Preparation method of branched epoxy resin pressure-bearing plugging material and oil-based drilling fluid

Abstract

The invention discloses a preparation method of a branched epoxy resin pressure-bearing plugging material and an oil-based drilling fluid. The pressure-bearing plugging material has a branched structure and is characterized in that the raw materials of the material include: tetrahalogenated phenyls, tetrahalogenated naphthalenes, epichlorohydrin, hexagonal boron nitride, and a silane coupling agent, and the molar ratio of the tetrahalogenated phenyls, 2,3,6,7-tetrachloromethyl-1,4,5,8-tetramethylnaphthalene, and epichlorohydrin is approximately (1-2): (1-2): 4. The synthesized branched epoxy resin polymer is combined with a modified hexagonal boron nitride with a hydroxyl carboxyl group on the surface by using a silane coupling agent, and the pressure bearing capacity of the final product branched epoxy resin pressure-bearing plugging material can reach 150-180MPa, and the compressive strength is 2-3 times that of a traditional epoxy resin plugging material. The material is applied to an oil-based drilling fluid to enhance the plugging performance of the drilling fluid.

Description

Technical Field

[0001] The invention relates to the field of oil and gas wells, and in particular to a preparation method of a branched epoxy resin pressure-bearing plugging material and application of an oil-based drilling fluid containing the plugging material. Background Art

[0002] During the drilling process, serious leakage of drilling fluid directly leads to extended drilling cycle and increased drilling cost. The development of cracks and caves in the formation can easily lead to mud loss, blowouts, formation collapse, buried drill bits and other accidents, which directly threaten the life safety of operators and affect the progress of oil and gas exploration and development in my country. In addition, as the well depth increases, the formation pressure increases, and when leakage occurs, there are certain requirements for the compressive strength of the plugging material.

[0003] At present, a large number of conventional plugging agents and new plugging agents of various types have achieved good application effects to a certain extent, but most plugging agents have weak pressure bearing capacity and are still limited to various cements and a small number of chemical agents and mixture plugging agents. The plugging practice shows that the complete loss of drilling fluid in fractures, cave formations and large-pore high-permeability formations is the most difficult to deal with. Drilling workers at home and abroad have also developed some polymer plugging materials and supporting plugging processes from a chemical point of view, but no breakthrough progress has been made in dealing with fracture and cave leakage.

[0004] Epoxy resin molecules have benzene rings, ether bonds, hydroxyl groups, epoxy groups and other groups. The benzene rings give epoxy resin very good mechanical strength and heat resistance, and the ether bonds give it good chemical resistance, making it a good choice as a plugging material. In the patented high-elasticity plugging modified epoxy resin grouting material and its preparation method (CN108084663B), bisphenol A, nylon-modified bisphenol A and phenolic amine curing agents are used to cure to obtain epoxy resin plugging materials, and their compressive strength is 50-65MPa. Bisphenol A and nylon-modified bisphenol A with straight-chain structures are cured with curing agents, and their compressive strength is not high. When used for pressure-bearing plugging, they cannot effectively plug leaks. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide a branched epoxy resin pressure-bearing plugging material.

[0006] The specific technical solutions are as follows:

[0007] A preparation method of a branched epoxy resin pressure-bearing plugging material and an oil-based drilling fluid, characterized in that the synthesized epoxy resin structure is a branched type, the raw materials of the material mainly include: tetrahalogenated benzenes, tetrahalogenated naphthalenes, epichlorohydrin, hexagonal boron nitride, and a silane coupling agent, wherein the silane coupling agent is glycidyl trimethoxysilane, and the molar ratio of the tetrahalogenated benzenes, tetrahalogenated naphthalenes, and epichlorohydrin is (1-2): (1-2): 4, and the branched epoxy resin pressure-bearing plugging material is synthesized by the following steps:

