Hydrophobic monomers and methods for their preparation, polymer gels and methods for their preparation and use, and lost circulation materials and use

Abstract

The present application relates to the field of petroleum aids, discloses a kind of hydrophobic monomer and its preparation method, polymer gel and its preparation method and application and plugging material and application.The structure of the hydrophobic monomer is as shown in formula (I):In formula (I), R 1 , R 2 And R 3 Each independently is H or C1-C 18 Alkyl;M1, M2 and M3 are each independently selected from H, Na, Li or K;N, m and z are each independently an integer of 0-6.Polymer gel containing structural unit from the hydrophobic monomer of the present application in the present application has good water dilution resistance and temperature and salt resistance.

Description

Technical Field

[0001] This invention relates to the field of petroleum additives technology, specifically to a hydrophobic monomer and its preparation method, a polymer gel and its preparation method and application, and a plugging material and its application. Background Technology

[0002] Well leakage is a common and complex issue in oil and gas exploration and development, posing a severe threat to normal drilling and completion operations. Severe leakage, due to its large leakage space and the presence of formation water, makes it difficult to guarantee the success rate and scientific validity of conventional plugging techniques. According to traditional plugging principles, successful plugging occurs when the plugging material enters the leakage zone and forms a plug with a strength exceeding the working fluid pressure in the wellbore, thus preventing the working fluid from further penetrating the formation. At this point, the plugging material remains stationary in the leakage channel near the wellbore, filling the entire channel. Subsequently, the plugging material undergoes physical and chemical changes, hardening to form a plug sufficient to withstand the pressure exerted by the working fluid on the formation. The larger the size of the formation leakage channel, the more difficult it is for the plugging material to remain within it, resulting in a lower success rate. Therefore, for severe leakage caused by large leakage channels, conventional plugging methods such as plugging while drilling, thickened fluid plugging, bridge plug plugging, chemical consolidation plugging, and cement slurry push plugging have a high failure rate.

[0003] In recent years, the isolated gel slug plugging technology has demonstrated a high success rate in addressing severe lost circulation (WS) encountered during drilling operations, particularly in formations with water-bearing layers. The principle behind this technology is that a structural fluid that easily enters the lost circulation zone automatically stops flowing within it, filling the fractures and pores. This fluid is difficult to dilute by formation fluids, thus forming a "slug" that isolates the fluids within the formation from those in the wellbore. This "slug" possesses sufficient initiation pressure; the pressure difference between the initiation pressure of the "slug" and the formation fluid pressure achieves temporary plugging. Cement slurry is then applied to seal the formation near the wellbore, achieving the purpose of plugging the leak. The structural fluid that forms the "slug" is the key to this technology. Currently, much research focuses on ZND smart gel developed by Southwest Petroleum University. This hydrophobic associative polymer exhibits good water solubility, withstands temperatures up to 120℃, and its most significant characteristic is its excellent shear dilution properties, achieving high dilution rates even at low shear rates (7.34s). -1 Under certain conditions, its apparent viscosity can reach 1.0 × 10⁻⁶. 4 -3.0×10 4 mPa·s, at high shear rates (1000 s) -1Its apparent viscosity is around 100 mPa·s. It flows easily in formations near surface pipelines and wells; after being pumped into the lost circulation zone, it quickly thickens into a gel upon stopping the flow, filling the entire fracture and cavern space. However, with the development of oil and gas exploration, the number of high-temperature deep wells is gradually increasing, and the formation water has a certain degree of mineralization. Therefore, there are relatively few types of heat-resistant, salt-resistant, and calcium-resistant plugging gels suitable for high-temperature lost circulation formations. Summary of the Invention

[0004] The purpose of this invention is to overcome the problem of poor temperature, salt and calcium resistance of existing plugging gels, and to provide a hydrophobic monomer and its preparation method, a polymer gel and its preparation method and application, and a polymer gel containing structural units from the hydrophobic monomer of this invention, which has good resistance to water dilution and temperature and salt resistance.

[0005] To achieve the above objectives, the first aspect of the present invention provides a hydrophobic monomer, the structure of which is shown in formula (I):

[0006]

[0007] In equation (I), R 1 R 2 and R 3 Each independently is H or Cl-C 18 alkyl;

[0008] M1, M2, and M3 are each independently selected from H, Na, Li, or K;

[0009] n, m, and z are each an independent integer between 0 and 6.

[0010] A second aspect of the present invention provides a method for preparing a hydrophobic monomer, the method comprising:

[0011] Under Ritter reaction conditions, the surfactant is contacted with the nitrile compound shown in formula (II);

[0012]

[0013] R 1 R 2 R 3 The definitions of , n, m and z are the same as the definitions of hydrophobic monomers in equation (I).

[0014] The surfactant is selected from at least one of 3-allyloxy-2-hydroxy-1-propanesulfonic acid, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, lithium 3-allyloxy-2-hydroxy-1-propanesulfonate, and potassium 3-allyloxy-2-hydroxy-1-propanesulfonate.

[0015] According to the present invention, the Ritter reaction refers to the reaction of the nitrile group in the nitrile compound of formula (II) of the present invention with the carbocation in sodium 3-allyloxy-2-hydroxy-1-propanesulfonate to form an N-alkylamide bond. The Ritter reaction conditions are only required to promote the formation of the N-alkylamide bond. In some embodiments, the conditions of the Ritter reaction include: a reaction temperature of 80-180°C, preferably 100-150°C; and a reaction time of 6-64 h, preferably 12-56 h.

[0016] A third aspect of the present invention provides a polymer gel containing structural unit A of formula (1) derived from the hydrophobic monomer of the present invention.

[0017]

[0018] R 1 R 2 R 3 The definitions of M1, M2 and M3, n, m and z correspond to the definitions of hydrophobic monomers in equation (I).

[0019] A fourth aspect of the present invention provides a method for preparing a polymer gel, the method comprising: subjecting a monomer mixture to a free radical polymerization reaction in the presence of an initiator, wherein the monomer mixture contains the hydrophobic monomers of the present invention.

[0020] The fifth aspect of the present invention provides a polymer gel prepared by the preparation method described in the fourth aspect of the present invention.

[0021] The sixth aspect of this invention provides the application of the polymer gel described herein as a plugging material in drilling operations.

[0022] A seventh aspect of the present invention provides a sealing material comprising water and the polymer gel described in the present invention.

[0023] The eighth aspect of this invention relates to the application of plugging materials in well drilling plugging.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] The hydrophobic monomer in this invention is a polyene-based hydrophobic monomer containing a phenyl structure. It has three reactive groups capable of chemical cross-linking, which facilitates the formation of an interpenetrating network structure and enhances gel strength. Furthermore, the benzene ring structure of the hydrophobic monomer increases the rigidity of the gel molecular chain. Experiments have also shown that polymer gels containing the structural units of the hydrophobic monomer of this invention can improve the polymer gel's temperature and salt resistance to a certain extent. Moreover, each hydrophobic monomer molecule contains only one benzene ring structure, maximizing molecular rigidity while minimizing the introduction of aromatic groups, thus giving the gel certain environmentally friendly properties. Attached Figure Description

[0026] Figure 1 The magnetic resonance spectrum of hydrophobic monomer-1 in Example 1 ( 1 H NMR spectrum;

[0027] Figure 2 The magnetic resonance spectrum of hydrophobic monomer-2 in Example 2 ( 1 H NMR spectrum

[0028] Figure 3 This is a transmission electron microscope image of the polymer gel in Example 5. Detailed Implementation

[0029] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0030] The first aspect of the present invention provides a hydrophobic monomer, the structure of which is shown in formula (I):

[0031]

[0032] In equation (I), R 1 R 2 and R 3 Each independently is H or Cl-C 18 alkyl;

[0033] M1, M2, and M3 are each independently selected from H, Na, Li, or K;

[0034] n, m, and z are each an independent integer between 0 and 6.

[0035] In this invention, the hydrophobic monomer has three reactive groups capable of chemical cross-linking, which facilitates the formation of an interpenetrating network three-dimensional structure, enhances the gel strength of the structural unit containing the hydrophobic monomer, and the benzene ring structure of the hydrophobic monomer can improve the rigidity of the gel molecular chain, thereby improving the stability of the gel under high temperature conditions; in addition, each hydrophobic monomer molecule contains only one benzene ring structure, which minimizes the introduction of aromatic groups while maximizing the improvement of molecular rigidity, thereby giving the gel certain environmental protection properties.

[0036] According to the present invention, as long as the purpose of the present invention can be achieved, R 1 R 2 and R 3 There are no special restrictions on the specific types of functional groups, and C1-C 18 Alkyl groups can have either a straight-chain or branched structure; this invention does not impose any particular limitation on this. However, considering the availability of raw materials, in some embodiments, R... 1 R 2 and R 3 Each independently is H or Cl-C 12 Alkyl groups, which can be listed as C1-C 12 Alkyl groups include methyl, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-decyl, undecyl, dodecyl, etc., preferably, R 1 R 2 and R 3 Each is independently H or C1-C6 alkyl.

[0037] According to the present invention, it is understood that the values ​​of n, m and z each represent the number of methylene groups corresponding to them. As long as the purpose of the present invention can be achieved, the number of methylene groups is not particularly limited. In some embodiments, n, m and z are each independently an integer from 0 to 3.

[0038] According to the present invention, in order to avoid the preparation process of hydrophobic monomers being too complicated, in some preferred embodiments, M1, M2 and M3 are the same.

