Composite clay stabilizer with scouring resistance and preparation method thereof

Abstract

The invention provides a composite clay stabilizer with scouring resistance and a preparation method thereof, and belongs to the field of clay stabilizers. The preparation method comprises the following steps: reacting o-diallyl bisphenol A, (3-mercaptopropyl) trimethoxysilane and azodiisobutyronitrile to obtain modified silane, reacting the modified silane, a quaternary ammonium mixture, acrylamide, glycidyl methacrylate, sodium p-styrenesulfonate and ammonium persulfate to obtain a prepolymer, reacting phenol, tetradecylamine, polyether amine and a formaldehyde aqueous solution to obtain modified polyether amine, and reacting the modified polyether amine and the ammonium persulfate to obtain a prepolymer. And reacting the prepolymer with the modified polyether amine to obtain the composite clay stabilizer. The scouring resistance of the composite clay stabilizer is improved through synergistic cooperation between multiple adsorption and a hydrophobic barrier, and the high temperature resistance of the composite clay stabilizer is improved through synergistic cooperation between siloxane crosslinking, quaternary ammonium charge stabilization, benzene ring rigid support and a crosslinking structure.

Description

Technical Field

[0001] The invention relates to the field of clay stabilizers, and in particular to a composite clay stabilizer with scour resistance and a preparation method thereof. Background Art

[0002] In the development of oil and gas fields, clay minerals such as montmorillonite and illite in the formation are prone to hydration expansion and dispersion migration after contacting water, leading to problems such as reservoir pore blockage, well wall instability and reduced fracturing fluid efficiency. Clay stabilizers are the core treatment agents to suppress such problems, and their performance directly affects the efficiency and cost of oil and gas production. Traditional clay stabilizers mainly rely on quaternary ammonium salt compounds to neutralize the negative charge on the clay surface through cationic electrostatic adsorption, which can reduce the expansion rate in the short term, or use polyetheramine substances to inhibit the penetration of water molecules through hydrogen bonding. However, traditional clay stabilizers are easily washed away by running water under water scouring or high water pressure conditions, and have poor water washability, resulting in a decrease in stabilization effect. This is particularly evident in oil fracturing, water injection and other operations, which can easily cause reservoir pollution and well wall instability.

[0003] Traditional quaternary ammonium salts rely on single cationic electrostatic adsorption, and their binding strength is significantly affected by fluid pH, ionic strength and temperature. Especially under high-speed fluid scouring, physically adsorbed quaternary ammonium molecules are easily desorbed from the clay surface, resulting in rapid attenuation of the stabilization effect. Although polyetheramine stabilizers have a flexible molecular structure, they lack rigid support and are difficult to maintain a stable adsorption layer under high-speed fluid scouring. In addition, conventional polyetheramine clay stabilizers lack effective hydrophobic groups and rigid skeletons, and cannot form a dense hydrophobic barrier on the clay surface. Interlayer expansion caused by water molecule penetration is still difficult to avoid.

[0004] Chinese patent CN 113088265B discloses a high-temperature resistant and efficient clay stabilizer, which mainly comprises three substances: organic amine, hexadecyltrimethylammonium bromide and potassium chloride. The clay stabilizer provided by the invention has good high-temperature resistance and anti-swelling ability. However, the clay stabilizer is mainly combined with the clay through electrostatic adsorption, and it does not mention whether chemical bonds or strong physical cross-linking mechanisms are introduced. It may gradually fall off under long-term scouring.

[0005] Therefore, providing a composite clay stabilizer that is both erosion-resistant and high-temperature-resistant is an important issue to be solved in the art. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a composite clay stabilizer with scour resistance and a preparation method thereof. Specifically, the technical solution of the present invention includes the following contents: A method for preparing a scour-resistant composite clay stabilizer, the preparation method comprising the following steps: Diallyl bisphenol A, (3-mercaptopropyl)trimethoxysilane and azobisisobutyronitrile react to obtain a modified silane. The modified silane, quaternary ammonium mixture, acrylamide, glycidyl methacrylate, sodium styrene sulfonate and ammonium persulfate react to obtain a prepolymer. Phenol, tetradecylamine, polyetheramine and aqueous formaldehyde solution react to obtain a modified polyetheramine. The prepolymer and the modified polyetheramine react to prepare a composite clay stabilizer.

