High-temperature-resistant solid emulsifier for oil-based drilling fluid and preparation method and application thereof

Abstract

The application provides a high-temperature-resistant solid emulsifier for oil-based drilling fluid and a preparation method and application thereof. The solid emulsifier has a structure of Formula 1, for example, R1 is a linear alkyl group with a length of C9-C 22 ; R2 is (CH2) m , and m is an integer of 1-20. The high-temperature-resistant solid emulsifier is prepared from specific diamino compounds, dibasic acids, fatty amines, substituted or unsubstituted alkyl sulfonic acid monomers, and is prepared through three-step reactions with a molar ratio of 1:(1-2.5):(0.5-2):(1-3). The application can form a solid-state emulsifier with a strong aggregate structure through hydrogen bonds between groups and molecules, and the high-temperature-resistant ability of the emulsifier is improved through the introduction of aromatic rings and sulfonic acid groups. The high-temperature-resistant ability is strong, the temperature resistance is up to 200 DEG C, the high-temperature emulsification stability is good, the oil-based drilling fluid can be prepared, the storage, transportation and use are convenient, and the application can better meet the use of high-temperature deep well oil-based drilling fluid.

Description

Technical Field

[0001] This application relates to the field of oil-based drilling fluid application technology for deep and ultra-deep well drilling in oil and gas, specifically to a high-temperature resistant solid emulsifier for oil-based drilling fluids, its preparation method, and its application. Background Technology

[0002] Oil-based drilling fluids are widely used due to their excellent thermal stability, inhibition properties, and reservoir protection capabilities. Although they present challenges such as pollution and subsequent remediation, their superior characteristics make them a crucial tool for drilling challenging and complex wells, such as high-temperature deep wells and shale gas horizontal wells. Furthermore, with the deepening of exploration and development, the number of deep and ultra-deep wells is increasing, placing higher demands on the temperature resistance of oil-based drilling fluid systems. Among these, the core processing agent used in oil-based drilling fluids is primarily the emulsifier, and its temperature resistance is key to ensuring the overall temperature resistance of the oil-based drilling fluid system.

[0003] In recent years, there has been considerable research and application of emulsifiers in China, with most currently being liquid emulsifiers, such as polyamide emulsifiers. The drawbacks of liquid emulsifiers are that they tend to thicken at low temperatures and are not easily flowable, posing difficulties for on-site measurement and use. Meanwhile, research and application of solid emulsifiers for oil-based drilling fluids are relatively limited both domestically and internationally. Chinese patent document CN104592958A discloses a powdered emulsifier for oil-based drilling fluids, which is prepared by reacting 2,6-diaminopyridine, a diacid, a diamine, and a fatty acid in a molar ratio of 1:2:2:1 to obtain the powdered emulsifier with the aforementioned structure.

[0004] This solid emulsifier is a light yellow solid powder at temperatures ranging from 0°C to 120°C, but its maximum temperature resistance is 180°C, which is not enough to fully meet the needs of some high-temperature deep wells. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem of insufficient temperature resistance of existing solid emulsifiers, and to provide a solid emulsifier for oil-based drilling fluids with stronger temperature resistance, as well as its preparation method and application. The high-temperature resistant solid emulsifier provided by this invention has better temperature resistance and is beneficial for application in high-temperature oil-based drilling fluids.

[0006] This invention provides a high-temperature resistant solid emulsifier for oil-based drilling fluids having a structure of Formula 1, the general formula of which is as follows:

[0007]

[0008] Where R1 is C9~C 22 A straight-chain alkyl group; R2 is (CH2). m m is an integer from 1 to 20;

[0009] A1 is A2 and A2' are both selected from H or And not all of them are H; R3 is C1~C 18 Substituted or unsubstituted alkyl groups.

[0010] Preferably, R1 is C 12 ~C 22 Alkyl groups, preferably C 14 ~C 22 Alkyl groups.

[0011] Preferably, m is an integer from 1 to 16, more preferably an integer from 1 to 12, and even more preferably an integer from 1 to 8.

[0012] Preferably, R3 is C1 to C 14 Substituted or unsubstituted alkyl groups, preferably C1 to C2. 12 Substituted or unsubstituted alkyl groups.