[0039] According to the present invention, in some embodiments, the hydrophobic monomer is selected from compounds represented by the following structural formulas:

[0040]

[0041] According to the present invention, in some embodiments, the hydrophobic monomer is selected from compounds represented by the following structural formulas:

[0042]

[0043] According to the present invention, in some embodiments, the hydrophobic monomer is selected from compounds represented by the following structural formulas:

[0044]

[0045] According to the present invention, in some embodiments, the hydrophobic monomer is selected from compounds represented by the following structural formulas:

[0046]

[0047] A second aspect of the present invention provides a method for preparing a hydrophobic monomer, the method comprising:

[0048] Under Ritter reaction conditions, the surfactant is contacted with the nitrile compound shown in formula (II);

[0049]

[0050] R 1 R 2 R 3 The definitions of , n, m and z are the same as the definitions of hydrophobic monomers in equation (I).

[0051] The surfactant is selected from at least one of 3-allyloxy-2-hydroxy-1-propanesulfonic acid, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, lithium 3-allyloxy-2-hydroxy-1-propanesulfonate, and potassium 3-allyloxy-2-hydroxy-1-propanesulfonate.

[0052] According to the present invention, in order to avoid cumbersome preparation processes, in some preferred embodiments, the surfactant is selected from one of 3-allyloxy-2-hydroxy-1-propanesulfonic acid, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, lithium 3-allyloxy-2-hydroxy-1-propanesulfonate, or potassium 3-allyloxy-2-hydroxy-1-propanesulfonate.

[0053] According to the present invention, the Ritter reaction refers to the reaction of the nitrile group in the nitrile compound of formula (II) of the present invention with the carbocation in the surfactant to generate an N-alkylamide bond. The Ritter reaction conditions are only required to promote the generation of the N-alkylamide bond. In some embodiments, the conditions of the Ritter reaction include: a reaction temperature of 80-180°C, preferably 100-150°C; and a reaction time of 6-64 h, preferably 12-56 h.

[0054] According to the present invention, the amount of nitrile compound and surfactant can be selected as needed. In some embodiments, the molar ratio of the nitrile compound to the surfactant is 1:(3-6), preferably 1:(3.6-5.6).

[0055] According to the present invention, in order to ensure the efficiency of the Ritter reaction and the purity of the obtained hydrophobic monomer, in some embodiments, the nitrile compound is contacted with a solution A containing a surfactant in a protective atmosphere and in the presence of a catalyst, and then the hydrophobic monomer is purified and separated.

[0056] According to the present invention, the purification and separation method is not particularly limited as long as it achieves the purpose of the present invention. In some embodiments, the purification and separation method includes: concentration, soaking, filtration, washing, and drying to obtain the hydrophobic monomer.

[0057] According to the present invention, the purpose of concentration is to remove part of the solvent. As long as the purpose of the present invention can be achieved, the method of concentration is not particularly limited. For example, vacuum distillation is used, and rotary evaporation under vacuum is preferred.

[0058] According to the present invention, concentration, soaking, filtration and washing only indicate the method of purification and separation, and do not represent the order in which purification and separation are performed. In some embodiments, the concentrated product is first soaked in a first soaking agent, washed with a first washing agent, then soaked in a second soaking agent and washed with a second washing agent.

[0059] According to the present invention, in some embodiments, the soaking time is 1-6 hours, preferably 2-4 hours.

[0060] According to some embodiments of the present invention, the first soaking agent is at least one of methanol, ethanol and diethyl ether.

[0061] According to the present invention, in some embodiments, the second soaking agent is acetone.

[0062] According to some embodiments of the present invention, the first detergent is the same as the first soaking agent, and the second detergent is the same as the second soaking agent.

[0063] According to the present invention, in some embodiments, the second detergent is dried after washing. There are no special restrictions on the drying method. For example, freeze drying to constant weight or vacuum drying to constant weight can be used. Constant weight means that the mass difference between two weighings of the product does not exceed 0.0003g.

[0064] According to the present invention, the protective gas includes, but is not limited to, inert gases (e.g., nitrogen or argon). The protective gas atmosphere is to ensure that there is no oxygen in the system. In order to achieve the protective gas atmosphere, a protective gas (e.g., an inert gas) can be introduced into the reaction system to remove oxygen from the system. In some embodiments, the time for introducing the protective gas is greater than 30 minutes, preferably 40-60 minutes.

[0065] According to the present invention, the amount of catalyst used is not particularly limited as long as the purpose of the present invention can be achieved. In some embodiments, the amount of catalyst used is 0.5 mol%-10 mol% of the nitrile compound, preferably 1 mol%-8 mol%, and more preferably 2 mol%-6 mol%.

[0066] According to the present invention, in some embodiments, the catalyst comprises Acids and / or Lewis acids.

[0067] According to the present invention, catalysts that can be listed include sulfuric acid, o-phenylenesulfonylimide, trifluoromethanesulfonic acid, trifluoromethanesulfonic anhydride, bismuth trifluoromethanesulfonate, calcium trifluoromethanesulfonate, copper trifluoromethanesulfonate, indium trifluoromethanesulfonate, bis(trifluoromethanesulfonylimide), boron trifluoride, boron trifluoride ether, perfluorosulfonic acid resin, 2,4-dinitrobenzenesulfonic acid, dodecaphosphotungstic acid, and acidic salts of cesium phosphotungsten (Cs). 2.5 H 0.5 PW 12 O 40 The present invention uses at least one of the following: cesium sulfate, cerium sulfate (Ce(SO4)2), phosphorus pentoxide, iodine, cuprous chloride, cuprous bromide, cuprous iodide, cuprous chloride, cobalt chloride, zinc chloride, and ferric chloride hexahydrate (FeCl3·6H2O). In this invention, at least one of boron trifluoride diethyl ether, bismuth trifluoromethanesulfonate, and copper trifluoromethanesulfonate without catalyst is used as an exemplary description of the present invention, but the present invention is not limited thereto.

[0068] According to the present invention, it is understood that solution A is prepared by mixing a surfactant with a suitable solvent, and in some embodiments, the mass concentration of the surfactant in solution A is 5wt%-12wt%.

[0069] According to the present invention, in some embodiments, the solvent in solution A is selected from at least one of the solvents including water, halogenated hydrocarbon solvents, ketone solvents, ether solvents, alkane solvents, nitrile solvents, ester solvents, aromatic hydrocarbon solvents, cycloalkane solvents, cycloether solvents, amine solvents, amide solvents, nitroalkane solvents, and sulfone solvents, preferably at least one of aromatic hydrocarbon solvents, amide solvents, and sulfone solvents.

[0070] According to the present invention, the types of solution A that can be listed include at least one of water, acetone, butanone, chloroform, dichloromethane, 1,1-dichloroethane, 1,2-dichloroethane, methyl ethyl ketone, tetrahydrofuran, petroleum ether, diethyl ether, acetonitrile, ethyl acetate, benzene, toluene, m-xylene, cyclohexane, ethylene glycol dimethyl ether, nitromethane, 1,4-dioxane, pyridine, morpholine, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide, preferably at least one of N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

[0071] According to the present invention, the reactor in which the reaction is carried out when preparing the hydrophobic monomer is not particularly limited, for example, the reaction is carried out in a reactor equipped with a temperature control device, a reflux condenser and a constant pressure feeding device.

[0072] A third aspect of the present invention provides a polymer gel containing structural unit A of formula (1) derived from the hydrophobic monomer of the present invention.

[0073]

[0074] R 1 R 2 R 3 The definitions of M1, M2 and M3, n, m and z correspond to the definitions of hydrophobic monomers in equation (I).

[0075] In this invention, the polymer gel containing structural unit A of formula (1) derived from the hydrophobic monomer of this invention can have good resistance to water dilution and resistance to temperature and salt.

[0076] According to some embodiments of the present invention, the molar content of structural unit A in the polymer gel is 1%-3% based on the total amount of all structural units in the polymer gel.

[0077] In this invention, unless otherwise specified, the content of structural units in the polymer gel corresponds to the content of the corresponding reactive monomers as raw materials.

[0078] According to the present invention, in some embodiments, the polymer gel further contains structural unit B derived from an alkenyl phosphonate monomer.

[0079] In this invention, the introduction of phosphonic acid groups into the polymer gel molecular chain not only provides excellent resistance to temperature, oxidation, and salt, but also allows the phosphonic acid groups to interact with Ca... 2+ Its strong complexing ability enhances its applicability in high-calcium formation water.

[0080] According to the present invention, in some embodiments, the structural unit B is as shown in formula (2).

[0081]

[0082] R0”” is H or C1-C6, preferably H, CH3 or C2H5, and more preferably H or CH3;

[0083] R3 is a phosphonate group, preferably R3 is...

[0084] Where o is an integer from 1 to 6, preferably an integer from 1 to 3, and more preferably 1 or 2;

[0085] R e and R f Each is independently selected from H or C1-C6 alkyl groups, preferably H, CH3, C2H5, CH2CH2CH3 or CH(CH3)2; more preferably H, CH3, C2H5, CH(CH3)2, and even more preferably R. e and R f They are not both H.

[0086] According to the present invention, in some embodiments, the molar ratio of structural unit B to structural unit A is (2-7):(1-3). By employing the aforementioned embodiments, the temperature and salt resistance of the polymer gel can be further increased.

