CN118652676A - A proppant and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of petroleum and natural gas exploitation, and particularly relates to a propping agent and a preparation method thereof. The propping agent provided by the invention comprises core particles and coating resin, wherein the coating resin is divided into coating film resin I and coating film II; the coating resin I is modified epoxy resin; the coating film II is super-hydrophobic sol-gel emulsion and nano silicon dioxide. According to the invention, the modified epoxy resin is adopted to coat the inner core particles, so that not only can the mechanical strength of the propping agent be improved, but also the inner core particles can be effectively coated, and gaps are prevented from being blocked after the inner core particles are crushed; meanwhile, under the combined action of the super-hydrophobic sol-gel emulsion and the nano silicon dioxide, a layer of hydrophobic layer is formed on the surface of the propping agent, so that the contact angle is further increased, the hydrophobic property of the propping agent is effectively improved, and the propping agent is prevented from adsorbing fracturing fluid and crude oil.

Description

A proppant and preparation method thereof

Technical Field

The invention belongs to the technical field of oil and natural gas exploitation, and in particular relates to a proppant and a preparation method thereof.

Background Art

With the development of social industry, the consumption of petroleum, natural gas and other petrochemical energy has increased year by year. Shale oil and gas, as a new type of resource, has received more and more attention. However, shale oil and gas reservoirs have the characteristics of low porosity and low permeability, and fracturing is required to increase production in order to achieve industrial development.

After fracturing treatment, the oil and gas-bearing rock formations of high closure pressure and low permeability deposits are cracked, and the oil and gas are collected from the channels formed by the cracks. The supporting material is introduced into the formation along with the high-pressure solution to fill the cracks in the rock formation, which plays a role in supporting the cracks from closing due to stress release, thereby maintaining high conductivity, allowing oil and gas to flow smoothly and increasing production.

Coated proppant is a commonly used proppant. Coated proppant refers to quartz sand or ceramsite coated with resin. Its density is reduced but its compressive strength is increased. With the development of chemical material synthesis and surface modification technologies, new low-density, ultra-high-strength, surface hydrophobic, and functionally controllable proppant has been further developed. However, the existing coated proppant does not solve the problem of quartz sand and ceramsite adsorption of fracturing fluid or crude oil, resulting in unsatisfactory conductivity of coated proppant. In addition, proppant is generally used in deep well operations, which requires the proppant to have good high temperature resistance.

The Chinese patent application with publication number CN117603674A discloses a ceramsite sand fracturing proppant, and its preparation method is as follows: add triallylphosphine, perfluorooctylethyl acrylate, (3-acryloxypropyl) tris(trimethylsiloxy)silane, styrene, distilled water, dodecyldimethylamine betaine lactone, ammonium pentafluorooctanoate, hydroxyethyl cellulose, potassium dihydrogen phosphate into a reactor, stir to form an emulsion; add an initiator aqueous solution, heat up, keep the temperature for reaction, heat up and continue to react to obtain a mixture; cool down and add ethanol, precipitate solid, dry to obtain a coating; mix the coating, triethylenediamine, and ceramsite sand uniformly in proportion, dry, and solidify to obtain a ceramsite sand fracturing proppant. This fracturing proppant has the advantages of high sphericity, low crushing rate, and high conductivity, but it cannot solve the problem of ceramsite sand adsorption of fracturing fluid.

The Chinese patent application document with publication number CN116218508A discloses a low-density proppant, and its preparation method is as follows: nut shell particles with a particle size range of 106μm-710μm and thermosetting phenolic resin with a preset solid content are mixed evenly according to a mass ratio of 10: (2-5), impregnated and stirred until there is no obvious liquid on the surface, and the first semi-finished particles are obtained; the first semi-finished particles are transferred to a granulator, a certain amount of coating material or binder and nut shell powder are added, stirred until the particle surface is smooth, and then cured at a preset temperature for a certain time, and the low-density proppant is obtained after screening. Although the proppant prepared by this method has a low core density, the strength of the nut shell particles is low and the supporting effect is weak.

Summary of the invention

In order to solve the technical problems of low strength, adsorption of fracturing fluid and crude oil, etc. existing in the related art, the purpose of the present invention is to provide a proppant and a preparation method thereof.

