High-salt-resistance microsphere gel modifying and flooding agent and preparation method thereof

Abstract

The invention relates to a high-salt-resistance microsphere gel modifying and flooding agent and a preparation method thereof, and relates to the technical field of petroleum additives. The modifying and flooding agent is composed of polymer microspheres, a surfactant and water, the polymer microspheres are based on an acrylamide copolymer, crown ether modified monomer copolymerization with a quaternary ammonium structure is introduced, a crown ether ring structure builds a stable three-dimensional water storage cavity, and meanwhile, a flexible ring chain is introduced into a polymer chain, so that the stratum shear stress is effectively buffered, the microsphere structure is prevented from being damaged, and the stability of the polymer microspheres is improved. And zwitter-ion pairs formed by quaternary ammonium cations and sulfonic acid anions of the comonomer AMPS not only significantly improve the hydrophilicity of the whole polymer network and enhance the water absorption capacity, but also effectively resist the damage of salt ions to a polymer chain hydration layer through the electrostatic shielding effect of the zwitter-ion pairs, and improve the water absorption capacity of the polymer. The sensitivity of the swelling behavior of the microspheres to the salt concentration is remarkably reduced, so that the microspheres can show stable swelling performance in a wide salinity range, and a guarantee is provided for prediction and control of profile control and flooding effects.

Description

Technical Field

[0001] This invention belongs to the field of petroleum additives technology, specifically relating to a high salt-resistant microsphere gel modulator and its preparation method. Background Technology

[0002] In oilfield development, modulated flow control (MFD) technology is one of the key means to enhance oil recovery. Its core function is to adjust the production profile and expand the swept volume by blocking high-permeability layers and driving residual crude oil in low-permeability layers. Microsphere gel MFD systems, as an advanced deep MFD technology, work by allowing microspheres to exhibit dynamic behavior of "migration-retention-expansion-re-migration" within formation pores, achieving step-by-step blocking and effectively overcoming the bottleneck of limited depth of action of traditional MFDs. Among them, polyacrylamide microspheres have become one of the most widely used MFD types due to their readily available raw materials, mature preparation processes, and good overall performance.

[0003] However, polyacrylamide microspheres still have significant technical shortcomings in practical applications, particularly regarding salt resistance and structural stability after swelling. The complex underground formation water environment and wide variation in salt concentration mean that salt ions significantly inhibit the water absorption and swelling capacity of microspheres by compressing the double electric layer of polymer chains and shielding hydrophilic groups. This strong salt sensitivity leads to significant differences in the moderating effect between different oilfields or different layers within the same oilfield, resulting in poor controllability. Furthermore, after swelling, the physical cross-linking points between the molecular chains of polyacrylamide microspheres are easily damaged by salt ions, causing structural softening, cracking, or deformation under high shear stress (such as formation flow), leading to decreased sealing performance. Fluctuations in salt concentration also cause repeated contraction and expansion of the microspheres, accelerating structural fatigue and shortening their effective duration.

[0004] To address these issues, existing technologies typically employ methods such as introducing hydrophobic monomers or increasing the amount of crosslinking agents. However, the former sacrifices the hydrophilicity and swelling capacity of the microspheres, while the latter may lead to excessive rigidity of the microspheres, affecting their transport performance in the formation. These improvements fail to fundamentally solve the problems of salt sensitivity and structural instability of polyacrylamide microspheres. Summary of the Invention

[0005] In order to solve the technical problems mentioned in the background art, the purpose of this invention is to provide a high salt-resistant microsphere gel modulator and its preparation method.

[0006] The objective of this invention can be achieved through the following technical solutions: A high salt-resistant microsphere gel modifier, used as a basic additive for oil well modifier treatment, is formulated from polymer microspheres, surfactants and water; The polymer microspheres were prepared by the following method: Step A1: Mix diaza-18-crown ether-6, allyl chloride and dimethylformamide, add anhydrous potassium carbonate and heat to 40-50℃ and reflux for 8-12 hours. After the reaction is completed, cool and filter. Inject the filtrate into n-hexane to precipitate and obtain the intermediate. Furthermore, the ratio of diaza-18-crown ether-6, allyl chloride, anhydrous potassium carbonate, and dimethylformamide is 10 mmol: 22-25 mmol: 2.8-3.3 g: 120-180 mL, with allyl chloride substituted with diaza-18-crown ether-6 and allyl groups grafted onto the crown ether ring.

