A clay stabilizer, its preparation method and application

Abstract

This invention provides a clay stabilizer and its preparation method. The stabilizer is prepared via an amidation reaction using polyethyleneamine or polyetheramine, aminosilane, and trimellitic acid as raw materials, a non-protic, highly polar organic solvent as solvent, and a solid acid as catalyst. The clay stabilizer provided by this invention has advantages such as small molecular weight, good anti-swelling effect, strong adhesion to the formation, effective prevention of clay particle migration, and high-temperature resistance. At a dosage of 0.5%, the anti-swelling rate is ≥85%; at a dosage of 1%, the anti-swelling rate after aging at 350℃ is ≥85%; and the water wash resistance is ≥98%.

Description

Technical Field

[0001] This invention belongs to the field of oilfield engineering technology. Specifically, this invention relates to a clay stabilizer, its preparation method, and its application. Background Technology

[0002] Clay is a common mineral found in geological formations. Because clay swells when exposed to water, during reservoir development processes such as water injection, acidizing, or fracturing in oilfields, the porosity in clay-rich reservoirs decreases due to clay expansion, leading to significant pore blockage and water-sensitive damage. To mitigate this reservoir damage, clay anti-swelling agents are widely used. These agents effectively adsorb onto the clay surface, preventing the hydration, expansion, and dispersion of water-sensitive minerals within the reservoir, thus preventing damage to the oil and gas layer and impacting oilfield development.

[0003] Currently used anti-swelling agents mainly include inorganic salts, cationic polymers, and quaternary ammonium salts. Inorganic salts, as the earliest clay anti-swelling agents, primarily utilize inorganic salt ions such as K+. ＋ Inorganic salt-based clay anti-swelling agents are embedded in the clay crystal structure to neutralize the electronegativity of the clay. However, they have weak bonding with the formation and poor ability to prevent clay migration. Cationic polymers contain multiple positive charges in their molecules, allowing for multi-point adsorption on the surface of clay minerals, resulting in good anti-swelling effects and erosion resistance. However, their large molecular weight easily clogs formation pores and throats, impairing formation permeability and making them unsuitable for dense formations. Furthermore, cationic polymers have poor temperature resistance and are prone to decomposition at high temperatures, causing their anti-swelling effect to disappear. Although quaternary ammonium salts have small molecular weights and do not clog the formation themselves, their anti-swelling effect is not as good as that of cationic polymers because they can only produce single-point adsorption on the clay surface.

[0004] CN105198757B discloses a small cationic bisquaternary ammonium salt clay stabilizer and its preparation method. Using epichlorohydrin, small molecule tertiary amine and hydrochloric acid as raw materials, a clay anti-swelling agent with relatively high charge density is prepared. However, due to the still relatively small number of adsorption sites on the clay surface, its anti-swelling effect is not ideal.

[0005] CN106279661B discloses a quaternary ammonium salt type cationic polymer, which is obtained by chemical reaction of aliphatic amines, acids, epichlorohydrin and terminal diamines. This polymer can be adsorbed on the surface of clay particles, which can greatly improve the anti-swelling effect of clay anti-swelling agent at low dosage. However, due to its large molecular weight and poor temperature resistance, it cannot be applied to low-permeability formations, thus limiting its application range.

[0006] CN101921366A discloses a three-branched cationic polymer synthesized from diallyl ammonium chloride and triallyl ammonium chloride for stabilizing clay during oil extraction. However, studies have shown that high molecular weight cationic polymers are unsuitable for low-permeability formations, easily forming plugs in formation pore channels and thus clogging the formation. Furthermore, due to their long molecular chains and numerous cationic groups, these polymers readily react with treatment agents containing anionic groups, significantly impacting the effectiveness of the treatment agents.

[0007] Therefore, there is a need to develop a high-efficiency clay stabilizer with low molecular weight, multi-point adsorption, strong binding force with the stratum, and good anti-swelling properties. Summary of the Invention

[0008] This invention addresses the technical problems existing in the background art by providing a clay stabilizer and its preparation method, thereby solving the problems of low high-temperature resistance, weak bonding with the formation, poor ability to prevent clay migration, and clogging of low-permeability formation pores in existing clay stabilizers. The clay stabilizer provided by this invention has advantages such as small molecular weight, good anti-swelling effect, strong bonding with the formation, effective prevention of clay particle migration, and high-temperature resistance.