[0087] According to the present invention, in order to improve the water absorption of the gel, in some embodiments, the polymer gel further contains structural units derived from water-soluble monomers, preferably including structural unit C from alkenyl amide monomers as shown in formula (3) and / or structural unit D from alkenyl carboxylic acid monomers as shown in formula (4).

[0088]

[0089] R0 is selected from H or C1-C6 alkyl, preferably H, CH3 or C2H5;

[0090] R1 is selected from amide groups;

[0091] R0', R0” and R0”' are each independently H or C1-C6 alkyl, preferably H, CH3, C2H5, CH2CH2CH3, CH(CH3)2 or CH2CH2CH2CH3;

[0092] R2 is a carboxylic acid group.

[0093] According to the present invention, in some embodiments, R1 is

[0094] R a and R bEach is independently selected from H, C1-C6 alkyl, C1-C6 alkyl alcohol, C1-C8 alkyl ketone, preferably H, CH3, CH2CH3, CH(CH3)2, CH2OH, CH2CH2OH, C(CH3)2CH2COCH3 or CH2CH(CH3)OH;

[0095] R c It is H or C1-C6 alkyl, preferably H, CH3, C2H5 or CH(CH3)2;

[0096] R d It is a C1-C6 alkyl group, preferably CH3, C2H5 or CH(CH3)2.

[0097] According to the present invention, in some embodiments, R2 is

[0098] A is selected from at least one of H, Na, K, Rb and Cs, preferably at least one of H, Na and K;

[0099] t is 0, 1, 2, or 4;

[0100] r is an integer from 0 to 6, preferably an integer from 0 to 2;

[0101] s is an integer from 0 to 6, preferably an integer from 0 to 2;

[0102] R is H or CH3.

[0103] According to the present invention, in some embodiments, the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3).

[0104] In this invention, the structural units A, B, C, and D contained in the polymer gel are repeating units formed in the polymer gel by the addition polymerization reaction of the olefin carbon-carbon double bonds contained in the hydrophobic monomer, alkenyl phosphonate monomer, alkenyl amide monomer, and alkenyl carboxylic acid monomer.

[0105] According to some embodiments of the present invention, the polymer gel has a weight-average molecular weight of 6.25 × 10⁻⁶. 5 -7.75×10 5 g / mol.

[0106] In this invention, the weight-average molecular weight is obtained by gel permeation chromatography (GPC).

[0107] According to some preferred embodiments of the present invention, the polymer gel comprises at least one of the following copolymers:

[0108] Copolymer-1 contains structural unit A derived from the compound shown in the following structural formula (A-1), structural unit B derived from dimethyl acryloyloxymethylphosphonate, structural unit C derived from acrylamide, and structural unit D derived from sodium acrylate, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); preferably, the molar ratio is 40:15:3:2.

[0109] Copolymer-2 contains structural unit A derived from the compound shown in the following structural formula (A-1), structural unit B derived from diethyl acryloyloxymethylphosphonate, structural unit C derived from diacetone acrylamide, and structural unit D derived from potassium methacrylate, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 50:10:2:1.

[0110] Copolymer-3 contains structural unit A derived from the compound shown in the following structural formula (A-1), structural unit B derived from diisopropyl acryloyloxymethylphosphonic acid, structural unit C derived from N-hydroxymethylacrylamide, and structural unit D derived from 6-heptenoic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 20:27:7:3.

[0111] Copolymer-4 contains structural unit A derived from the compound shown in the following structural formula (A-1), structural unit B derived from diisopropyl 2-methacryloyloxyethylphosphonic acid, structural unit C derived from N,N-diethylmethacrylamide, and structural unit D derived from 3,3-dimethyl-4-pentenoic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 30:20:5:2.5.

[0112] Copolymer-5 contains structural unit A derived from the compound shown in the following structural formula (A-1), structural unit B derived from dimethyl acryloyloxyethylphosphonate, structural unit C derived from N-hydroxyethylacrylamide, and structural unit D derived from 2-methyl-4-envalonic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 20:25:2:1.

[0113] Copolymer-6 contains structural unit A derived from the compound shown in the following structural formula (A-1), structural unit B derived from dimethyl 2-methacryloyloxymethylphosphonate, structural unit C derived from N-vinyl-N-methylacetamide, and structural unit D derived from 2-methyl-3-butenoic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 20:10:7:1.

[0114] Copolymer-7 contains structural unit A derived from the compound shown in the following structural formula (A-2), structural unit B derived from diethyl acryloyloxyethylphosphonate, structural unit C derived from acrylamide, and structural unit D derived from potassium acrylate, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 45:18:6:2.

[0115] Copolymer-8 contains structural unit A derived from the compound shown in the following structural formula (A-2), structural unit B derived from diisopropyl acryloyloxyethylphosphonic acid, structural unit C derived from N,N-bis(2-hydroxyethyl)methylacrylamide, and structural unit D derived from 2-heptenoic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 50:15:4:3.

[0116] Copolymer-9 contains structural unit A derived from the compound shown in the following structural formula (A-2), structural unit B derived from diethyl 2-methacryloyloxymethylphosphonic acid, structural unit C derived from N-isopropylacrylamide, and structural unit D derived from 2-propyl-2-pentenoic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 25:12:5:3.

[0117] Copolymer-10, wherein structural unit A is derived from the compound shown in the following structural formula (A-2), structural unit B is derived from diisopropyl 2-methacryloyloxymethylphosphonic acid, structural unit C is derived from N-vinylacetamide, and structural unit D is derived from acrylic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 40:20:3:1.5.

[0118] Copolymer-11 contains structural unit A derived from the compound shown in the following structural formula (A-3), structural unit B derived from dimethyl 2-methacryloyloxyethylphosphonic acid, structural unit C derived from N,N-diethylacrylamide, and structural unit D derived from 2,4-dimethyl-2-pentenoic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 20:10:2:3.

[0119] Copolymer-12 contains structural unit A derived from the compound shown in the following structural formula (A-3), structural unit B derived from diethyl 2-methacryloyloxyethylphosphonic acid, structural unit C derived from N-ethylacrylamide, and structural unit D derived from 3-pentenoic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 50:25:7:1.

[0120] Copolymer-13 contains structural unit A derived from the compound shown in the following structural formula (A-3), structural unit B derived from dimethyl acryloyloxymethylphosphonate, structural unit C derived from methacrylamide, and structural unit D derived from 3-methyl-2-butenoic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 50:25:2:3.

[0121] Copolymer-14 contains structural unit A derived from the compound shown in the following structural formula (A-4), structural unit B derived from diethyl 2-methacryloyloxymethylphosphonic acid, structural unit C derived from N-(2-hydroxypropyl)acrylamide, and structural unit D derived from 2-methyl-2-pentenoic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 35:20:4:2.

[0122] Copolymer-15 contains structural unit A derived from the compound shown in the following structural formula (A-4), structural unit B derived from diethyl acryloyloxymethylphosphonic acid, structural unit C derived from N,N-dimethylacrylamide, and structural unit D derived from 2,2-dimethyl-4-pentenoic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 25:16:3.5:2.

[0123] Copolymer-16 contains structural unit A derived from the compound shown in the following structural formula (A-4), structural unit B derived from diisopropyl acryloyloxyethylphosphonic acid, structural unit C derived from N-hydroxymethylacrylamide, and structural unit D derived from 4-enpentonic acid, wherein the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3), preferably 28:25:6:3.

[0124]

[0125]

[0126] A fourth aspect of the present invention provides a method for preparing a polymer gel, the method comprising: subjecting a monomer mixture to a free radical polymerization reaction in the presence of an initiator, wherein the monomer mixture contains the hydrophobic monomers of the present invention.

[0127] According to some embodiments of the present invention, the molar content of the hydrophobic monomer in the monomer mixture is 1%-10% (e.g., 1%, 1.2%, 1.5%, 2.5%, 4%, 5.5%, 6%, 6.7%, 7%, 8.6%, 9%, 10%, or any combination of two of the above values) based on the total amount of the monomer mixture.

[0128] According to the present invention, in some embodiments, the monomer mixture further includes an alkenyl phosphonate monomer represented by formula (2-1);

[0129]

[0130] The definitions of R0”” and R3 are the same as those in structural unit B.

[0131] According to the present invention, in some embodiments, the molar ratio of the alkenyl phosphonate monomer to the hydrophobic monomer is (2-7):(1-3).

[0132] According to some embodiments of the present invention, the monomer mixture further includes water-soluble monomers.

[0133] According to the present invention, in some embodiments, the water-soluble monomer includes alkenylamide monomers represented by formula (3-1) and / or alkenylcarboxylic acid monomers represented by formula (4-1);

[0134]

[0135] The definitions of R0, R1, R0', R0”R0”' and R2 are the same as the definitions of structural unit C and structural unit D.

[0136] According to the present invention, in some embodiments, the molar ratio of the alkenylamide monomer, alkenyl carboxylic acid monomer, alkenyl phosphonate monomer and hydrophobic monomer is (20-50):(10-25):(2-7):(1-3).

