Hydrophobic cross-linking monomer and preparation method thereof, polymer plugging agent and preparation method thereof

Abstract

The present invention discloses a hydrophobic cross-linking monomer, a preparation method thereof, and a polymer plugging agent, and a preparation method thereof. Alkenyl compounds and phenyl compounds are dissolved in a solvent and then mixed with a low-valent titanium reducing agent. The hydrophobic cross-linking monomer is then obtained by quenching, filtering, rinsing, drying, vacuum distillation, and purification. The polymer plugging agent is obtained by polymerizing an alkenyl amide monomer, an alkenyl carboxylic acid monomer, and a hydrophobic cross-linking monomer. The hydrophobic cross-linking monomer has good temperature resistance, and the polymer plugging agent has good dispersibility, thermal stability, and viscoelasticity, and can effectively block nano-micrometer-scale pores. The molecular formula of the hydrophobic cross-linking monomer is: #imgabs0#

Description

Technical Field

[0001] The present invention relates to a petroleum additive, in particular to a hydrophobic cross-linking monomer and a preparation method thereof. The present invention also relates to a polymer plugging agent and a preparation method thereof, belonging to the technical field of drilling plugging. Background Art

[0002] Wellbore instability is a common but poorly addressed engineering and technical issue in drilling projects. Severe wellbore collapse is common when drilling into stratified microcracks, formations with strong geostress, abnormal pore pressure, long stretches of mudstone, or certain formations with steep inclinations and potential wellbore deflection. After the formation rock is drilled through, drilling fluid filtrate intrudes through the microcracks, increasing the pore pressure within the wellbore. When this pressure exceeds the expansion limit of the fractures within the formation rock, it causes the fractures to expand, interconnecting previously unconnected fractures. This weakens the rock and can lead to spalling and shedding of the wellbore wall.

[0003] To overcome the challenge of wellbore instability in collapse-prone formations, researchers both domestically and internationally have conducted extensive research on the mechanisms of wellbore instability. This research has found that the main factors contributing to wellbore instability include the effects of hydration on wellbore stability and collapse pressure, as well as the destructive effects of pressure transmission on the wellbore's well-developed micropores. Hydration is the result of the combined effects of specific surface area and exchangeable ions. Hydration occurring on the surface of clay minerals is called surface hydration, or lattice expansion, and is caused by water molecules indirectly adsorbed by electrical interactions. After surface hydration is complete, water molecules enter the interlayers of the rock in large quantities, further deepening the hydration process. This is called osmotic hydration, also known as osmotic expansion. Hydration of clay minerals increases the spacing between clay minerals, weakens cementation, expands the shale volume, and significantly reduces its strength, thereby compromising the stability of the entire wellbore. For the majority of hard and brittle mudstones, their water sensitivity is not prominent, and the inhibitory effect of drilling fluid alone cannot prevent collapse and protect the wall. At this time, the existence of micro-nano pores on hard and brittle mudstones in the non-traditional sense should be taken into consideration. If the sealing of these micro-cracks and pores can be strengthened to prevent drilling fluid or filtrate from entering them, and the impact of hydration or capillary force and pore pressure penetration on the prone to collapse formations can be reduced, the wellbore stability problem during drilling will be fundamentally solved.

[0004] The main causes of wellbore instability can be summarized as physical and chemical factors, engineering and technical factors, and mechanical factors. The first two factors ultimately arise from changes in the stress distribution and mechanical properties of the surrounding rock formations, exceeding the rock's inherent strength. Therefore, effectively sealing shale pores and microcracks to slow water ingress and pressure transmission is the key to water-based drilling fluid anti-collapse technology.

[0005] At present, research on anti-collapse plugging theory mainly includes rigid plugging theory and flexible plugging theory. Rigid plugging theory refers to first using larger rigid granular materials to build bridges to increase the pressure-bearing capacity of the leakage channel, and then using smaller secondary materials to fill the remaining space after the first-level rigid material builds bridges, as well as secondary leakage channels smaller than the first-level rigid material, filling them step by step, thereby reducing the permeability of the leakage formation. Rigid plugging materials represented by ultrafine calcium carbonate and nano-silica have been widely used in drilling projects. Flexible plugging theory refers to the use of non-rigid materials without a fixed shape, such as polymers, which will undergo physical and chemical changes and deformation under conditions such as formation temperature and pressure, thereby sealing the formation pores and cracks.

[0006] The core of flexible plugging theory is that after a plugging material is mixed or dissolved in a liquid, it undergoes physical and chemical changes such as cross-linking, adsorption, expansion, and solidification under the influence of underground temperature, salinity, and seepage fields. This process fills and seals formation pores and fractures, forming a sealing zone with a certain pressure-bearing capacity. Flexible plugging technology originates from earlier concepts of filling and plugging, as well as the concept of filling with softening materials proposed in the "two-thirds rule." Its purpose is to block widespread leakage pathways in heterogeneous formations that cannot be blocked by rigid materials, as well as to bridge pores between granular materials, thereby reducing formation permeability and enhancing formation pressure-bearing capacity. To date, a systematic theoretical framework for flexible plugging has not been established. Flexible plugging materials used in drilling operations are primarily asphalt or modified asphalt products. However, asphalt-based plugging materials generally have a high softening point, requiring higher formation temperatures to be effective. Furthermore, asphalt-based plugging materials exhibit a fluorescence effect, which negatively impacts geological logging. Summary of the Invention

[0007] The primary purpose of the present invention is to overcome the problem of poor formation plugging effect in the prior art and provide a hydrophobic cross-linked monomer. A polymer plugging agent synthesized based on the monomer can improve the plugging ability of drilling fluid on micropores in formation rocks.

[0008] In order to solve the above technical problems, a hydrophobic cross-linking monomer of the present invention comprises a plurality of benzene rings, and its structural formula is shown below:

[0009]

[0010] Wherein, R is selected from one of -H or C1~C6 alkyl, R 10 、R 20 、R 30 、R 10 、R 20 、R 30 One selected from -H or C1~C6 alkyl, R00 One selected from -H or C1~C6 alkyl.

[0011] As an improvement of the present invention, R is -CH3, R 10 、R 20 、R 30 、R 10 、R 20 、R 30 -CH3, R 00 For -CH3.

[0012] Another object of the present invention is to overcome the problems existing in the prior art and provide a method for preparing a hydrophobic cross-linked monomer. The polymer plugging agent synthesized based on the monomer can improve the plugging ability of the drilling fluid on the micropores of the formation rock.

[0013] In order to solve the above technical problems, the present invention provides a method for preparing a hydrophobic cross-linking monomer, which is synthesized using an alkenyl compound having a structure of formula II-1 and a phenyl compound having a structure of formula II-2 as raw materials.

[0014] Formula II-1:

[0015] Formula II-2:

[0016] Wherein, R is selected from one of -H or C1~C6 alkyl, R 10 、R 20 、R 30 、R 10 、R 20 、R 30 One selected from -H or C1~C6 alkyl, R 00 One selected from -H or C1~C6 alkyl.