[0009] The present invention achieves the above objectives through the following technical solutions.

[0010] The present invention provides a clay stabilizer having a structure as shown in formula (1) or formula (2);

[0011]

[0012] Where n1 = 0 or 1, n2 = any integer from 0 to 4, n3 = any number from 1 to 5, R1 and R2 may be the same or different, and each is independently H, CH3, or C2H. 5、 .

[0013] Furthermore, the method for preparing a clay stabilizer according to the present invention uses polyethyleneamine or polyetheramine, aminosilane, and pyromellitic acid as raw materials, aprotic highly polar organic solvent as solvent, and solid acid as catalyst, and obtains it through an amidation reaction.

[0014] Furthermore, in the method for preparing a clay stabilizer according to the present invention, the conditions for the amidation reaction include: n 均苯三酸 :n 多乙烯胺或聚醚胺 :n 胺基硅烷 =1:3:1.5~1:6:3, the amount of solid acid catalyst added is 0.5%-2% of the total mass of polyethyleneamine or polyetheramine, aminosilane, and pyromellitic acid, the reaction temperature is 130-190℃, and the reaction time is 3-6h.

[0015] Furthermore, in the method for preparing a clay stabilizer according to the present invention, the polyethyleneamine is at least one selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine.

[0016] Furthermore, in the method for preparing a clay stabilizer according to the present invention, the aprotic highly polar organic solvent is at least one of dimethyl sulfoxide and dimethylformamide.

[0017] Furthermore, in the method for preparing a clay stabilizer according to the present invention, the pyromellitic acid is at least one of pyromellitic tricarboxylic acid and pyromellitic triacetic acid.

[0018] Furthermore, in the method for preparing a clay stabilizer according to the present invention, the aminosilane is at least one of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltrihydroxysilane.

[0019] The present invention also provides a method for preparing the clay stabilizer, wherein the solid acid catalyst is prepared from graphite, tin chloride, bentonite, potassium permanganate and concentrated sulfuric acid.

[0020] Furthermore, in the method for preparing a clay stabilizer according to the present invention, the solid acid catalyst is composed of 10-30% graphite (400-600 mesh), 20-45% tin chloride and 25-70% bentonite by mass fraction, and is obtained by soaking in potassium permanganate and concentrated sulfuric acid in a mass ratio of 1:10-20, drying and calcining at 500-600°C.

[0021] The clay stabilizer described in this invention is applied in the field of oilfield production.

[0022] The benefits and features of this invention are as follows:

[0023] (1) The clay stabilizer of the present invention contains an amine group in its molecular structure, which forms an amine positive ion in aqueous solution. It has a high charge density, which can neutralize the negative charge on the surface of clay and can also be electrostatically adsorbed with the stratum, thus giving it excellent anti-swelling performance and water washability. The anti-swelling rate reaches more than 85% at a dosage of 0.5%.

[0024] (2) The clay stabilizer of the present invention contains siloxane in its molecular structure. The siloxane utilizes the hydrolyzed Si-OH to undergo a condensation reaction with the Si-OH on the surface of the clay, thereby achieving chemical adsorption of the clay stabilizer on the surface of the clay. This further enhances the water resistance and prevents clay migration of the clay stabilizer, and the water resistance rate reaches more than 98%.

[0025] (3) The clay stabilizer of the present invention contains a rigid benzene ring in its molecular structure, which has good temperature resistance and can withstand temperatures up to 350°C;

[0026] (4) The clay stabilizer of the present invention has a small molecular weight and will not cause blockage in low-permeability formations;

[0027] (5) The solid acid catalyst developed in this invention contains acidic groups and hydrophilic groups, which greatly improves the catalytic activity of solid acid. Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Example 1

[0029] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethyl sulfoxide, 70g of trimesic acid, 7.02g of solid acid catalyst, and 221g of 3-aminopropyltriethoxysilane were added. The temperature was slowly raised to 130℃ and the reaction was carried out for 1 hour. 60g of ethylenediamine was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 130℃ for 2 hours. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S1.