[0008] S1, taking a tetrahalogenated benzene substance or a tetrahalogenated naphthalene substance, adding it to a reactor containing 200 mL of deionized water, and adding 10 g of sodium bicarbonate and 2.5 g of 1-butyl-3-methylimidazolium tetrafluoroborate, mixing and heating to 100-120° C., reacting for 1-3 h, and rectifying and purifying to obtain a tetrahydroxybenzene substance or a tetrahydroxynaphthalene substance;

[0009] S2, add 3g of tetrabutylammonium bromide and epichlorohydrin into a round-bottom flask, add 50% sodium hydroxide solution by mass, stir the resulting mixture, cool it to 0°C, add the tetrahydroxybenzene substance or tetrahydroxynaphthalene substance prepared in S1 into the mixture, warm it to room temperature, stir overnight, and purify it by rectification to obtain tetracycloxybenzene substance or tetracycloxynaphthalene substance;

[0010] S3, add 100 mL of toluene to a reaction flask, dissolve the tetrahalogenated benzene or tetrahalogenated naphthalene in toluene, add 100 mL of aqueous ammonia (25%), then add 5 g of copper sulfate, heat to 50-70° C., react for 2-4 h, and purify to obtain the corresponding amine tetraaminobenzene or tetraaminonaphthalene;

[0011] S4, adding hexagonal boron nitride and hydroquinone to distilled water, using a bipolar pulse power supply to generate plasma in the distilled water containing hexagonal boron nitride and hydroquinone, circulating the suspension in a cavitation-based dispersion device, and generating plasma in the suspension for 0.5 to 2 hours, allowing the suspension to stand for 12 to 24 hours, filtering and washing the product, and then placing it at 100 to 140° C. for vacuum drying for 1 to 3 hours to obtain modified hexagonal boron nitride containing hydroxyl carboxyl groups on the surface;

[0012] S5. Mix the tetracycloxybenzene or tetracycloxynaphthalene substances prepared in S2 and the tetraaminobenzene or tetraaminonaphthalene substances prepared in S3, heat them up to 140-160° C., and react for 4-6 hours to obtain a branched epoxy resin polymer. Mix the branched epoxy resin polymer, the modified hexagonal boron nitride containing hydroxyl carboxyl groups on the surface prepared in S4, and glycidyl trimethoxysilane, heat them up to 140-160° C., and react for 2-4 hours to obtain a branched epoxy resin pressure-bearing plugging material.

[0013] The tetrahalogenated phenyls are at least one of 1,1′,1″,1″-methyltetrayltetrakis[4-(chloromethyl)benzene] and 1,1′,1″,1″-methyltetrayltetrakis[4-(bromomethyl)benzene].

[0014] The tetrahalonaphthalene is 2,3,6,7-tetrachloromethyl-1,4,5,8-tetramethylnaphthalene.

[0015] The silane coupling agent is glycidyl trimethoxy silane.

[0016] The molar ratio of the tetrahalogenated phenyl substance, 2,3,6,7-tetrachloromethyl-1,4,5,8-tetramethylnaphthalene and epichlorohydrin is approximately (1-2):(1-2):4.

[0017] The mass of the hexagonal boron nitride is between 5 and 30 g.

[0018] The mass of the silane coupling agent is between 5 and 40 g.

[0019] An oil-based drilling fluid, characterized in that the drilling fluid contains the branched epoxy resin pressure-bearing plugging material according to claims 1-3, and the drilling fluid comprises the following components by weight: 80 parts of base oil, 25-30 parts of CaCl2 brine, 4-5 parts of primary emulsifier, 3-4 parts of auxiliary emulsifier, 3-5 parts of organic soil, 2-4 parts of wetting agent, 2-5 parts of quicklime, 4-5 parts of filtration reducer, 3-5 parts of plugging agent, 1-2 parts of flow regulator, 80-290 parts of barite, 1-5 parts of the branched epoxy resin pressure-bearing plugging material according to claim 1, and the drilling fluid density is 1.20-2.10 g / cm 3 .