[0007] Further, the preparation method of the quaternary ammonium mixture includes the following steps: Pentaerythritol allyl ether, o-dichlorobenzyl and potassium carbonate react to obtain an intermediate product, and the intermediate product reacts with a long-chain alkylamine to obtain a quaternary ammonium mixture.

[0008] Further, the weight ratio of pentaerythritol allyl ether, o-dichlorobenzyl and potassium carbonate is 8-12:41-44:43-46.

[0009] Further, the reaction conditions of pentaerythritol allyl ether, o-dichlorobenzyl and potassium carbonate include a reaction temperature of 55-60 °C and a reaction time of 24-36 h.

[0010] Further, the long-chain alkylamine is N,N-dimethylhexadecylamine.

[0011] Further, the weight ratio of the intermediate product and the long-chain alkylamine is 18-20:9-10.

[0012] Further, the reaction conditions of the intermediate product and the long-chain alkylamine include a reaction temperature of 75-85 °C and a reaction time of 24-48 h.

[0013] Further, the weight ratio of diallyl bisphenol A and (3-mercaptopropyl)trimethoxysilane is 10-12:11-12.

[0014] Further, the weight ratio of diallyl bisphenol A and azobisisobutyronitrile is 10-12:0.11-0.21.

[0015] Further, the reaction conditions of diallyl bisphenol A, (3-mercaptopropyl)trimethoxysilane and azobisisobutyronitrile include a reaction temperature of 70-80 °C and a reaction time of 8-12 h.

[0016] Further, the weight ratio of the modified silane, quaternary ammonium mixture, acrylamide, glycidyl methacrylate and sodium styrene sulfonate is 6.9-7.2:17-20:0.9-1.1:1.9-2.1:3.3-3.5.

[0017] Further, the weight ratio of the modified silane and ammonium persulfate is 6.9-7.2:0.30-0.35.

[0018] Further, the reaction conditions of the modified silane, quaternary ammonium mixture, acrylamide, glycidyl methacrylate, sodium p-styrenesulfonate and ammonium persulfate include a reaction temperature of 65-75°C and a reaction time of 6-8 h.

[0019] Further, the polyetheramine is polyetheramine D-230.

[0020] Further, the mass fraction of formaldehyde in the aqueous formaldehyde solution is 40%.

[0021] Further, the weight ratio of phenol, tetradecylamine, polyetheramine and aqueous formaldehyde solution is 20-25:50-55:90-100:56-61.

[0022] Further, the reaction conditions of phenol, tetradecylamine, polyetheramine and aqueous formaldehyde solution include a reaction temperature of 100-105°C and a reaction time of 3-4 h.

[0023] Further, the weight ratio of the prepolymer to the modified polyetheramine is 10:6-8.

[0024] Further, the reaction conditions of the prepolymer and the modified polyetheramine include reacting at 70-80°C for 2-4 h and then reacting at 150-180°C for 30-60 min.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In the present invention, a nucleophilic substitution reaction occurs between the hydroxyl group in pentaerythritol allyl ether and the chlorine atom in o-dichlorobenzyl to obtain an intermediate product, and a nucleophilic substitution reaction occurs between the chlorine atom in the intermediate product and the tertiary amine group in N,N-dimethylhexadecylamine to obtain a quaternary ammonium mixture containing a quaternary ammonium group; the alkene in o-diallylbisphenol A and the mercapto group in (3-mercaptopropyl)trimethoxysilane undergo a thiol-ene click reaction to obtain a modified silane, and the modified silane, quaternary ammonium mixture, acrylamide, glycidyl methacrylate and sodium p-styrenesulfonate undergo a polymerization reaction to obtain a prepolymer with siloxane, quaternary ammonium group, epoxy group and sulfonic acid group in the side chain; phenol, tetradecylamine, formaldehyde and polyetheramine undergo a Mannich modification reaction to obtain a modified polyetheramine containing a benzene ring and a long-chain alkane; the prepolymer and the modified polyetheramine undergo a ring-opening reaction to obtain a composite clay stabilizer.