[0137] According to the present invention, the free radical polymerization reaction generally consists of three elementary reactions: chain initiation, chain propagation, and chain termination. Chain transfer reaction may also be present. There is no particular limitation on the type of initiator, as long as it can achieve free radical polymerization. It is understood that the type of initiator includes one of azo compound initiators, organic peroxide initiators, inorganic peroxide initiators, and oil-soluble redox initiators, with azo initiators being preferred. Examples of azo compound initiators include one or more of the following: azobisisobutyrazoline hydrochloride, azoisobutyronitrile, azobisisobutyronitrile, azobiscarboxyethyl-2-isobutylamidine hydrate, azodimethyl N-2-hydroxybutylacrylamide, azobiscyclohexylformitrile, azobisisovalerate, azobisisoheptanenitrile, azobiscyanopentanoic acid, azobisisobutyronitrile hydrochloride, azobisisopropylimidazoline, azobisN-hydroxyisobutylamidine hydrate, azobisN,N'-cyclobutylisobutylamidine hydrate, dimethyl azobisisobutyrate, and 2,2'-azobis(N-cyclohexylisobutylamidine) hydrochloride.

[0138] According to some embodiments of the present invention, the amount of the initiator is 0.2%-2.5% of the total weight of the monomer mixture.

[0139] According to the present invention, in some embodiments, the conditions for the free radical polymerization reaction include: a reaction temperature of 35-120°C, preferably 40-105°C; and a reaction time of 15-50 h.

[0140] According to some preferred embodiments of the present invention, the free radical polymerization reaction is carried out in the presence of solvent A and a protective atmosphere.

[0141] According to the present invention, the initiator exhibits high activity at a certain temperature. To better control the reaction rate, during the preparation of the polymer gel, solvent A can be mixed with the monomer mixture, then heated to the temperature for free radical polymerization, followed by the introduction of a protective gas and the addition of an initiator to carry out the free radical polymerization reaction. According to some embodiments of the present invention, solvent A is selected from at least one of halogenated hydrocarbon solvents, ketone solvents, ether solvents, alkane solvents, nitrile solvents, ester solvents, aromatic hydrocarbon solvents, cycloalkane solvents, cyclic ether solvents, amine solvents, amide solvents, nitroalkane solvents, and sulfone solvents.

[0142] According to the present invention, solvent A may be one or more of the following: water, acetone, butanone, chloroform, dichloromethane, 1,1-dichloroethane, 1,2-dichloroethane, methyl ethyl ketone, tetrahydrofuran, petroleum ether, diethyl ether, acetonitrile, ethyl acetate, benzene, toluene, m-xylene, cyclohexane, ethylene glycol dimethyl ether, nitromethane, 1,4-dioxane, pyridine, morpholine, 4-methyl-2-pentanone, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

[0143] According to some preferred embodiments of the present invention, the concentration of the monomer mixture in solvent A is 5wt%-15wt%.

[0144] According to the present invention, after the free radical polymerization reaction is completed, the polymer gel can be obtained by means known in the art, for example, by removing the reaction raw materials by precipitation and washing, and by removing the solvent by extraction and drying. Specifically, the reaction material obtained from the free radical polymerization reaction is precipitated in an alcohol solvent or an ether solvent and then filtered. The product is washed several times with a ketone solvent, and then the product is extracted with a solvent containing organic acid and polyol as an extractant. Finally, it is vacuum dried to constant weight to obtain the polymer gel.

[0145] The fifth aspect of the present invention provides a polymer gel prepared by the preparation method described in the fourth aspect of the present invention.

[0146] The sixth aspect of this invention provides the application of the polymer gel described herein as a plugging material in drilling operations.

[0147] The polymer gel of this invention can be used in the plugging of leaks in high-temperature deep wells, and is particularly suitable for plugging leaks in high-temperature loss formations with well-developed high-salinity water layers.

[0148] According to the present invention, the polymer gel of the present invention can be mixed with water and then pumped into the formation, or it can be mixed with drilling fluid and then pumped into the formation, or other methods of use can be selected as needed. A seventh aspect of the present invention provides a plugging material comprising water and the polymer gel described in the present invention.

[0149] The eighth aspect of this invention relates to the application of plugging materials in well drilling plugging.

[0150] The present invention will be described in detail below through examples. Unless otherwise specified, all raw materials in the following examples and comparative examples are commercially available products. The molar ratio of each structural unit in the polymer gel in Examples 5-21 and Comparative Examples 1-3 is the molar ratio of the corresponding monomer feed amount.

[0151] Example 1

[0152] Synthesis of hydrophobic monomer-1:

[0153] 122.19 g (0.56 mol) of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and 1000 g of dimethyl sulfoxide were added to a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device. After stirring thoroughly until dissolved, 15.3144 g (0.1 mol) of 1,3,5-benzenetricarbonitrile was added. After purging with nitrogen for 40 min, the temperature was raised to 100 °C, and 0.71 g (0.005 mol) of boron trifluoride diethyl ether was added. The reaction was continued for 24 h under stirring.

[0154] After the reaction was completed, dimethyl sulfoxide was removed by vacuum distillation. The product was then soaked in diethyl ether for 2 hours and filtered, followed by rinsing with diethyl ether. It was then soaked in acetone for 2 hours and filtered, followed by rinsing with acetone. Finally, it was dried under vacuum to constant weight to obtain hydrophobic monomer-1.

[0155] The chemical reaction formula is shown below:

[0156]

[0157] The hydrophobic monomer-1 obtained in Example 1 was characterized by nuclear magnetic resonance [(CD3)2SO, 25℃], and its magnetic resonance spectrum was analyzed. 1 HNMR) such as Figure 1 ;according to Figure 1 In 1 ¹H NMR analysis revealed that the structure of the hydrophobic monomer-1 obtained in Example 1 is shown in formula c-1.

[0158] Example 2

[0159] Synthesis of hydrophobic monomer-2:

[0160] 78.5516 g (0.36 mol) of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and 1480 g of N,N-dimethylformamide were added to a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device. After thorough stirring until dissolved, 19.5225 g (0.1 mol) of 2,4,6-tricyano-1,3,5-trimethylbenzene was added. After purging with nitrogen for 50 min, the temperature was raised to 126 °C, and 2.6248 g (0.004 mol) of bismuth trifluoromethanesulfonate was added. The reaction was continued for 48 h under stirring.

[0161] After the reaction was completed, N,N-dimethylformamide was removed by vacuum distillation. The product was then soaked in diethyl ether for 2 hours and filtered, followed by rinsing with diethyl ether. The product was then soaked in acetone for 2 hours and filtered, followed by rinsing with acetone. Finally, it was dried under vacuum to constant weight to obtain hydrophobic monomer-2.

[0162] The chemical reaction formula is shown below:

[0163]

[0164] The hydrophobic monomer-2 obtained in Example 2 was characterized by nuclear magnetic resonance [(CD3)2SO, 25℃], and its magnetic resonance spectrum was obtained. 1 HNMR) such as Figure 2 ;according to Figure 2 In 1 H NMR analysis revealed that the structure of the hydrophobic monomer-2 obtained in Example 2 is shown in formula c-2.

[0165] Example 3

[0166] Synthesis of hydrophobic monomer-3:

[0167] 91.6435 g (0.42 mol) of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and 1000 g of N,N-dimethylacetamide were added to a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device. After thorough stirring until dissolved, 19.5225 g (0.1 mol) (benzene-1,3,5-triacyl)triacetonitrile was added. After purging with nitrogen for 60 min, the temperature was raised to 136 °C, and 0.7234 g (0.002 mol) of copper trifluoromethanesulfonate was added. The reaction was continued for 36 h under stirring.

[0168] After the reaction was completed, N,N-dimethylacetamide was removed by vacuum distillation. The product was then soaked in diethyl ether for 2 hours and filtered, followed by rinsing with diethyl ether. The product was then soaked in acetone for 2 hours and filtered, followed by rinsing with acetone. Finally, it was dried under vacuum to constant weight to obtain hydrophobic monomer-3.

[0169] The chemical reaction formula is shown below:

[0170]

[0171] Example 4

[0172] Synthesis of hydrophobic monomer-4:

[0173] 109.1 g (0.5 mol) sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and 1250 g dimethyl sulfoxide were added to a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device. After stirring thoroughly until dissolved, 27.9387 g (0.1 mol) 1,3,5-benzenetributonitrile was added. Nitrogen gas was introduced for 30 min, and the temperature was raised to 147 °C. 1.302 g (0.0036 mol) copper trifluoromethanesulfonate was added, and the reaction was continued for 32 h under stirring.

[0174] After the reaction was completed, the above product was soaked in ether for 2 hours and then filtered. After rinsing with ether, it was soaked in acetone for 2 hours and then filtered. After rinsing with acetone, it was dried under vacuum to constant weight to obtain hydrophobic monomer-4.

[0175] The chemical reaction formula is shown below:

[0176]

[0177] Example 5

[0178] Synthesis of polymer gels

[0179] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 28.4316 g (0.4 mol) of acrylamide, 14.106 g (0.15 mol) of sodium acrylate, 5.8237 g (0.03 mol) of dimethyl acryloyloxymethylphosphonate and 16.1548 g (0.02 mol) of hydrophobic monomer-1 prepared in Example 1 were added sequentially to 600 mL of 1,4-dioxane for mixing and stirring, and the temperature was raised to 44 °C.

[0180] After passing N2 for 30 minutes, 1.2 g of azobisisobutyrazoline hydrochloride was added to the above mixed solution, and the reaction was continued for 32 hours to obtain the crude product of gel.

[0181] After adding 350 mL of anhydrous ethanol to the crude gel product for precipitation and filtering, the product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0182] The weight-average molecular weight of the polymer gel is 7.14 × 10⁻⁶. 5 g / mol.