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention introduces a large number of rigid structures (benzene rings) through the synthesis path of epoxy compounds and amine curing agents, which can greatly improve the compressive strength of epoxy resins. Tetrahalogenated benzenes and tetrahalogenated naphthalenes in the raw materials are used as reactants to undergo branching reactions, so that the structure of the final product epoxy resin is highly branched. The present invention performs plasma treatment on the rigid material hexagonal boron nitride to generate functional groups such as hydroxyl and carboxyl groups on its surface, and uses a silane coupling agent to combine the epoxy resin with the rigid material, thereby greatly improving the compressive strength of the plugging material. Compared with conventional epoxy resin plugging materials, the compressive strength is increased by 1 to 2 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the reaction process designed for the first step in the preparation of branched epoxy resin pressure-bearing plugging materials.

[0023] Figure 2 Schematic diagram of the reaction process designed for the second step in the preparation of branched epoxy resin pressure-bearing plugging materials.

[0024] Figure 3 Schematic diagram of the reaction process designed for the third step in the preparation of branched epoxy resin pressure-bearing plugging materials.

[0025] Figure 4 A partial schematic diagram of a branched epoxy resin polymer. DETAILED DESCRIPTION

[0026] The technical solution 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 the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The embodiments of the present invention are as follows:

[0028] 1. Preparation of branched epoxy resin pressure-bearing plugging material

[0029] Example 1

[0030] S1, take 0.1mol 1,1′,1″,1″-methyltetrayltetra[4-(chloromethyl)benzene] (CAS: 477274-00-3) and add it to a reactor containing 200mL of deionized water, and add 10g of sodium bicarbonate and 2.5g of 1-butyl-3-methylimidazolium tetrafluoroborate, mix and heat to 110°C, react for 2h, and purify by rectification to obtain 1,1′,1″,1″-methyltetrayltetra[4-(hydroxymethyl)benzene];

[0031] S2, add 3g of tetrabutylammonium bromide and 0.4mol of epichlorohydrin into a round-bottom flask, add 50% sodium hydroxide solution by mass, stir the resulting mixture and cool to 0°C, add 1,1′,1″,1″-tetramethyltetrakis[4-(hydroxymethyl)benzene] prepared in S1 into the mixture, warm to room temperature, stir overnight, and purify by rectification to obtain 1,1′,1″,1″-tetramethyltetrakis[4-(epoxy)benzene];

[0032] S3, add 100 mL of toluene to the reaction bottle, take 0.05 mol of 2,3,6,7-tetrachloromethyl-1,4,5,8-tetramethylnaphthalene (CAS: 158466-73-0) and dissolve it in toluene, add 100 mL of ammonia water (25%), then add 5 g of copper sulfate, heat to 60° C., react for 3 h, and purify to obtain 2,3,6,7-tetraaminomethyl-1,4,5,8-tetramethylnaphthalene;

[0033] S4, adding 10g of hexagonal boron nitride and 20g of hydroquinone to 1000mL of distilled water, using a bipolar pulse power supply to generate plasma, circulating the suspension in a cavitation-based dispersion device, and generating plasma in the suspension for 2h, allowing the suspension to stand for 15h, filtering the product, washing it with acetone, and drying it in a vacuum at 120°C for 2h to obtain a modified hexagonal boron nitride having hydroxyl carboxyl groups on the surface;

[0034] S5. Mix the 1,1′,1″,1″-tetramethyltetra[4-(epoxy)benzene] prepared in S2 and the 2,3,6,7-tetraaminomethyl-1,4,5,8-tetramethylnaphthalene prepared in S3, and react at 150° C. for 5 hours to obtain a branched epoxy resin polymer. Mix the branched epoxy resin polymer, the modified hexagonal boron nitride containing hydroxyl carboxyl groups on the surface prepared in S4, and glycidyltrimethoxysilane (CAS: 20222-57-5), raise the temperature to 150° C., and react for 3 hours to obtain a branched epoxy resin pressure-bearing plugging material.