[0030] The solid acid catalyst is composed of 10% graphite (400 mesh), 20% tin chloride and 70% bentonite by mass fraction, and is prepared by soaking in potassium permanganate and concentrated sulfuric acid in a mass ratio of 1:10, drying and calcining at 500℃. Example 2

[0031] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethyl sulfoxide, 70g of trimesic acid, 0.731g of solid acid catalyst, and 89.5g of 3-aminopropyltrimethoxysilane were added. The temperature was slowly raised to 130℃ and the reaction was carried out for 1.5h. 206g of diethylenetriamine was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 190℃ for 4.5h. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S2.

[0032] The solid acid catalyst is composed of 20% graphite (500 mesh), 30% tin chloride and 50% bentonite by mass fraction, and is prepared by soaking in potassium permanganate and concentrated sulfuric acid in a mass ratio of 1:15, drying and calcining at 550℃. Example 3

[0033] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethyl sulfoxide, 70g of trimesic acid, 3.65g of solid acid catalyst, and 91g of 3-aminopropyltrihydroxysilane were added. The temperature was slowly raised to 140℃ and the reaction was carried out for 2 hours. 195g of triethylenetetramine was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 170℃ for 3 hours. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S3.

[0034] The solid acid catalyst is composed of 30% graphite (600 mesh), 20% tin chloride and 50% bentonite by mass fraction, and is prepared by soaking and drying in potassium permanganate and concentrated sulfuric acid at a mass ratio of 1:20 and calcining at 600℃. Example 4

[0035] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethylformamide, 84g of pyromellitic acid, 5.82g of solid acid catalyst, and 120g of 3-aminopropyltriethoxysilane were added. The temperature was slowly raised to 130℃ and the reaction was carried out for 2 hours. Then, 378g of tetraethylenepentamine was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 160℃ for 4 hours. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S4.

[0036] The solid acid catalyst is composed of 15% graphite (450 mesh), 45% tin chloride and 40% bentonite by mass fraction, and is prepared by soaking in potassium permanganate and concentrated sulfuric acid in a mass ratio of 1:20, drying and calcining at 500℃. Example 5

[0037] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethyl sulfoxide, 84g of pyromellitic acid, 7.452g of solid acid catalyst, and 179g of 3-aminopropyltrimethoxysilane were added. The temperature was slowly raised to 140℃ and the reaction was carried out for 1.5h. 232g of pentaethylenetetramine was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 180℃ for 1.5h. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S5.

[0038] The solid acid catalyst is composed of 20% graphite (500 mesh), 20% tin chloride and 60% bentonite by mass fraction, and is prepared by soaking and drying in potassium permanganate and concentrated sulfuric acid at a mass ratio of 1:10 and calcining at 600℃. Example 6

[0039] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethylformamide, 84g of pyromellitic acid, 7.42g of solid acid catalyst, and 137g of 3-aminopropyltrihydroxysilane were added. The mixture was slowly heated to 130℃ and reacted for 2 hours. 150g of polyetheramine with the structural formula of Formula 1 was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 150℃ for 3 hours. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S6.

[0040] The structural formula of polyetheramine is:

[0041] Equation (3)

[0042] The solid acid catalyst is composed of 30% graphite (400 mesh), 45% tin chloride and 25% bentonite by mass fraction, and is prepared by soaking and drying in potassium permanganate and concentrated sulfuric acid at a mass ratio of 1:15 and calcining at 550℃.

[0043] Example 7

[0044] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethylformamide, 70g of trimesic acid, 1.334g of solid acid catalyst, and 137g of 3-aminopropyltrihydroxysilane were added. The temperature was slowly raised to 140℃ and the reaction was carried out for 1 hour. 460g of polyetheramine with the structural formula of Formula 2 was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 190℃ for 3 hours. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S7.

[0045] The structural formula of polyetheramine is:

[0046] Equation (4)

[0047] The solid acid catalyst is composed of 10% graphite (600 mesh), 40% tin chloride and 50% bentonite by mass fraction, and is prepared by soaking in potassium permanganate and concentrated sulfuric acid in a mass ratio of 1:20, drying and calcining at 500℃.

[0048] Example 8

[0049] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethyl sulfoxide, 70g of trimesic acid, 14.4g of solid acid catalyst, and 200g of 3-aminopropyltrimethoxysilane were added. The temperature was slowly raised to 140℃ and the reaction was carried out for 2.5h. 450g of polyetheramine with the structural formula of Formula 3 was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 140℃ for 3.5h. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S8.