[0013] This invention provides a method for preparing a high-temperature resistant solid emulsifier for oil-based drilling fluids, comprising the following steps:

[0014] The diamino compound and dicarboxylic acid are first added to the reactor and heated to react in a molar ratio, then fatty amine is added and heated to react, and finally alkyl sulfonic acid is added and heated to react, to obtain a high-temperature resistant solid emulsifier.

[0015] The molar ratio of the diamino compound, dicarboxylic acid, fatty amine, and alkyl sulfonic acid is 1:(1-2.5):(0.5-2):(1-3);

[0016] The diamino compound is 2,6-diaminotoluene or 2,6-diaminopyridine; the dicarboxylic acid is selected from one of C3 to C22 dicarboxylic fatty acids; the fatty amine is selected from one of C9 to C22 fatty amines; and the alkyl sulfonic acid has an integer number of alkyl carbon atoms from 1 to 18.

[0017] Preferably, the dicarboxylic acid is selected from one of malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, and sebacic acid.

[0018] Preferably, the fatty amine is selected from one of tetradecylamine, hexadecylamine, oleylamine, octadecylamine, eicosamine, and didiamine.

[0019] Preferably, the alkyl sulfonic acid is selected from one of methanesulfonic acid, taurine, 3-hydroxypropanesulfonic acid, 1-butanesulfonic acid, hexane sulfonate, octyl sulfonic acid, dodecyl sulfonic acid, and dodecylbenzene sulfonic acid.

[0020] Preferably, the addition of fatty amines and the addition of alkyl sulfonic acid and the heating reaction are both carried out under stirring conditions, and the reaction temperature is independently 140℃~180℃.

[0021] Preferably, the heating reaction time for adding fatty amine and heating reaction for adding alkyl sulfonic acid are independently 2 to 4 hours. After cooling to room temperature, a black-brown solid emulsifier is obtained.

[0022] This invention also provides the application of any of the aforementioned high-temperature resistant solid emulsifiers for oil-based drilling fluids in the preparation of oil-based drilling fluids.

[0023] Compared with existing technologies, the high-temperature resistant solid emulsifier for oil-based drilling fluids obtained by this invention has the structure shown in Formula 1. The high-temperature resistant solid emulsifier is prepared in three steps by reacting a specific diamino compound, a dicarboxylic acid, a fatty amine, and an alkyl sulfonic acid monomer in a molar ratio of 1:(1-2.5):(0.5-2):(1-3). This invention can form a solid emulsifier with a strong internal force through hydrogen bonding between groups and molecules. Simultaneously, by introducing aromatic rings and sulfonic acid groups, the high-temperature resistance of the emulsifier is improved. It exhibits strong high-temperature resistance, reaching up to 200℃, and good high-temperature emulsification stability. It can be used in the formulation of high-temperature oil-based drilling fluids and is convenient to store, transport, and use, better meeting the needs of high-temperature deep well oil-based drilling fluids. Detailed Implementation

[0024] The technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0025] This application provides a high-temperature resistant solid emulsifier for oil-based drilling fluids, having the structure of Formula 1:

[0026]

[0027] Where R1 is C9~C 22 A straight-chain alkyl group; R2 is (CH2). m m is an integer from 1 to 20;

[0028] A1 is A2 and A2' are both selected from H or And not all of them are H; R3 is C1~C 18 Substituted or unsubstituted alkyl groups.

[0029] The high-temperature resistant solid emulsifier provided by this invention has better temperature resistance, which is beneficial for its application in oil-based drilling fluids.

[0030] In the high-temperature resistant solid emulsifier for oil-based drilling fluids described in this invention, R1 is C9~C10. 22 Straight-chain alkyl groups, preferably C12 ~C 22 Alkyl groups, more preferably C14 groups. 14 ~C 22 Alkyl groups. C9~C 22 Representing carbon atoms ranging from 9 to 22, for example, C 22 Straight-chain alkyl groups can be represented as CH3-(CH2). 20 -CH2-, CH3-(CH2) 21 -

[0031] In Formula 1 of this invention, R2 is (CH2). m It is a straight-chain alkylene group, which can also be represented as R2=C. m H 2m m is an integer from 1 to 20, preferably an integer from 1 to 16, more preferably an integer from 1 to 12, and even more preferably an integer from 1 to 8. For example, if m = 1, R2 is CH2, and m can also be 2, 5, 6, 8, etc.