[0026] (2) In the composite clay stabilizer provided by the present invention, the quaternary ammonium group neutralizes the negative charge on the clay surface and intercalates into the clay lamellae, inhibiting the swelling caused by the penetration of water molecules. The sulfonic acid group provides negative charges to disperse the clay particles, reducing aggregation and swelling. At the same time, it forms a "positive-negative charge synergy" with the quaternary ammonium group, enhancing the adsorption firmness and resisting water flow scouring; the siloxane group can form Si-O-Si covalent bonds with the hydroxyl groups on the clay surface, combined with the electrostatic adsorption of the quaternary ammonium group, forming a physical-chemical dual adsorption and enhancing the erosion resistance; the hydrophobicity of the long-chain alkanes and the rigidity of the benzene rings in the prepolymer and modified polyetheramine act together to form a dense hydrophobic protective layer, reducing the penetration of water molecules to the clay surface and reducing the risk of scouring and peeling, further enhancing the erosion resistance of the composite clay stabilizer.

[0027] (3) In the composite clay stabilizer provided by the present invention, the quaternary ammonium group is adsorbed and fixed on the clay surface through strong electrostatic interaction, and the long-chain cetyl group covers the clay layer through hydrophobic interaction, reducing the interlayer swelling caused by the penetration of water molecules at high temperature; the siloxane structure can form a stable Si-O-Si crosslinked network, restricting the movement of molecular chains and enhancing the thermal stability of the composite clay stabilizer; the benzene rings in the prepolymer and modified polyetheramine form a locally ordered structure through π-π stacking, providing a rigid framework, and the flexibility of the ether bonds in the modified polyetheramine can buffer thermal stress, synergistically enhancing the heat resistance; the prepolymer and modified polyetheramine form a crosslinked structure through the ring-opening reaction of epoxy group-amine, restricting the thermal movement of molecular chains at high temperature, slowing down thermal decomposition, and enhancing the high-temperature resistance of the composite clay stabilizer.

[0028] (4) The present invention improves the erosion resistance of the composite clay stabilizer through the synergistic cooperation between multiple adsorption and hydrophobic barriers, and improves the high-temperature resistance of the composite clay stabilizer through the synergistic cooperation between siloxane crosslinking, quaternary ammonium charge stabilization, benzene ring rigid support and crosslinked structure. Through the organic combination of chemical bonds and physical effects, good erosion resistance and high-temperature resistance are achieved. Detailed implementation mode

[0029] The technical solutions of the present invention will be clearly and completely described below through the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present invention.

[0030] Unless otherwise specified, the raw materials and reagents used in the present invention below are all commercially available products or can be prepared by known methods.

[0031] Preparation example 1: The preparation method of the quaternary ammonium mixture includes the following steps: 8 parts by weight of pentaerythritol allyl ether, 41 parts by weight of o-dichlorobenzyl, and 43 parts by weight of potassium carbonate are dispersed in 500 parts by weight of acetone, and stirred at 55 °C for 24 h. After the reaction, filtration, washing, and vacuum drying are carried out in sequence to obtain an intermediate product; 18 parts by weight of the intermediate product and 9 parts by weight of N,N-dimethylhexadecylamine are dispersed in 100 parts by weight of ethanol, and stirred at 75 °C for 24 h. After the reaction, ethanol is removed by rotary evaporation, dissolved in acetone, dispersed in diethyl ether, and allowed to stand at 0 °C for 8 h. Then, filtration, washing, and vacuum drying are carried out in sequence to obtain a quaternary ammonium mixture.

