A silicon-containing polymer crosslinking system for deep profile control and application thereof

Abstract

This invention discloses a silicon-containing polymer crosslinking system for deep profile control and its application. The preparation method of the silicon-containing polymer crosslinking system includes the following steps: S1, in an inert atmosphere, in the presence of initiator A and a co-solvent, nonionic monomer-1, anionic monomer-1, and silicon-containing monomer-1 are polymerized in water to obtain silicon-containing polymer-1; S2, in an inert atmosphere, in the presence of initiator B, nonionic monomer-2, anionic monomer-2, and silicon-containing monomer-2 are polymerized in an organic solvent to obtain silicon-containing polymer-2; S3, silicon-containing polymer-1 and silicon-containing polymer-2 are crosslinked in water to obtain the final product; silicon-containing monomer-1 is one or a mixture of two or more of silicon-containing monomer-1-A, silicon-containing monomer-1-B, and silicon-containing monomer-1-C. This invention forms a dynamic covalent crosslinking structure through siloxane bonds, the reaction process is reversible and mild, the system has better injectability, and can achieve deep profile control.

Description

Technical Field

[0001] This invention relates to a silicon-containing polymer crosslinking system for deep profile control and its application, belonging to the field of oilfield chemical technology. Background Technology

[0002] With the continuous development of the global economy and human society, the demand for oil in all sectors of production and daily life is increasing daily. Therefore, maximizing the production of existing oil fields is of paramount importance. It is estimated that primary and secondary oil recovery can only extract one-third of the formation crude oil, leaving a large amount of residual oil in the formation. Although tertiary oil recovery technologies such as chemical flooding can further improve the recovery rate of oil fields, due to the heterogeneity of the formation, once a water flow advantage channel is formed in the middle and late stages of oil field production, the water production of oil wells increases. This produced water will not only corrode production pipelines and occupy a large amount of construction space, but also lead to persistently high water cut in oil wells, significantly affecting oil production.

[0003] Subsurface crosslinked polymer systems, as important profile control agents, offer advantages such as controllable gelation time, high gel strength, and simple construction processes, leading to their widespread application in oilfields both domestically and internationally. These systems primarily consist of polymers and crosslinking agents, which react to form gel materials with a certain mechanical strength. The most commonly used polymers are acrylamide-based polymers, including partially hydrolyzed polyacrylamide and acrylamide / 2-acrylamido-2-methylpropanesulfonic acid copolymers. The most commonly used crosslinking agents are high-valent heavy metal salts, phenolic resin prepolymers, and polyethyleneimine. High-valent heavy metal ions crosslink through coordination with carboxyl groups on the polymer, but suffer from drawbacks such as rapid crosslinking speed and poor long-term gel stability. Phenolic resin prepolymers crosslink through reaction with amide groups on the polymer, but exhibit drawbacks such as high toxicity and self-crosslinking at high temperatures. Polyethyleneimine offers controllable crosslinking time and good long-term stability, but is characterized by large dosage requirements and high cost. In addition, the above-mentioned crosslinking system utilizes the coordination or covalent interaction between the polymer and the crosslinking agent to form a three-dimensional network structure between molecules. It can generally only be applied to profile control operations in near-wellbore areas and is difficult to maintain good gelling properties after being transported to deeper formations.

[0004] Dynamic covalent bonds are chemical bonds that can reversibly break, form, and recombine under certain external stimuli, possessing the characteristics of "reversibility" and "dynamic nature." Common dynamic covalent bonds include imine bonds, borate ester bonds, silicon-oxygen bonds, and acylhydrazone bonds. Using dynamic covalent bonds to construct three-dimensional network structures, when local over-crosslinking occurs, the crosslinked structures can spontaneously diffuse from high-concentration areas to low-concentration areas, eventually forming a homogeneous gel. When the overall crosslinking density is high, dynamic covalent bonds can form a new equilibrium with the dissociated structures, gradually improving the system's flow properties and making the crosslinking more gentle. Therefore, polymer crosslinking systems based on dynamic covalent bonds have better injection and flowability, overcoming the shortcomings of conventional profile control systems such as difficulty in controlling the crosslinking process and dehydration caused by over-crosslinking. Summary of the Invention

[0005] The purpose of this invention is to provide a polymer crosslinking system for deep profile control with a siloxane structure, which has excellent gelation properties, certain delayed crosslinking characteristics, and excellent temperature and salt resistance.