[0007] Step A2: Mix the intermediate with acetonitrile-methanol, add iodomethane and pressurize with dry nitrogen to 6-8 bar, heat to 55-70℃ and reflux for 15-20 h. After the reaction is completed, release the pressure and remove the mixed solvent and excess iodomethane by rotary evaporation to obtain the modified monomer. Furthermore, the ratio of intermediate, iodomethane, and acetonitrile-methanol is 10 mmol: 35-42 mmol: 150-200 mL, and iodomethane quaternizes the intermediate molecule.

[0008] Step A3: Mix acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid, N-isopropylacrylamide and deionized water, add emulsifier-white oil pre-dispersion for shear emulsification, purge with nitrogen and add ammonium persulfate, heat to 60-70℃ and stir for 4.5-5.5 h. After the reaction is completed, demulsify with ethanol, centrifuge, wash and dry to obtain polymer microspheres; Furthermore, the ratio of acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid, N-isopropylacrylamide, ammonium persulfate, emulsifier, white oil, and deionized water is 50 mmol: 6-10 mmol: 15-22 mmol: 10-15 mmol: 0.4-0.5 g: 1.2-1.5 g: 40-50 mL: 180-210 mL. The modified monomer and other monomers are polymerized through emulsion polymerization to form polymer microspheres.

[0009] Preferably, the proportion of polymer microspheres is 0.42-0.55 wt%, which provides a stable displacement effect and is suitable for most existing oil wells.

[0010] Preferably, the surfactant is a nonionic formulation, accounting for 0.08-0.1 wt%, which has good salt resistance and stable permeation and displacement effect in high-salt wells.

[0011] A method for preparing a highly salt-resistant microsphere gel modulator is as follows: a surfactant is premixed with water, then polymer microspheres are added and stirred evenly, and the mixture is allowed to stand and gel to obtain the microsphere gel modulator.

[0012] The beneficial effects of this invention are: The high salt-resistant microsphere gel modulator developed in this invention successfully overcomes the inherent defects of traditional polyacrylamide microspheres in terms of salt resistance and structural stability through innovative molecular structure design. Its core advantage stems from the unique physicochemical properties of the modified polymer microspheres. These properties work synergistically to ensure the high efficiency and reliability of the modulator in complex oilfield environments.

[0013] From a molecular perspective, the crown ether ring structure formed after the polymerization of the modified monomers constructs a stable three-dimensional water-retaining cavity within the polymer network. The crown ether ring itself possesses good flexibility and mechanical strength, effectively buffering formation shear stress and preventing microsphere structural damage. Simultaneously, its ring structure exhibits a strong complexing ability for water molecules, forming an "in-situ reservoir" effect, maintaining the water-holding capacity of the microspheres even in the presence of salt ions. This is the structural basis for maintaining swelling stability. More importantly, the zwitterionic pair formed by the quaternary ammonium cation in the modified monomer and the sulfonic acid anion in the comonomer AMPS not only significantly enhances the hydrophilicity of the entire polymer network and strengthens its water absorption capacity, but also effectively resists the damage to the polymer chain hydration layer by salt ions through its electrostatic shielding effect, significantly reducing the sensitivity of microsphere swelling behavior to salt concentration. This synergistic protection of the zwitterionic pair and the crown ether ring water-retaining structure allows the microspheres to exhibit stable swelling performance over a wide salinity range, providing a guarantee for the prediction and control of the modulated displacement effect.

