Gel breaker for shale oil and preparation process of gel breaker

Abstract

The invention relates to the technical field of petrochemical engineering, and discloses a gel breaker for shale oil and a preparation process thereof, cellulose reacts with bis [4-(2-formylchlorobenzamide) phenoxy] dimethylsilane and the like, cellulose gel is crosslinked by organic silicon, then ammonium persulfate is adsorbed and coated, and freeze drying is performed to obtain the gel breaker for shale oil. The microcapsule sustained-release gel breaker takes the cellulose aerogel as a capsule wall and the ammonium persulfate as a capsule core. According to the invention, siloxane and a benzene ring structure are introduced into a cellulose matrix, so that the thermal decomposition temperature and the water contact angle of cellulose gel are increased, the cellulose gel has good water resistance and high temperature resistance, and the microcapsule gel breaker can be prevented from being quickly dissolved and releasing ammonium persulfate when meeting water; the effect of slowly releasing the ammonium persulfate gel breaker is achieved, and meanwhile, the high temperature resistance can meet the requirement that the microcapsule gel breaker is applied to a high-temperature fracturing fluid system.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical engineering, and specifically relates to a breaker for shale oil and a preparation process thereof. Background Art

[0002] Fracturing technology is one of the effective ways to increase the production of shale oil. The common fracturing fluid for shale oil is guar gum gel fracturing fluid. In the actual oil reservoir exploitation process, a breaker such as ammonium persulfate needs to be added to the gel fracturing fluid to degrade the gel structure of the fracturing fluid, reduce the viscosity of the fracturing fluid, thereby enhancing fluidity, promoting the backflow operation of the fracturing fluid after the fracturing operation, and reducing the damage to the reservoir. When the dosage of ammonium persulfate breaker is too small, the breaking effect is not good in a short time, while when the dosage is too large, the gel of the fracturing fluid will break quickly and the viscosity will drop rapidly, resulting in poor sand-carrying capacity of the fracturing fluid.

[0003] Coating ammonium persulfate with a capsule wall to make a microcapsule-type sustained-release breaker can effectively solve the above problems. Common capsule wall materials include paraffin, vinyl copolymer, aerogel, etc., and the capsule wall materials are required to have good water isolation, heat resistance, and sustained-release properties. Chinese Patent CN112852401B discloses a highly suspended and dispersed capsule breaker and a preparation method thereof, using thiophene or aniline as the shell film material and an organic bentonite suspending agent. The prepared persulfate capsule breaker has good suspended dispersibility, but the capsule breaker of this patent does not improve the properties such as waterproofing, water isolation, and heat resistance, nor does it improve the sustained-release breaking performance of the breaker. Summary of the Invention

[0004] The present invention solves the problems that the existing microcapsule breakers have poor waterproofing, water isolation, heat resistance and other properties, and poor breaking performance.

[0005] Technical Solution: A preparation process of a breaker for shale oil, comprising: S1: Add cellulose to an aqueous sodium hydroxide solution, heat and stir, then filter, wash with deionized water, and dry; then add the cellulose to N,N-dimethylacetamide, stir, and add pyridine, bis[4-(2-formylchlorobenzamide)phenoxy]dimethylsilane, and 1,4-dioxane cosolvent in a nitrogen atmosphere, and control the mass ratio of cellulose, pyridine, and bis[4-(2-formylchlorobenzamide)phenoxy]dimethylsilane to be 100:(150 - 350):(230 - 520); stir and react, then filter, wash successively with deionized water, ethanol, and dichloromethane, and dry to obtain an organosilicon crosslinked cellulose gel.

[0006] S2: Add the organosilicon crosslinked cellulose gel to an ammonium persulfate aqueous solution with a mass concentration of (100 - 400) g / L, stir, then freeze the solution with liquid nitrogen, and then freeze-dry in a freeze dryer, wash with water and dry to obtain a breaker for shale oil.

[0007] Among them, the mass fraction of the sodium hydroxide aqueous solution in S1 is 20 - 40%.

[0008] Among them, the temperature during heating and stirring in S1 is 30 - 40°C, and the time is 1 - 2 h; the temperature during stirring reaction is 15 - 30°C, and the time is 3 - 6 h.

[0009] Among them, the volume ratio of N,N - dimethylacetamide to 1,4 - dioxane in S1 is 100:(30 - 50).

[0010] Among them, the ratio of the ammonium persulfate aqueous solution to the organosilicon cross - linked cellulose gel in S2 is 1 L:(3 - 10) g.