[0032] Furthermore, A1 is The two single keys are connection keys.

[0033] A2 and A2' are both selected from hydrogen (H) or (or represented as -SO2R3), and not simultaneously H; where R3 is C1 to C2. 18 Substituted or unsubstituted alkyl groups, preferably C1 to C2. 14 Alkyl groups, preferably C1 to C2. 12 Alkyl groups.

[0034] Among them, R3 can be a substituted alkyl group, and the substituents are mainly amino, hydroxyl, phenyl, etc. Amino and hydroxyl groups are both adsorption groups. Appropriately introducing these two groups into the emulsifier molecule is beneficial to forming multi-point adsorption at the oil-water interface, which is beneficial to emulsion stability. Phenyl and sulfonic acid (benzenesulfonic acid) are more beneficial to improving the temperature resistance of the molecule.

[0035] In this invention, the HLB value of the molecule can be controlled by adjusting the ratio of lipophilic (hydrophobic segments) and hydrophilic (hydrophilic segments) groups to ensure the emulsifying ability of the molecule. Simultaneously, strong aggregated structures with internal forces are formed through hydrogen bonding between groups and molecules. The introduction of aromatic rings and sulfonic acid groups enhances the high-temperature resistance of the emulsifier. Therefore, the solid emulsifier with Formula 1 exhibits good emulsification effect and strong high-temperature resistance, withstanding temperatures up to 200℃. It is a blackish-brown solid emulsifier that can be pulverized into a free-flowing brownish-brown powder. The aforementioned high-temperature resistant solid emulsifier demonstrates good emulsification stability in high-temperature oil-based drilling fluids, is convenient to package, transport, and use, and is less affected by the environment. It better meets the needs of high-temperature deep well oil-based drilling fluids in different climatic regions, especially cold regions, further expanding the application range of solid emulsifiers. This invention provides a method for preparing the high-temperature resistant solid emulsifier for oil-based drilling fluids with the Formula 1 structure described above, comprising the following steps:

[0036] The diamino compound and dicarboxylic acid are first added to the reactor and heated to react in a molar ratio, then a fatty amine is added and heated to react, and finally an alkyl sulfonic acid is added and heated to react, to obtain a high-temperature resistant solid emulsifier with the structure shown in Formula 1.

[0037] The molar ratio of the diamino compound, dicarboxylic acid, fatty amine, and alkyl sulfonic acid is 1:(1-2.5):(0.5-2):(1-3);

[0038] The diamino compound is 2,6-diaminotoluene or 2,6-diaminopyridine; the dicarboxylic acid is selected from one of C3 to C22 dicarboxylic fatty acids; the fatty amine is selected from one of C9 to C22 fatty amines; and the alkyl sulfonic acid has an integer number of alkyl carbon atoms from 1 to 18.

[0039] In an embodiment of the present invention, the high-temperature resistant solid emulsifier is prepared by reacting a diamino compound, a dicarboxylic acid, a fatty amine, and an alkyl sulfonic acid monomer in a molar ratio of 1:(1-2.5):(0.5-2):(1-3). The reaction temperature is preferably controlled at 140°C to 180°C, and the reaction is carried out in three steps, with each step lasting 2-4 hours. After the reaction is completed, the material is discharged, cooled at room temperature, and solidified to obtain the blackish-brown high-temperature resistant solid emulsifier for oil-based drilling fluid, which is then pulverized into a free-flowing brownish-brown powder.

[0040] In this invention, the diamino compound is 2,6-diaminotoluene or 2,6-diaminopyridine. The dicarboxylic acid is selected from one of C3-C22 dicarboxylic fatty acids; preferably, it is selected from one of malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, and sebacic acid.

[0041] The fatty amine is selected from one of C9 to C22 fatty amines; preferably, it is selected from one of tetradecylamine, hexadecylamine, oleylamine, octadecylamine, eicosamine, and didiamine.