[0032] Preparation Example 2: A method for preparing a quaternary ammonium mixture, comprising the following steps: 9 parts by weight of pentaerythritol allyl ether, 42 parts by weight of o-dichlorobenzyl, and 44 parts by weight of potassium carbonate are dispersed in 500 parts by weight of acetone, and stirred at 56 °C for 28 h. After the reaction, filtration, washing, and vacuum drying are carried out in sequence to obtain an intermediate product; 18.5 parts by weight of the intermediate product and 9.2 parts by weight of N,N-dimethylhexadecylamine are dispersed in 100 parts by weight of ethanol, and stirred at 78 °C for 30 h. After the reaction, ethanol is removed by rotary evaporation, dissolved in acetone, dispersed in diethyl ether, and allowed to stand at 2 °C for 10 h. Then, filtration, washing, and vacuum drying are carried out in sequence to obtain a quaternary ammonium mixture.

[0033] Preparation Example 3: A method for preparing a quaternary ammonium mixture, comprising the following steps: 11 parts by weight of pentaerythritol allyl ether, 43 parts by weight of o-dichlorobenzyl, and 45 parts by weight of potassium carbonate are dispersed in 500 parts by weight of acetone, and stirred at 58 °C for 32 h. After the reaction, filtration, washing, and vacuum drying are carried out in sequence to obtain an intermediate product; 19 parts by weight of the intermediate product and 9.7 parts by weight of N,N-dimethylhexadecylamine are dispersed in 100 parts by weight of ethanol, and stirred at 82 °C for 36 h. After the reaction, ethanol is removed by rotary evaporation, dissolved in acetone, dispersed in diethyl ether, and allowed to stand at 3 °C for 10 h. Then, filtration, washing, and vacuum drying are carried out in sequence to obtain a quaternary ammonium mixture.

[0034] Preparation Example 4: A method for preparing a quaternary ammonium mixture, comprising the following steps: 12 parts by weight of pentaerythritol allyl ether, 44 parts by weight of o-dichlorobenzyl, and 46 parts by weight of potassium carbonate are dispersed in 500 parts by weight of acetone, and stirred at 60 °C for 36 h. After the reaction, filtration, washing, and vacuum drying are carried out in sequence to obtain an intermediate product; 20 parts by weight of the intermediate product and 10 parts by weight of N,N-dimethylhexadecylamine are dispersed in parts by weight of ethanol, and stirred at 85 °C for 48 h. After the reaction, ethanol is removed by rotary evaporation, dissolved in acetone, dispersed in diethyl ether, and allowed to stand at 4 °C for 12 h. Then, filtration, washing, and vacuum drying are carried out in sequence to obtain a quaternary ammonium mixture.

[0035] Preparation Example 5: A method for preparing a quaternary ammonium mixture, comprising the following steps: Replace o-dichlorobenzyl in Preparation Example 4 with 1,4-dichlorobutane, and keep other operations the same as in Preparation Example 4.

[0036] Preparation Example 6: A method for preparing a quaternary ammonium mixture, comprising the following steps: Replace N,N-dimethylhexadecylamine in Preparation Example 4 with N,N-dimethylbutylamine, and keep other operations the same as in Preparation Example 4. Example 1

[0037] A method for preparing an erosion-resistant composite clay stabilizer, comprising the following steps: 10 parts by weight of o-diallylbisphenol A, 11 parts by weight of (3-mercaptopropyl)trimethoxysilane, and 0.11 parts by weight of azobisisobutyronitrile are dispersed in 100 parts by weight of anhydrous toluene, and stirred and reacted at 70 °C for 8 h in a nitrogen protection environment. After the reaction, the modified silane is obtained by vacuum distillation and column chromatography in sequence; 6.9 parts by weight of the modified silane, 17 parts by weight of the quaternary ammonium mixture prepared in Preparation Example 1, 0.9 parts by weight of acrylamide, 1.9 parts by weight of glycidyl methacrylate, and 3.3 parts by weight of sodium p-styrenesulfonate are dispersed in 100 parts by weight of a mixed solvent (V 去离子水 :V 无水乙醇 =7:3), stirred and mixed for 5 min in a nitrogen protection environment, then 0.30 parts by weight of ammonium persulfate is added and stirred and reacted at 65 °C for 6 h to obtain a prepolymer; After mixing 20 parts by weight of phenol and 50 parts by weight of tetradecylamine, while stirring and heating, 23 parts by weight of a 40% formaldehyde aqueous solution is added at 80 °C, and after stirring and reacting for 2 h, 90 parts by weight of polyetheramine D-230 and 33 parts by weight of a 40% formaldehyde aqueous solution are added, and stirred and reacted at 100 °C for 3 h. After the reaction, vacuum distillation is carried out to obtain a modified polyetheramine; After mixing 10 parts by weight of the prepolymer and 6 parts by weight of the modified polyetheramine and adjusting the pH to 7, in a nitrogen protection environment, stirred and reacted at 70 °C for 2 h, then reacted at 150 °C for 30 min. After the reaction, it is cooled to 24 °C and then pulverized and sieved to obtain the composite clay stabilizer. Example 2