[0011] Among them, the temperature during stirring in S2 is 15 - 40°C, and the time is 12 - 18 h; the temperature for freeze - drying is - 50°C to - 60°C, and the time is 48 - 72 h.

[0012] Among them, the preparation process of bis[4 - (2 - formylchlorobenzamide)phenoxy]dimethylsilane is as follows: (1) Add bis(4 - aminophenoxy)dimethylsilane and phthalic anhydride to N,N - dimethylacetamide, stir and react at 15 - 30°C for 12 - 18 h, add deionized water for dilution, extract with dichloromethane, distill the organic phase under reduced pressure, wash with acetone, dry, add the product to thionyl chloride, and control the molar ratio of bis(4 - aminophenoxy)dimethylsilane, phthalic anhydride, and thionyl chloride to be 1:(2 - 2.2):(12 - 16); carry out condensation reflux reaction at 65 - 75°C for 4 - 6 h, distill under reduced pressure, and dry to obtain bis[4 - (2 - formylchlorobenzamide)phenoxy]dimethylsilane. The reaction formula is: .

[0013] The beneficial technical effects of the present invention: The present invention uses the acyl chloride group of bis[4 - (2 - formylchlorobenzamide)phenoxy]dimethylsilane to react with cellulose to generate a cellulose cross - linked gel, then adsorbs and coats ammonium persulfate, and finally freeze - dries to obtain a micro - capsule sustained - release breaker with a cellulose aerogel as the capsule wall and ammonium persulfate as the capsule core.

[0014] The bis[4-(2-chloroformylbenzamide)phenoxy]dimethylsilane of the present invention contains heat-resistant and hydrophobic siloxane and polyphenyl ring structures. After esterification and cross-linking reaction with cellulose, the siloxane and benzene ring structures are introduced into the cellulose matrix, which significantly improves the thermal decomposition temperature and water contact angle of the cellulose gel, has good water-proof and high temperature resistance, can avoid the microcapsule breaker from rapidly dissolving and releasing ammonium persulfate when it encounters water, and is conducive to achieving the effect of slowly releasing the ammonium persulfate breaker. At the same time, the high temperature resistance can meet the application of the microcapsule breaker in the high temperature fracturing fluid system.

[0015] The present invention adds a degelling agent to the water-based gel fracturing fluid. After a long period of shearing, the fracturing fluid still maintains a relatively high viscosity and has a good slow-release degelling effect, which is beneficial for overcoming the problem that after the gel fracturing fluid is degelled, the viscosity drops rapidly, resulting in poor sand carrying capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the infrared spectrum of bis[4-(2-chloroformylbenzamide)phenoxy]dimethylsilane.

[0017] Figure 2 This is the infrared spectrum of silicone cross-linked cellulose gel. DETAILED DESCRIPTION

[0018] The embodiments described below are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The following cellulose, with an effective substance content of 99%, was purchased from Jinan Hongyu Chemical Co., Ltd. Hydroxypropyl guar gum, with an effective substance content of 99%, was purchased from Shandong Guangpu Biotechnology Co., Ltd. Drainage aid model LX-2009 was purchased from Shaanxi Lanxin Chemical Co., Ltd. Organic boron crosslinking agent model DB-2000 was purchased from Shaanxi Lanxin Chemical Co., Ltd.

[0020] Example 1 (1) Add 30 mmol of bis(4-aminophenoxy)dimethylsilane and 60 mmol of phthalic anhydride to 80 mL of N,N-dimethylacetamide, stir and react at 30°C for 12 h, add 200 mL of deionized water to dilute, extract with dichloromethane, distill the organic phase under reduced pressure, wash with acetone, and dry. Add the product to 360 mmol of thionyl chloride, condense and reflux at 75°C for 5 h, distill under reduced pressure, and dry to obtain bis[4-(2-chloroformylbenzamide)phenoxy]dimethylsilane. Figure 1 In the infrared spectrum, 2930 cm -1is the Si-CH of bis[4-(2-formylchlorobenzamide)phenoxy]dimethylsilane 3 is the stretching vibration peak of the methyl C-H in 3 , 1050 cm -1 is the characteristic peak of Si-O-Si. 1789 cm -1 is the absorption peak of the C=O of the acyl chloride group, 1685 cm -1 is the absorption peak of the C=O of the amide bond.