[0014] In terms of macroscopic performance, the aforementioned molecular properties translate into superior modulator-displacement behavior. The microspheres maintain good structural integrity after swelling, making them less prone to breakage or degradation during formation migration and retention, thus achieving durable and effective stepwise plugging. Indoor core displacement experiments confirm that this modulator-displacement agent can significantly improve oil recovery in high-salinity reservoirs. Furthermore, due to its low sensitivity to changes in formation water salinity, the same modulator-displacement agent formulation can be adapted to a wider range of oilfield geological conditions, reducing the need for frequent formulation adjustments due to differences in oilfield or stratigraphic position. This not only improves the success rate of modulator-displacement operations but also reduces extraction costs. In summary, this invention achieves a fundamental improvement in the salt resistance and structural stability of microsphere gel modulator-displacement agents, providing a more reliable technical solution for the efficient development of deep oilfield modulator-displacement, especially in high-salinity reservoirs. Detailed Implementation

[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0016] Example 1: Preparation of a highly salt-resistant microsphere gel modulator. The specific implementation process is as follows: (1) Preparation of polymer microspheres Step A1: Mix diaza-18-crown ether-6, allyl chloride, and dimethylformamide, add anhydrous potassium carbonate and mix again, heat to 40℃ and reflux for 12 h. The ratio of diaza-18-crown ether-6, allyl chloride, anhydrous potassium carbonate, and dimethylformamide is 10 mmol: 22 mmol: 2.8 g: 120 mL. After the reaction is complete, cool and filter to remove salts. Inject the filtrate into n-hexane to precipitate. Wash and dry the precipitate to obtain the intermediate.

[0017] Step A2: Acetonitrile and methanol are premixed at a volume ratio of 1:2 to prepare a mixed solvent of acetonitrile and methanol (hereinafter referred to as: acetonitrile-methanol). The intermediate and acetonitrile-methanol are stirred and mixed, iodomethane is added, and the mixture is pressurized to 6 bar with dry nitrogen. The mixture is heated to 55°C and refluxed for 20 h. The ratio of intermediate, iodomethane and acetonitrile-methanol is 10 mmol: 35 mmol: 150 mL. After the reaction is completed, the pressure is released and the mixed solvent and excess iodomethane are removed by rotary evaporation to obtain the modified monomer.

[0018] Step A3: Take acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), N-isopropylacrylamide and deionized water and stir to mix. Pre-stir and disperse the emulsifier (Span-80) and white oil (5#), then add them to the above mixture, and stir at 20000s. -1 High-speed shear emulsification was performed for 30 min, nitrogen protection was introduced, and ammonium persulfate was added. The mixture was heated to 60 °C and stirred for 5.5 h. The ratio of acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid, N-isopropylacrylamide, ammonium persulfate, emulsifier, white oil, and deionized water was 50 mmol: 9 mmol: 20 mmol: 15 mmol: 0.4 g: 1.2 g: 40 mL: 180 mL. After the reaction was completed, the emulsion was broken with ethanol, and the mixture was centrifuged, washed, and dried to obtain polymer microspheres.

[0019] (2) Preparation of the modulator According to the weight percentage, 0.08 wt% of surfactant (nonionic formulation, coconut oil fatty acid diethanolamide, industrial grade) is stirred and premixed with water, and then more than 0.42 wt% of the prepared polymer microspheres are added and stirred to form a uniform dispersion. After standing and gelling, the microsphere gel modifier is obtained.

[0020] Example 2: Preparation of a highly salt-resistant microsphere gel modulator. The specific implementation process is as follows: (1) Preparation of polymer microspheres Step A1: Mix diaza-18-crown ether-6, allyl chloride, and dimethylformamide, add anhydrous potassium carbonate and mix again, heat to 50℃ and reflux for 8 hours. The ratio of diaza-18-crown ether-6, allyl chloride, anhydrous potassium carbonate, and dimethylformamide is 10 mmol: 25 mmol: 3.3 g: 180 mL. After the reaction is complete, cool and filter to remove salts. Inject the filtrate into n-hexane to precipitate. Wash and dry the precipitate to obtain the intermediate.