[0006] This invention involves copolymerizing nonionic monomers, anionic monomers, and silicon-containing monomers in an aqueous solution. By controlling the content and structure of the silicon-containing monomers, a polymer powder with high molecular weight and excellent water solubility is prepared. Furthermore, nonionic monomers, anionic monomers, and silicon-containing monomers are copolymerized in an organic solvent. By controlling the type and ratio of the organic solvent, a polymer solution with high silicon content and excellent water solubility is prepared. Based on this, a polymer crosslinking system is constructed using the condensation reaction between the silicon-containing units of the two polymers. Test results show that the polymer crosslinking system exhibits excellent gel-forming properties, certain delayed crosslinking characteristics, and excellent temperature and salt resistance.

[0007] Specifically, the preparation method of the polymer crosslinking system for deep profile control provided by the present invention includes the following steps:

[0008] S1. In an inert atmosphere, in the presence of initiator A and cosolvent, nonionic monomer-1, anionic monomer-1 and silicon-containing monomer-1 are polymerized in water to obtain silicon-containing polymer-1.

[0009] S2. In an inert atmosphere and in the presence of initiator B, nonionic monomer-2, anionic monomer-2 and silicon-containing monomer-2 are polymerized in an organic solvent to obtain silicon-containing polymer-2.

[0010] S3, the silicon-containing polymer-1 and the silicon-containing polymer-2 are cross-linked in water to obtain the product;

[0011] The silicon-containing monomer-1 is one or a mixture of two or more of silicon-containing monomer-1-A, silicon-containing monomer-1-B, and silicon-containing monomer-1-C.

[0012] The structural formula of the silicon-containing monomer-1-A is as follows:

[0013]

[0014] The structural formula of the silicon-containing monomer-1-B is as follows:

[0015]

[0016] The structural formula of the silicon-containing monomer-1-C is as follows:

[0017]

[0018] In the formula, m is 1 to 30, n is 1 to 6, and R1, R2, and R3 are alkyl chains with 1 to 4 carbon atoms;

[0019] Preferably, m is 8 to 30 and n is 1 to 4.

[0020] The silicon-containing monomer-2 is one or a mixture of two or more of the following: vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, methacryloyloxypropyltrimethoxysilane, acryloyloxypropyltrimethoxysilane, methacryloyloxypropyltriethoxysilane, and acryloyloxypropyltriethoxysilane.

[0021] In the above preparation method, the polymerization reaction conditions in step S1 are as follows:

[0022] The pH value is 6-11, preferably 6-9; the temperature is 0-20℃, preferably 0-10℃; and the time is 1-24h, preferably 1-12h.

[0023] In the above preparation method, in step S1, the mass ratio of the nonionic monomer-1 to the anionic monomer-1 is 1:0.01 to 1, preferably 1:0.05 to 0.8, and the mass ratio of the total mass of the nonionic monomer-1 and the anionic monomer-1 to the mass of the silicon-containing monomer-1 is 1:0.001 to 0.15, preferably 1:0.005 to 0.1.

[0024] The total mass ratio of the nonionic monomer-1, the anionic monomer-1, and the silicon-containing monomer-1 to the mass ratio of the water is 1:1 to 25, preferably 1:1.5 to 10.

[0025] The initiator A includes azo initiator-1, reducing initiators, and oxidizing initiators;

[0026] The total mass ratio of the nonionic monomer-1, the anionic monomer-1, the silicon-containing monomer-1, and the water to the mass ratio of the cosolvent, the azo initiator-1, the reducing initiator, and the oxidizing initiator is 1:0.001~0.1:0.00001~0.005:0.00001~0.002:0.00001~0.002, preferably 1:0.001~0.05:0.00006~0.002:0.00004~0.001:0.00004~0.001.