[0017] As an improvement of the present invention, an alkenyl compound of formula II-1 and a phenyl compound of formula II-2 are dissolved in a solvent and then mixed with a low-valent titanium reducing agent. The mixture is then quenched, filtered, rinsed, dried, distilled under reduced pressure, and purified to obtain a hydrophobic cross-linking monomer, the structural formula of which is shown below:

[0018]

[0019] As a further improvement of the present invention, the specific synthesis steps are as follows:

[0020] S1. Under inert gas protection, activated Zn powder, CuCl and solvent 1 are added to a reactor, cooled and stirred, and then TiCl4 is added, the temperature is raised to reflux, and cooled again to obtain the low-valent titanium reducing agent;

[0021] S2, dissolving the alkenyl compound and the phenyl compound in solvent 2, mixing the mixture with the low-valent titanium reducing agent obtained in step S1, and continuing the reaction under stirring;

[0022] S3, adding K2CO3 solution to the reactor to quench the reaction;

[0023] S4, filtering through diatomaceous earth to remove the low-valent titanium reducing agent, collecting the filtrate, and then flushing with CH2Cl2, mixing the flushing liquid with the filtrate to obtain a mixed solution;

[0024] S5, the mixed solution is dried with a desiccant, filtered and then distilled under reduced pressure to remove the solvent to obtain a light yellow crude product;

[0025] S6. Recrystallize the crude product obtained in step S5 with methanol or ethanol to obtain a white frosty powder, namely, the hydrophobic cross-linking monomer.

[0026] As a further improvement of the present invention, in step S1: the inert gas is at least one of nitrogen or argon, the particle size of the activated Zn powder is 200-600 mesh, the solvent one is one of tetrahydrofuran or dimethyl ether, the concentration of the activated Zn powder in the solvent one is 0.2-0.5 mmol / mL, the concentration of the activated CuCl in the solvent one is 0.03-0.07 mmol / mL, the concentration of the activated TiCl4 in the solvent one is 0.3-0.8 mmol / mL, and the cooling temperature is -10-0°C.

[0027] As a further improvement of the present invention, in step S2: the molar ratio of the alkenyl compound to the phenyl compound is 3: (1.6 to 2.0), the solvent two is the same as the solvent one, the volume ratio of solvent two to solvent one is 1: (2 to 4), the concentration of the alkenyl compound in solvent two is 0.3 to 0.6 mmol / mL, when the solvents one and two are tetrahydrofuran, step S2 is heated and refluxed under stirring, the reflux temperature is 68 to 76°C, and the reflux time is 1 to 10 hours; when the solvents one and two are dimethyl ether, there is no need to heat in step S2.

[0028] As a further improvement of the present invention, in step S3: the concentration of the K2CO3 is 5.0wt% to 20.0wt%, and the volume ratio of the K2CO3 solution to the solvent 2 is 1:(5 to 10); in step S5: the desiccant is one of the inorganic neutral desiccant MgSO4, Na2SO4, CaSO4 or CaCl2.

[0029] As a further improvement of the present invention, the reflux time in step S2 is 4 to 8 hours; and the concentration of K2CO3 in step S3 is 8.0 wt% to 12.0 wt%.

[0030] Another object of the present invention is to overcome the problems existing in the prior art and provide a polymer plugging agent that can improve the plugging ability of drilling fluid on micropores in formation rocks.

[0031] To solve the above technical problems, the present invention provides a polymer plugging agent obtained by polymerizing monomers, wherein the monomers include alkenyl amide monomers, alkenyl carboxylic acid monomers and hydrophobic cross-linking monomers, and the hydrophobic cross-linking monomers have the molecular formula structure as described in claim 1.

[0032] As an improvement of the present invention, the chemical structural formula of the polymer plugging agent is:

[0033]

[0034] The subscripts a, b, c, d and e respectively represent the molar numbers of the corresponding three types of monomers, wherein c=d=e, and are all the molar numbers of the corresponding hydrophobic cross-linking monomers. In the structural formula, a:b:c=(20~60):(15~35):(1~3).

[0035] As a further improvement of the present invention, in the alkenyl amide monomer, R1 is selected from one of -H or C1 to C6 alkyl groups, and R2 is selected from amide groups.

[0036] As a further improvement of the present invention, R1 is selected from one of -CH3 or -C2H5,

[0037] R2 is selected from

[0038] Among them, R a and R b Each independently selected from one of -H, C1-C6 alkyl, C1-C6 alkyl alcohol, and C1-C8 alkyl ketone,

[0039] R c One selected from -H or C1-C6 alkyl,

[0040] R d Selected from -CH3, -CH2CH3 or One of them.

[0041] As a further improvement of the present invention, R a and R b Each independently selected from -CH3, -CH2CH3, —CH2OH, —CH2CH2OH, One of the following;

[0042] R c Selected from -CH3, -CH2CH3 or One of them.

[0043] As a further improvement of the present invention, in the alkenyl carboxylic acid monomer, R3 is selected from one of -H or C1-C6 alkyl, and R4 is a carboxylic acid group.

[0044] As a further improvement of the present invention, R3 is selected from one of -CH3 or -C2H5;

[0045] R4 is selected from One of the following;

[0046] A is selected from at least one of H, Na, K, Rb and Cs.

[0047] As a further improvement of the present invention, for R4, s, r, and t are integers of 0 to 6, respectively, and R is selected from -H or -CH3.

[0048] As a further improvement of the present invention, s is an integer of 0 to 4, r is an integer of 0 to 2, and t is an integer of 0 to 2.

[0049] As a further improvement of the present invention, R is selected from one of -H or C1 to C6 alkyl, R 10 、R 20 、R 30 、R 10 、R 20 、R 30 One selected from -H or C1~C6 alkyl, R 00 One selected from -H or C1~C6 alkyl.

[0050] As a further improvement of the present invention, R is selected from -H or -CH3, R 10 、R 20 、R 30 、R 10 、R 20 、R 30 Selected from -H or -CH3, R 00 Selected from -H or -CH3.

[0051] Another object of the present invention is to overcome the problems existing in the prior art and provide a method for preparing a polymer plugging agent. The prepared polymer plugging agent can improve the plugging ability of the drilling fluid on the micropores of the formation rock.

[0052] To solve the above technical problems, the present invention provides a method for preparing a polymer plugging agent, which is prepared from an alkenyl amide monomer, an alkenyl carboxylic acid monomer, and a hydrophobic crosslinking monomer by inverse microemulsion polymerization, and specifically comprises the following steps:

[0053] A1. Weigh a certain amount of organic solvent and emulsifier, add them to the reactor, stir at high speed until clear, and set aside;

[0054] A2. Quantitatively weigh alkenyl amide, alkenyl carboxylic acid, and hydrophobic crosslinking monomer, add these three monomers to water, stir evenly, and adjust the pH value to 7.5-8.5 with NaOH (or KOH) for later use;

[0055] A3, nitrogen is introduced into the reactor and the temperature is raised to the reaction temperature, an initiator is added under continuous stirring, and the reaction solution obtained in step A2 is added to the solution in the reactor;

[0056] A4. After continuing the reaction for a while, stop heating and stirring, pour the reaction product into methanol or ethanol, stir for 30 minutes, and then filter, and rinse the obtained solid with methanol or ethanol;

[0057] A5. Transfer the solid obtained after rinsing to acetone solution, stir for 30 minutes, filter again, and rinse with acetone;

[0058] A6. Transfer the obtained solid to a vacuum oven, vacuum dry it at 35°C to a constant weight, and grind it into fine particles to obtain a polymer plugging agent.