[0183] The lens scan image of the polymer gel in this embodiment is as follows: Figure 3 As shown, through Figure 3 The polymer gel prepared in this embodiment has molecular chains that aggregate to form a spatial network structure. These network structures are composed of countless polygonal "mesh" and "nodes" that connect these meshes.

[0184] Through research and analysis, the inventors discovered that polymer gel molecular chains in the liquid phase entangle with each other and aggregate into chain bundles under the hydrophobic association of hydrophobic polymers, thereby forming interconnected supramolecular aggregates, which in turn form a three-dimensional network structure that fills the entire system in three-dimensional space.

[0185] Example 6

[0186] Synthesis of polymer gels

[0187] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 84.6105 g (0.5 mol) of diacetone acrylamide, 12.418 g (0.1 mol) of potassium methacrylate, 4.4435 g (0.02 mol) of diethyl acryloyloxymethylphosphonate and 8.0774 g (0.01 mol) of hydrophobic monomer-1 prepared in Example 1 were sequentially added to 1900 mL of dimethyl sulfoxide for mixing and stirring, and the temperature was raised to 86 °C.

[0188] After passing N2 for 30 minutes, 0.75 g of azodimethyl N-2-hydroxybutylacrylamide was added to the above mixed solution, and the reaction was continued for 24 hours to obtain the crude product of gel.

[0189] After adding 750 mL of anhydrous ethanol to the crude gel product for precipitation and filtering, the product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0190] The weight-average molecular weight of the polymer gel is 6.35 × 10⁻⁶. 5 g / mol.

[0191] Example 7

[0192] Synthesis of polymer gels

[0193] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 20.221 g (0.2 mol) of N-hydroxymethylacrylamide, 32.0428 g (0.25 mol) of 6-heptenic acid, 17.5162 g (0.07 mol) of diisopropyl acryloyloxymethylphosphonic acid and 24.2322 g (0.03 mol) of hydrophobic monomer-1 prepared in Example 1 were sequentially added to 800 mL of dimethyl sulfoxide, mixed and stirred, and heated to 51 °C.

[0194] After passing N2 for 30 minutes, 1.88 g of azobisisobutyronitrile was added to the above mixed solution, and the reaction was continued for 48 hours to obtain the crude product of gel.

[0195] After adding 600 mL of anhydrous methanol to the crude gel product to precipitate, the product was filtered. The product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the gel product.

[0196] The weight-average molecular weight of the polymer gel is 6.94 × 10⁻⁶. 5 g / mol.

[0197] Example 8

[0198] Synthesis of polymer gels

[0199] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 42.36332 g (0.3 mol) of N,N-diethylmethacrylamide, 25.6342 g (0.2 mol) of 3,3-dimethyl-4-pentenoic acid, 13.9142 g (0.05 mol) of 2-methacryloyloxyethylphosphonic acid diisopropyl ester and 20.1935 g (0.025 mol) of hydrophobic monomer-1 prepared in Example 1 were sequentially added to 1200 mL of N,N-dimethylformamide for mixing and stirring, and the temperature was raised to 104 °C.

[0200] After passing N2 for 30 minutes, 0.8 g of azoisobutyl cyanoformamide was added to the above mixed solution, and the reaction was continued for 16 hours to obtain the crude product of gel.

[0201] After adding 800 mL of anhydrous diethyl ether to the crude gel product to precipitate, the product was filtered. The product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0202] The weight-average molecular weight of the polymer gel is 6.25 × 10⁻⁶. 5 g / mol.

[0203] Example 9

[0204] Synthesis of polymer gels

[0205] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 23.0264 g (0.2 mol) of N-hydroxyethyl acrylamide, 28.536 g (0.25 mol) of 2-methyl-4-envalonic acid, 4.163 g (0.02 mol) of dimethyl acryloyloxyethylphosphonate and 8.0774 g (0.01 mol) of hydrophobic monomer-1 prepared in Example 1 were sequentially added to 400 mL of N,N-dimethylacetamide for mixing and stirring, and the temperature was raised to 76 °C.

[0206] After passing N2 through for 30 minutes, 1 g of 2,2'-azobis(N-cyclohexylisobutylamidine) hydrochloride was added to the above mixed solution, and the reaction was continued for 28 hours to obtain the crude product of gel.

[0207] After adding 500 mL of anhydrous ethanol to the crude gel product for precipitation and filtering, the product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0208] The weight-average molecular weight of the polymer gel is 7.00 × 10⁻⁶. 5 g / mol.

[0209] Example 10

[0210] Synthesis of polymer gels

[0211] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 19.8266 g (0.2 mol) of N-vinyl-N-methylacetamide, 25.0293 g (0.1 mol) of 2-methyl-3-butenoic acid, 14.56 g (0.07 mol) of dimethyl 2-methacryloyloxymethylphosphonic acid and 8.0774 g (0.01 mol) of the hydrophobic monomer-1 prepared in Example 1 were sequentially added to 750 mL of pyridine, mixed and stirred, and heated to 88 °C.

[0212] After passing N2 for 30 min, 1.14 g of azobiscyclohexylformonitrile was added to the above mixed solution, and the reaction was continued for 18 h to obtain the crude product of gel.

[0213] After adding 500 mL of anhydrous ethanol to the crude gel product for precipitation and filtering, the product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0214] The weight-average molecular weight of the polymer gel is 6.58 × 10⁻⁶. 5 g / mol.

[0215] Example 11

[0216] Synthesis of polymer gels

[0217] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 31.9856 g (0.45 mol) of acrylamide, 19.8275 g (0.18 mol) of potassium acrylate, 14.1722 g (0.06 mol) of diethyl acryloyloxyethylphosphonate and 16.9964 g (0.02 mol) of hydrophobic monomer-2 prepared in Example 2 were added sequentially to 800 mL of N,N-dimethylformamide for mixing and stirring, and the temperature was raised to 66 °C.

[0218] After passing N2 for 30 minutes, 1.2 g of dimethyl azobisisobutyrate was added to the above mixed solution, and the reaction was continued for 42 hours to obtain the crude product of gel.

[0219] After adding 500 mL of anhydrous methanol to the crude gel product to precipitate, the product was filtered. The product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0220] The weight-average molecular weight of the polymer gel is 7.75 × 10⁻⁶. 5 g / mol.

[0221] Example 12

[0222] Synthesis of polymer gels

[0223] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 86.6048 g (0.5 mol) of N,N-bis(2-hydroxyethyl)methacrylamide, 19.2257 g (0.15 mol) of 2-heptenic acid, 10.5703 g (0.04 mol) of diisopropyl acryloyloxyethylphosphonic acid and 25.4946 g (0.03 mol) of the hydrophobic monomer-2 prepared in Example 2 were added sequentially to 1500 mL of N,N-dimethylformamide for mixing and stirring, and the temperature was raised to 64 °C.

[0224] After passing N2 for 30 minutes, 2.8 g of azobisisobutyronitrile was added to the above mixed solution, and the reaction was continued for 18 hours to obtain the crude product of gel.

[0225] After adding 800 mL of anhydrous ethanol to the crude gel product for precipitation and filtering, the product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0226] The weight-average molecular weight of the polymer gel is 7.26 × 10⁻⁶. 5 g / mol.

[0227] Example 13

[0228] Synthesis of polymer gels

[0229] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 28.2894 g (0.25 mol) of N-isopropylacrylamide, 17.0638 g (0.12 mol) of 2-propyl-2-pentenoic acid, 11.9102 g (0.05 mol) of diethyl 2-methacryloyloxymethylphosphonic acid and 25.4946 g (0.03 mol) of the hydrophobic monomer-2 prepared in Example 2 were sequentially added to 1400 mL of dimethyl sulfoxide, mixed and stirred, and heated to 57 °C.

[0230] After passing N2 for 30 minutes, 0.18 g of azobis(N-hydroxyisobutylamidine) hydrate was added to the above mixed solution, and the reaction was continued for 48 hours to obtain the crude product of gel.

[0231] After adding 1500 mL of anhydrous methanol to the crude gel product to precipitate, the product was filtered. The product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extractant. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0232] The weight-average molecular weight of the polymer gel is 7.20 × 10⁻⁶. 5 g / mol.

[0233] Example 14

[0234] Synthesis of polymer gels

[0235] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 34.0424 g (0.4 mol) of N-vinylacetamide, 14.412 g (0.2 mol) of acrylic acid, 7.9277 g (0.03 mol) of 2-methacryloyloxymethylphosphonic acid diisopropyl ester and 12.7473 g (0.015 mol) of the hydrophobic monomer-2 prepared in Example 2 were sequentially added to 900 mL of dimethyl sulfoxide for mixing and stirring, and the temperature was raised to 67 °C.

[0236] After passing N2 for 30 min, 0.75 g of azobis(N,N'-cyclobutylisobutylamididine) hydrate was added to the above mixed solution, and the reaction was continued for 36 h to obtain the crude product of gel.

[0237] After adding 900 mL of anhydrous diethyl ether to the crude gel product to precipitate, the product was filtered. The product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0238] The weight-average molecular weight of the polymer gel is 6.79 × 10⁻⁶. 5 g / mol.

[0239] Example 15

[0240] Synthesis of polymer gels

[0241] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 25.4374 g (0.2 mol) of N,N-diethylacrylamide, 12.8171 g (0.1 mol) of 2,4-dimethyl-2-pentenoic acid, 4.4435 g (0.02 mol) of dimethyl 2-methacryloyloxyethylphosphonic acid and 25.4946 g (0.03 mol) of the hydrophobic monomer-3 prepared in Example 3 were sequentially added to 1150 mL of dimethyl sulfoxide for mixing and stirring, and the temperature was raised to 69 °C.