[0038] A method for preparing an erosion-resistant composite clay stabilizer, comprising the following steps: 10.5 parts by weight of diallylbisphenol A, 11.2 parts by weight of (3-mercaptopropyl)trimethoxysilane, and 0.14 part by weight of azobisisobutyronitrile are dispersed in 100 parts by weight of anhydrous toluene, and stirred and reacted at 72 °C for 9 h in a nitrogen protection environment. After the reaction is completed, the modified silane is obtained by vacuum distillation and column chromatography in sequence; 7.0 parts by weight of the modified silane, 18 parts by weight of the quaternary ammonium mixture prepared in Preparation Example 2, 0.95 part by weight of acrylamide, 2.0 parts by weight of glycidyl methacrylate, and 3.4 parts by weight of sodium p-styrenesulfonate are dispersed in 100 parts by weight of a mixed solvent (V 去离子水 :V 无水乙醇 =7:3), stirred and mixed in a nitrogen protection environment for 8 min, and then 0.32 - 0.35 part by weight of ammonium persulfate is added and stirred and reacted at 68 °C for 6.5 h to obtain a prepolymer; After mixing 22 parts by weight of phenol and 51 parts by weight of tetradecylamine, while stirring, the temperature is raised. At 81 °C, 24 parts by weight of a 40% aqueous formaldehyde solution is added, and after stirring and reacting for 2.2 h, 92 parts by weight of polyetheramine D-230 and 34 parts by weight of a 40% aqueous formaldehyde solution are added, and stirred and reacted at 102 °C for 3.3 h. After the reaction is completed, vacuum distillation is carried out to obtain the modified polyetheramine; After mixing 10 parts by weight of the prepolymer and 6.5 parts by weight of the modified polyetheramine and adjusting the pH to 7.5, in a nitrogen protection environment, stirred and reacted at 72 °C for 2.5 h, and then reacted at 160 °C for 40 min. After the reaction is completed, it is cooled to 25 °C and then pulverized and sieved to obtain the composite clay stabilizer. Example 3

[0039] A preparation method of an erosion-resistant composite clay stabilizer, comprising the following steps: 11 parts by weight of diallylbisphenol A, 11.7 parts by weight of (3-mercaptopropyl)trimethoxysilane, and 0.17 part by weight of azobisisobutyronitrile are dispersed in 100 parts by weight of anhydrous toluene, and stirred and reacted at 78 °C for 11 h in a nitrogen protection environment. After the reaction is completed, the modified silane is obtained by vacuum distillation and column chromatography in sequence; 7.1 parts by weight of the modified silane, 19 parts by weight of the quaternary ammonium mixture prepared in Preparation Example 3, 1.0 part by weight of acrylamide, 2.0 parts by weight of glycidyl methacrylate, and 3.4 parts by weight of sodium p-styrenesulfonate are dispersed in 100 parts by weight of a mixed solvent (V 去离子水 :V 无水乙醇 =7:3), stirred and mixed in a nitrogen protection environment for 12 min, and then 0.33 part by weight of ammonium persulfate is added and stirred and reacted at 71 °C for 7 h to obtain a prepolymer; After mixing 22 parts by weight of phenol and 52 parts by weight of tetradecylamine, while stirring, the temperature is raised. At 82 °C, 24 parts by weight of an aqueous formaldehyde solution with a mass fraction of 40% is added. After stirring and reacting for 2.8 h, 98 parts by weight of polyetheramine D-230 and 35 parts by weight of an aqueous formaldehyde solution with a mass fraction of 40% are added. The mixture is stirred and reacted at 103 °C for 3.7 h. After the reaction is completed, the modified polyetheramine is obtained by vacuum distillation. After mixing 10 parts by weight of the prepolymer and 7 parts by weight of the modified polyetheramine and adjusting the pH to 8, in a nitrogen protection environment, the mixture is stirred and reacted at 78 °C for 3 h, and then reacted at 170 °C for 50 min. After the reaction is completed, it is cooled to 26 °C and then pulverized and sieved to obtain the composite clay stabilizer. Example 4