In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

A proppant comprises a core particle and a coating resin, wherein the coating resin is divided into a coating film resin I and a coating film II; the coating resin I is a modified epoxy resin; and the coating film II is a super-hydrophobic sol-gel emulsion and nano-silica;

The preparation method of the super-hydrophobic sol-gel emulsion in the coating film II is as follows: methyl hydrogen silicone oil, 3-aminopropyltrimethoxysilane, propanol and dibutyltin dilaurate are mixed, stirred at high speed for 2-2.4 hours at room temperature, and the gas generated during the reaction is collected; then the stirring speed is reduced, deionized water and ammonia water are added dropwise to the reaction system, and after the addition is completed, the stirring is continued for 17-20 hours to obtain a super-hydrophobic sol-gel emulsion.

In the present invention, methyl hydrogen silicone oil and 3-aminopropyltrimethoxysilane are reacted, and then ammonia water is added dropwise and stirred to generate a super-hydrophobic sol-gel emulsion, and a super-hydrophobic coating is formed on the coating film I by spraying, which effectively improves the hydrophobic property of the proppant, thereby preventing the proppant from adsorbing fracturing fluid and crude oil.

Furthermore, the weight proportions of the components in the preparation method of the super hydrophobic sol-gel emulsion are: 10-12 parts of methyl hydrogen silicone oil, 40-45 parts of 3-aminopropyltrimethoxysilane, 70-80 parts of propanol, 2-4 parts of dibutyltin dilaurate, 50-60 parts of deionized water, and 14-17 parts of ammonia water.

Since one side of the methyl hydrogen silicone oil contains a large number of methyl groups, these methyl groups make the surface energy of the sprayed film formed by the sol-gel lower. In the present invention, the surface energy and roughness of the sol-gel sprayed film are controlled by controlling the amount of methyl hydrogen silicone oil and 3-aminopropyltrimethoxysilane. Studies have found that when the amount of 3-aminopropyltrimethoxysilane added exceeds the range specified in the present invention, the hydrophobic properties of the obtained sol-gel sprayed film deteriorate, which indicates that 3-aminopropyltrimethoxysilane can change the structure of the sol-gel, thereby causing changes in the surface energy and roughness of the sprayed film surface.

Furthermore, in the method for preparing the superhydrophobic sol-gel emulsion, the rotation speed of the high-speed stirring is 1000-1200 rpm, and the stirring speed is reduced to 500-700 rpm.

Furthermore, the mass ratio of the super hydrophobic sol-gel emulsion and the nano-silicon dioxide in the coating film II is 7-9:3-5; and the particle size of the nano-silicon dioxide is 200-300 nm.

The present invention uses super hydrophobic sol-gel emulsion and nano-silica to work together to form a hydrophobic layer on the surface of the proppant. Nano-silica can form tiny protrusions or nano-pillars on the surface of the coating, further increasing the contact angle and improving the hydrophobic performance.

Furthermore, the preparation method of the modified epoxy resin is: epoxy resin and terminal hydroxyl polybutadiene are mixed evenly at room temperature, added into a mold after preheating, placed in a vacuum oven for degassing, silicon powder is added after heating, mixed evenly, cooled, and the modified epoxy resin is obtained.

In the present invention, hydroxy-terminated polybutadiene and silicon powder are used to modify epoxy resin. The hydroxy-terminated polybutadiene can react with the epoxy group in the epoxy resin during the reaction to form a block structure, which improves the brittleness of the epoxy resin while retaining the mechanical strength and heat resistance of the epoxy resin; silicon powder can reduce stress concentration in the epoxy resin and improve the toughness of the epoxy resin. At the same time, silicon powder can fill the gaps of the epoxy resin and improve the strength of the epoxy resin. The modified epoxy resin is used to coat the core particles, which can not only improve the mechanical strength of the proppant, but also effectively wrap the core particles because of its good flexibility, so as to avoid the core particles being crushed and blocking the gaps, thereby affecting the oil and gas production.

Furthermore, in the preparation method of the modified epoxy resin, the mass ratio of the epoxy resin, the terminal hydroxyl polybutadiene and the silicon micropowder is 21-24:8-11:3-5; the preheating temperature is 50-55°C; the temperature of the vacuum oven is 60-65°C; the heating temperature is 120-125°C; and the average particle size of the silicon micropowder is 0.1-0.3 μm.

Furthermore, the mass ratio of the core particles to the coating resin in the proppant is 11-14:2-5; the mass ratio of the coating resin I to the coating film II is 5-8:1-3.

Furthermore, the core particles in the proppant are slag; the particle size of the slag is 0.45-0.6 mm.