[0027] In the above preparation method, the azo initiator-1 is one or a mixture of two or more of azobisisobutylamidine hydrochloride, azobisisopropylimidazoline hydrochloride, and azobiscyanopentanoic acid;

[0028] The reducing initiator is one or a mixture of two or more of sodium sulfite, sodium bisulfite, sodium dithionite and sodium thiosulfate;

[0029] The oxidation initiator is one or a mixture of two or more of potassium persulfate, ammonium persulfate, sodium persulfate, and hydrogen peroxide.

[0030] In the above preparation method, in step S1, the nonionic monomer-1 is one or a mixture of two or more of acrylamide, methacrylamide, N-hydroxymethylacrylamide, N-ethylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, N-n-butylacrylamide, acrylmorpholine, vinylpyrrolidone and vinylcaprolactam;

[0031] The anionic monomer-1 is one or a mixture of two or more of the following: acrylic acid, methacrylic acid, maleic acid, 2-acrylamido-2-methylpropanesulfonic acid, sodium styrene sulfonate, sodium vinyl sulfonate, sodium propylene sulfonate, and sodium methpropylene sulfonate.

[0032] The co-solvent is one or a mixture of two or more of urea, acetamide, sodium silicate, and polyethylene glycol.

[0033] In the above preparation method, in step S2, the temperature of the polymerization reaction is 25-70°C, preferably 35-60°C, and the time is 1-24h, preferably 1-8h.

[0034] In the above preparation method, in step S2, the mass ratio of the nonionic monomer-2 to the anionic monomer-2 is 1:0.01 to 1, preferably 1:0.01 to 0.5, and the mass ratio of the total mass of the nonionic monomer-2 and the anionic monomer-2 to the mass of the silicon-containing monomer-2 is 1:0.01 to 0.8, preferably 1:0.05 to 0.6.

[0035] The organic solvents include organic solvent-1 and organic solvent-2;

[0036] The total mass ratio of the nonionic monomer-2, the anionic monomer-2, and the silicon-containing monomer-2 to the organic solvent-1 and the organic solvent-2 is 1:1 to 20:0.1 to 10, preferably 1:3 to 10:0.2 to 2;

[0037] The ratio of the total mass of the nonionic monomer-2, the anionic monomer-2, the silicon-containing monomer-2, the organic solvent-1, and the organic solvent-2 to the mass of the initiator B is 1:0.0005 to 0.01, preferably 1:0.001 to 0.01;

[0038] The initiator B is an azo initiator, selected from one of azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, and dimethyl azobisisobutyrate.

[0039] In the above preparation method, the nonionic monomer-2 is one or a mixture of two or more of acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide and vinylpyrrolidone;

[0040] The anionic monomer-2 is one or a mixture of two or more of sodium acrylate, sodium methacrylate, sodium 2-acrylamido-2-methylpropanesulfonate, sodium styrene sulfonate and sodium vinyl sulfonate.

[0041] The organic solvent-1 is one or a mixture of two or more of formamide, N,N-dimethylformamide and dimethyl sulfoxide;

[0042] The organic solvent-2 is one or a mixture of two or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol and tert-butanol;

[0043] In step S3, the mass ratio of the silicon-containing polymer-1 to the silicon-containing polymer-2 is 1:0.2 to 5, preferably 1:0.5 to 4, and the mass ratio of the total mass of the silicon-containing polymer-1 and the silicon-containing polymer-2 to the mass of the water is 1:20 to 2500, preferably 1:20 to 1000.

[0044] In step S1, the water is preferably deionized water;

[0045] In step S3, the water is preferably polymerized water.

[0046] The polymer crosslinking system prepared by the method of this invention is also within the scope of protection of this invention.

[0047] The present invention has the following beneficial technical effects:

[0048] 1. The raw materials of this invention are readily available, the reaction conditions are mild, the process is simple and safe, and it can be used for large-scale industrial production.

[0049] 2. This invention forms a dynamic covalent cross-linked structure through siloxane bonds. The reaction process is reversible and mild, and the system has better injectability, enabling deep profile control.