[0040] A preparation method of an erosion-resistant composite clay stabilizer includes the following steps: 12 parts by weight of o-diallylbisphenol A, 12 parts by weight of (3-mercaptopropyl)trimethoxysilane, and 0.21 parts by weight of azobisisobutyronitrile are dispersed in 100 parts by weight of anhydrous toluene. In a nitrogen protection environment, the mixture is stirred and reacted at 80 °C for 12 h. After the reaction is completed, the modified silane is obtained by vacuum distillation. 7.2 parts by weight of the modified silane, 20 parts by weight of the quaternary ammonium mixture prepared in Preparation Example 4, 1.1 parts by weight of acrylamide, 2.1 parts by weight of glycidyl methacrylate, and 3.5 parts by weight of sodium p-styrenesulfonate are dispersed in 100 parts by weight of a mixed solvent (V 去离子水 :V 无水乙醇 = 7:3). After stirring and mixing in a nitrogen protection environment for 15 min, 0.35 parts by weight of ammonium persulfate is added, and the mixture is stirred and reacted at 75 °C for 8 h to obtain the prepolymer. After mixing 25 parts by weight of phenol and 55 parts by weight of tetradecylamine, while stirring, the temperature is raised. At 85 °C, 25 parts by weight of an aqueous formaldehyde solution with a mass fraction of 40% is added. After stirring and reacting for 3 h, 100 parts by weight of polyetheramine D-230 and 36 parts by weight of an aqueous formaldehyde solution with a mass fraction of 40% are added. The mixture is stirred and reacted at 105 °C for 4 h. After the reaction is completed, the modified polyetheramine is obtained by vacuum distillation. After mixing 10 parts by weight of the prepolymer and 8 parts by weight of the modified polyetheramine and adjusting the pH to 8, in a nitrogen protection environment, the mixture is stirred and reacted at 80 °C for 4 h, and then reacted at 180 °C for 60 min. After the reaction is completed, it is cooled to 26 °C and then pulverized and sieved to obtain the composite clay stabilizer.

[0041] Comparative Example 1: A preparation method of an erosion-resistant composite clay stabilizer includes the following steps: The quaternary ammonium mixture prepared in Preparation Example 4 in Example 4 is replaced with the quaternary ammonium mixture prepared in Preparation Example 5, and other operations are the same as those in Example 4.

[0042] Comparative Example 2: A preparation method of an erosion-resistant composite clay stabilizer, comprising the following steps: Replace the quaternary ammonium mixture obtained in Preparation Example 4 in Example 4 with the quaternary ammonium mixture obtained in Preparation Example 6, and keep other operations the same as those in Example 4.

[0043] Comparative Example 3: A preparation method of an erosion-resistant composite clay stabilizer, comprising the following steps: Replace the o-diallylbisphenol in Example 4 with isoprene, and keep other operations the same as those in Example 4.

[0044] Comparative Example 4: A preparation method of an erosion-resistant composite clay stabilizer, comprising the following steps: Remove the modified silane in Example 4, and keep other operations the same as those in Example 4.

[0045] Comparative Example 5: A preparation method of an erosion-resistant composite clay stabilizer, comprising the following steps: Remove the glycidyl methacrylate in Example 4, and keep other operations the same as those in Example 4.

[0046] Comparative Example 6: A preparation method of an erosion-resistant composite clay stabilizer, comprising the following steps: Remove the sodium p-styrenesulfonate in Example 4, and keep other operations the same as those in Example 4.