In the iron-making process, iron oxide is reduced to metallic iron at high temperature, and impurities such as silicon dioxide and aluminum oxide in the iron ore react with lime and the like to form a melt with silicate and aluminosilicate as the main components, which is then quenched to obtain loose, porous granular blast furnace slag. The present invention uses slag as the core particle of the proppant, which not only avoids the technical problem of precipitation caused by high density of quartz sand or ceramsite, but also improves the strength of the proppant particles.

The present invention also provides a method for preparing the proppant, comprising the following steps:

S1: heating and melting the coating resin I, adding the preheated core particles, stirring and coating, spraying a curing agent to cure, and cooling to obtain primary coated particles;

S2: Spraying the super-hydrophobic sol-gel emulsion and nano-silica onto the surface of the primary coated particles obtained in step S1, stirring evenly, and drying to obtain a proppant.

Furthermore, in the step S1 of the proppant preparation method, the preheating temperature of the core particles is 135-140°C; the curing agent is 2-ethyl-4-methylimidazole, the amount of the curing agent is 10-13% of the mass of the core particles, the curing temperature is 120-125°C, the curing time is 17-18h; and the cooling temperature is 25-30°C.

Compared with the prior art, the proppant and preparation method thereof provided by the present invention have the following technical advantages:

(1) The present invention uses modified epoxy resin to coat the core particles, which can not only improve the mechanical strength of the proppant, but also effectively coat the core particles due to its good flexibility, thereby preventing the core particles from being crushed and clogging the gaps, thereby affecting the oil and gas production;

(2) The present invention uses super hydrophobic sol-gel emulsion and nano-silica to work together to form a hydrophobic layer on the surface of the proppant. Nano-silica can form tiny protrusions or nano-pillars on the surface of the coating, further increasing the contact angle and effectively improving the hydrophobic properties of the proppant, thereby preventing the proppant from adsorbing fracturing fluid and crude oil;

(3) The present invention uses slag as the core particles of the proppant, which not only avoids the technical problem of precipitation caused by quartz sand or ceramsite due to high density, but also improves the strength of the proppant particles.

DETAILED DESCRIPTION

The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to the following embodiments. Those skilled in the art can make various modifications based on the basic idea of the present invention, but as long as they do not deviate from the basic idea of the present invention, they are all within the scope of the present invention.

Example 1

A proppant comprises slag with a particle size of 0.45 mm and a coating resin, wherein the mass ratio of the slag to the coating resin is 11:2; the coating resin is composed of a modified epoxy resin and a coating film II in a mass ratio of 5:1; and the coating film II is composed of a superhydrophobic sol-gel emulsion and nano-silicon dioxide with a particle size of 200 nm in a mass ratio of 7:3.

The preparation method of the super hydrophobic sol-gel emulsion is as follows: 12 parts of methyl hydrogen silicone oil, 45 parts of 3-aminopropyltrimethoxysilane, 80 parts of propanol and 4 parts of dibutyltin dilaurate are mixed, stirred at a rotation speed of 1200 rpm for 2.4 hours at room temperature, and the gas generated during the reaction is collected; then the stirring speed is reduced to 700 rpm, 50 parts of deionized water and 17 parts of ammonia water are added dropwise to the reaction system, and stirring is continued for 20 hours after the dropwise addition is completed to obtain the super hydrophobic sol-gel emulsion.

The preparation method of the modified epoxy resin is as follows: epoxy resin and terminal hydroxyl polybutadiene are mixed uniformly at room temperature, preheated to 50° C., added to a mold, placed in a vacuum oven at 60° C. for degassing, heated to 120° C., added with silicon micropowder having an average particle size of 0.1 μm, mixed uniformly, cooled, and the modified epoxy resin is obtained. The mass ratio of the epoxy resin, terminal hydroxyl polybutadiene, and silicon micropowder is 21:8:3.

The preparation method of the proppant comprises the following steps: S1: heating and melting the modified epoxy resin, adding slag preheated to 135° C., stirring and wrapping, spraying 2-ethyl-4-methylimidazole and curing at 120° C. for 17 hours, wherein the amount of 2-ethyl-4-methylimidazole is 10% of the mass of the slag, cooling to 25° C., and obtaining primary coated particles; S2: spraying super hydrophobic sol-gel emulsion and nano-silica onto the surface of the primary coated particles obtained in step S1, stirring evenly, and drying to obtain the proppant.

Example 2

A proppant comprises slag with a particle size of 0.6 mm and a coating resin, wherein the mass ratio of the slag to the coating resin is 14:5; the coating resin is composed of a modified epoxy resin and a coating film II in a mass ratio of 8:3; the coating film II is composed of a superhydrophobic sol-gel emulsion and nano-silicon dioxide with a particle size of 300 nm in a mass ratio of 9:5.