[0059] As an improvement of the present invention, in step A1, the organic solvent is selected from one or more of white oil, liquid paraffin, cyclohexane, isooctane, benzene, toluene, xylene, diesel, kerosene, methyl nylonate, petroleum ether, butanone, and isoparaffin with a boiling point of 207-245° C.

[0060] In step A1, the emulsifier is selected from one or more of a cationic surfactant, an anionic surfactant, an amphoteric surfactant, and a nonionic surfactant, and the mass percentage concentration of the emulsifier is 10.0% to 60.0%;

[0061] In step A2, the mass of the water is 1 to 2.5 times that of the organic solvent;

[0062] In step A2, the molar ratio of the alkenyl amide monomer, the alkenyl carboxylic acid monomer and the hydrophobic crosslinking monomer is (20-60): (15-35): (1-3);

[0063] In step A2, the mass percentage concentration of the three monomers of the alkenyl amide monomer, the alkenyl carboxylic acid monomer and the hydrophobic crosslinking monomer in the aqueous solution is 5.0% to 50.0%;

[0064] In step A3, the reaction temperature is 30-150° C.;

[0065] In step A3, the initiator is one of K2S2O8 or (NH4)2S2O8 in the water-soluble redox system initiator, and can also be one of the azo compound initiator azobisisobutylimidazoline hydrochloride, azoisobutylcyanoformamide, azobisisobutyronitrile, benzoyl peroxide, azodicarboxyethyl-2-isobutylamidine hydrate, azodimethyl N-2-hydroxybutylacrylamide, azobiscyclohexylcarbonitrile, azobisisovaleronitrile, azobisisoheptylnitrile, azobiscyanovaleric acid, azobisisobutylamidine hydrochloride, azobisisopropylimidazoline, azobisN-hydroxyisobutylamidine hydrate, azobisN,N'cyclobutylisobutylamidine hydrate, azobisdimethylisobutyrate or 2,2'-azobis(N-cyclohexylisobutylamidine) hydrochloride;

[0066] The amount of the initiator added is 0.02% to 4.0% of the total mass of the three monomers, preferably 0.05% to 3.0%, more preferably 0.5% to 1.5%;

[0067] In step A4, the reaction duration is 1 to 12 hours.

[0068] As a further improvement of the present invention, the emulsifier in step A1 is a mixture of one or two polysorbate nonionic surfactants with an HLB range of 0 to 10, or sodium di(2-ethylhexyl)sulfosuccinate;

[0069] In step A1, the mass percentage concentration of the emulsifier is 20.0% to 40.0%;

[0070] In step A2, the mass percentage concentration of the three monomers, namely, the alkenyl amide monomer, the alkenyl carboxylic acid monomer, and the hydrophobic crosslinking monomer, in the aqueous solution is 10.0 to 25.0%;

[0071] In step A3, the reaction temperature is 40-100° C.;

[0072] In step A3, the amount of the initiator added is 0.05% to 3.0% of the total mass of the three monomers;

[0073] In step A4, the reaction duration is 1 to 8 hours.

[0074] As a further improvement of the present invention, the amount of the initiator added is 0.5% to 1.5% of the total mass of the three monomers;

[0075] In step A4, the reaction time is 2 to 6 hours;

[0076] The emulsifier in step A1 is a mixture of one or two polysorbate nonionic surfactants with an HLB range of 3 to 9, or sodium di(2-ethylhexyl)sulfosuccinate.

[0077] Compared with the prior art, the present invention has the following beneficial effects: 1. The hydrophobic crosslinking monomer contains a conjugated diene, which has higher polymerization activity than the reaction monomer of a monoolefin, that is, the polymerization reaction time is shorter, which is conducive to industrial production.

[0078] 2. The hydrophobic cross-linking monomer contains multiple benzene ring structures, which increases the molecular rigidity of the polymer plugging agent and can effectively reduce the thermal motion of the molecular chain under high temperature conditions, thereby giving the gel good temperature resistance.

[0079] 3. Compared with the linear gel synthesized using a cross-linking monomer with only two chemical cross-linking groups, the hyperbranched polymer obtained using a monomer containing three chemical cross-linking groups has more branching points, and the molecular chains are not easily entangled, which effectively increases the dissolution and gelation speed and is not easy to agglomerate.

[0080] 4. The prepared polymer plugging agent is spherical and has good dispersibility, thermal stability and viscoelasticity. It can effectively block nano-micrometer-scale pores, thereby facilitating the formation of a continuous and dense pressure-bearing plugging layer around the well wall, reducing the pressure transmission rate, preventing filtrate intrusion, and providing stability to the well wall.

[0081] 5. The resulting polymer plugging agent is a hydrophobically associating gel with both chemical and physical crosslinking. In addition to possessing the high mechanical strength, self-healing, and reprocessability inherent to hydrophobic associating gels, hydrophobic association causes the hydrophobic groups in the gel molecules to associate, forming hydrophobically associating microdomains. These microdomains act as physical crosslinking points within the gel network, making the gel molecules a fluid with excellent shear-thinning properties before gelation, thus facilitating their penetration into the micropores and fissures within the rock.

[0082] 6. The average flow rate of the prepared polymer plugging agent in the simulated nano-micron formation is less than 0.54 cm 2 ·s-1, the permeability of the simulated formation before and after plugging is lower than 84*10-2mD, and the plugging rate is above 79%. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The accompanying drawings are only provided for reference and illustration and are not intended to limit the present invention.

[0084] Figure 1 This is a magnetic resonance spectrum of the hydrophobic cross-linking monomer of Example 1 of the present invention;

[0085] Figure 2 This is a magnetic resonance spectrum of the water-crosslinked monomer of Example 2 of the present invention;

[0086] Figure 3 This is a scanning electron microscope image of the polymer plugging agent prepared in Example 7 of the present invention. DETAILED DESCRIPTION

[0087] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0088] Example 1

[0089] Synthesis of hydrophobic cross-linking monomers

[0090] Under nitrogen protection, 19.614 g (300 mmol) of 200 mesh activated Zn powder, 4.95 g (50 mmol) of CuCl and 1000 mL of tetrahydrofuran (THF) were added to the reactor, cooled to 0°C and stirred, 94.8375 g (500 mmol) of TiCl4 was added, the temperature was raised to 68°C and refluxed for 2.5 h, and then cooled to 0°C again to obtain a low-valent titanium reducing agent.

[0091] 14.7218 g (150 mmol) of 3-methyl-3-penten-2-one and 38.9267 g (90 mmol) of [1,3,5-trimethyl-2,4,6-tris(4'-formylphenyl)]benzene were dissolved in 300 mL of tetrahydrofuran, mixed with a low-valent titanium reducing agent, heated to 68°C with stirring, and refluxed for 6 h.