[0050] 3. In silicon-containing polymer-1, the structure and amount of silicon-containing monomers are controlled to ensure that the polymer powder has good water solubility; in silicon-containing polymer-2, the polymer solution has good water solubility by reacting in an organic solvent and controlling the molecular weight of the product.

[0051] 4. The product of this invention has excellent temperature and salt resistance properties and is applicable to a wide range of oil reservoirs.

[0052] 5. The product of this invention has good compatibility with conventional oil displacement additives.

[0053] 6. The products prepared by this invention are easy to store and meet environmental protection requirements. Attached Figure Description

[0054] Figure 1 This is a diagram illustrating codes for different gel strengths. Detailed Implementation

[0055] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0056] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0057] Example 1:

[0058] (1) Preparation of silicon-containing polymer-1

[0059] 100g acrylamide, 25g acrylic acid, 2.5g silicon-containing monomer-1-B (m=20, n=2, R1, R2, R3 are ethyl groups), 7g urea, and 600g deionized water were added to a three-necked glass flask equipped with a stirrer, a nitrogen inlet tube, and a thermometer. After stirring until all raw materials were dissolved, nitrogen gas was introduced for 30 minutes, the pH was controlled at 7.8, and the temperature was controlled at 5℃. Then, 0.45g azobisisobutylamidine hydrochloride, 0.35g sodium bisulfite, and 0.3g ammonium persulfate were added, and the reaction was carried out for 10 hours. The product was dried and pulverized to obtain silicon-containing polymer-1.

[0060] (2) Preparation of silicon-containing polymer-2

[0061] 50g acrylamide, 5g sodium acrylate, 10g vinyltriethoxysilane, 400g formamide, and 60g ethanol were added to a three-necked glass flask equipped with a stirrer, a nitrogen purging tube, and a thermometer. After stirring until all the raw materials were dissolved, nitrogen gas was purged for 30 minutes, and the temperature was controlled at 50℃. Then, 1g azobisisobutyronitrile was added, and the reaction was carried out for 6 hours to obtain silicon-containing polymer-2.

[0062] (3) Preparation of polymer crosslinking system

[0063] Add 1g of silicon-containing polymer-1 to 200g of on-site polymer water, stir and dissolve, then add 2g of silicon-containing polymer-2, stir and mix evenly to obtain a polymer crosslinking system.

[0064] Example 2:

[0065] As described in Example 1, except that in step (1) the nonionic monomer-1 is 70g of acrylamide and 30g of vinylpyrrolidone.

[0066] Example 3:

[0067] As described in Example 1, except that in step (1), the anionic monomer is 10g of acrylic acid and 30g of 2-acrylamido-2-methylpropanesulfonic acid.

[0068] Example 4:

[0069] As described in Example 1, the difference is that in step (1), the silicon monomer-1 is 3g of silicon monomer-1-A (m is 15, n is 2, R1, R2, R3 are ethyl) and 2g of silicon monomer-1-C (m is 28, n is 4, R1, R2, R3 are methyl).

[0070] Example 5:

[0071] As described in Example 1, the difference is that in step (1), the silicon monomer-1 is 0.5g of silicon monomer-1-B (m is 9, n is 2, R1, R2, R3 are methyl) and 1g of silicon monomer-1-C (m is 12, n is 2, R1, R2, R3 are methyl).

[0072] Example 6:

[0073] As described in Example 1, except that the co-solvent in step (1) is 7g acetamide and 3g sodium silicate.

[0074] Example 7:

[0075] As described in Example 1, the difference is that in step (1), the azo initiator-1 is 0.3g of azodicyanovalerate, the reducing initiator is 0.45g of sodium thiosulfate, and the oxidizing initiator is 0.4g of potassium persulfate.

[0076] Example 8:

[0077] As described in Example 1, except that in step (1), the reaction pH is 6.8, the temperature is 2°C, and the time is 8 hours.

[0078] Example 9:

[0079] As described in Example 1, except that in step (2), the nonionic monomer-2 is 35g of acrylamide and 15g of N,N-dimethylacrylamide.