The preparation method of the super hydrophobic sol-gel emulsion is as follows: 10 parts of methyl hydrogen silicone oil, 40 parts of 3-aminopropyltrimethoxysilane, 70 parts of propanol and 2 parts of dibutyltin dilaurate are mixed, stirred at a rotation speed of 1000 rpm for 2 hours at room temperature, and the gas generated during the reaction is collected; then the stirring speed is reduced to 500 rpm, 60 parts of deionized water and 14 parts of ammonia water are added dropwise to the reaction system, and stirring is continued for 17 hours after the dropwise addition is completed to obtain the super hydrophobic sol-gel emulsion.

The preparation method of the modified epoxy resin is as follows: epoxy resin and terminal hydroxyl polybutadiene are mixed uniformly at room temperature, preheated to 55° C., added to a mold, placed in a vacuum oven at 65° C. for degassing, heated to 125° C., added with silicon micropowder having an average particle size of 0.3 μm, mixed uniformly, cooled, and the modified epoxy resin is obtained. The mass ratio of the epoxy resin, terminal hydroxyl polybutadiene, and silicon micropowder is 24:11:5.

The preparation method of the proppant comprises the following steps: S1: heating and melting the modified epoxy resin, adding slag preheated to 140° C., stirring and wrapping, spraying 2-ethyl-4-methylimidazole and curing at 125° C. for 18 hours, wherein the amount of 2-ethyl-4-methylimidazole is 13% of the mass of the slag, cooling to 30° C., and obtaining primary coated particles; S2: spraying super hydrophobic sol-gel emulsion and nano-silica onto the surface of the primary coated particles obtained in step S1, stirring evenly, and drying to obtain the proppant.

Example 3

A proppant comprises slag with a particle size of 0.55 mm and a coating resin, wherein the mass ratio of the slag to the coating resin is 13:4; the coating resin is composed of a modified epoxy resin and a coating film II in a mass ratio of 7:2; and the coating film II is composed of a super-hydrophobic sol-gel emulsion and nano-silicon dioxide with a particle size of 250 nm in a mass ratio of 8:3.

The preparation method of the super hydrophobic sol-gel emulsion is as follows: 11 parts of methyl hydrogen silicone oil, 43 parts of 3-aminopropyltrimethoxysilane, 76 parts of propanol and 3 parts of dibutyltin dilaurate are mixed, stirred at a rotation speed of 1100 rpm for 2.2 hours at room temperature, and the gas generated during the reaction is collected; then the stirring speed is reduced to 600 rpm, 56 parts of deionized water and 15 parts of ammonia water are added dropwise to the reaction system, and stirring is continued for 18 hours after the dropwise addition is completed to obtain the super hydrophobic sol-gel emulsion.

The preparation method of the modified epoxy resin is as follows: epoxy resin and terminal hydroxyl polybutadiene are mixed uniformly at room temperature, preheated to 53° C., added to a mold, placed in a vacuum oven at 62° C. for degassing, heated to 123° C., added with silicon micropowder having an average particle size of 0.2 μm, mixed uniformly, cooled, and the modified epoxy resin is obtained. The mass ratio of the epoxy resin, terminal hydroxyl polybutadiene, and silicon micropowder is 23:10:4.

The preparation method of the proppant comprises the following steps: S1: heating and melting the modified epoxy resin, adding slag preheated to 138° C., stirring and wrapping, spraying 2-ethyl-4-methylimidazole and curing at 123° C. for 17.5 hours, wherein the amount of 2-ethyl-4-methylimidazole is 12% of the mass of the slag, cooling to 27° C., and obtaining primary coated particles; S2: spraying a superhydrophobic sol-gel emulsion and nano-silica onto the surface of the primary coated particles obtained in step S1, stirring evenly, and drying to obtain the proppant.

Comparative Example 1

This comparative example is similar to Example 3, and the difference between this comparative example and Example 3 is that in the present invention, an equal amount of modified epoxy resin is used instead of the super-hydrophobic sol-gel emulsion; the increase in the amount of modified epoxy resin in step S1 of the proppant preparation method is equal to the amount of super-hydrophobic sol-gel emulsion, and only nano-silica is sprayed in step S2.