[0242] After passing N2 for 30 minutes, 0.5 g of azodicyanovalerate was added to the above mixed solution, and the reaction was continued for 36 hours to obtain the crude product of gel.

[0243] After adding 1150 mL of anhydrous diethyl ether to the crude gel product to precipitate, the product was filtered and washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the gel product.

[0244] The weight-average molecular weight of the polymer gel is 7.62 × 10⁻⁶. 5 g / mol.

[0245] Example 16

[0246] Synthesis of polymer gels

[0247] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 49.5656 g (0.5 mol) of N-ethylacrylamide, 25.0293 g (0.25 mol) of 3-pentenoic acid, 17.5143 g (0.07 mol) of 2-methacryloyloxyethylphosphonic acid diethyl ester and 8.4982 g (0.01 mol) of the hydrophobic monomer-3 prepared in Example 3 were added sequentially to 1500 mL of 1,4-dioxane for mixing and stirring, and the temperature was raised to 57 °C.

[0248] After passing N2 for 30 min, 1.2 g of azobiscarboxyethyl-2-isobutylamidine hydrate was added to the above mixed solution, and the reaction was continued for 25 h to obtain the crude product of gel.

[0249] After adding 1500 mL of anhydrous ethanol to the crude gel product to precipitate it, the product was filtered. The product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0250] The weight-average molecular weight of the polymer gel is 6.61 × 10⁻⁶. 5 g / mol.

[0251] Example 17

[0252] Synthesis of polymer gels

[0253] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 42.553 g (0.5 mol) of methacrylamide, 25.0293 g (0.25 mol) of 3-methyl-2-butenoic acid, 3.8825 g (0.02 mol) of dimethyl acryloyloxymethylphosphonate and 25.4946 g (0.03 mol) of hydrophobic monomer-3 prepared in Example 3 were sequentially added to 800 mL of N,N-dimethylacetamide for mixing and stirring, and the temperature was raised to 56 °C.

[0254] After passing N2 for 30 minutes, 1.5 g of azobisisobutylamidine hydrochloride was added to the above mixed solution, and the reaction was continued for 38 hours to obtain the crude product of gel.

[0255] After adding 800 mL of anhydrous ethanol to the crude gel product for precipitation and filtering, the product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0256] The weight-average molecular weight of the polymer gel is 7.26 × 10⁻⁶. 5 g / mol.

[0257] Example 18

[0258] Synthesis of polymer gels

[0259] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 45.205 g (0.35 mol) of N-(2-hydroxypropyl)acrylamide, 22.8288 g (0.2 mol) of 2-methyl-2-pentenoic acid, 9.4482 g (0.04 mol) of diethyl 2-methacryloyloxymethylphosphonic acid and 18.6797 g (0.02 mol) of hydrophobic monomer-4 prepared in Example 4 were added sequentially to 1200 mL of N,N-dimethylacetamide for mixing and stirring, and the temperature was raised to 61 °C.

[0260] After passing N2 through for 30 minutes, 1.35 g of azobisisopropylimidazoline was added to the above mixed solution, and the reaction was continued for 42 hours to obtain the crude product of gel.

[0261] After adding 1200 mL of anhydrous diethyl ether to the crude gel product to precipitate it, the product was filtered. The product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0262] The weight-average molecular weight of the polymer gel is 7.47 × 10⁻⁶. 5 g / mol.

[0263] Example 19

[0264] Synthesis of polymer gels

[0265] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 24.7828 g (0.25 mol) of N,N-dimethylacrylamide, 20.5074 g (0.16 mol) of 2,2-dimethyl-4-pentenoic acid, 7.7762 g (0.035 mol) of diethyl acryloyloxymethylphosphonic acid and 18.6797 g (0.02 mol) of the hydrophobic monomer-4 prepared in Example 4 were added sequentially to 1200 mL of N,N-dimethylformamide for mixing and stirring, and the temperature was raised to 67 °C.

[0266] After passing N2 for 30 minutes, 1.25 g of azobisisovalerate was added to the above mixed solution, and the reaction was continued for 42 hours to obtain the crude product of gel.

[0267] After adding 1200 mL of anhydrous ethanol to the crude gel product to precipitate it, the product was filtered. The product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extraction solvent. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0268] The weight-average molecular weight of the polymer gel is 6.84 × 10⁻⁶. 5 g / mol.

[0269] Example 20

[0270] Synthesis of polymer gels

[0271] In a reactor equipped with a temperature control device, a reflux condenser, and a constant pressure feeding device, 28.3094 g (0.28 mol) of N-hydroxymethylacrylamide, 25.0293 g (0.25 mol) of 4-enpentonic acid, 15.8555 g (0.06 mol) of diisopropyl acryloyloxyethylphosphonic acid and 28.0195 g (0.03 mol) of the hydrophobic monomer prepared in Example 4 were sequentially added to 850 mL of dimethyl sulfoxide, mixed and stirred, and heated to 86 °C.

[0272] After passing N2 through for 30 minutes, 0.6 g of azodimethyl N-2-hydroxybutylacrylamide was added to the above mixed solution, and the reaction was continued for 22 hours to obtain the crude product of gel.

[0273] After adding 850 mL of anhydrous methanol to the crude gel product to precipitate, the product was filtered. The product was washed three times with acetone. Then, the product was extracted with a Soxhlet extractor for 24 h using a 3:2 glacial acetic acid-ethylene glycol mixed solvent as the extractant. The product was then vacuum dried at 25 °C to constant weight to obtain the polymer gel product.

[0274] The weight-average molecular weight of the polymer gel is 7.23 × 10⁻⁶. 5 g / mol.

[0275] Example 21

[0276] The method of Example 5 is the same, except that dimethyl acryloyloxymethylphosphonate is not added;

[0277] The rest is the same as in Example 5.

[0278] The weight-average molecular weight of the polymer gel is 7.16 × 10⁻⁶. 5 g / mol.

[0279] Comparative Example 1

[0280] The method of Example 5 is followed, except that the hydrophobic monomer-1 prepared in Example 1 is not added;

[0281] The rest is the same as in Example 5.

[0282] The weight-average molecular weight of the polymer gel is 7.19 × 10⁻⁶. 5 g / mol.

[0283] Comparative Example 2

[0284] The method of Example 5 is followed, except that 0.02 mol of octadecyl acrylate is used to replace the hydrophobic monomer-1 prepared in Example 1;

[0285] The rest is the same as in Example 5.

[0286] The weight-average molecular weight of the polymer gel is 7.26 × 10⁻⁶. 5 g / mol.

[0287] Comparative Example 3

[0288] The method of Example 5 is followed, except that 0.02 mol of N,N'-methylenebisacrylamide is used to replace the hydrophobic monomer-1 prepared in Example 1.

[0289] The rest is the same as in Example 5.

[0290] The weight-average molecular weight of the polymer gel is 7.45 × 10⁻⁶. 5 g / mol.

[0291] Test case

[0292] 1. Test of gelation time

[0293] The polymer gels prepared in Examples 5-21 and Comparative Examples 1-3 were dissolved in water to prepare polymer solutions with a mass concentration of 1.5 wt% as test products. These solutions were then placed in a water bath at 25°C to test the gelation time and viscosity (test conditions: shear rate 7.34 s). -1 The polymer solution loses its fluidity and exhibits clumping properties during the initial gelation stage, and reaches final gelation once the viscosity remains unchanged. The experimental results are shown in Table 1.

[0294] Table 1. Gel formation time and maximum viscosity of different products

[0295] reagents Gel formation time (min) Maximum viscosity (mPa·s) Example 5 185 39410 Example 6 169 39400 Example 7 177 38360 Example 8 190 37720 Example 9 190 35040 Example 10 192 35010 Example 11 170 37850 Example 12 186 38200 Example 13 174 36120 Example 14 199 36550 Example 15 185 37320 Example 16 182 38200 Example 17 190 37140 Example 18 195 36750 Example 19 188 39000 Example 20 172 38310 Example 21 185 28800 Comparative Example 1 / 4200 Comparative Example 2 181 18600 Comparative Example 3 187 21000

[0296] As can be seen from the results in Table 1, the polymer gels prepared in Examples 5-21 and 5-20 using the structural units of the polymer gels containing the hydrophobic monomers of the present invention all had gelation times of less than 200 min and maximum viscosities of more than 28,000 mPa·s. In particular, the maximum viscosities of the polymer gels in Examples 5-20 were all higher than 35,000 mPa·s, which is suitable for the requirements of on-site leak sealing construction. Comparative Example 1 did not gel, and the viscosity remained at 4,200 mPa·s. The maximum viscosities of Comparative Examples 2 and 3 were only 18,600 mPa·s and 21,000 mPa·s, respectively. This indicates that the polymer gel products prepared by replacing Example 1 with octadecyl acrylate or N,N'-methylenebisacrylamide had weaker gelation effects.