[0035] Example 2

[0036] S1, take 0.1mol 2,3,6,7-tetrachloromethyl-1,4,5,8-tetramethylnaphthalene and add it into a reactor containing 200mL deionized water, and add 10g sodium bicarbonate and 2.5g 1-butyl-3-methylimidazolium tetrafluoroborate, mix and heat to 110°C, react for 2h, and purify by rectification to obtain 2,3,6,7-tetrahydroxymethyl-1,4,5,8-tetramethylnaphthalene;

[0037] S2, take 3g of tetrabutylammonium bromide and 0.4mol of epichlorohydrin and add them into a round-bottom flask, add 50% sodium hydroxide solution by mass, stir the resulting mixture and cool it to 0°C, add 2,3,6,7-tetrahydroxymethyl-1,4,5,8-tetramethylnaphthalene prepared in S1 to the mixture, warm it to room temperature, stir overnight, and purify it by rectification to obtain 2,3,6,7-tetraepoxy-1,4,5,8-tetramethylnaphthalene;

[0038] S3, add 100 mL of toluene to a reaction flask, take 0.05 mol of 1,1′,1″,1″-tetramethyltetrakis[4-(chloromethyl)benzene] and dissolve it in toluene, add 100 mL of ammonia water (25%), then add 5 g of copper sulfate, heat to 60° C., react for 3 h, and purify to obtain 1,1′,1″,1″-tetramethyltetrakis[4-(aminomethyl)benzene];

[0039] S4, adding 15g of hexagonal boron nitride and 30g of hydroquinone to 1000mL of distilled water, using a bipolar pulse power supply to generate plasma, circulating the suspension in a cavitation-based dispersion device, and generating plasma in the suspension for 2h, allowing the suspension to stand for 15h, filtering the product, washing it with acetone, and drying it in a vacuum at 120°C for 2h to obtain modified hexagonal boron nitride containing hydroxyl carboxyl groups on the surface;

[0040] S5. Mix the 2,3,6,7-tetraepoxy-1,4,5,8-tetramethylnaphthalene prepared in S2 and the 1,1′,1″,1″-tetramethyltetra[4-(aminomethyl)benzene] prepared in S3, and react at 150°C for 5 hours to obtain a branched epoxy resin polymer. Mix the branched epoxy resin polymer, the modified hexagonal boron nitride containing hydroxyl carboxyl groups on the surface prepared in S4, and glycidyl trimethoxysilane, and heat to 150°C and react for 3 hours to obtain a branched epoxy resin pressure-bearing plugging material.

[0041] Example 3

[0042] S1, take 0.1mol 1,1′,1″,1″-methyltetrayltetra[4-(bromomethyl)benzene] (CAS: 15352222-54-8) and add it to a reactor containing 200mL of deionized water, and add 10g of sodium bicarbonate and 2.5g of 1-butyl-3-methylimidazolium tetrafluoroborate, mix and heat to 110°C, react for 2h, and purify by rectification to obtain 1,1′,1″,1″-methyltetrayltetra[4-(hydroxymethyl)benzene];

[0043] S2, add 3g of tetrabutylammonium bromide and 0.4mol of epichlorohydrin into a round-bottom flask, add 50% sodium hydroxide solution by mass, stir the resulting mixture and cool to 0°C, add 1,1′,1″,1″-tetramethyltetrakis[4-(hydroxymethyl)benzene] prepared in S1 into the mixture, warm to room temperature, stir overnight, and purify by rectification to obtain 1,1′,1″,1″-tetramethyltetrakis[4-(epoxy)benzene];