[0092] After adding 50 mL of 8.0 wt% K2CO3 solution, filter through diatomaceous earth, collect the filtrate, rinse with CH2Cl2, and mix the rinse liquid with the filtrate to obtain a mixed solution.

[0093] Add sufficient amount of Na2SO4 to the mixed solution, filter it and distill it under reduced pressure to remove THF to obtain a light yellow crude product.

[0094] The crude product was recrystallized from methanol to obtain a white waxy substance, which was the target product, the hydrophobic cross-linking monomer.

[0095] The product obtained in Example 1 was characterized by nuclear magnetic resonance [(CD3)2SO, 25 ° C], magnetic resonance spectrum ( 1 H NMR) Figure 1 According to its 1 H NMR analysis showed that the present invention obtained a hydrophobic cross-linking monomer with the aforementioned structure.

[0096] Example 2

[0097] Synthesis of hydrophobic cross-linking monomers

[0098] Under argon protection, 10.4638 g (160 mmol) of 600 mesh activated Zn powder, 4.752 g (48 mmol) of CuCl and 800 mL of dimethyl ether (DME) were added to the reactor, the temperature was controlled to -10°C, stirred, 45.523 g (240 mmol) of TiCl4 was added, and refluxed for 4 h to obtain a low-valent titanium reducing agent.

[0099] Dissolve 3.3638 g (60 mmol) of acrolein and 18.984 g (40 mmol) of [1,3,5-trimethyl-2,4,6-tris(4'-acetylphenyl)]benzene in 200 mL of dimethyl ether, add the mixture to a low-valent titanium reducing agent, and reflux for 8 hours. Add 40 mL of a 10.0 wt% KCO solution, filter through celite, collect the filtrate, rinse with CHCl, and combine the rinse with the filtrate to obtain a mixed solution.

[0100] Add sufficient amount of MgSO4 to the mixed solution, filter it and distill it under reduced pressure to remove DME to obtain a light yellow crude product.

[0101] The crude product was recrystallized from methanol to obtain a white waxy substance, which was the target product, the hydrophobic cross-linking monomer.

[0102] The product obtained in Example 2 was characterized by nuclear magnetic resonance [(CD3)2SO, 25 ° C], magnetic resonance spectrum ( 1 H NMR) Figure 2 According to its 1 H NMR analysis showed that the present invention obtained a hydrophobic cross-linking monomer with the aforementioned structure.

[0103] Example 3

[0104] Synthesis of hydrophobic cross-linking monomers

[0105] Under nitrogen protection, 32.69 g (500 mmol) of 200 mesh activated Zn powder, 2.97 g (30 mmol) of CuCl and 1000 mL of tetrahydrofuran were added to the reactor, cooled to -4 ° C, stirred, 151.7432 g (800 mmol) of TiCl4 was added, the temperature was raised to 76 ° C and refluxed for 2 h, and then cooled to -4 ° C again to obtain a low-valent titanium reducing agent.

[0106] 14.0182 g (200 mmol) of methyl vinyl ketone and 42.1673 g (108 mmol) of [1,3,5-tris(4'-formylphenyl)]benzene were dissolved in 500 mL of tetrahydrofuran, mixed with a low-valent titanium reducing agent, heated to 76° C. with stirring, and refluxed for 4 h.

[0107] Add 50 mL of a 12.0 wt% K2CO3 solution, filter through diatomaceous earth, collect the filtrate, rinse with CH2Cl2, and mix the rinse with the filtrate to obtain a mixed solution. Add sufficient CaSO4 to the mixed solution, filter, and distill under reduced pressure to remove THF, thereby obtaining a pale yellow crude product.

[0108] The crude product was recrystallized from ethanol to obtain a white waxy substance, which was the target product, the hydrophobic cross-linking monomer.

[0109] Example 4

[0110] Synthesis of hydrophobic cross-linking monomers

[0111] Under nitrogen protection, 26.152 g (400 mmol) of 400 mesh activated Zn powder, 6.93 g (70 mmol) of CuCl and 1000 mL of tetrahydrofuran were added to the reactor, cooled to -10 ° C, stirred, 75.8716 g (400 mmol) of TiCl4 was added, the temperature was raised to 72 ° C and refluxed for 4 h, and then cooled to -10 ° C again to obtain a low-valent titanium reducing agent.

[0112] 20.1883 g (240 mmol) of 3-methyl-2-butenal and 55.3624 g (128 mmol) of [1,3,5-tris(4'-acetylphenyl)]benzene were dissolved in 400 mL of tetrahydrofuran, mixed with a low-valent titanium reducing agent, heated to 72° C. with stirring, and refluxed for 7.5 h.

[0113] After adding 50 mL of a 12.0 wt% K2CO3 solution, the mixture was filtered through diatomaceous earth, and the filtrate was collected and rinsed with CH2Cl2. The rinse liquid was mixed with the filtrate to obtain a mixed solution.

[0114] Add sufficient amount of CaSO4 to the mixed solution, filter it and distill it under reduced pressure to remove THF to obtain a light yellow crude product.

[0115] The crude product was recrystallized from ethanol to obtain a white waxy substance, which was the target product, the hydrophobic cross-linking monomer.

[0116] Example 5

[0117] Synthesis of hydrophobic cross-linking monomers

[0118] Under nitrogen protection, 32.69 g (500 mmol) of 500 mesh activated Zn powder, 3.96 g (40 mmol) of CuCl and 1000 mL of dimethyl ether (DME) were added to the reactor, the temperature was controlled to -6 ° C, and stirred. 113.8074 g (600 mmol) of TiCl4 was added and refluxed for 3 h to obtain a low-valent titanium reducing agent.

[0119] 12.6164 g (180 mmol) of 2-butenal and 40.996 g (105 mmol) of [1,3,5-tris(4'-formylphenyl)]benzene were dissolved in 360 mL of dimethyl ether, mixed with a low-valent titanium reducing agent, and refluxed for 4 h.

[0120] After adding 72 mL of a 12.0 wt% K2CO3 solution, the mixture was filtered through diatomaceous earth, and the filtrate was collected and rinsed with CH2Cl2. The rinse liquid was mixed with the filtrate to obtain a mixed solution.

[0121] Add sufficient amount of CaCl2 to the mixed solution, filter it and distill it under reduced pressure to remove DME to obtain a light yellow crude product.

[0122] The crude product was recrystallized from methanol to obtain a white waxy substance, which was the target product, the hydrophobic cross-linking monomer.

[0123] Example 6

[0124] Synthesis of hydrophobic cross-linking monomers

[0125] Under argon protection, 26.152 g (400 mmol) of 300 mesh activated Zn powder, 3.96 g (40 mmol) of CuCl and 1000 mL of dimethyl ether were added to the reactor, the temperature was controlled to 0°C, and the mixture was stirred. 75.8716 g (400 mmol) of TiCl4 was added and refluxed for 3 h to obtain a low-valent titanium reducing agent.

[0126] 9.4219 g (96 mmol) of 4-methyl-3-penten-2-one and 27.6812 g (64 mmol) of [1,3,5-tris(4'-acetylphenyl)]benzene were dissolved in 320 mL of dimethyl ether, mixed with a low-valent titanium reducing agent, and refluxed for 4 h.