Comparative Example 2

This comparative example is similar to Example 3, and the difference between this comparative example and Example 3 is that in the preparation method of the super hydrophobic sol-gel emulsion in this comparative example, the amount of 3-aminopropyltrimethoxysilane used is 70 parts.

Comparative Example 3

This comparative example is similar to Example 3, and the difference between this comparative example and Example 3 is that in the preparation method of the super hydrophobic sol-gel emulsion in this comparative example, the amount of 3-aminopropyltrimethoxysilane used is 10 parts.

Comparative Example 4

This comparative example is similar to Example 3, and the difference between this comparative example and Example 3 is that an equal amount of superhydrophobic sol-gel is used to replace nano-silica in this comparative example.

Comparative Example 5

This comparative example is similar to Example 3, and the difference between this comparative example and Example 3 is that in the preparation method of the modified epoxy resin in this comparative example, an equal amount of carboxyl-terminated nitrile rubber is used instead of hydroxyl-terminated polybutadiene.

Comparative Example 6

This comparative example is similar to Example 3, and the difference between this comparative example and Example 3 is that silicon micropowder is not added in the preparation method of the modified epoxy resin in this comparative example.

Comparative Example 7

This comparative example is similar to Example 3, and the difference between this comparative example and Example 3 is that an equal amount of silicon dioxide is used instead of silicon powder in this comparative example.

Test example

Adsorption performance test: Fracturing fluid was prepared according to the formula disclosed in the Chinese patent document with publication number CN117887441B, and the proppants prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were soaked in the fracturing fluid for 48 hours. The weight m ₀ and the weight m ₁ of the proppants before and after soaking were weighed respectively, and the weight increase rate of the proppants was calculated; weight increase rate = (m ₁ -m ₀ )/m ₀ × 100%. The test results are shown in Table 1.

Mechanical properties test: According to SY/T 17125-2019 “Performance Indicators and Evaluation Test Methods for Fracturing Fluid Proppants”, the crushing rates of the proppants prepared in Examples 1 to 3 and Comparative Examples 5 to 7 were tested at a closing pressure of 86 MPa. The test results are shown in Table 2.

Other performance tests: According to SY/T 17125-2019 "Performance Indicators and Evaluation Test Methods for Fracturing Fluid Proppants", the bulk density and apparent density of the proppants prepared in Examples 1 to 3 were tested; according to SY/T 6302-2019 "Test Method for Conductivity of Fracturing Proppants", the conductivity of the proppants prepared in Examples 1 to 3 was tested, and the test results are shown in Table 3.

Table 1 Adsorption performance test results

As shown in Table 1, the weight increase rate of the proppants prepared in Examples 1 to 3 after being immersed in the fracturing fluid for 48 hours is 1.8-2.5%, indicating that the adsorption performance of the proppants provided by the present invention to the fracturing fluid and crude oil is relatively poor. Among them, the weight increase rate of the proppant prepared in Example 3 is the lowest, which is the best example of the present invention.

Compared with Example 3, in Comparative Example 1, an equal amount of modified epoxy resin is used instead of the super-hydrophobic sol-gel emulsion, but the weight gain rate of the prepared proppant is significantly increased, which indicates that the film layer formed by the super-hydrophobic sol-gel emulsion can prevent the proppant from adsorbing fracturing fluid and crude oil; in Comparative Example 2, the amount of 3-aminopropyltrimethoxysilane is increased, and in Comparative Example 3, the amount of 3-aminopropyltrimethoxysilane is reduced, but the weight gain rate of the prepared proppant is increased, which indicates that 3-aminopropyltrimethoxysilane can change the structure of the sol-gel, affect the surface energy and roughness of the sprayed film, and thus affect the hydrophobic properties; in Comparative Example 4, an equal amount of super-hydrophobic sol-gel is used instead of nano-silica, but the weight gain rate of the prepared proppant is increased, which indicates that nano-silica can form tiny protrusions or nano-columns on the coating surface, further increase the contact angle, and improve the hydrophobic properties.

Table 2 Mechanical properties test results

It can be seen from Table 2 that the breakage rate of the proppant provided by the present invention under a closing pressure of 86 MPa is only 3.6-4.2%, indicating that the proppant provided by the present invention has a good compressive resistance effect.