[0044] S3, add 100 mL of toluene to a reaction flask, take 0.05 mol of 1,1′,1″,1″-tetramethyltetrakis[4-(chloromethyl)benzene] and dissolve it in toluene, add 100 mL of ammonia water (25%), then add 5 g of copper sulfate, heat to 60° C., react for 3 h, and purify to obtain 1,1′,1″,1″-tetramethyltetrakis[4-(aminomethyl)benzene];

[0045] S4, adding 20g of hexagonal boron nitride and 40g of hydroquinone to 1000mL of distilled water, using a bipolar pulse power supply to generate plasma, circulating the suspension in a cavitation-based dispersion device, and generating plasma in the suspension for 2h, allowing the suspension to stand for 15h, filtering the product, washing it with acetone, and drying it in a vacuum at 120°C for 2h to obtain modified hexagonal boron nitride having hydroxyl carboxyl groups on the surface;

[0046] S5. Mix the 1,1′,1″,1″-tetramethyltetrakis[4-(epoxy)benzene] prepared in S2 and the 1,1′,1″,1″-tetramethyltetrakis[4-(aminomethyl)benzene] prepared in S3, and react at 150°C for 5 hours to obtain a branched epoxy resin polymer. Mix the branched epoxy resin polymer, the modified hexagonal boron nitride containing hydroxyl carboxyl groups on the surface prepared in S4, and glycidyl trimethoxysilane, raise the temperature to 150°C, and react for 3 hours to obtain a branched epoxy resin pressure-bearing plugging material.

[0047] Example 4

[0048] S1, take 0.1mol 2,3,6,7-tetrachloromethyl-1,4,5,8-tetramethylnaphthalene and add it into a reactor containing 200mL deionized water, and add 10g sodium bicarbonate and 2.5g 1-butyl-3-methylimidazolium tetrafluoroborate, mix and heat to 110°C, react for 2h, and purify by rectification to obtain 2,3,6,7-tetrahydroxymethyl-1,4,5,8-tetramethylnaphthalene;

[0049] S2, take 3g of tetrabutylammonium bromide and 0.4mol of epichlorohydrin and add them into a round-bottom flask, add 50% sodium hydroxide solution by mass, stir the resulting mixture and cool it to 0°C, add 2,3,6,7-tetrahydroxymethyl-1,4,5,8-tetramethylnaphthalene prepared in S1 to the mixture, warm it to room temperature, stir overnight, and purify it by rectification to obtain 2,3,6,7-tetraepoxy-1,4,5,8-tetramethylnaphthalene;

[0050] S3, add 100 mL of toluene to the reaction flask, take 0.05 mol of 2,3,6,7-tetrachloromethyl-1,4,5,8-tetramethylnaphthalene and dissolve it in toluene, add 100 mL of ammonia water (25%), then add 5 g of copper sulfate, heat to 60 ° C, react for 3 h, and purify to obtain 2,3,6,7-tetraaminomethyl-1,4,5,8-tetramethylnaphthalene;

[0051] S4, adding 25g of hexagonal boron nitride and 50g of hydroquinone to 1000mL of distilled water, using a bipolar pulse power supply to generate plasma, circulating the suspension in a cavitation-based dispersion device, and generating plasma in the suspension for 2h, allowing the suspension to stand for 15h, filtering the product, washing it with acetone, and drying it in a vacuum at 120°C for 2h to obtain modified hexagonal boron nitride containing hydroxyl carboxyl groups on the surface;

[0052] S5. Mix the 2,3,6,7-tetrahydroxymethyl-1,4,5,8-tetramethylnaphthalene prepared in S2 and the 2,3,6,7-tetraaminomethyl-1,4,5,8-tetramethylnaphthalene prepared in S3, and react at 150°C for 5 hours to obtain a branched epoxy resin polymer. Mix the branched epoxy resin polymer, the modified hexagonal boron nitride containing hydroxyl carboxyl groups on the surface prepared in S4, and glycidyl trimethoxysilane, raise the temperature to 150°C, and react for 3 hours to obtain a branched epoxy resin pressure-bearing plugging material.