[0127] After adding 64 mL of a 12.0 wt% K2CO3 solution, the mixture was filtered through diatomaceous earth, the filtrate was collected, and then rinsed with CH2Cl2. The rinse liquid was mixed with the filtrate to obtain a mixed solution.

[0128] Add sufficient amount of CaCl2 to the mixed solution, filter it and distill it under reduced pressure to remove DME to obtain a light yellow crude product.

[0129] The crude product was recrystallized from ethanol to obtain a white waxy substance, which was the target product, the hydrophobic cross-linking monomer.

[0130] Example 7

[0131] Synthesis of polymer plugging agents

[0132] Weigh 280 g of benzene, 50 g of Span 65, and 50 g of Tween 40 (HLB = 8.85) into a reactor and stir at high speed until the mixture becomes clear. Set aside.

[0133] Weigh 14.2158 g (0.2 mol) of acrylamide, 18.627 g (0.15 mol) of potassium methacrylate, and 18.9288 g (0.03 mol) of the crosslinking monomer prepared in Example 1 (molar ratio 20:15:3), add these three monomers to 400 g of water, stir evenly, adjust the pH to 8.5 with NaOH, and set aside;

[0134] Nitrogen was introduced into the reactor and the temperature was raised to 72° C. 0.6 g of 2,2′-azobis(N-cyclohexylisobutylamidine) hydrochloride was added under continuous stirring, and the solution containing the reaction monomers was added to the solution in the reactor.

[0135] After the reaction was continued for 4 hours, heating and stirring were stopped, and the reaction product was poured into ethanol. After stirring for 30 minutes, the mixture was filtered and the obtained solid was rinsed with ethanol.

[0136] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0137] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0138] 1.0 g of the polymer plugging agent prepared in Example 7 was added to 100 mL of clean water, aged at 150° C. for 16 h, cooled to room temperature, and allowed to stand for 48 h. The micromorphology of the polymer plugging agent in the clean water was observed using a scanning electron microscope (SEM). The SEM photograph is shown in FIG. Figure 3 .

[0139] Example 8

[0140] Synthesis of polymer plugging agents

[0141] Weigh 150 g of petroleum ether, 60 g of Span 85, and 40 g of Tween 61 (HLB = 4.92) and add them to the reactor. Stir at high speed until the mixture becomes clear. Set aside.

[0142] Weigh 84.612 g (0.6 mol) of diacetone acrylamide, 15.0176 g (0.15 mol) of 3-enevaleric acid, and 18.9288 g (0.03 mol) of the crosslinking monomer prepared in Example 1 (molar ratio 60:15:3), add these three monomers to 375 g of water, stir evenly, adjust the pH to 8.0 with NaOH, and set aside;

[0143] Nitrogen was introduced into the reactor and the temperature was raised to 66° C. 0.6 g of dimethyl azobisisobutyrate was added under continuous stirring, and the solution containing the reaction monomers was added to the solution in the reactor.

[0144] After the reaction was continued for 6 h, heating and stirring were stopped, and the reaction product was poured into methanol. After stirring for 30 min, the mixture was filtered and the obtained solid was rinsed with methanol.

[0145] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0146] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0147] Example 9

[0148] Synthesis of polymer plugging agents

[0149] Weigh 400 g of toluene and 100 g of sodium di(2-ethylhexyl)sulfosuccinate (AOT) into a reactor, stir at high speed until the solution becomes clear, and set aside.

[0150] Weigh 60.663 g (0.6 mol) of N-hydroxymethyl acrylamide, 32.9157 g (0.35 mol) of sodium acrylate, and 6.3096 g (0.01 mol) of the crosslinking monomer prepared in Example 1 (molar ratio 60:35:1), add these three monomers to 400 g of water, stir evenly, adjust the pH to 7.5 with NaOH, and set aside;

[0151] Nitrogen was introduced into the reactor and the temperature was raised to 67° C. 1.49 g of azobisisovaleronitrile was added under continuous stirring, and the solution containing the reaction monomer was added to the solution in the reactor.

[0152] After the reaction was continued for 2 h, heating and stirring were stopped, and the reaction product was poured into methanol. After stirring for 30 min, the mixture was filtered and the obtained solid was rinsed with methanol.

[0153] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0154] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0155] Example 10

[0156] Synthesis of polymer plugging agents

[0157] Weigh 320g 5 # Add white oil and 100g Tween 20 (HLB=8.6) into the reactor, stir at high speed until clear, and set aside;

[0158] Weigh 29.7399 g (0.3 mol) of N,N-bis(2-hydroxyethyl)methacrylamide, 25.6342 g (0.2 mol) of 3,3-dimethyl-4-pentenoic acid, and 12.6192 g (0.03 mol) of the crosslinking monomer prepared in Example 1 (molar ratio 30:20:3), add these three monomers to 400 g of water, stir evenly, adjust the pH to 8.5 with NaOH, and set aside;

[0159] Nitrogen was introduced into the reactor and the temperature was raised to 100° C. 0.68 g of azoisobutylcyanamide was added under continuous stirring, and the solution containing the reaction monomers was added to the solution in the reactor.

[0160] After the reaction was continued for 2.5 h, heating and stirring were stopped, and the reaction product was poured into ethanol. After stirring for 30 min, the mixture was filtered and the obtained solid was rinsed with ethanol.

[0161] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0162] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0163] Example 11

[0164] Synthesis of polymer plugging agents

[0165] Weigh 260 g of cyclohexane, 62 g of Span 80, and 38 g of Tween 20 (HLB = 9) into a reactor and stir at high speed until the mixture becomes clear. Set aside.

[0166] 103.9272 g (0.6 mol) of N,N-bis(2-hydroxyethyl)methacrylamide, 19.2257 g (0.15 mol) of 3,3-dimethyl-4-pentenoic acid, and 18.9288 g (0.03 mol) of the crosslinking monomer prepared in Example 1 (molar ratio 60:15:3) were weighed, and these three monomers were added to 650 g of water, stirred evenly, and the pH value was adjusted to 8.5 with NaOH for later use; nitrogen was introduced into the reactor and the temperature was raised to 88° C., 1 g of azobiscyclohexylcarbonitrile was added under continuous stirring, and the solution containing the reaction monomers was added to the solution in the reactor.

[0167] After the reaction was continued for 5 h, heating and stirring were stopped, the reaction product was poured into ethanol, stirred for 30 min, and then filtered, and the obtained solid was rinsed with ethanol.

[0168] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0169] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0170] Example 12

[0171] Synthesis of polymer plugging agents

[0172] Weigh 240 g of isooctane, 75 g of Span 40, and 25 g of Tween 81 (HLB = 7.53) into a reactor and stir at high speed until the mixture becomes clear. Set aside.