[0042] The alkyl sulfonic acid has an alkyl carbon number of 1 to 18, corresponding to R3 being C1 to C3 as mentioned above. 18 The substituted or unsubstituted alkyl group; the alkyl sulfonic acid is preferably selected from one of methanesulfonic acid, taurine, 3-hydroxypropanesulfonic acid, 1-butanesulfonic acid, hexane sulfonate, octylsulfonic acid, dodecyl sulfonic acid, and dodecylbenzene sulfonic acid.

[0043] The present invention does not limit the source of the above-mentioned diamino compound, diacid, fatty amine and alkyl sulfonic acid, whichever is known to those skilled in the art is acceptable. According to the present invention, the molar ratio of the diamino compound, diacid, fatty amine and alkyl sulfonic acid is controlled as 1:(1-2.5):(0.5-2):(1-3); preferably 1:(1.5-2):(0.5-1):(1-2).

[0044] According to the solid emulsifier of the present invention, the heating reaction specifically involves heating to 140–180°C for reaction, with each step of the reaction lasting 2–4 hours. For example, the heating reaction involving the addition of aliphatic amines and the heating reaction involving the addition of alkyl sulfonic acids are both carried out under stirring conditions, with the reaction temperature independently ranging from 140°C to 180°C.

[0045] The high-temperature resistant solid emulsifier for oil-based drilling fluids with the structure of Formula 1 provided in this embodiment of the invention is prepared by a method comprising the following steps: first, a diamino compound and a diacid are added to a reactor in a certain proportion, and the mixture is heated and stirred to react; then, a fatty amine is added, and the mixture is heated and stirred to react again; finally, an alkyl sulfonic acid is added, and the mixture is heated and stirred to react again; after the reaction is completed, the mixture is discharged and cooled at room temperature to obtain the solid emulsifier product. This invention does not limit the specific method of stirring, as is known to those skilled in the art.

[0046] According to the solid emulsifier of the present invention, the heating reaction temperature can be 140°C, 150°C, 160°C, 170°C or 180°C respectively; the copolymerization reaction time of each step is 2 to 4 hours, specifically 2 hours, 3 hours or 4 hours respectively.

[0047] On the other hand, the present invention also provides the application of any of the aforementioned high-temperature resistant solid emulsifiers for oil-based drilling fluids in the preparation of oil-based drilling fluids, which can improve the high-temperature emulsification stability of oil-based drilling fluid systems.

[0048] The high-temperature resistant solid emulsifier provided by this invention can be used to prepare high-temperature resistant oil-based drilling fluids, exhibiting excellent technical effects. This invention does not limit the other components used in the preparation of high-temperature resistant oil-based drilling fluids; those well-known to those skilled in the art are acceptable.

[0049] To further understand this application, the following detailed description, in conjunction with embodiments, of the high-temperature resistant solid emulsifier for oil-based drilling fluids provided in this application, its preparation method, and its application.

[0050] Example 1

[0051] 0.3 mol of 2,6-diaminopyridine and 0.6 mol of succinic acid were heated and stirred until homogeneous, reacting at 150°C for 2 hours. Then, 0.3 mol of octadecylamine was added, and the reaction was carried out at 160°C for 2 hours. Finally, 0.6 mol of taurine was added, and the reaction was carried out at 180°C for 3 hours. The mixture was discharged and allowed to cool naturally to obtain a solid product, which was then pulverized to obtain a powder. Its structural formula is:

[0052]

[0053] Example 2

[0054] 0.5 mol of 2,6-diaminopyridine and 1 mol of glutaric acid were heated and stirred until homogeneous, reacting at 140°C for 2 hours. Then, 0.5 mol of octadecylamine was added, and the reaction was stirred at 150°C for 2 hours. Finally, 0.5 mol of hexane sulfonate was added, and the copolymerization reaction was carried out at 160°C for 4 hours. The product was discharged and allowed to cool naturally to obtain a solid product, which was then pulverized to obtain a powder. Its structural formula is:

[0055]

[0056] Example 3

[0057] 0.4 mol of 2,6-diaminotoluene and 0.8 mol of adipic acid were heated and stirred until homogeneous, reacting at 160°C for 3 hours. Then, 0.4 mol of tetradecylamine was added, and the reaction was carried out at 170°C for 2 hours. Finally, 0.4 mol of dodecyl sulfonic acid was added, and the reaction was carried out at 180°C for 3 hours. The mixture was discharged and allowed to cool naturally to obtain a solid product, which was then pulverized to obtain a powder. Its structural formula is:

[0058]

[0059] Example 4

[0060] 0.6 mol of 2,6-diaminotoluene and 1.2 mol of octanediic acid were heated and mixed thoroughly, then stirred at 150°C for 3 hours. Next, 0.6 mol of hexadecylamine was added, and the mixture was stirred at 160°C for 3 hours. Finally, 1.2 mol of 1-butanesulfonic acid was added, and the mixture was stirred at 170°C for 4 hours. The mixture was discharged and allowed to cool naturally to obtain a solid product, which was then pulverized to obtain a powder. Its structural formula is:

[0061]

[0062] Comparative Examples 1-2, Examples 5-12

[0063] The reaction steps and conditions of Comparative Examples 1-2 and Examples 5-12 were the same as those of Example 1. Comparative Examples 1-2 mainly compared the synthesis effects of short-chain aliphatic amines. The reactants and their amounts are shown in Table 1.

[0064] Table 1. Reaction Components of Examples 5-12 (in moles, mol)

[0065]

[0066]

[0067] To further illustrate the effects of the present invention, the sample examples and comparative examples are comprehensively evaluated.

[0068] 1. Emulsifying properties

[0069] The products of the examples and comparative examples were formulated into an emulsion with an oil-water ratio of 85:15: 255ml diesel (No. 0) + 45ml distilled water + 2% product + 2% organic soil. The emulsion was aged at 200℃ for 16h, and the demulsification voltage was measured at 50℃. The emulsion was then poured into a 500ml graduated cylinder and allowed to stand for 24h. The volume V (ml) of the separated oil phase was measured. The emulsification rate was calculated according to the formula (300-V) / 300×100%). The emulsification effects of the examples and comparative examples are shown in Table 2.

[0070] Table 2 High-temperature emulsification effect of the products in the examples

[0071]

[0072]

[0073] 2. Pulp mixing performance

[0074] The properties of the oil-based drilling fluid were determined according to the requirements of GB / T16783.2-2013. The product of this invention obtained in Example 1 was used to prepare the oil-based drilling fluid. The basic formula was: 300ml base fluid (different oil-water ratios) + 4% product of Example 1 + 4% organic clay + 4% oxidized asphalt + 3% CaO + 400g barite, with a density of 1.6g / cm³. 3 The samples were aged at 200℃ for 16 hours. The experimental results are shown in Table 3.

[0075] Table 3. Performance of diesel-based drilling fluid in Example 1 at different oil-water ratios.

[0076]

[0077] Note: AV is apparent viscosity, PV is plastic viscosity, YP is dynamic shear strength, and Q is... 10s / Q10min For initial and final cuts, ES is the demulsification voltage, and FL is the medium-voltage filtration loss.

[0078] As shown in Tables 2 and 3, the solid emulsifier prepared by this invention exhibits excellent high-temperature resistance, reaching up to 200℃. After aging at 200℃, it demonstrates good emulsification stability, achieving 100% emulsification rate within 24 hours. It also exhibits good rheological properties and emulsification stability in drilling fluid systems with different oil-to-water ratios. With no auxiliary emulsifier added, a dosage of only 4%, and an oil-to-water ratio of 85:15, the demulsification voltage is 750 kJ / L, and the dynamic plasticity ratio is 0.25. This invention retains the advantages of solid emulsifiers—low susceptibility to environmental influences and ease of use—while improving their temperature resistance, thus expanding the application range of solid emulsifiers in oil-based drilling fluids.

[0079] Specifically, this invention controls the HLB value of the molecule by controlling the ratio of lipophilic (hydrophobic segments) and hydrophilic (hydrophilic segments) groups to achieve an ideal emulsification effect. It forms a solid emulsifier with a strong internal force through hydrogen bonding between groups and molecules, and simultaneously improves the emulsifier's high-temperature resistance by introducing aromatic rings and sulfonic acid groups, achieving a high temperature resistance up to 200℃. This invention can be used to formulate high-temperature oil-based drilling fluids, exhibiting excellent emulsification and stabilization effects in high-temperature oil-based drilling fluids. Furthermore, it is convenient to package, transport, and use, less affected by the environment, and better meets the needs of high-temperature deep well oil-based drilling fluids in different climate regions, especially cold regions.