[0021] Step A2: Acetonitrile and methanol are premixed at a volume ratio of 1:2 to prepare a mixed solvent of acetonitrile and methanol (hereinafter referred to as: acetonitrile-methanol). The intermediate and acetonitrile-methanol are stirred and mixed, iodomethane is added, and the mixture is pressurized to 8 bar with dry nitrogen. The mixture is heated to 70°C and refluxed for 15 h. The ratio of intermediate, iodomethane and acetonitrile-methanol is 10 mmol: 42 mmol: 200 mL. After the reaction is completed, the mixed solvent and excess iodomethane are removed by rotary evaporation to obtain the modified monomer.

[0022] Step A3: Take acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid, N-isopropylacrylamide and deionized water and stir to mix. Pre-stir and disperse the emulsifier (Span-80) and white oil (5#), then add them to the above mixture and stir at 20000s. -1 High-speed shear emulsification was performed for 30 min, followed by nitrogen protection and the addition of ammonium persulfate. The mixture was then heated to 70 °C and stirred for 4.5 h. The ratio of acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid, N-isopropylacrylamide, ammonium persulfate, emulsifier, white oil, and deionized water was 50 mmol: 6 mmol: 15 mmol: 15 mmol: 0.5 g: 1.5 g: 50 mL: 210 mL. After the reaction was completed, the emulsion was broken with ethanol, and the product was washed by centrifugation and dried to obtain polymer microspheres.

[0023] (2) Preparation of the modulator According to the weight percentage, 0.1 wt% of surfactant (nonionic formulation, coconut oil fatty acid diethanolamide, industrial grade) is stirred and premixed with water, and then more than 0.55 wt% of the prepared polymer microspheres are added and stirred to form a uniform dispersion. After standing and gelling, the microsphere gel modifier is obtained.

[0024] Example 3: Preparation of a highly salt-resistant microsphere gel modulator. The specific implementation process is as follows: (1) Preparation of polymer microspheres Step A1: Mix diaza-18-crown ether-6, allyl chloride, and dimethylformamide, add anhydrous potassium carbonate and mix again, heat to 45℃ and reflux for 10 h. The ratio of diaza-18-crown ether-6, allyl chloride, anhydrous potassium carbonate, and dimethylformamide is 10 mmol: 23 mmol: 3.1 g: 150 mL. After the reaction is complete, cool and filter to remove salts. Inject the filtrate into n-hexane to precipitate. Wash and dry the precipitate to obtain the intermediate.

[0025] Step A2: Acetonitrile and methanol are premixed at a volume ratio of 1:2 to prepare a mixed solvent of acetonitrile and methanol (hereinafter referred to as: acetonitrile-methanol). The intermediate and acetonitrile-methanol are stirred and mixed, iodomethane is added, and the mixture is pressurized to 7 bar with dry nitrogen. The mixture is heated to 60 °C and refluxed for 18 h. The ratio of intermediate, iodomethane and acetonitrile-methanol is 10 mmol: 40 mmol: 170 mL. After the reaction is completed, the mixed solvent and excess iodomethane are removed by rotary evaporation to obtain the modified monomer.

[0026] Step A3: Take acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid, N-isopropylacrylamide and deionized water and stir to mix. Pre-stir and disperse the emulsifier (Span-80) and white oil (5#), then add them to the above mixture and stir at 20000s. -1 High-speed shear emulsification was performed for 30 min, followed by nitrogen protection and the addition of ammonium persulfate. The mixture was then heated to 65°C and stirred for 5 h. The ratio of acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid, N-isopropylacrylamide, ammonium persulfate, emulsifier, white oil, and deionized water was 50 mmol: 10 mmol: 22 mmol: 10 mmol: 0.5 g: 1.4 g: 40 mL: 200 mL. After the reaction was completed, the emulsion was broken with ethanol, and the product was washed by centrifugation and dried to obtain polymer microspheres.

[0027] (2) Preparation of the modulator According to the weight percentage, 0.09 wt% of surfactant (nonionic formulation, coconut oil fatty acid diethanolamide, industrial grade) is stirred and premixed with water, and then more than 0.50 wt% of the prepared polymer microspheres are added and stirred to form a uniform dispersion. After standing and gelling, the microsphere gel modifier is obtained.