[0047] Comparative Example 7: A preparation method of an erosion-resistant composite clay stabilizer, comprising the following steps: Replace the modified polyetheramine in Example 4 with polyetheramine D-230, and keep other operations the same as those in Example 4.

[0048] Comparative Example 8: A preparation method of an erosion-resistant composite clay stabilizer, comprising the following steps: Remove the quaternary ammonium mixture obtained in Preparation Example 4 in Example 4, and keep other operations the same as those in Example 4.

[0049] Performance test: Test Example 1: Swelling prevention rate detection: The clay stabilizers prepared in Examples 1 to 4, the composite clay stabilizers prepared in Comparative Examples 1 to 7, and the ammonium chloride clay stabilizer were added with water to prepare aqueous solutions of clay stabilizer samples with a mass concentration of 1% respectively. 0.5 g of bentonite was weighed and placed into 8 10-mL centrifuge tubes respectively. 10 mL of the above-mentioned aqueous solution of the composite clay stabilizer sample was added to each centrifuge tube. After shaking well, it was left to stand at room temperature for 2 h, then placed into a centrifuge and centrifuged at a rotational speed of 1500 r / min for 15 min to obtain the volume V1 of the expanded bentonite. 10 mL of water and kerosene were used to replace the aqueous solution of the composite clay stabilizer sample respectively to measure the swelling volumes V2 and V0 of the bentonite in water and kerosene. The above test results are shown in Table 1, and the calculation formula is as follows:

[0050] In the formula: η—anti-swelling rate, %; V0—swelling volume of bentonite in kerosene, mL; V1—swelling volume of bentonite in the aqueous solution of the clay stabilizer sample, mL; V2—swelling volume of bentonite in water, mL; Detection of water washing resistance: Pour out the supernatant in the centrifuge tube after centrifugation, add deionized water to 10 mL, stir well, leave to stand at room temperature for 2 h, then place into a centrifuge and centrifuge at a rotational speed of 1500 r / min for 15 min. Repeat the above steps 4 times, and finally read out the final volume V3 of the expanded bentonite. The above test results are shown in Table 1. The calculation formula is as follows:

[0051] In the formula: N—water resistance of the composite clay stabilizer, %; V1—swelling volume of bentonite in the aqueous solution of the clay stabilizer sample, mL; V3—swelling volume of bentonite after water washing, mL.

[0052]

[0053] It can be seen from the data in Table 1 that the composite clay stabilizer provided by the present invention has good anti-swelling effect and erosion resistance in a room temperature environment. The reduction of the anti-swelling effect and erosion resistance in Comparative Examples 1 to 3 and Comparative Example 7 may be due to the reduction of hydrophobic groups such as benzene rings and long-chain alkanes, making it difficult to form a dense hydrophobic protective layer, resulting in the reduction of its erosion resistance; the reduction of the anti-swelling effect and erosion resistance in Comparative Example 4 may be due to the lack of sulfonic acid groups, unable to form "positive-negative charge synergy" with quaternary ammonium groups; the reduction of the anti-swelling effect and erosion resistance in Comparative Example 8 may be due to the lack of quaternary ammonium groups, relying only on the Si-O-Si covalent bond formed by siloxane and the surface hydroxyl groups of clay, making it difficult to achieve good erosion resistance effect.

[0054] Test Example 2: High-temperature resistance test: The clay stabilizers prepared in Examples 1 to 4, the composite clay stabilizers prepared in Comparative Examples 1 to 8, and ammonium chloride clay stabilizer were added with water to prepare aqueous solutions of clay stabilizer samples with a mass concentration of 1% respectively. 0.5 g of bentonite was weighed and placed into 8 10-mL centrifuge tubes respectively, and 10 mL of the above-mentioned aqueous solutions of composite clay stabilizer samples were added respectively. After shaking well, they were left standing at 200 °C for 12 h, then placed into a centrifuge and centrifuged at a rotational speed of 1500 r / min for 15 min to obtain the volume V1 of the expanded bentonite; 10 mL of water and kerosene were used to replace the aqueous solutions of composite clay stabilizer samples respectively to measure the swelling volumes V2 and V0 of bentonite in water and kerosene. The anti-swelling rate was calculated through the following calculation formula, and the results are shown in Table 2:

[0055] In the formula: η—anti-swelling rate, %; V0—swelling volume of bentonite in kerosene, mL; V1—swelling volume of bentonite in the aqueous solution of clay stabilizer sample, mL; V2—swelling volume of bentonite in water, mL;

[0056] It can be seen from the test results in Table 2 that the composite clay stabilizers prepared in Examples 1 to 4 of the present invention have good high-temperature resistance. The reason for the decrease in high-temperature resistance of Comparative Example 1 and Comparative Example 3 may be that the lack of benzene rings cannot provide a rigid skeleton, affecting its thermal stability and resulting in a decrease in its high-temperature resistance; the decrease in high-temperature resistance of Comparative Example 4 may be due to the inability to form a stable Si-O-Si cross-linked network after removing the siloxane structure, leading to a decrease in its thermal stability; the decrease in high-temperature resistance of Comparative Example 5 may be due to the lack of epoxy alkyl groups, and the prepolymer cannot form a cross-linked structure with the modified polyetheramine, unable to slow down its thermal decomposition, resulting in a decrease in the high-temperature resistance of the composite clay stabilizer.

[0057] The above-mentioned embodiments have described the technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A preparation method of an erosion-resistant composite clay stabilizer, characterized in that, The preparation method comprises the following steps: Diallylbisphenol A, (3-mercaptopropyl)trimethoxysilane and azobisisobutyronitrile react to obtain a modified silane. The modified silane, quaternary ammonium mixture, acrylamide, glycidyl methacrylate, sodium p-styrenesulfonate and ammonium persulfate react to obtain a prepolymer. Phenol, tetradecylamine, polyetheramine and aqueous formaldehyde solution react to obtain a modified polyetheramine. The prepolymer and the modified polyetheramine react to prepare a composite clay stabilizer.

2. The preparation method of a composite clay stabilizer resistant to erosion according to claim 1, characterized in that, The preparation method of the quaternary ammonium mixture comprises the following steps: Pentaerythritol allyl ether, o-dichlorobenzyl and potassium carbonate react to obtain an intermediate product. The intermediate product and long-chain alkylamine react to prepare the quaternary ammonium mixture.

3. The preparation method of a composite clay stabilizer resistant to erosion according to claim 2, characterized in that, The weight ratio of pentaerythritol allyl ether, o-dichlorobenzyl and potassium carbonate is 8-12:41-44:43-46.

4. The preparation method of a composite clay stabilizer resistant to erosion according to claim 2, wherein, The long-chain alkylamine is N,N-dimethylhexadecylamine.

5. The preparation method of a composite clay stabilizer resistant to erosion according to claim 1, characterized in that, The weight ratio of diallylbisphenol A and (3-mercaptopropyl)trimethoxysilane is 10-12:11-12.

6. The preparation method of a composite clay stabilizer resistant to erosion according to claim 1, characterized in that, The weight ratio of the modified silane, quaternary ammonium mixture, acrylamide, glycidyl methacrylate and sodium p-styrenesulfonate is 6.9-7.2:17-20:0.9-1.1:1.9-2.1:3.3-3.

5.

7. The preparation method of a composite clay stabilizer resistant to erosion according to claim 1, characterized in that, The polyetheramine is polyetheramine D-230.

8. The preparation method of a composite clay stabilizer resistant to erosion according to claim 1, characterized in that, The mass fraction of formaldehyde in the aqueous formaldehyde solution is 40%.

9. The preparation method of a composite clay stabilizer resistant to erosion according to claim 1, characterized in that, The weight ratio of phenol, tetradecylamine, polyetheramine and aqueous formaldehyde solution is 20-25:50-55:90-100:56-61.

10. A composite clay stabilizer resistant to erosion, characterized in that, It is prepared by the preparation method of a scouring-resistant composite clay stabilizer according to any one of claims 1-9.

Images