[0080] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various modifications to these embodiments without departing from the technical principles of the present invention, and these modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high temperature resistant solid emulsifier for oil-based drilling fluids, characterized in that, having the structure of Formula 1: Formula 1; wherein R1is a linear alkyl group of C9to C 22 ; R2is (CH2) m m is an integer from 1 to 20; A1is or ; A2and A2' are both selected from H or , and are not simultaneously H; R3is C1-C 18 substituted or unsubstituted alkyl.

2. The high temperature resistant solid emulsifier for oil-based drilling fluids according to claim 1, characterized in that, R1is C 12 ~C 22 a straight-chain alkyl group.

3. The high temperature resistant solid emulsifier for oil-based drilling fluids according to claim 2, characterized in that, R1is C 14 ~C 22 a straight-chain alkyl group.

4. The high temperature resistant solid emulsifier for oil-based drilling fluids according to claim 1, characterized in that, m is an integer from 1 to 16.

5. The high temperature resistant solid emulsifier for oil-based drilling fluids according to claim 4, characterized in that, m is an integer from 1 to 12.

6. The high temperature resistant solid emulsifier for oil-based drilling fluids according to claim 5, characterized in that, m is an integer from 1 to 8.

7. The high temperature resistant solid emulsifier for oil-based drilling fluids according to any one of claims 1 to 6, characterized in that, R3is a substituted or unsubstituted alkyl group of from 1 to 6 carbon atoms. 14 R3is a substituted or unsubstituted alkyl group of from 1 to 6 carbon atoms.

8. The high temperature resistant solid emulsifier for oil-based drilling fluids according to claim 7, characterized in that, R3is a substituted or unsubstituted alkyl group of from 1 to 6 carbon atoms. 12 R3is a substituted or unsubstituted alkyl group of from 1 to 6 carbon atoms.

9. A process for the preparation of the high temperature resistant solid emulsifier for oil-based drilling fluids according to any one of claims 1 to 8, characterized in that, comprising the following steps: The diamino compound and the dibasic acid are first added into a reactor in a molar ratio, heated and reacted, then the fatty amine is added, heated and reacted, finally the alkyl sulfonic acid is added, heated and reacted to obtain the high-temperature-resistant solid emulsifier; The molar ratio of the diamino compound, the dibasic acid, the fatty amine, and the alkyl sulfonic acid is 1: (1-2.5): (0.5-2): (1-3); The diamino compound is 2,6-diaminotoluene or 2,6-diaminopyridine; the dibasic acid is selected from one of C3-C22 dibasic fatty acids; the fatty amine is selected from one of C9-C22 fatty amines; the alkyl sulfonic acid has an alkyl carbon atom number of an integer from 1 to 18.

10. The method of claim 9, wherein, The dibasic acid is selected from one of malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid.

11. The preparation method according to claim 9, characterized in that, The fatty amine is selected from one of myristylamine, cetylamine, oleylamine, stearylamine, eicosylamine, and behenylamine.

12. The method of claim 9, wherein, The alkyl sulfonic acid is selected from one of methyl sulfonic acid, taurine, 3-hydroxypropane sulfonic acid, 1-butane sulfonic acid, sulfonic acid hexane, octyl sulfonic acid, dodecyl sulfonic acid, and dodecyl benzene sulfonic acid.

13. The method of any one of claims 9-12, wherein, The addition of the fatty amine and the addition of the alkyl sulfonic acid are both carried out under stirring, and the reaction temperature is independently 140°C-180°C.

14. The method of claim 13, wherein, The addition of the fatty amine and the addition of the alkyl sulfonic acid are both carried out under stirring, and the reaction temperature is independently 140°C-180°C. The time for the addition of the fatty amine and the addition of the alkyl sulfonic acid is independently 2-4 hours, and after cooling at room temperature, a black-brown solid emulsifier is obtained.

15. Use of the high-temperature-resistant solid emulsifier for oil-based drilling fluid according to any one of claims 1-8 in the preparation of oil-based drilling fluid.

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