[0053] Comparative Example 1

[0054] Pour 100g of bisphenol A epoxy resin (DGEBA) (CAS: 1675-54-3) into a reaction container, add 40g of 4,4'-methylenebis(2-ethyl)aniline (CAS: 19900-65-3) and mix, heat to 55°C, react for 48h, and obtain a bisphenol A epoxy resin plugging material.

[0055] 1. Test on the compression resistance of plugging materials

[0056] The final products of Examples 1 to 4 and the bisphenol A epoxy resin plugging material in Comparative Example 1 were sampled for compression resistance test, and three groups of samples were taken for each material. The compression test was carried out according to ASTM D6641, and two strain gauges, one longitudinal and one transverse, were attached to the front and rear surfaces of the test piece respectively, so as to obtain the average compression strain and Poisson's ratio of the two surfaces of the test piece. An Instron 5882 testing machine (range 100 kN) was used in combination with a combined loading compression fixture (CLC) to apply a compression load to the test piece, and the test data were averaged.

[0057] Table 1 is made based on the experimental data. It can be seen from Table 1 that the higher the degree of branching of the molecular structure, the stronger the pressure bearing capacity of the epoxy resin, and as the amount of rigid material particles increases, the pressure resistance will also increase accordingly.

[0058] Table 1 Compression performance test of branched epoxy resin plugging material

[0059] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Compressive strength(MPa) 164.4 168.7 175.5 180.1 51.3

[0060] 2. Preparation of oil-based drilling fluid

[0061] Weigh 10.0g of primary emulsifier, 10.0g of auxiliary emulsifier, and 3.2g of wetting agent directly into a high-stirring cup; measure 320mL of 3# white oil and introduce it into the high-stirring cup, place the high-stirring cup on a high-stirring machine, and stir at a high speed of 11000rpm for 10min; weigh 12.0g of organic soil with cellophane, and slowly add the organic soil into the high-stirring cup under high-stirring state to prevent splashing, and stir at high speed for 10min; measure 80mL of 25% Ca Add Cl2 aqueous solution into the high-stirring cup to prevent splashing and stir at high speed for 10 minutes; under high stirring, slowly add 10.0g quicklime into the high-stirring cup and stir at high speed for 10 minutes; under high stirring, slowly add 14.0g filtration agent into the high-stirring cup and stir for 10 minutes; under high stirring, slowly add 7.0g flow regulator into the high-stirring cup and slowly add 420.0g barite into the high-stirring cup and continue stirring for 30 minutes to obtain base slurry.

[0062] In order to further illustrate the effects of the branched epoxy resin pressure-bearing plugging material and the oil-based drilling fluid of the present invention, plugging performance tests were performed on the branched epoxy resin pressure-bearing plugging materials in Examples 1 to 4, the A epoxy resin plugging material in Comparative Example 1, and the oil-based drilling fluid.

[0063] 2. Wedge-shaped 1mm-3mm crack plugging test

[0064] 1%, 3%, and 5% of the branched epoxy resin pressure-bearing plugging materials of Examples 1 to 4 and the bisphenol A epoxy resin plugging material of Comparative Example 1 were added to the above-configured base slurry to conduct plugging effect experiments.

[0065] The base slurry with different types and amounts of materials added was subjected to a wedge-shaped 1mm-3mm crack plugging experiment. According to Table 2, as the amount of plugging material added increased, the plugging effect of the drilling fluid improved, and the formula with the best plugging effect in the embodiment was: base slurry + 5% embodiment 3, the plugging position was 0-7mm, and the plugging effect was good.