[0297] 2. Temperature resistance test

[0298] The polymer gels prepared in Examples 5-21 and Comparative Examples 1-3 were dissolved in water to prepare polymer solutions with a mass concentration of 1.5% as test products. These solutions were aged for 16 hours at different temperatures, cooled to room temperature, and then placed in a 25°C water bath to test their maximum viscosity (test conditions: shear rate 7.34 s⁻¹). -1 The experimental results are shown in Table 2:

[0299] Table 2. Maximum viscosity of the product at different temperatures (mPa·s)

[0300]

[0301] Table 2 shows that the maximum viscosity of Examples 5-21 and Comparative Examples 1-3 gradually decreased with increasing aging temperature. After aging at 160℃ for 16 hours, the maximum viscosity of Examples 5-21 was higher than 25000 mPa·s, especially that of Examples 5-20, which was higher than 30000 mPa·s, demonstrating good temperature resistance. In contrast, the maximum viscosity of Comparative Examples 1-3 was lower after high-temperature aging, indicating weaker temperature resistance. The above test results indicate that the polymer gels prepared using octadecyl acrylate or N,N'-methylenebisacrylamide have relatively weak temperature resistance.

[0302] 3. Salt tolerance test

[0303] The polymer gels prepared in Examples 5-21 and Comparative Examples 1-3 were dissolved in NaCl solutions of different concentrations to prepare polymer solutions with a mass concentration of 1.5% as test products. After cooling to room temperature, the solutions were placed in a water bath at 25°C to test their maximum viscosity (test conditions: shear rate 7.34 s). -1 The experimental results are shown in Table 3:

[0304] Table 3. Maximum viscosity (mPa·s) of the product in different NaCl solutions.

[0305]

[0306]

[0307] As shown in Table 3, the maximum viscosity of Examples 5-21 and Comparative Examples 1-3 gradually decreased with increasing NaCl concentration, with the most significant decrease observed in Examples 21 and Comparative Example 1. When the NaCl concentration increased to 12.0 wt%, the maximum viscosity of Examples 5-20 was consistently above 30,000 mPa·s, demonstrating excellent salt resistance. These test results indicate that the synergistic effect of phosphonate monomers and the hydrophobic monomers in this invention plays a positive role in improving the salt resistance of the polymer gel.

[0308] 4. Calcium resistance test

[0309] The polymer gels prepared in Examples 5-21 and Comparative Examples 1-3 were dissolved in CaCl2 solutions of different concentrations to prepare polymer solutions with a mass concentration of 1.5% as test products. After cooling to room temperature, the solutions were placed in a water bath at 25°C to test their maximum viscosity (test conditions: shear rate 7.34 s). -1 The experimental results are shown in Table 4:

[0310] Table 4. Maximum viscosity (mPa·s) of the product in different CaCl2 solutions.

[0311]

[0312]

[0313] As shown in Table 4, the maximum viscosity of Examples 5-21 and Comparative Examples 1-3 gradually decreased with increasing CaCl2 concentration, especially Example 21 and Comparative Example 1, where the decrease in maximum viscosity was most significant. When the CaCl2 concentration increased to 1.5 wt%, the maximum viscosity of Examples 5-20 was all above 30000 mPa·s, exhibiting good calcium resistance. These test results indicate that the synergistic effect of phosphonate monomers and the hydrophobic monomers in this invention has a positive effect on improving the calcium resistance of the polymer gel.

[0314] 5. Evaluation of water dilution resistance

[0315] The polymer gels prepared in Examples 5-21 and Comparative Examples 2-3 were respectively formulated into polymer solutions with a mass percentage concentration of 1.5% as test products. After standing for 12 hours and allowing them to fully gel, they were cut into gel blocks of 0.5cm×0.5cm×0.5cm for later use.

[0316] A cubic sieve cage, 5.0 cm in length, width, and height, was made using an 80-mesh sieve with a 0.2 mm wire diameter. The sieve cage had an opening at the top for mounting to the stirrer blades. A polymer block of mass m1 was placed in the sieve cage, which was then fixed to the stirrer. Water of mass m2 was measured in a beaker, and the sieve cage was immersed in the water. The stirrer was turned on at 50 rpm to stir the aqueous solution above the polymer block. After stirring for a certain period, the sieve cage was lifted and suspended until no water dripped out. The mass of the water in the beaker was measured as m3. The difference between the mass of m3 and m2 represents the mass of the diluted polymer gel. The hydrogel's dilution resistance is... The smaller the K value, the better the hydrogel's anti-dilution performance. The experimental results are shown in Table 5.

[0317] Table 5. Anti-dilution properties (%) at different stirring times

[0318]

[0319] As shown in Table 5, the dilution resistance of the polymer gels prepared in Examples 5-21 and Comparative Examples 2-3 gradually increased with time. After stirring for 60 minutes, the dilution resistance of Examples 5-21 was less than 11%, which can meet the needs of on-site leak sealing construction.

[0320] 6. Shear dilution test

[0321] The polymer gels prepared in Examples 5-21 were formulated into polymer solutions with a mass percentage concentration of 1.5% as test products. Shear rates were measured using a temperature-controlled rheometer at 25°C, ranging from 7.34 to 100 s⁻¹. -1 The apparent viscosity under the specified conditions was tested, and the change of apparent viscosity (AV) of different polymer gels before gelation with shear rate was measured. The test results are shown in Table 6.

[0322] Table 6. AV (mPa·s) at different shear rates

[0323]

[0324] As can be seen from Table 6, the AV of the solutions prepared using Examples 5-20 first decreases rapidly with the increase of shear rate, and then tends to stabilize, indicating that the polymer gel of the present invention has good shear dilution properties, which is beneficial for the leakage channel injected from the wellbore into the leaky layer.

[0325] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A hydrophobic monomer, characterized in that, The structure of the hydrophobic monomer is shown in formula (I): In equation (I), R 1 R 2 and R 3 Each independently is H or Cl-C 18 alkyl; M1, M2, and M3 are each independently selected from H, Na, Li, or K; n, m, and z are each an independent integer between 0 and 6.

2. The hydrophobic monomer according to claim 1, wherein, R 1 R 2 and R 3 Each independently is H or Cl-C 12 Alkyl groups; and / or n, m, and z are each an independent integer between 0 and 3; and / or M1, M2 and M3 are the same.

3. The hydrophobic monomer according to claim 2, wherein, R 1 R 2 and R 3 Each is independently H or C1-C6 alkyl.

4. The hydrophobic monomer according to any one of claims 1-3, wherein, The hydrophobic monomer is selected from compounds with the following structural formulas:

5. A method for preparing a hydrophobic monomer, characterized in that, The preparation method includes: Under Ritter reaction conditions, the surfactant is contacted with the nitrile compound shown in formula (II); R 1 R 2 R 3 The definitions of , n, m and z correspond to the definitions described in any one of claims 1-4; The surfactant is selected from at least one of 3-allyloxy-2-hydroxy-1-propanesulfonic acid, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, lithium 3-allyloxy-2-hydroxy-1-propanesulfonate, and potassium 3-allyloxy-2-hydroxy-1-propanesulfonate.

6. The preparation method according to claim 5, wherein, The conditions for the Ritter reaction include: a reaction temperature of 80-180℃; a reaction time of 6-64 hours; and / or The molar ratio of the nitrile compound to the surfactant is 1:(3-6); and / or In a protective atmosphere and in the presence of a catalyst, the nitrile compound is contacted with a solution A containing a surfactant, and then purified and separated to obtain the hydrophobic monomer.

7. The preparation method according to claim 6, wherein, The conditions for the Ritter reaction include: a reaction temperature of 100-150°C; a reaction time of 12-56 hours; and / or The molar ratio of the nitrile compound to the surfactant is 1:(3.6-5.6); and / or The purification and separation method includes: concentration, soaking, filtration, washing, and drying to obtain the hydrophobic monomer.

8. The preparation method according to claim 6, wherein, The amount of catalyst used is 0.5 mol% to 10 mol% of the nitrile compound; The catalyst includes Acids and / or Lewis acids; And / or, The mass concentration of the surfactant in solution A is 5wt%-13wt%; The solvent in solution A includes at least one of the following: water, halogenated hydrocarbon solvents, ketone solvents, ether solvents, alkane solvents, nitrile solvents, ester solvents, aromatic hydrocarbon solvents, cycloalkane solvents, cycloether solvents, amine solvents, amide solvents, nitroalkane solvents, and sulfone solvents.

9. The preparation method according to claim 8, wherein, The amount of catalyst used is 1 mol% to 8 mol% of the nitrile compound; And / or, The solvent in solution A is at least one of aromatic hydrocarbon solvents, amide solvents, and sulfone solvents.

10. The preparation method according to claim 9, wherein, The amount of catalyst used is 2 mol% to 6 mol% of the nitrile compound.

11. A polymer gel, characterized in that, The polymer gel contains structural unit A of formula (1) derived from the hydrophobic monomer of any one of claims 1-4. R 1 R 2 R 3 The definitions of M1, M2 and M3, n, m and z correspond to the definitions described in any one of claims 1-4.

12. The polymer gel according to claim 11, wherein, Based on the total amount of all structural units in the polymer gel, the molar content of structural unit A in the polymer gel is 1%-10%.

13. The polymer gel according to claim 11, wherein, The polymer gel also contains structural unit B derived from alkenyl phosphonate monomers.

14. The polymer gel according to claim 13, wherein, The structural unit B is shown in equation (2). R0”” represents H, CH3 or C2H5; R3 is a phosphonate group; Where o is an integer from 1 to 6; R e and R f Each is independently selected from H or C1-C6 alkyl groups; The molar ratio of structural unit B to structural unit A is (2-7):(1-3).