[0173] Weigh 17.0212 g (0.2 mol) of methacrylamide, 19.2257 g (0.15 mol) of 2,2-dimethyl-4-pentenoic acid, and 6.3096 g (0.01 mol) of the crosslinking monomer prepared in Example 1 (molar ratio 20:15:1), add these three monomers to 240 g of water, stir evenly, adjust the pH to 8.0 with NaOH, and set aside;

[0174] Nitrogen was introduced into the reactor and the temperature was raised to 44° C. 1 g of azobisisobutylimidazoline hydrochloride was added under continuous stirring, and the solution containing the reaction monomer was added to the solution in the reactor.

[0175] After the reaction was continued for 3.5 h, heating and stirring were stopped, and the reaction product was poured into ethanol. After stirring for 30 min, the mixture was filtered and the obtained solid was rinsed with ethanol.

[0176] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0177] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0178] Example 13

[0179] Synthesis of polymer plugging agents

[0180] Weigh 300 g of toluene, 75 g of Span 65, and 25 g of Tween 65 (HLB = 4.2) into a reactor, stir at high speed until clear, and set aside;

[0181] Weigh 39.6524 g (0.4 mol) of N-ethylacrylamide, 31.0451 g (0.25 mol) of potassium methacrylate, and 8.202 g (0.015 mol) of the crosslinking monomer prepared in Example 2 (molar ratio 40:25:1.5), add these three monomers to 450 g of water, stir evenly, adjust the pH to 8.0 with NaOH, and set aside;

[0182] Nitrogen was introduced into the reactor and the temperature was raised to 64° C. 0.4 g of azobisisobutyronitrile was added under continuous stirring, and the solution containing the reaction monomer was added to the solution in the reactor.

[0183] After the reaction was continued for 4 hours, heating and stirring were stopped, and the reaction product was poured into ethanol. After stirring for 30 minutes, the mixture was filtered and the obtained solid was rinsed with ethanol.

[0184] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0185] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0186] Example 14

[0187] Synthesis of polymer plugging agents

[0188] Weigh 300 g of benzene, 75 g of Span 65, and 25 g of Tween 65 (HLB = 4.2) into a reactor and stir at high speed until the mixture becomes clear. Set aside.

[0189] Weigh 25.5318 g (0.3 mol) of N-vinyl acetamide, 13.9713 g (0.18 mol) of acrylic acid, and 10.936 g (0.02 mol) of the crosslinking monomer prepared in Example 2 (molar ratio 30:18:2), add these three monomers to 440 g of water, stir evenly, adjust the pH to 8.0 with NaOH, and set aside;

[0190] Nitrogen was introduced into the reactor and the temperature was raised to 57° C. 0.52 g of azodicarboxyethyl-2-isobutylamidine hydrate was added under continuous stirring, and the solution containing the reaction monomers was added to the solution in the reactor.

[0191] After the reaction was continued for 3 h, heating and stirring were stopped, the reaction product was poured into ethanol, stirred for 30 min, and then filtered, and the obtained solid was rinsed with ethanol.

[0192] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0193] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0194] Example 15

[0195] Synthesis of polymer plugging agents

[0196] Weigh 200 g of cyclohexane, 90 g of Span 60, and 10 g of Tween 80 (HLB = 5.73) into a reactor and stir at high speed until the mixture becomes clear. Set aside.

[0197] Weigh 22.632 g (0.2 mol) of N-isopropylacrylamide, 44.8599 g (0.35 mol) of 2,4-dimethyl-2-pentenoic acid, and 16.4039 g (0.03 mol) of the crosslinking monomer prepared in Example 2 (molar ratio 20:35:3), add these three monomers to 500 g of water, stir evenly, adjust the pH to 7.5 with NaOH, and set aside;

[0198] Nitrogen was introduced into the reactor and the temperature was raised to 61° C. 1.2 g of azobisisopropylimidazoline was added under continuous stirring, and the solution containing the reaction monomer was added to the solution in the reactor.

[0199] After the reaction was continued for 2 h, heating and stirring were stopped, and the reaction product was poured into methanol. After stirring for 30 min, the mixture was filtered and the obtained solid was rinsed with methanol.

[0200] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0201] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0202] Example 16

[0203] Synthesis of polymer plugging agents

[0204] Weigh 260g 3 # Add white oil, 95g Span 20 and 5g Tween 81 (HLB=8.67) into the reactor and stir at high speed until it becomes clear.

[0205] Weigh 77.4954 g (0.6 mol) of N-isopropylacrylamide, 12.9135 g (0.15 mol) of 2,4-dimethyl-2-pentenoic acid, and 5.468 g (0.01 mol) of the crosslinking monomer prepared in Example 2 (molar ratio 60:15:1), add these three monomers to 360 g of water, stir evenly, adjust the pH to 8.0 with NaOH, and set aside;

[0206] Nitrogen was introduced into the reactor and the temperature was raised to 69° C. 0.8 g of azobiscyanovaleric acid was added under continuous stirring, and the solution containing the reaction monomer was added to the solution in the reactor.

[0207] After the reaction was continued for 2.5 h, heating and stirring were stopped, and the reaction product was poured into methanol. After stirring for 30 min, the mixture was filtered and the obtained solid was rinsed with methanol.

[0208] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0209] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0210] Example 17

[0211] Synthesis of polymer plugging agents

[0212] Weigh 280 g of cyclohexane and 100 g of sodium di(2-ethylhexyl)sulfosuccinate (AOT) into a reactor, stir at high speed until the solution becomes clear, and set aside.

[0213] Weigh 28.2428 g (0.2 mol) of N,N-diethylmethacrylamide, 21.3297 g (0.15 mol) of 2-propyl-2-pentenoic acid, and 16.4039 g (0.03 mol) of the crosslinking monomer prepared in Example 3 (molar ratio 20:15:3), add these three monomers to 560 g of water, stir evenly, adjust the pH to 8.5 with NaOH, and set aside;

[0214] Nitrogen was introduced into the reactor and the temperature was raised to 56° C. 0.96 g of azobisisobutylamidine hydrochloride was added under continuous stirring, and the solution containing the reaction monomers was added to the solution in the reactor.

[0215] After the reaction was continued for 4.5 h, heating and stirring were stopped, and the reaction product was poured into methanol. After stirring for 30 min, the mixture was filtered and the obtained solid was rinsed with methanol.

[0216] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0217] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0218] Example 18

[0219] Synthesis of polymer plugging agents

[0220] Weigh 320 g of petroleum ether, 80 g of Span 40, and 20 g of Tween 21 (HLB = 8.02) into a reactor and stir at high speed until the mixture becomes clear. Set aside.

[0221] Weigh 45.2057 g (0.35 mol) of N-(2-hydroxypropyl)acrylamide, 17.02 g (0.17 mol) of 2-methyl-3-butenoic acid, and 10.936 g (0.02 mol) of the crosslinking monomer prepared in Example 3 (molar ratio 35:17:2), add these three monomers to 480 g of water, stir evenly, adjust the pH to 8.5 with NaOH, and set aside;

[0222] Nitrogen was introduced into the reactor and the temperature was raised to 51° C. 0.75 g of azobisisoheptanonitrile was added under continuous stirring, and the solution containing the reaction monomer was added to the solution in the reactor.

[0223] After the reaction was continued for 5.5 h, heating and stirring were stopped, and the reaction product was poured into methanol. After stirring for 30 min, the mixture was filtered and the obtained solid was rinsed with methanol.