[0028] Example 4: Preparation of a highly salt-resistant microsphere gel modulator. The specific implementation process is as follows: (1) Preparation of polymer microspheres Step A1: Mix diaza-18-crown ether-6, allyl chloride, and dimethylformamide, add anhydrous potassium carbonate and mix again, heat to 50℃ and reflux for 11 h. The ratio of diaza-18-crown ether-6, allyl chloride, anhydrous potassium carbonate, and dimethylformamide is 10 mmol: 24 mmol: 3.0 g: 160 mL. After the reaction is complete, cool and filter to remove salts. Inject the filtrate into n-hexane to precipitate. Wash and dry the precipitate to obtain the intermediate.

[0029] Step A2: Acetonitrile and methanol are premixed at a volume ratio of 1:2 to prepare a mixed solvent of acetonitrile and methanol (hereinafter referred to as: acetonitrile-methanol). The intermediate and acetonitrile-methanol are stirred and mixed, iodomethane is added, and the mixture is pressurized to 6.5 bar with dry nitrogen. The mixture is heated to 60 °C and refluxed for 20 h. The ratio of intermediate, iodomethane and acetonitrile-methanol is 10 mmol: 38 mmol: 200 mL. After the reaction is completed, the pressure is released and the mixed solvent and excess iodomethane are removed by rotary evaporation to obtain the modified monomer.

[0030] Step A3: Take acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid, N-isopropylacrylamide and deionized water and stir to mix. Pre-stir and disperse the emulsifier (Span-80) and white oil (5#), then add them to the above mixture and stir at 20000s. -1 High-speed shear emulsification was performed for 30 min, followed by nitrogen protection and the addition of ammonium persulfate. The mixture was then heated to 65°C and stirred for 5.2 h. The ratio of acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid, N-isopropylacrylamide, ammonium persulfate, emulsifier, white oil, and deionized water was 50 mmol: 8 mmol: 18 mmol: 12 mmol: 0.4 g: 1.3 g: 50 mL: 200 mL. After the reaction was completed, the emulsion was broken with ethanol, and the product was washed by centrifugation and dried to obtain polymer microspheres.

[0031] (2) Preparation of the modulator According to the weight percentage, 0.1 wt% of surfactant (nonionic formulation, coconut oil fatty acid diethanolamide, industrial grade) is stirred and premixed with water, and then more than 0.52 wt% of the prepared polymer microspheres are added and stirred to form a uniform dispersion. After standing and gelling, the microsphere gel modifier is obtained.

[0032] Comparative Example 1: WQ800 type nanoscale polymer microspheres for driving were selected from a chemical company in Shangnan County, Shaanxi Province. They were diluted with deionized water to the same concentration as in Example 4, and surfactant was added.

[0033] Comparative Example 2, based on core-shell polymer microspheres of patent CN102504793B: styrene as a hydrophobic monomer, acrylamide as a hydrophilic monomer, divinylbenzene as a core-phase crosslinking agent, methylenebisacrylamide as a shell-phase crosslinking agent, and ammonium persulfate as an initiator, were prepared according to the method of Example 1 of the patent; a modulator was prepared according to the proportions of Example 4.

[0034] A mixture of calcium chloride, sodium chloride, and potassium chloride in a molar ratio of 2:1:1 was used as the salt. To verify the salt-resistance stability of the revelation agent, solutions with different mineralization were prepared using the above-mentioned mixed salt at 80℃. The expansion ratio of the polymer microspheres was measured. The revelation agent was injected twice into a 0.35 mm sieve tube at a constant flow rate of 1.0 mL / min, and the maximum pressure passing through the sieve tube was recorded as P1 and P2, respectively. The stability coefficient K = P2 / P1 was calculated. The specific test results are shown in Tables 1-3. Table 1 5×10 4 Salt-water displacement stability test results at mg / L mineralization

[0035] Table 2 15×10 4 Salt-water displacement stability test results at mg / L mineralization

[0036] Table 3 20×10 4 Salt-water displacement stability test results at mg / L mineralization

[0037] Based on the test results in Tables 1-3, it can be seen that the polymer microspheres in the displacement agent of the examples exhibit smaller expansion ratios under different salinity environments, demonstrating excellent salt resistance. Furthermore, during the two sieve tube injection processes, the stability coefficient is significantly higher than that of the comparative example, indicating that the microsphere structure is stable during the displacement process, which is beneficial for stepwise plugging and displacement.