15. The polymer gel according to claim 14, wherein, R0”” represents H or CH3; R3 is o is an integer between 1 and 3; R e and R f Each is independently selected from H, CH3, C2H5, CH2CH2CH3 or CH(CH3)2.

16. The polymer gel according to claim 15, wherein, o is 1 or 2; R e and R f Each is independently selected from H, CH3, C2H5, and CH(CH3)2.

17. The polymer gel according to claim 16, wherein, R e and R f They are not both H.

18. The polymer gel according to claim 11, wherein, The polymer gel also contains structural units derived from water-soluble monomers.

19. The polymer gel according to claim 18, wherein, The structural units derived from water-soluble monomers include structural unit C from alkenyl amide monomers as shown in formula (3) and / or structural unit D from alkenyl carboxylic acid monomers as shown in formula (4). R0 is selected from H or C1-C6 alkyl groups; R1 is selected from amide groups; R0', R0” and R0”' are each independently H or C1-C6 alkyl; R2 is a carboxylic acid group.

20. The polymer gel according to claim 19, wherein, R0 is selected from H, CH3, or C2H5; R0', R0” and R0”' are each independently H, CH3, C2H5, CH2CH2CH3, CH(CH3)2 or CH2CH2CH2CH3.

21. The polymer gel according to claim 19, wherein, R1 is R a and R b Each is independently selected from H, C1-C6 alkyl groups, C1-C6 alkyl alcohols, and C1-C8 alkyl ketones; R c It is H or C1-C6 alkyl; R d It is a C1-C6 alkyl group; And / or, R2 is A is selected from at least one of H, Na, K, Rb, and Cs; t is 0, 1, 2, or 4; r is an integer between 0 and 6; s is an integer between 0 and 6; R is H or CH3; And / or, The molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3).

22. The polymer gel according to claim 21, wherein, R a and R b Each is independently selected from H, CH3, CH2CH3, CH(CH3)2, CH2OH, CH2CH2OH, C(CH3)2CH2COCH3 or CH2CH(CH3)OH; R c It can be H, CH3, C2H5 or CH(CH3)2; R d It can be CH3, C2H5 or CH(CH3)2; And / or, A is at least one of H, Na, and K; r is an integer between 0 and 2; s is an integer between 0 and 2.

23. The polymer gel according to any one of claims 11-22, wherein, The polymer gel has a weight-average molecular weight of 6.25 × 10⁻⁶. 5 -7.75×10 5 g / mol.

24. The polymer gel according to claim 21, wherein, The polymer gel comprises at least one of the following copolymers: Copolymer-1, wherein structural unit A is derived from the compound shown in the following structural formula (A-1), structural unit B is derived from dimethyl acryloyloxymethylphosphonate, structural unit C is derived from acrylamide, and structural unit D is derived from sodium acrylate, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-2, wherein structural unit A is derived from the compound shown in the following structural formula (A-1), structural unit B is derived from diethyl acryloyloxymethylphosphonate, structural unit C is derived from diacetone acrylamide, and structural unit D is derived from potassium methacrylate, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-3, wherein structural unit A is derived from the compound shown in the following structural formula (A-1), structural unit B is derived from diisopropyl acryloyloxymethylphosphonic acid, structural unit C is derived from N-hydroxymethylacrylamide, and structural unit D is derived from 6-heptenic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-4, wherein structural unit A is derived from the compound shown in the following structural formula (A-1), structural unit B is derived from diisopropyl 2-methacryloyloxyethylphosphonic acid, structural unit C is derived from N,N-diethylmethacrylamide, and structural unit D is derived from 3,3-dimethyl-4-pentenoic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-5, wherein structural unit A is derived from the compound shown in the following structural formula (A-1), structural unit B is derived from dimethyl acryloyloxyethylphosphonate, structural unit C is derived from N-hydroxyethylacrylamide, and structural unit D is derived from 2-methyl-4-envalonic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-6, wherein structural unit A is derived from the compound shown in the following structural formula (A-1), structural unit B is derived from dimethyl 2-methacryloyloxymethylphosphonate, structural unit C is derived from N-vinyl-N-methylacetamide, and structural unit D is derived from 2-methyl-3-butenoic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-7, wherein structural unit A is derived from the compound shown in the following structural formula (A-2), structural unit B is derived from diethyl acryloyloxyethylphosphonate, structural unit C is derived from acrylamide, and structural unit D is derived from potassium acrylate, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-8, wherein structural unit A is derived from the compound shown in the following structural formula (A-2), structural unit B is derived from diisopropyl acryloyloxyethylphosphonic acid, structural unit C is derived from N,N-bis(2-hydroxyethyl)methacrylamide, and structural unit D is derived from 2-heptenoic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-9, wherein structural unit A is derived from the compound shown in the following structural formula (A-2), structural unit B is derived from diethyl 2-methacryloyloxymethylphosphonic acid, structural unit C is derived from N-isopropylacrylamide, and structural unit D is derived from 2-propyl-2-pentenoic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-10, wherein structural unit A is derived from the compound shown in the following structural formula (A-2), structural unit B is derived from diisopropyl 2-methacryloyloxymethylphosphonic acid, structural unit C is derived from N-vinylacetamide, and structural unit D is derived from acrylic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-11, wherein structural unit A is derived from the compound shown in the following structural formula (A-3), structural unit B is derived from dimethyl 2-methacryloyloxyethylphosphonic acid, structural unit C is derived from N,N-diethylacrylamide, and structural unit D is derived from 2,4-dimethyl-2-pentenoic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-12, wherein structural unit A is derived from the compound shown in the following structural formula (A-3), structural unit B is derived from diethyl 2-methacryloyloxyethylphosphonic acid, structural unit C is derived from N-ethylacrylamide, and structural unit D is derived from 3-pentenoic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-13, wherein structural unit A is derived from the compound shown in the following structural formula (A-3), structural unit B is derived from dimethyl acryloyloxymethylphosphonate, structural unit C is derived from methacrylamide, and structural unit D is derived from 3-methyl-2-butenoic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-14, wherein structural unit A is derived from the compound shown in the following structural formula (A-4), structural unit B is derived from diethyl 2-methacryloyloxymethylphosphonic acid, structural unit C is derived from N-(2-hydroxypropyl)acrylamide, and structural unit D is derived from 2-methyl-2-pentenoic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-15, wherein structural unit A is derived from the compound shown in the following structural formula (A-4), structural unit B is derived from diethyl acryloyloxymethylphosphonic acid, structural unit C is derived from N,N-dimethylacrylamide, and structural unit D is derived from 2,2-dimethyl-4-pentenoic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); Copolymer-16, wherein structural unit A is derived from the compound shown in the following structural formula (A-4), structural unit B is derived from diisopropyl acryloyloxyethylphosphonic acid, structural unit C is derived from N-hydroxymethylacrylamide, and structural unit D is derived from 4-enivalic acid, and the molar ratio of structural unit C, structural unit D, structural unit B to structural unit A is (20-50):(10-25):(2-7):(1-3); 25. A method for preparing a polymer gel, the method comprising: In the presence of an initiator, a monomer mixture undergoes a free radical polymerization reaction, characterized in that the monomer mixture contains the hydrophobic monomer described in any one of claims 1-4.

26. The preparation method according to claim 25, wherein, In the monomer mixture, the molar content of the hydrophobic monomer is 1%-10% based on the total amount of the monomer mixture.

27. The preparation method according to claim 25, wherein, The monomer mixture also includes the alkenyl phosphonate monomer shown in formula (2-1); The definitions of R0”” and R3 are the same as those in claim 14.

28. The preparation method according to claim 27, wherein, The molar ratio of the alkenyl phosphonate monomer to the hydrophobic monomer is (2-7):(1-3).

29. The preparation method according to claim 25, wherein, The monomer mixture also includes water-soluble monomers.

30. The preparation method according to claim 29, wherein, The water-soluble monomers include alkenylamide monomers represented by formula (3-1) and / or alkenylcarboxylic acid monomers represented by formula (4-1); The definitions of R0, R1, R0', R0”R0”' and R2 correspond to the definitions in claim 19.

31. The preparation method according to claim 30, wherein, The molar ratio of the alkenylamide monomer, alkenyl carboxylic acid monomer, alkenyl phosphonate monomer and hydrophobic monomer is (20-50):(10-25):(2-7):(1-3).

32. The preparation method according to any one of claims 25-31, wherein, The conditions for the free radical polymerization reaction include: a reaction temperature of 35-120℃; a reaction time of 15-50 h; and / or The amount of the initiator is 0.2%-2.5% of the total weight of the monomer mixture.

33. The preparation method according to claim 25, wherein, The free radical polymerization reaction is carried out in the presence of solvent A and a protective atmosphere.

34. The preparation method according to claim 33, wherein, Solvent A is selected from at least one of halogenated hydrocarbon solvents, ketone solvents, ether solvents, alkane solvents, nitrile solvents, ester solvents, aromatic hydrocarbon solvents, cycloalkane solvents, cycloether solvents, amine solvents, amide solvents, nitroalkane solvents, and sulfone solvents; and / or The concentration of the monomer mixture in solvent A is 5wt%-15wt%.

35. A polymer gel prepared by the preparation method according to any one of claims 25-34.

36. The use of the polymer gel according to any one of claims 11-24 and 35 as a plugging material in drilling operations.

37. A leak-sealing material, characterized in that, The sealing material comprises water and the polymer gel according to any one of claims 11-24 and 35.

38. The application of the plugging material according to claim 37 in well drilling plugging.

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