[0021] (2) Add 2 g of cellulose to 120 mL of an aqueous sodium hydroxide solution with a mass fraction of 40%, heat to 30 °C, stir for 2 h, filter, wash with deionized water, and dry; then add the cellulose to 60 mL of N,N-dimethylacetamide, stir, and add 4.2 g of pyridine, 6.5 g of bis[4-(2-formylchlorobenzamide)phenoxy]dimethylsilane, and 25 mL of 1,4-dioxane cosolvent in a nitrogen atmosphere, stir and react at 15 °C for 6 h, filter, wash successively with deionized water, ethanol, and dichloromethane, and dry to obtain an organosilicon crosslinked cellulose gel. Figure 2 In 1633 cm -1 is the absorption peak of the C=O of the ester group, and at the same time, the absorption peak of the C=O of the acyl chloride group at 1789 cm -1 almost disappears, indicating that the hydroxyl group of cellulose and the acyl chloride group of bis[4-(2-formylchlorobenzamide)phenoxy]dimethylsilane undergo an esterification reaction to form an ester group. 2924 cm -1 is the Si-CH of 3 is the stretching vibration peak of the methyl C-H in 3 , 1041 cm -1 is the characteristic peak of Si-O-Si, 1698 cm -1 is the absorption peak of the C=O of the amide bond, indicating that bis[4-(2-formylchlorobenzamide)phenoxy]dimethylsilane has been grafted onto the cellulose matrix.

[0022] (3) Add 0.3 g of the organosilicon crosslinked cellulose gel to 100 mL of an aqueous ammonium persulfate solution with a mass concentration of 100 g / L, stir at 25 °C for 12 h, freeze the solution in liquid nitrogen, and then freeze-dry at -50 °C for 72 h in a freeze dryer, wash with water and dry to obtain a breaker for shale oil.

[0023] Example 2 (1) 30 mmol of bis(4-aminophenoxy)dimethylsilane and 66 mmol of phthalic anhydride were added to 100 mL of N,N-dimethylacetamide, and the mixture was stirred at 25 °C for 18 h. Then, 200 mL of deionized water was added for dilution, and the mixture was extracted with dichloromethane. The organic phase was distilled under reduced pressure, washed with acetone, and dried. The product was added to 480 mmol of thionyl chloride, and the mixture was refluxed with condensation at 65 °C for 6 h. After distillation under reduced pressure and drying, bis[4-(2-formylchlorobenzamide)phenoxy]dimethylsilane was obtained.

[0024] (2) 2 g of cellulose was added to 150 mL of an aqueous sodium hydroxide solution with a mass fraction of 30%, and the mixture was heated to 30 °C and stirred for 2 h. After filtration, it was washed with deionized water and dried. Then, the cellulose was added to 60 mL of N,N-dimethylacetamide. After stirring, 7 g of pyridine, 10.4 g of bis[4-(2-formylchlorobenzamide)phenoxy]dimethylsilane (prepared in Example 1), and 30 mL of 1,4-dioxane co-solvent were added under a nitrogen atmosphere. The mixture was stirred at 20 °C for 6 h, filtered, and washed successively with deionized water, ethanol, and dichloromethane, and then dried to obtain an organosilicon crosslinked cellulose gel.

[0025] (3) 0.5 g of the organosilicon crosslinked cellulose gel was added to 100 mL of an aqueous ammonium persulfate solution with a mass concentration of 200 g / L, and the mixture was stirred at 40 °C for 12 h. The solution was frozen with liquid nitrogen, and then freeze-dried at -60 °C for 48 h in a freeze dryer. After washing with water and drying, a breaker for shale oil was obtained.

[0026] Example 3 (1) 30 mmol of bis(4-aminophenoxy)dimethylsilane and 66 mmol of phthalic anhydride were added to 100 mL of N,N-dimethylacetamide, and the mixture was stirred at 15 °C for 18 h. Then, 200 mL of deionized water was added for dilution, and the mixture was extracted with dichloromethane. The organic phase was distilled under reduced pressure, washed with acetone, and dried. The product was added to 420 mmol of thionyl chloride, and the mixture was refluxed with condensation at 75 °C for 4 h. After distillation under reduced pressure and drying, bis[4-(2-formylchlorobenzamide)phenoxy]dimethylsilane was obtained.