[0038] Based on the above test results, a simulated displacement test was conducted using the prepared displacement modulator, with a mineralization of 10 × 10⁻⁶. 4 mg / L, specific tests include: Static plugging test: A sandbag test was used to inject the refluxing agent into the sand-filled pipe (permeability 2000mD), measure the pressure difference before and after plugging, and calculate the plugging rate; Dynamic plugging test: Using a core flow device (core length 10cm, diameter 2.5cm, permeability 1500mD), a modulator was injected under simulated formation conditions (80℃, 5MPa), and pressure changes and breakthrough pressure were measured. Oil displacement test: A core displacement test was conducted. After the core was saturated with crude oil, water was first injected to a water cut of 98%, and then 0.5 PV modifier was injected. Subsequent water flooding was carried out, and the increase in oil recovery was calculated.

[0039] The specific test results are shown in Table 4: Table 4 Results of Simulated Drive Test

[0040] Based on the test results in Table 4, it can be seen that the modulator in the example has a good modulator effect, achieving efficient plugging, increasing dynamic breakthrough pressure, and increasing recovery rate under simulated conditions.

[0041] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0042] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A highly salt-resistant microsphere gel modulator, composed of polymer microspheres, surfactants, and water, characterized in that, The polymer microspheres were prepared by the following method: Step A1: Mix diaza-18-crown ether-6, allyl chloride and dimethylformamide, add anhydrous potassium carbonate and reflux at 40-50℃ for 8-12 hours to prepare an intermediate; Step A2: Mix the intermediate with acetonitrile-methanol, add iodomethane and pressurize with dry nitrogen to 6-8 bar, heat to 55-70℃ and reflux for 15-20 h to prepare the modified monomer; Step A3: Mix acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid, N-isopropylacrylamide and deionized water, add emulsifier-white oil pre-dispersion for shear emulsification, purge with nitrogen and add ammonium persulfate, heat to 60-70℃ and stir for 4.5-5.5 h to prepare polymer microspheres.

2. The high salt-resistant microsphere gel modulator according to claim 1, characterized in that, The ratio of diaza-18-crown ether-6, allyl chloride, anhydrous potassium carbonate, and dimethylformamide is 10 mmol: 22-25 mmol: 2.8-3.3 g: 120-180 mL.

3. The high salt-resistant microsphere gel modulator according to claim 2, characterized in that, The ratio of intermediate, iodomethane, and acetonitrile-methanol is 10 mmol: 35-42 mmol: 150-200 mL.

4. The high salt-resistant microsphere gel modulator according to claim 3, characterized in that, The ratio of acrylamide, modified monomer, 2-acrylamido-2-methylpropanesulfonic acid, N-isopropylacrylamide, ammonium persulfate, emulsifier, white oil and deionized water is 50 mmol: 6-10 mmol: 15-22 mmol: 10-15 mmol: 0.4-0.5 g: 1.2-1.5 g: 40-50 mL: 180-210 mL.

5. The high salt-resistant microsphere gel modulator according to claim 4, characterized in that, The proportion of polymer microspheres is 0.42-0.55 wt%.

6. The high salt-resistant microsphere gel modulator according to claim 1, characterized in that, The surfactant is a nonionic formulation.

7. The high salt-resistant microsphere gel modulator according to claim 6, characterized in that, The surfactant content is 0.08-0.1 wt%.

8. A method for preparing a high salt-resistant microsphere gel modulator according to any one of claims 1-7, characterized in that, Specifically, the surfactant is premixed with water, then polymer microspheres are added and mixed evenly. After standing and gelling, the microsphere gel modulator is obtained.

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