[0040] Example 4 This embodiment provides a method for preparing a low-viscosity hyperbranched epoxy resin, comprising the following steps: 10 g of bisphenol F (A2) and 25.00 g of trimethylolpropane triglycidyl ether (B3), which had been vacuum dried at 40 °C for 12 h, were added sequentially to a four-necked flask at room temperature.

[0041] Nitrogen protection was turned on, the flow rate was 100 mL / min, and the mixture was stirred at 200 rpm. The temperature was increased to 100℃ at a programmed rate of 5℃ / min. 0.035 g of triphenylphosphine was added and the mixture was kept at this temperature for 3 h. Then 0.07 g of ethyltriphenylphosphine bromide was added and the mixture was kept at this temperature for another 2 h until the reaction endpoint was reached. After heating was stopped, the product was cooled to room temperature to obtain a low-viscosity hyperbranched epoxy resin.

[0042] Example 5 This embodiment provides a method for preparing a low-viscosity hyperbranched epoxy resin, comprising the following steps: 10 g of bisphenol F (A2) and 25.00 g of trimethylolpropane triglycidyl ether (B3), which had been vacuum dried at 40 °C for 12 h, were added sequentially to a four-necked flask at room temperature.

[0043] Nitrogen protection was turned on, the flow rate was 100 mL / min, and the mixture was stirred at 200 rpm. The temperature was increased to 100℃ at a programmed rate of 5℃ / min. 0.175 g of triphenylphosphine was added and the mixture was kept at this temperature for 3 h. Then 0.105 g of ethyltriphenylphosphine bromide was added and the mixture was kept at this temperature for another 2 h until the reaction endpoint was reached. After heating was stopped, the product was cooled to room temperature to obtain a low-viscosity hyperbranched epoxy resin.

[0044] Example 6 This embodiment provides a method for preparing a low-viscosity hyperbranched epoxy resin, comprising the following steps: 10 g of bisphenol F (A2) and 25.00 g of trimethylolpropane triglycidyl ether (B3), which had been vacuum dried at 40 °C for 12 h, were added sequentially to a four-necked flask at room temperature.

[0045] Nitrogen protection was turned on, the flow rate was 100 mL / min, and the mixture was stirred at 200 rpm. The temperature was increased to 100℃ at a programmed rate of 5℃ / min. 0.35 g of triphenylphosphine was added and the mixture was kept at this temperature for 3 h. Then 0.175 g of ethyltriphenylphosphine bromide was added and the mixture was kept at this temperature for another 2 h until the reaction endpoint was reached. After heating was stopped, the product was cooled to room temperature to obtain a low-viscosity hyperbranched epoxy resin.

[0046] The product parameters of the low-viscosity hyperbranched epoxy resins obtained in Examples 1 to 6 are shown in Table 1 below.

[0047] Table 1 Product Parameters of Examples

[0048] Table 1 shows that the branching degree of the low-viscosity epoxy resin is between 56.3% and 57.8%; the epoxy value is between 0.51 and 0.52; the number-average molecular weight is between 2252.1 kDa and 3616.8 kDa, which has a relatively high molecular weight; and the viscosity is between 5319 mPa·s and 5883 mPa·s, which has a relatively low viscosity.

[0049] This invention provides a method for preparing a low-viscosity hyperbranched epoxy resin. First, monomers A2 (bisphenol F) and B3 (trimethylolpropane triglycidyl ether) are weighed according to a stoichiometric ratio and placed in a four-necked flask. Under nitrogen protection, the mixture is stirred and slowly heated. Triphenylphosphine is added for catalytic reaction. After maintaining the temperature for a period of time, ethyltriphenylphosphine bromide is added for secondary catalysis. The mixture is then kept at this temperature for another period and cooled to room temperature to obtain a low-viscosity hyperbranched epoxy resin. The abundant end-functional groups of the hyperbranched molecules in this invention provide numerous active reaction sites, increasing the crosslinking density. Through reaction with isocyanate groups, a high-strength, high-toughness three-dimensional crosslinked network structure can be formed. This significantly improves the strength and toughness of the sealing system and effectively reduces the volume shrinkage of the system during curing, enabling the composite sealing system to form a long-term effective seal.

[0050] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A process for the preparation of a low viscosity hyperbranched epoxy resin, characterized in that, Includes the following steps: 4,4'-dihydroxydiphenylmethane was vacuum dried and then mixed with trimethylolpropane triglycidyl ether. Under nitrogen protection, the mixture was heated for the first time. After the first heating was completed, the first catalyst, triphenylphosphine, was added and the mixture was kept at the temperature for the first reaction. Then, the mixture was heated for the second time. After the second heating was completed, the second catalyst was added and the mixture was kept at the temperature for the second reaction, thus obtaining a low-viscosity hyperbranched epoxy resin.

2. The process for the preparation of a low viscosity hyperbranched epoxy resin according to claim 1, characterized in that, The vacuum drying temperature is 40℃, and the time is 12-24h.

3. The method for preparing a low-viscosity hyperbranched epoxy resin according to claim 1, characterized in that, The mass ratio of 4,4'-dihydroxydiphenylmethane to trimethylolpropane triglycidyl ether is 1:2.

5.

4. The process for the preparation of a low viscosity hyperbranched epoxy resin according to claim 1, characterized in that, The heating rate for the first heating is 5°C / min, and the target temperature for the first heating is 100°C.

5. The process for the preparation of a low viscosity hyperbranched epoxy resin as claimed in claim 1, wherein, The heating rate for the second heating is 5°C / min, and the target temperature for the second heating is 120°C.

6. The method for preparing a low-viscosity hyperbranched epoxy resin according to claim 1, characterized in that, The amount of the first catalyst, triphenylphosphine, added is 0.1%-1% of the total mass of 4,4'-dihydroxydiphenylmethane and trimethylolpropane triglycidyl ether.

7. The method for preparing a low-viscosity hyperbranched epoxy resin according to claim 1, characterized in that, The second catalyst is ethyltriphenylphosphine bromide, and the amount of the second catalyst added is 0.2%-0.5% of the total mass of 4,4'-dihydroxydiphenylmethane and trimethylolpropane triglycidyl ether.

8. The method for preparing a low-viscosity hyperbranched epoxy resin according to claim 1, characterized in that, The first reaction took 3 hours, and the second reaction took 2 hours.

9. A low-viscosity hyperbranched epoxy resin, characterized in that, It is prepared by the method for preparing a low-viscosity hyperbranched epoxy resin as described in any one of claims 1 to 8.

10. The application of a low-viscosity hyperbranched epoxy resin in the sealing of old fractures in deep oil and gas reservoir development, characterized in that... The low-viscosity hyperbranched epoxy resin described in claim 9 is used.

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