Compared with Example 3, in Comparative Example 5, an equal amount of terminal carboxyl nitrile rubber is used instead of terminal hydroxyl polybutadiene, but the breakage rate of the proppant is increased, which indicates that the toughening modification effect of terminal carboxyl nitrile rubber on epoxy resin is worse than that of terminal hydroxyl polybutadiene on epoxy resin; in the preparation method of modified epoxy resin in Comparative Example 6, silicon micropowder is not added, but the breakage rate of the proppant is significantly increased, which indicates that silicon micropowder can reduce stress concentration in epoxy resin and improve the toughness of epoxy resin. At the same time, silicon micropowder can fill the seams of epoxy resin and improve the strength of epoxy resin; in Comparative Example 7, an equal amount of silicon dioxide is used instead of silicon micropowder, but the breakage rate of the proppant is increased, which indicates that not all inorganic fillers can achieve the technical effect of the present invention.

Table 3 Other performance test results

It can be seen from Table 3 that the proppant provided by the present invention has a relatively low bulk density and apparent density, and the flow conductivity is greater than 37 μm·cm, and the performance is excellent.

The above embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any person familiar with the art shall not modify the above embodiments without violating the spirit and scope of the present invention. Therefore, any modification, equivalent substitution and improvement made by those skilled in the art under the technical concept of the present invention shall still be covered by the claims of the present invention.

Claims (10)

1. A propping agent comprising core particles and coating resin, wherein the coating resin is divided into coating film resin I and coating film II; the coating resin I is modified epoxy resin; the coating film II is super-hydrophobic sol-gel emulsion and nano silicon dioxide;

The preparation method of the super-hydrophobic sol-gel emulsion in the coating film II comprises the following steps: mixing methyl hydrogen silicone oil, 3-aminopropyl trimethoxy silane, propanol and dibutyl tin dilaurate, stirring at room temperature for 2-2.4h at high speed, and collecting gas generated in the reaction process; and then reducing the stirring rotation speed, dropwise adding deionized water and ammonia water into the reaction system, and continuously stirring for 17-20h after the dropwise adding is completed to obtain the super-hydrophobic sol-gel emulsion.

2. The proppant of claim 1, wherein the preparation method of the super-hydrophobic sol-gel emulsion comprises the following components in parts by weight: 10-12 parts of methyl hydrogen silicone oil, 40-45 parts of 3-aminopropyl trimethoxy silane, 70-80 parts of propanol, 2-4 parts of dibutyl tin dilaurate, 50-60 parts of deionized water and 14-17 parts of ammonia water.

3. A proppant according to claim 1 wherein the high speed agitation in the method of preparing the superhydrophobic sol gel emulsion is at a rotational speed of 1000-1200rpm, and the agitation speed is reduced to 500-700rpm.

4. The proppant of claim 1, wherein the mass ratio of the superhydrophobic sol-gel emulsion and the nanosilica in the coating film II is 7-9:3-5; the particle size of the nano silicon dioxide is 200-300nm.

5. The proppant of claim 1, wherein the modified epoxy resin is prepared by a process comprising: uniformly mixing epoxy resin and hydroxyl-terminated polybutadiene at normal temperature, preheating, adding into a mold, putting into a vacuum oven for degassing, heating, adding silicon micropowder, uniformly mixing, and cooling to obtain the modified epoxy resin.

6. The proppant of claim 5, wherein the mass ratio of the epoxy resin, the hydroxyl-terminated polybutadiene, and the silica micropowder is 21-24:8-11:3-5; the preheating temperature is 50-55 ℃; the temperature of the vacuum oven is 60-65 ℃; the temperature of the heating is 120-125 ℃; the average grain diameter of the silicon micropowder is 0.1-0.3 mu m.

7. A proppant according to claim 1 wherein the mass ratio of the core particle to the coating resin is 11-14:2-5; the mass ratio of the coating resin I to the coating film II is 5-8:1-3.

8. A proppant according to claim 1 wherein said core particle is slag; the grain size of slag is 0.45-0.6mm.

9. A method of preparing a proppant as set forth in any one of claims 1-8 comprising the steps of:

s1: heating and melting the coating resin I, adding preheated core particles, stirring and wrapping, spraying a curing agent for curing, and cooling to obtain primary coated particles;

S2: spraying the super-hydrophobic sol-gel emulsion and nano silicon dioxide on the surface of the primary coated particles prepared in the step S1, uniformly stirring, and drying to obtain the propping agent.

10. The method of preparing a proppant of claim 9, wherein the preheating temperature of the core particle in step S1 is 135-140 ℃; the curing agent is 2-ethyl-4-methylimidazole, the dosage of the curing agent is 10-13% of the mass of the core particles, the curing temperature is 120-125 ℃, and the curing time is 17-18h; the cooling temperature is 25-30 ℃.