[0027] (2) 2 g of cellulose was added to 12 mL of an aqueous sodium hydroxide solution with a mass fraction of 30%, and the mixture was heated to 30 °C and stirred for 2 h. After filtration, it was washed with deionized water and dried. Then, the cellulose was added to 60 mL of N,N-dimethylacetamide. After stirring, 3 g of pyridine, 4.6 g of bis[4-(2-formylchlorobenzamide)phenoxy]dimethylsilane, and 18 mL of 1,4-dioxane co-solvent were added under a nitrogen atmosphere. The mixture was stirred at 20 °C for 4 h, filtered, and washed successively with deionized water, ethanol, and dichloromethane, and then dried to obtain an organosilicon crosslinked cellulose gel.

[0028] (3) Add 0.75 g of organosilicon cross-linked cellulose gel to 100 mL of ammonium persulfate aqueous solution with a mass concentration of 300 g / L, stir at 15 °C for 18 h, freeze the solution with liquid nitrogen, then freeze-dry at -50 °C for 72 h in a freeze dryer, wash with water and dry to obtain a breaker for shale oil.

[0029] Example 4 (1) Add 2 g of cellulose to 150 mL of sodium hydroxide aqueous solution with a mass fraction of 20%, heat to 40 °C, stir for 1 h, filter, wash with deionized water, and dry; then add the cellulose to 60 mL of N,N-dimethylacetamide, stir and add 5.6 g of pyridine, 8.6 g of bis[4-(2-formylchlorobenzamide)phenoxy]dimethylsilane, and 30 mL of 1,4-dioxane co-solvent in a nitrogen atmosphere, stir and react at 30 °C for 4 h, filter, wash successively with deionized water, ethanol, and dichloromethane, and dry to obtain organosilicon cross-linked cellulose gel.

[0030] (2) Add 1 g of organosilicon cross-linked cellulose gel to 100 mL of ammonium persulfate aqueous solution with a mass concentration of 400 g / L, stir at 30 °C for 18 h, freeze the solution with liquid nitrogen, then freeze-dry at -50 °C for 72 h in a freeze dryer, wash with water and dry to obtain a breaker for shale oil.

[0031] Comparative Example 1 (2) Add 2 g of cellulose to 120 mL of sodium hydroxide aqueous solution with a mass fraction of 40%, heat to 30 °C, stir for 2 h, filter, wash with deionized water, and dry; then add the cellulose to 60 mL of N,N-dimethylacetamide, stir and add 4.2 g of pyridine, 6.5 g of adipoyl chloride, and 25 mL of 1,4-dioxane co-solvent in a nitrogen atmosphere, stir and react at 15 °C for 6 h, filter, wash successively with deionized water, ethanol, and dichloromethane, and dry to obtain cross-linked cellulose gel.

[0032] (3) Add 0.3 g of cross-linked cellulose gel to 100 mL of ammonium persulfate aqueous solution with a mass concentration of 100 g / L, stir at 25 °C for 12 h, freeze the solution with liquid nitrogen, then freeze-dry at -50 °C for 72 h in a freeze dryer, wash with water and dry to obtain a breaker for shale oil.

[0033] Comparative Example 2 (1) 30 mmol of 4,4-diaminodiphenyl ether and 60 mmol of phthalic anhydride were added to 80 mL of N,N-dimethylacetamide, and the mixture was stirred at 30 °C for 12 h. Then, 200 mL of deionized water was added for dilution, and the mixture was extracted with dichloromethane. The organic phase was distilled under reduced pressure, washed with acetone, and dried. The product was added to 360 mmol of thionyl chloride, and the mixture was refluxed with condensation at 75 °C for 5 h. After distillation under reduced pressure and drying, 4,4-bis(2-formylchlorobenzamide)diphenyl ether was obtained. The structural formula is .

[0034] (2) 2 g of cellulose was added to 120 mL of an aqueous sodium hydroxide solution with a mass fraction of 40%, and the mixture was heated to 30 °C and stirred for 2 h. After filtration, it was washed with deionized water and dried. Then, the cellulose was added to 60 mL of N,N-dimethylacetamide. After stirring, 4.2 g of pyridine, 6.5 g of 4,4-bis(2-formylchlorobenzamide)diphenyl ether, and 25 mL of 1,4-dioxane co-solvent were added under a nitrogen atmosphere. The mixture was stirred at 15 °C for 6 h, filtered, and washed successively with deionized water, ethanol, and dichloromethane, and then dried to obtain crosslinked cellulose gel.

[0035] (3) 0.3 g of crosslinked cellulose gel was added to 100 mL of an aqueous ammonium persulfate solution with a mass concentration of 100 g / L, and the mixture was stirred at 25 °C for 12 h. The solution was frozen with liquid nitrogen, and then freeze-dried at -50 °C for 72 h in a freeze dryer. After washing with water and drying, a gel breaker for shale oil was obtained.