[0080] Example 10:

[0081] As described in Example 1, the difference is that in step (2), the anionic monomer-2 is 7g of sodium 2-acrylamido-2-methylpropanesulfonate and 3g of sodium styrenesulfonate.

[0082] Example 11:

[0083] As described in Example 1, the difference is that in step (2), the silicon monomer-2 is 5g of allyltrimethoxysilane and 15g of methacryloyloxypropyltrimethoxysilane.

[0084] Example 12:

[0085] As described in Example 1, except that in step (2), organic solvent-1 is 250g formamide and 50g N,N-dimethylformamide, and organic solvent-2 is 25g methanol and 5g n-propanol.

[0086] Example 13:

[0087] As described in Example 1, except that in step (2) organic solvent-1 is 150g formamide and 70g N,N-dimethylformamide, and organic solvent-2 is 90g ethanol and 20g isopropanol.

[0088] Example 14:

[0089] As described in Example 1, except that in step (2), organic solvent-1 is 550g formamide and 50g dimethyl sulfoxide, and organic solvent-2 is 15g methanol and 15g isobutanol.

[0090] Example 15:

[0091] As described in Example 1, except that in step (2), the azo initiator-2 is 2g of azobisisovalerate.

[0092] Example 16:

[0093] As described in Example 1, except that the reaction temperature in step (2) is 60°C and the time is 5 hours.

[0094] Example 17:

[0095] As described in Example 1, except that the amount of silicon-containing polymer-2 added in step (3) is 3g.

[0096] Example 18:

[0097] As described in Example 1, except that the amount of water added in step (3) is 300g.

[0098] Example 19:

[0099] As described in Example 1, the difference is that in step (1), the silicon monomer-1 is 20g of silicon monomer-1-C (m is 20, n is 2, and R1, R2, and R3 are ethyl groups).

[0100] Example 20:

[0101] As described in Example 1, the difference is that in step (1), the silicon monomer-1 is 30g of silicon monomer-1-B (m is 20, n is 2, and R1, R2, and R3 are ethyl groups).

[0102] Example 21:

[0103] As described in Example 1, the difference is that in step (1), the silicon monomer-1 is 15g of silicon monomer-1-C (m is 1, n is 2, and R1, R2, and R3 are ethyl groups).

[0104] Example 22:

[0105] As described in Example 1, the difference is that in step (1), the silicon monomer-1 is 15g of silicon monomer-1-C (m is 12, n is 2, and R1, R2, and R3 are ethyl groups).

[0106] Example 23:

[0107] As described in Example 1, the difference is that in step (1), the silicon monomer-1 is 10g of silicon monomer-1-C (m is 12, n is 2, R1, R2, R3 are ethyl) and 5g of silicon monomer-1-A (m is 12, n is 2, R1, R2, R3 are ethyl).

[0108] Example 24:

[0109] As described in Example 1, the difference is that in step (1), the silicon-containing monomer-1 is 6g of silicon-containing monomer-1-C (m is 12, n is 2, R1, R2, R3 are ethyl), 3g of silicon-containing monomer-1-A (m is 12, n is 2, R1, R2, R3 are ethyl) and 6g of silicon-containing monomer-1-B (m is 12, n is 2, R1, R2, R3 are ethyl).

[0110] Performance evaluation:

[0111] (1) Sample preparation

[0112] Prepare the polymer crosslinking system according to the composition in Table 1. After the polymer crosslinking system is prepared, add it to the ampoule, seal it, and set it aside for later use.

[0113] (2) Evaluation of gelling performance

[0114] The ampoules were placed in a 90°C constant temperature oven, and the crosslinking dynamics were determined by observing the changes in the flow state of the crosslinking system over time. Based on different flow states, suspension states, and tongue-out states, the system can be divided into 9 levels (A to I), such as... Figure 1 As shown. The time when the system strength in the ampoule reaches grade D is recorded as the initial gelation time, and the time when the system strength no longer changes under high temperature conditions is recorded as the gelation time. The system strength at this point is recorded as the gelation strength of the system.