[0050] Polyetheramine structural formula:

[0051] Equation (5)

[0052] The solid acid catalyst is composed of 10% graphite (400 mesh), 30% tin chloride and 60% bentonite by mass fraction, and is prepared by soaking and drying in potassium permanganate and concentrated sulfuric acid at a mass ratio of 1:15 and calcining at 600℃.

[0053] Example 9

[0054] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethyl sulfoxide, 84g of pyromellitic acid, 3.7g of solid acid catalyst, and 80g of 3-aminopropyltrihydroxysilane were added. The temperature was slowly raised to 140℃ and the reaction was carried out for 2 hours. 206g of diethylenetriamine was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 170℃ for 2.5 hours. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S9.

[0055] The solid acid catalyst is composed of 25% graphite (400 mesh), 30% tin chloride and 45% bentonite by mass fraction, and is prepared by soaking and drying potassium permanganate and concentrated sulfuric acid in a mass ratio of 1:10 and calcining at 550℃.

[0056] Example 10

[0057] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethylformamide, 84g of pyromellitic acid, 8.76g of solid acid catalyst, and 200g of 3-aminopropyltriethoxysilane were added. The temperature was slowly raised to 140℃ and the reaction was carried out for 1 hour. Then, 300g of tetraethylenepentamine was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 160℃ for 2 hours. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S10.

[0058] The solid acid catalyst is composed of 15% graphite (500 mesh), 20% tin chloride and 65% bentonite by mass fraction, and is prepared by soaking in potassium permanganate and concentrated sulfuric acid in a mass ratio of 1:20, drying and calcining at 500℃.

[0059] Example 11

[0060] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethyl sulfoxide, 84g of pyromellitic acid, 10.22g of solid acid catalyst, and 120g of 3-aminopropyltrimethoxysilane were added. The temperature was slowly raised to 130℃ and the reaction was carried out for 2 hours. 307g of polyetheramine with the structural formula of Formula 4 was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 150℃ for 4 hours. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S11.

[0061] polyetheramine structural formula

[0062] Equation (6)

[0063] The solid acid catalyst is composed of 15% graphite (400 mesh), 15% tin chloride and 70% bentonite by mass fraction, and is prepared by soaking in potassium permanganate and concentrated sulfuric acid in a mass ratio of 1:15, drying and calcining at 500℃.

[0064] Example 12

[0065] A four-necked flask equipped with a stirrer, thermometer, constant-pressure dropping funnel, and water separator was placed in an oil bath. 100g of dimethyl sulfoxide, 70g of trimesic acid, 7.8g of solid acid catalyst, and 120g of 3-aminopropyltrimethoxysilane were added. The temperature was slowly raised to 140℃ and the reaction was carried out for 3 hours. 200g of polyetheramine with the structural formula of Formula 5 was added through the constant-pressure dropping funnel. After the addition was completed, the reaction was continued at 170℃ for 3 hours. Finally, the solvent dimethyl sulfoxide was removed by vacuum distillation to obtain clay stabilizer S12.

[0066] polyetheramine structural formula

[0067] Equation (7)

[0068] The solid acid catalyst is composed of 20% graphite (600 mesh), 40% tin chloride and 40% bentonite by mass fraction, and is prepared by soaking and drying in potassium permanganate and concentrated sulfuric acid at a mass ratio of 1:20 and calcining at 600℃.

[0069] Comparative Example 1

[0070] The method of Example 1 was followed, except that the solid acid catalyst was replaced with concentrated sulfuric acid. All other conditions were the same as in Example 1. Clay stabilizer D1 was thus prepared.

[0071] Comparative Example 2

[0072] The method of Example 2 was followed, except that the reactant diethylenetriamine was removed. All other conditions were the same as in Example 2. Clay stabilizer D2 was thus prepared.

[0073] Comparative Example 3

[0074] The method of Example 2 was followed, except that the reactant 3-aminopropyltrimethoxysilane was removed. All other conditions were the same as in Example 2. Clay stabilizer D3 was obtained.

[0075] Comparative Example 4

[0076] The method of Example 7 was followed, except that the reactant polyetheramine D230 was removed. Other conditions were the same as in Example 6. Clay stabilizer D4 was thus prepared.