[0036] Comparative Example 3 (1) 30 mmol of 1,3-bis(3-carboxypropyl)tetramethyldisiloxane was added to 360 mmol of thionyl chloride, and the mixture was refluxed with condensation at 75 °C for 5 h. After distillation under reduced pressure and drying, 1,3-bis(3-acylchloropropyl)tetramethyldisiloxane was obtained. The structural formula is .

[0037] (2) 2 g of cellulose was added to 120 mL of an aqueous sodium hydroxide solution with a mass fraction of 40%, and the mixture was heated to 30 °C and stirred for 2 h. After filtration, it was washed with deionized water and dried. Then, the cellulose was added to 60 mL of N,N-dimethylacetamide. After stirring, 4.2 g of pyridine, 6.5 g of 1,3-bis(3-acylchloropropyl)tetramethyldisiloxane, and 25 mL of 1,4-dioxane co-solvent were added under a nitrogen atmosphere. The mixture was stirred at 15 °C for 6 h, filtered, and washed successively with deionized water, ethanol, and dichloromethane, and then dried to obtain crosslinked cellulose gel.

[0038] (3) Add 0.3 g of cross-linked cellulose gel to 100 mL of an aqueous solution of ammonium persulfate with a mass concentration of 100 g / L, stir at 25 °C for 12 h, freeze the solution with liquid nitrogen, and then freeze-dry it in a freeze dryer at -50 °C for 72 h. Wash with water and then dry to obtain a shale oil breaker.

[0039] Thermogravimetric analysis of cellulose gel was performed using a thermogravimetric analyzer, with nitrogen atmosphere as the test atmosphere, a heating rate of 10°C / min, and a temperature range of 25-700°C.

[0040] The water contact angle of cellulose gel was measured using a contact angle meter. Deionized water was added to the gel surface through a syringe, and the water contact angles at 5 different positions were tested and the average value was taken.

[0041] Table 1 Cellulose gel performance test Temperature at 5% mass loss (°C) Water contact angle (°) Example 1 258.7 98.6 Example 2 269.1 113.5 Example 3 254.0 92.3 Example 4 263.8 107.9 Comparative Example 1 236.4 76.7 Comparative Example 2 251.3 84.6 Comparative Example 3 244.9 87.2 After testing, the silicone cross-linked cellulose gel of Examples 1-4 has higher thermal decomposition temperature and water contact angle, and has better high temperature resistance and hydrophobic water-isolating properties. This is mainly because bis[4-(2-chloroformylbenzamide)phenoxy]dimethylsilane contains heat-resistant, hydrophobic siloxane and multi-benzene ring structure. After esterification and cross-linking reaction with cellulose, the siloxane and benzene ring structure are introduced into the cellulose matrix, which significantly improves the thermal decomposition temperature and water contact angle of the cellulose gel, and can meet the requirements of the microcapsule breaker for water resistance, water isolation, high temperature resistance and other properties, which is conducive to achieving the effect of slowly releasing the ammonium persulfate breaker.

[0042] The adipoyl chloride of Comparative Example 1 does not contain heat-resistant and hydrophobic siloxane and benzene ring structures. After the esterification and cross-linking reaction with cellulose, the obtained cellulose gel has low thermal decomposition temperature and water contact angle, and poor high temperature resistance and hydrophobic water barrier properties. The 4,4-bis(2-formylchlorobenzamide)diphenyl ether of Comparative Example 2 does not contain heat-resistant and hydrophobic siloxane structures, and the 1.3-bis(3-acylchloridepropyl)tetramethyldisiloxane of Comparative Example 3 does not contain heat-resistant and hydrophobic polyphenyl ring structures. The thermal decomposition temperatures and water contact angles of the two are low, and the high temperature resistance and hydrophobic water barrier properties are poor.

[0043] To 100 mL of deionized water, 0.6 g of hydroxypropyl guar gum, 0.2 g of drainage aid, 0.13 g of organic boron cross-linking agent, and 0.06 g of shale oil breaker were added and stirred for 2 minutes to prepare a simulated water-based frozen fracturing fluid.

[0044] The simulated water-based gel fracturing fluid was heated at 90°C for 170 seconds. -1 The viscosity was measured at shearing times of 3 min and 120 min, and the viscosity retention rate was calculated.