[0115] (3) Evaluation of temperature resistance

[0116] After gelation, the ampoules were placed in a 90°C constant temperature chamber, and the amount of water dehydrated was recorded at different aging times. The dehydration rate of the crosslinked system was calculated according to the following formula.

[0117]

[0118] In the formula, WR represents the dehydration rate, in percentages (%).

[0119] V0 - Volume of the crosslinked system during gelation, in mL;

[0120] V t - Volume of the crosslinked system after aging time t, in mL.

[0121] (4) Evaluation of the solubility of silicon-containing polymer-1

[0122] With stirring at 300 rpm, approximately 1 g of silicon-containing polymer-1 powder was added to 500 mL of simulated mineralized water. The mixture was stirred and dissolved at room temperature for 2 hours, then allowed to stand for 12 hours. The solution was filtered through filter paper, the filtrate was dried, and the mass was measured. The insoluble content of silicon-containing polymer-1 was calculated according to the following formula.

[0123]

[0124] In the formula, DR represents the insoluble content, in percentages (%).

[0125] Mass of m0-silicon-containing polymer-1 powder, g;

[0126] m1 - Mass of the dried filtrate, in grams.

[0127] As can be seen from Table 2, the two silicon-containing polymers prepared by this invention have good reaction gelation effect; during the gelation process, the crosslinking reaction between polymers has a certain delay property, which is suitable for profile control operations in deep formations; the crosslinking system has excellent anti-aging properties, with a dehydration rate of less than 10% after 120 days of aging, which meets the needs of oilfield sites.

[0128] As can be seen from Table 3, when the amount of silicon-containing monomers, the number of polyoxyethylene chain segments, and the ratio of different silicon-containing monomers are not appropriate, the content of insoluble matter in the silicon-containing polymer-1 in simulated mineralized water is very high, which cannot meet the application requirements. However, by optimizing the amount of silicon-containing monomers, structure, and ratio, a product with excellent solubility can be obtained.

[0129] Table 1 Composition of simulated mineralized water

[0130]

[0131] Table 2. Gel formation and anti-aging properties of different samples

[0132]

[0133] Table 3 Solubility of different silicon-containing polymers-1

[0134]

[0135]

Claims

1. A method for preparing a silicon-containing polymer crosslinking system for deep profile control, comprising the following steps: S1. In an inert atmosphere, in the presence of initiator A and cosolvent, nonionic monomer-1, anionic monomer-1 and silicon-containing monomer-1 are polymerized in water to obtain silicon-containing polymer-1. The nonionic monomer-1 is one or a mixture of two or more of acrylamide, methacrylamide, N-hydroxymethylacrylamide, N-ethylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, N-n-butylacrylamide, acryloylmorpholine, vinylpyrrolidone and vinylcaprolactam. The anionic monomer-1 is one or a mixture of two or more of the following: acrylic acid, methacrylic acid, maleic acid, 2-acrylamido-2-methylpropanesulfonic acid, sodium styrene sulfonate, sodium vinyl sulfonate, sodium propylene sulfonate, and sodium methpropylene sulfonate. The initiator A includes azo initiator-1, reducing initiators, and oxidizing initiators; The mass ratio of the nonionic monomer-1 to the anionic monomer-1 is 1:0.01 to 1, and the mass ratio of the total mass of the nonionic monomer-1 and the anionic monomer-1 to the mass of the silicon-containing monomer-1 is 1:0.001 to 0.

15. The total mass ratio of the nonionic monomer-1, the anionic monomer-1, and the silicon-containing monomer-1 to the mass ratio of the water is 1:1 to 25. The total mass ratio of the nonionic monomer-1, the anionic monomer-1, the silicon-containing monomer-1, and the water to the mass ratio of the cosolvent, the azo initiator-1, the reducing initiator, and the oxidizing initiator is 1:0.001~0.1:0.00001~0.005:0.00001~0.002:0.00001~0.002; S2. In an inert atmosphere and in the presence of initiator B, nonionic monomer-2, anionic monomer-2 and silicon-containing monomer-2 are polymerized in an organic solvent to obtain silicon-containing polymer-2. The nonionic monomer-2 is one or a mixture of two or more of acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide and vinylpyrrolidone; The anionic monomer-2 is one or a mixture of two or more of sodium acrylate, sodium methacrylate, sodium 2-acrylamido-2-methylpropanesulfonate, sodium styrene sulfonate and sodium vinyl sulfonate; The mass ratio of the nonionic monomer-2 to the anionic monomer-2 is 1:0.01 to 1, and the mass ratio of the total mass of the nonionic monomer-2 and the anionic monomer-2 to the mass of the silicon-containing monomer-2 is 1:0.01 to 0.