[0066] Table 2 Results of wedge-shaped 1mm-3mm crack plugging test

[0067]

[0068]

[0069] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a branched epoxy resin pressure-bearing plugging material and an oil-based drilling fluid, characterized in that The synthesized epoxy resin structure is a branched type. The raw materials of the material mainly include: tetrahalogenated benzenes, tetrahalogenated naphthalenes, epichlorohydrin, hexagonal boron nitride, and a silane coupling agent, wherein the silane coupling agent is glycidyl trimethoxysilane, and the molar ratio of the tetrahalogenated benzenes, the tetrahalogenated naphthalenes, and the epichlorohydrin is (1-2): (1-2):

4. The branched epoxy resin pressure-bearing plugging material is synthesized by the following steps: S1, taking a tetrahalogenated benzene substance or a tetrahalogenated naphthalene substance, adding it to a reactor containing 200 mL of deionized water, and adding 10 g of sodium bicarbonate and 2.5 g of 1-butyl-3-methylimidazolium tetrafluoroborate, mixing and heating to 100-120° C., reacting for 1-3 h, and rectifying and purifying to obtain a tetrahydroxybenzene substance or a tetrahydroxynaphthalene substance; S2, add 3g of tetrabutylammonium bromide and epichlorohydrin into a round-bottom flask, add 50% sodium hydroxide solution by mass, stir the resulting mixture, cool it to 0°C, add the tetrahydroxybenzene substance or tetrahydroxynaphthalene substance prepared in S1 into the mixture, warm it to room temperature, stir overnight, and purify it by rectification to obtain tetracycloxybenzene substance or tetracycloxynaphthalene substance; S3, add 100 mL of toluene to a reaction flask, dissolve the tetrahalogenated benzene or tetrahalogenated naphthalene in toluene, add 100 mL of aqueous ammonia (25%), then add 5 g of copper sulfate, heat to 50-70° C., react for 2-4 h, and purify to obtain tetraaminobenzene or tetraaminonaphthalene; S4, adding hexagonal boron nitride and hydroquinone to distilled water, using a bipolar pulse power supply to generate plasma in the distilled water containing hexagonal boron nitride and hydroquinone, circulating the suspension in a cavitation-based dispersion device, and generating plasma in the suspension for 0.5 to 2 hours, allowing the suspension to stand for 12 to 24 hours, filtering and washing the product, and then placing it at 100 to 140° C. for vacuum drying for 1 to 3 hours to obtain modified hexagonal boron nitride containing hydroxyl carboxyl groups on the surface; S5, the tetracycloxybenzene or tetracycloxynaphthalene prepared in S2 and the tetraaminobenzene or tetraaminonaphthalene prepared in S3 are mixed, the temperature is raised to 140-160° C., and the reaction is performed for 4-6 hours to obtain a branched epoxy resin polymer, and the branched epoxy resin polymer, the modified hexagonal boron nitride containing hydroxyl carboxyl groups on the surface prepared in S4, and glycidyl trimethoxysilane are mixed, the temperature is raised to 140-160° C., and the reaction is performed for 2-4 hours to obtain a branched epoxy resin pressure-bearing plugging material; The tetrahalogenated phenyls are at least one of 1,1',1",1"-tetramethyltetrakis[4-(chloromethyl)benzene] and 1,1',1",1"-tetramethyltetrakis[4-(bromomethyl)benzene]; the tetrahalogenated naphthalenes are 2,3,6,7-tetrachloromethyl-1,4,5,8-tetramethylnaphthalene.

2. An oil-based drilling fluid, characterized in that: The drilling fluid contains the branched epoxy resin pressure-bearing plugging material according to claim 1, and the drilling fluid comprises the following components by weight: 80 parts of base oil, 25-30 parts of CaCl2 brine, 4-5 parts of primary emulsifier, 3-4 parts of auxiliary emulsifier, 3-5 parts of organic soil, 2-4 parts of wetting agent, 2-5 parts of quicklime, 4-5 parts of filtration reducer, 3-5 parts of plugging agent, 1-2 parts of flow regulator, 80-290 parts of barite, 1-5 parts of the branched epoxy resin pressure-bearing plugging material according to claim 1, and the drilling fluid density is 1.20-2.10 g / cm 3 .

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