[0224] The solid obtained after rinsing was transferred to an acetone solution, stirred for 30 min, and then filtered again and rinsed with acetone.

[0225] The obtained solid was transferred to a vacuum oven, vacuum dried at 35° C. to a constant weight, and ground into fine particles to obtain a polymer plugging agent.

[0226] Example 19

[0227] The method of Example 18 was followed, except that the hydrophobic cross-linking monomer was replaced with the hydrophobic monomer prepared in Example 4 in the same molar amount. Other conditions were the same as in Example 18.

[0228] Example 20

[0229] The method of Example 18 was followed, except that the hydrophobic cross-linking monomer was replaced with the hydrophobic monomer prepared in Example 5 in the same molar amount. Other conditions were the same as in Example 18.

[0230] Example 21

[0231] The method of Example 18 was followed, except that the hydrophobic cross-linking monomer was replaced with the hydrophobic monomer prepared in Example 6 in the same molar amount. Other conditions were the same as in Example 18.

[0232] Test Case

[0233] Plugging performance test

[0234] The fixed permeability (400×10 -2An artificial rock core (mD) was used to simulate nano-micron formations. The average flow rates of 800-mesh ultrafine calcium carbonate, 2500-mesh ultrafine calcium carbonate, 6000-mesh ultrafine calcium carbonate, and Examples 7-21 (experimental slurry formula: 0.5% bentonite + 0.05% high-viscosity carboxymethyl cellulose sodium salt + 1.0% plugging material) in the simulated nano-micron formation were measured respectively. The permeability of the simulated formation before and after plugging was calculated using the Darcy formula, thereby obtaining the plugging rates of the simulated formations with different plugging materials. The experimental results are shown in Table 1:

[0235] Table 1 Plugging rates of different plugging materials

[0236]

[0237] As can be seen from Table 1, compared with 800 mesh ultrafine calcium carbonate, 2500 mesh ultrafine calcium carbonate, and 6000 mesh ultrafine calcium carbonate, the polymer plugging agents prepared by Examples 7 to 21 and Comparative Example 1 have better plugging effects on nano-micron-sized formations.

[0238] It should be noted that, considering that the polymerization reaction between the monomers is non-specific and the reactivity ratios of the reaction monomers are different, the structural formula only shows the combination of the reaction structural units in one of the molecular structures of the polymer plugging agent; the proportional relationship between a, b, c, d and e only shows the molar ratio relationship of the reaction monomers to which the reaction structural units originally belong when used as raw materials, and does not represent the actual ratio relationship of the reaction structural units in the polymer plugging agent molecule as a polymerization product.

[0239] The above is only a preferred embodiment of the present invention, which shows and describes the basic principles and main features of the present invention and the advantages of the present invention, but does not limit the scope of patent protection of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. In addition to the above embodiments, the present invention may also have other implementation modes without departing from the spirit and scope of the present invention. The present invention may also have various changes and improvements, and all technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention. The scope of protection required by the present invention is defined by the attached claims and their equivalents. Technical features not described in the present invention can be achieved by or using existing technologies, and will not be described here.

Claims

1. A hydrophobic cross-linking monomer comprising a plurality of benzene rings, characterized in that: Its structural formula is shown below: Wherein, R is selected from one of -H or C1~C6 alkyl, R 10 、R 20 、R 30 、R 10 、R 20 、R 30 One selected from -H or C1~C6 alkyl, R 00 One selected from -H or C1~C6 alkyl.

2. The hydrophobic cross-linking monomer according to claim 1, characterized in that: R is -CH3, R 10 、R 20 、R 30 、R 10 、R 20 、R 30 -CH3, R 00 For -CH3.

3. A method for preparing a hydrophobic cross-linking monomer, characterized in that: The synthesis is carried out using an alkenyl compound having a structure of formula II-1 and a phenyl compound having a structure of formula II-2 as raw materials. Wherein, R is selected from one of -H or C1~C6 alkyl, R 10 、R 20 、R 30 、R 10 、R 20 、R 30 One selected from -H or C1~C6 alkyl, R 00 One selected from -H or C1~C6 alkyl.

4. The method for preparing a hydrophobic cross-linking monomer according to claim 3, wherein: The alkenyl compound of formula II-1 and the phenyl compound of formula II-2 are dissolved in a solvent and then mixed with a low-valent titanium reducing agent. The mixture is then quenched, filtered, rinsed, dried, distilled under reduced pressure, and purified to obtain a hydrophobic cross-linking monomer having the following structural formula:

5. The method for preparing a hydrophobic cross-linking monomer according to claim 4, wherein: The specific synthesis steps are as follows: S1. Under inert gas protection, activated Zn powder, CuCl and solvent 1 are added to a reactor, cooled and stirred, and then TiCl4 is added, the temperature is raised to reflux, and cooled again to obtain the low-valent titanium reducing agent; S2, dissolving the alkenyl compound and the phenyl compound in solvent 2, mixing the mixture with the low-valent titanium reducing agent obtained in step S1, and continuing the reaction under stirring; S3, adding K2CO3 solution to the reactor to quench the reaction; S4, filtering through diatomaceous earth to remove the low-valent titanium reducing agent, collecting the filtrate, and then flushing with CH2Cl2, mixing the flushing liquid with the filtrate to obtain a mixed solution; S5, the mixed solution is dried with a desiccant, filtered and then distilled under reduced pressure to remove the solvent to obtain a light yellow crude product; S6. Recrystallize the crude product obtained in step S5 with methanol or ethanol to obtain a white frosty powder, namely, the hydrophobic cross-linking monomer.

6. The method for preparing a hydrophobic cross-linking monomer according to claim 5, wherein: In step S1: the inert gas is at least one of nitrogen or argon, the particle size of the activated Zn powder is 200-600 mesh, the solvent one is one of tetrahydrofuran or dimethyl ether, the concentration of the activated Zn powder in the solvent one is 0.2-0.5 mmol / mL, the concentration of the activated CuCl in the solvent one is 0.03-0.07 mmol / mL, the concentration of the activated TiCl4 in the solvent one is 0.3-0.8 mmol / mL, and the cooling temperature is -10-0°C.

7. The method for preparing a hydrophobic cross-linking monomer according to claim 5, wherein: In step S2: the molar ratio of the alkenyl compound to the phenyl compound is 3: (1.6 to 2.0), the solvent two is the same as the solvent one, the volume ratio of solvent two to solvent one is 1: (2 to 4), the concentration of the alkenyl compound in solvent two is 0.3 to 0.6 mmol / mL, when the solvents one and two are tetrahydrofuran, step S2 is heated and refluxed under stirring, the reflux temperature is 68 to 76° C., and the reflux time is 1 to 10 hours; when the solvents one and two are dimethyl ether, no heating is required in step S2.

8. The method for preparing a hydrophobic cross-linking monomer according to claim 7, wherein: In step S3: the concentration of the K2CO3 is 5.0wt% to 20.0wt%, and the volume ratio of the K2CO3 solution to the solvent 2 is 1:(5 to 10); in step S5: the desiccant is one of the inorganic neutral desiccant MgSO4, Na2SO4, CaSO4 or CaCl2.