8. The total mass ratio of the nonionic monomer-2, the anionic monomer-2, and the silicon-containing monomer-2 to the organic solvent-1 and the organic solvent-2 is 1:1 to 20:0.1 to 10. The ratio of the total mass of the nonionic monomer-2, the anionic monomer-2, the silicon-containing monomer-2, the organic solvent-1, and the organic solvent-2 to the mass of the initiator B is 1:0.0005 to 0.

01. S3, the silicon-containing polymer-1 and the silicon-containing polymer-2 are cross-linked in water to obtain the product; The silicon-containing monomer-1 is one or a mixture of two or more of silicon-containing monomer-1-A, silicon-containing monomer-1-B, and silicon-containing monomer-1-C. The structural formula of the silicon-containing monomer-1-A is as follows: The structural formula of the silicon-containing monomer-1-B is as follows: ， The structural formula of the silicon-containing monomer-1-C is as follows: ， In the formula, m The range is 1 to 30. n The number of carbon atoms is 1 to 6, and R1, R2, and R3 are all alkyl chains with 1 to 4 carbon atoms; The silicon-containing monomer-2 is one or a mixture of two or more of the following: vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, methacryloyloxypropyltrimethoxysilane, acryloyloxypropyltrimethoxysilane, methacryloyloxypropyltriethoxysilane, and acryloyloxypropyltriethoxysilane. The mass ratio of the silicon-containing polymer-1 to the silicon-containing polymer-2 is 1:0.2 to 5, and the mass ratio of the total mass of the silicon-containing polymer-1 and the silicon-containing polymer-2 to the mass of the water is 1:20 to 2500.

2. The preparation method according to claim 1, characterized in that: In step S1, the conditions for the polymerization reaction are as follows: pH value 6–11, temperature 0–20℃, time 1–24 h.

3. The preparation method according to claim 1 or 2, characterized in that: The azo initiator-1 is one or a mixture of two or more of azobisisobutylamidine hydrochloride, azobisisopropylimidazoline hydrochloride, and azobiscyanopentanoic acid; The reducing initiator is one or a mixture of two or more of sodium sulfite, sodium bisulfite, sodium dithionite and sodium thiosulfate; The oxidation initiator is one or a mixture of two or more of potassium persulfate, ammonium persulfate, sodium persulfate, and hydrogen peroxide.

4. The preparation method according to claim 1 or 2, characterized in that: In step S1, the co-solvent is one or a mixture of two or more of urea, acetamide, sodium silicate and polyethylene glycol.

5. The preparation method according to claim 1 or 2, characterized in that: In step S2, the polymerization reaction is carried out at a temperature of 25–70°C for 1–24 hours.

6. The preparation method according to claim 1 or 2, characterized in that: In step S2, the organic solvent includes organic solvent-1 and organic solvent-2; The initiator B is an azo initiator, selected from one of azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, and dimethyl azobisisobutyrate.

7. The preparation method according to claim 6, characterized in that: The organic solvent-1 is one or a mixture of two or more of formamide, N,N-dimethylformamide and dimethyl sulfoxide; The organic solvent-2 is one or a mixture of two or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and tert-butanol.

8. The silicon-containing polymer crosslinking system prepared by the method of any one of claims 1-7.

9. The application of the silicon-containing polymer crosslinking system of claim 8 as a deep profile control agent for high-temperature and high-salinity oil reservoirs or in the deep profile control of high-temperature and high-salinity oil reservoirs.

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