[0077] Comparative Example 5

[0078] The method of Example 7 was followed, except that the reactant 3-aminopropyltrihydroxysilane was removed. All other conditions were the same as in Example 7. Clay stabilizer D5 was obtained.

[0079] Test Example 1

[0080] The anti-swelling rate of clay stabilizers S1-S12, D1-D5 prepared in Examples 1-12 and Comparative Examples 1-5, as well as commercially available clay stabilizers, was tested at mass concentrations of 0.5%, 1.0% and 2%, in accordance with the "Sy / T5971-2016 Performance Evaluation Method of Clay Stabilizers for Water Injection".

[0081] The water wash resistance of clay stabilizers S1-S12, D1-D5 prepared in Examples 1-12 and Comparative Examples 1-5, as well as commercially available clay stabilizers, was tested after three water washes at a mass concentration of 1% in accordance with the "Sy / T5971-2016 Performance Evaluation Method of Clay Stabilizers for Water Injection".

[0082] High-temperature aging tests were conducted to assess the temperature resistance of clay stabilizers S1-S12 and D1-D5 prepared in Examples 1-12 and Comparative Examples 1-5, as well as commercially available clay stabilizers. The anti-swelling rate test procedure after aging at 350℃ was as follows: 3.00g of sodium bentonite was added to 60mL of a 1% (w / v) clay stabilizer solution, thoroughly mixed, and then placed in an aging vessel. The mixture was then placed in a high-temperature aging furnace and aged at 350±2℃ for 24 hours. After cooling to room temperature, the entire clay stabilizer solution in the aging vessel was transferred to a 100mL beaker, thoroughly mixed, and 10mL was quickly added to a centrifuge tube. The tube was then placed in a centrifuge with an automatic balancing function and centrifuged at 1500r / min for 15min. The expansion volume V1 of the bentonite was read. The high-temperature anti-swelling rate calculation formula is shown in Equation 8.

[0083] (Equation 8)

[0084] Where: F—high temperature anti-swelling rate, %

[0085] V0—Volume of sodium bentonite in kerosene, mL;

[0086] V1—Volume of sodium bentonite in clay anti-swelling agent, mL;

[0087] V2—Volume of sodium bentonite in pure water, mL;

[0088] Table 1 shows the anti-swelling properties, water washability, and temperature resistance of clay stabilizers S1-S12, D1-D5 prepared in Examples 1-12 and Comparative Examples 1-5, as well as commercially available clay stabilizers.

[0089] Table 1 Performance Evaluation Results

[0090]

[0091] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0092] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A clay stabilizer, characterized in that, The clay stabilizer has the structure shown in formula (1) or formula (2); Where n1 = 0 or 1, n2 = any integer from 0 to 4, n3 = any number from 1 to 5, R1 and R2 are the same or different, and each is independently H, CH3, or C2H5; The clay stabilizer is prepared by using polyethyleneamine or polyetheramine, aminosilane, and pyromellitic acid as raw materials, a non-protic highly polar organic solvent as solvent, and a solid acid as catalyst, and is obtained through an amidation reaction. The conditions for the amidation reaction include: n 均苯三酸 :n 多乙烯胺或聚醚胺 :n 胺基硅烷 =1:3:1.5~1:6:3, the amount of solid acid catalyst added is 0.5%-2% of the total mass of polyethyleneamine or polyetheramine, aminosilane, and pyromellitic acid, the reaction temperature is 130-190℃, and the reaction time is 3-6h; The polyethyleneamine is at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine; The pyromellitic acid is at least one of pyromellitic tricarboxylic acid and pyromellitic triacetic acid; The aminosilane is at least one of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltrihydroxysilane; The solid acid catalyst is prepared from graphite, tin chloride, bentonite, potassium permanganate, and concentrated sulfuric acid. The solid acid catalyst consists of 10-30% by mass of 400-600 mesh graphite, 20-45% by mass of tin chloride, and 25-70% by mass of bentonite. It is obtained by soaking and drying in potassium permanganate and concentrated sulfuric acid at a mass ratio of 1:10-20 and calcining at 500-600℃.

2. The clay stabilizer according to claim 1, characterized in that, The aprotic highly polar organic solvent is at least one of dimethyl sulfoxide and dimethylformamide.

3. The application of the clay stabilizer according to claim 1, characterized in that: This clay stabilizer is used in oilfield production.

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