[0045] Table 2 Gel breaking performance test

[0046] After testing, compared with Comparative Examples 1-3, the gel fracturing fluid of Examples 1-4 can reach a viscosity retention rate of 38.30-45.67% after shearing for 120 min, and has a good slow-release gel-breaking effect.

[0047] Add 0.6 g of hydroxypropyl guar gum, 0.2 g of a flowback aid, 0.13 g of an organic boron crosslinking agent, and 0.06-0.12 g of a gel breaker for shale oil (prepared in Example 3) to 100 mL of deionized water, and stir for 2 min to prepare a simulated water-based gel fracturing fluid.

[0048] Keep the simulated water-based gel fracturing fluid at 90 °C and shear at a rate of 170 s -1 Measure the viscosity at 3 min and 120 min of shearing time, and calculate the viscosity retention rate.

[0049] Table 3 Gel-breaking performance test at different dosages of the gel breaker for shale oil Dosage of breaker (g) Viscosity at 3 min of shearing time (mPa·s) Viscosity at 120 min of shearing time (mPa·s) Viscosity retention rate (%) 0.06 387.8 177.1 45.67 0.08 388.1 186.4 48.03 0.1 389.7 197.5 50.68 0.12 389.3 199.8 51.32 0.14 389.0 201.9 51.90 After testing, when the dosage of the gel breaker for shale oil is 0.06-0.14 g, the viscosity retention rate reaches 45.67-51.90% after shearing for 120 min, effectively achieving a slow-release gel-breaking effect.

[0050] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A process for preparing a shale oil breaker, characterized in that: The preparation process comprises: S1: Add cellulose to a sodium hydroxide aqueous solution, heat and stir, filter, wash with deionized water, and dry; then add cellulose to N,N-dimethylacetamide, stir, add pyridine, bis[4-(2-chloroformylbenzamide)phenoxy]dimethylsilane, and 1,4-dioxane cosolvent in a nitrogen atmosphere, stir and react, filter, wash, and dry to obtain a silicone cross-linked cellulose gel; The mass ratio of cellulose, pyridine and bis[4-(2-chloroformylbenzamide)phenoxy]dimethylsilane in S1 is 100:(150-350):(230-520); The structural formula of the bis[4-(2-chloroformylbenzamide)phenoxy]dimethylsilane is: ; S2: adding organosilicon cross-linked cellulose gel to the ammonium persulfate aqueous solution, freezing the solution with liquid nitrogen after stirring, freeze-drying it in a freeze dryer, washing it with water and drying it to obtain a shale oil breaker; The ratio of the ammonium persulfate aqueous solution to the organosilicon cross-linked cellulose gel in S2 is 1L: (3-10)g; the mass concentration of the ammonium persulfate aqueous solution is (100-400)g / L.

2. The preparation process of the shale oil breaker according to claim 1, characterized in that: The mass fraction of the sodium hydroxide aqueous solution in S1 is 20-40%.

3. The preparation process of the shale oil breaker according to claim 1, characterized in that: The temperature during heating and stirring in S1 is 30-40°C for 1-2 hours; the temperature during stirring reaction is 15-30°C for 3-6 hours.

4. The preparation process of the shale oil breaker according to claim 1, characterized in that: The volume ratio of N,N-dimethylacetamide to 1,4-dioxane in S1 is 100:(30-50).

5. The preparation process of the shale oil breaker according to claim 1, characterized in that: The stirring temperature in S2 is 15-40°C for 12-18 hours; the freeze-drying temperature is -50°C to -60°C for 48-72 hours.

6. The preparation process of the shale oil breaker according to claim 1, characterized in that: The preparation process of the bis[4-(2-chloroformylbenzamide)phenoxy]dimethylsilane is as follows: bis(4-aminophenoxy)dimethylsilane and phthalic anhydride are added to N,N-dimethylacetamide, stirred for reaction at 15-30° C. for 12-18 hours, added with deionized water for dilution, extracted with dichloromethane, distilled the organic phase under reduced pressure, washed, and dried, the product was added to thionyl chloride, condensed and refluxed for reaction at 65-75° C. for 4-6 hours, distilled under reduced pressure, and dried to obtain bis[4-(2-chloroformylbenzamide)phenoxy]dimethylsilane.

7. The preparation process of the shale oil breaker according to claim 6, characterized in that: The molar ratio of the bis(4-aminophenoxy)dimethylsilane, phthalic anhydride and thionyl chloride is 1:(2-2.2):(12-16).

8. A shale oil breaker obtained by the preparation process according to any one of claims 1 to 7.

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