9. The method for preparing a hydrophobic cross-linking monomer according to claim 7, wherein: In step S3: the reflux time of step S2 is 4 to 8 hours; the concentration of K2CO3 in step S3 is 8.0 wt% to 12.0 wt%.

10. A polymer plugging agent obtained by polymerization of monomers, characterized in that: The monomers include alkenyl amide monomers, alkenyl carboxylic acid monomers and hydrophobic cross-linking monomers, and the hydrophobic cross-linking monomers have the molecular formula structure as claimed in claim 1.

11. The polymer plugging agent according to claim 10, characterized in that: The chemical structure of polymer plugging agent is: The subscripts a, b, c, d and e respectively represent the molar numbers of the corresponding three types of monomers, wherein c=d=e, and are all the molar numbers of the corresponding hydrophobic cross-linking monomers. In the structural formula, a:b:c=(20~60):(15~35):(1~3).

12. The polymer plugging agent according to claim 10, characterized in that In the alkenyl amide monomer, R1 is selected from one of -H or C1-C6 alkyl groups, and R2 is selected from amide groups.

13. The polymer plugging agent according to claim 12, characterized in that: R1 is selected from one of -CH3 or -C2H5, R2 is selected from Among them, R a and R b Each independently selected from one of -H, C1-C6 alkyl, C1-C6 alkyl alcohol, and C1-C8 alkyl ketone, R c One selected from -H or C1-C6 alkyl, R d Selected from -CH3, -CH2CH3 or One of them.

14. The polymer plugging agent according to claim 13, characterized in that R a and R b Each independently selected from -CH3, -CH2CH3, —CH2OH, —CH2CH2OH, One of the following; R c Selected from -CH3, -CH2CH3 or One of them.

15. The polymer plugging agent according to claim 10, characterized in that In the alkenyl carboxylic acid monomer, R3 is selected from one of -H or C1-C6 alkyl groups, and R4 is a carboxylic acid group.

16. The polymer plugging agent according to claim 15, characterized in that R3 is selected from one of —CH3 or —C2H5; R4 is selected from One of the following; A is selected from at least one of H, Na, K, Rb and Cs.

17. The polymer plugging agent according to claim 16, characterized in that For R4, s, r, and t are integers of 0 to 6, respectively, and R is selected from -H or -CH3.

18. The polymer plugging agent according to claim 17, characterized in that s is an integer of 0 to 4, r is an integer of 0 to 2, and t is an integer of 0 to 2.

19. The polymer plugging agent according to claim 10, characterized in that R is selected from -H or C1~C6 alkyl, R 10 、R 20 、R 30 、R 10 、R 20 、R 30 One selected from -H or C1~C6 alkyl, R 00 One selected from -H or C1~C6 alkyl.

20. The polymer plugging agent according to claim 19, characterized in that R is selected from -H or -CH3, R 10 、R 20 、R 30 、R 10 、R 20 、R 30 Selected from -H or -CH3, R 00 Selected from -H or -CH3.

21. A method for preparing a polymer plugging agent according to any one of claims 10 to 19, characterized in that: The polyol is prepared from vinyl amide monomers, vinyl carboxylic acid monomers and hydrophobic crosslinking monomers by inverse microemulsion polymerization, which specifically includes the following steps: A1. Weigh a certain amount of organic solvent and emulsifier, add them to the reactor, stir at high speed until clear, and set aside; A2. Quantitatively weigh alkenyl amide, alkenyl carboxylic acid, and hydrophobic crosslinking monomer, add these three monomers to water, stir evenly, and adjust the pH value to 7.5-8.5 with NaOH (or KOH) for later use; A3, nitrogen is introduced into the reactor and the temperature is raised to the reaction temperature, an initiator is added under continuous stirring, and the reaction solution obtained in step A2 is added to the solution in the reactor; A4. After continuing the reaction for a while, stop heating and stirring, pour the reaction product into methanol or ethanol, stir for 30 minutes, and then filter, and rinse the obtained solid with methanol or ethanol; A5. Transfer the solid obtained after rinsing to acetone solution, stir for 30 minutes, filter again, and rinse with acetone; A6. Transfer the obtained solid to a vacuum oven, vacuum dry it at 35°C to a constant weight, and grind it into fine particles to obtain a polymer plugging agent.

22. The method for preparing a polymer plugging agent according to claim 21, characterized in that: In step A1, the organic solvent is selected from one or more of white oil, liquid paraffin, cyclohexane, isooctane, benzene, toluene, xylene, diesel, kerosene, methyl nylonate, petroleum ether, butanone, and isoparaffin with a boiling point of 207-245° C. In step A1, the emulsifier is selected from one or more of a cationic surfactant, an anionic surfactant, an amphoteric surfactant, and a nonionic surfactant, and the mass percentage concentration of the emulsifier is 10.0% to 60.0%; In step A2, the mass of the water is 1 to 2.5 times that of the organic solvent; In step A2, the molar ratio of the alkenyl amide monomer, the alkenyl carboxylic acid monomer and the hydrophobic crosslinking monomer is (20-60): (15-35): (1-3); In step A2, the mass percentage concentration of the three monomers of the alkenyl amide monomer, the alkenyl carboxylic acid monomer and the hydrophobic crosslinking monomer in the aqueous solution is 5.0% to 50.0%; In step A3, the reaction temperature is 30-150° C.; In step A3, the initiator is one of K2S2O8 or (NH4)2S2O8 in the water-soluble redox system initiator, or an azo compound initiator azobisisobutylimidazoline hydrochloride, azoisobutylcyanamide, azobisisobutyronitrile, benzoyl peroxide, azodicarboxyethyl-2-isobutylamidine hydrate, azodimethyl N-2-hydroxybutylacrylamide, azobiscyclohexylcarbonitrile, azobisisobutylcyanamide ... One of azobisisovaleronitrile, azobisisoheptanenitrile, azobiscyanovaleric acid, azobisisobutylamidine hydrochloride, azobisisopropylimidazoline, azobisN-hydroxyisobutylamidine hydrate, azobisN,N'-cyclobutylisobutylamidine hydrate, azobisisobutyric acid dimethyl ester or 2,2'-azobis(N-cyclohexylisobutylamidine) hydrochloride; the amount of the initiator added is 0.02% to 4.0% of the total mass of the three monomers; In step A4, the reaction duration is 1 to 12 hours.

23. The method for preparing a polymer plugging agent according to claim 22, characterized in that: The emulsifier in step A1 is a mixture of one or two polysorbate nonionic surfactants with an HLB range of 0 to 10, or sodium di(2-ethylhexyl)sulfosuccinate; In step A1, the mass percentage concentration of the emulsifier is 20.0% to 40.0%; In step A2, the mass percentage concentration of the three monomers, namely, the alkenyl amide monomer, the alkenyl carboxylic acid monomer, and the hydrophobic crosslinking monomer, in the aqueous solution is 10.0 to 25.0%; In step A3, the reaction temperature is 40-100° C.; In step A3, the amount of the initiator added is 0.05% to 3.0% of the total mass of the three monomers; In step A4, the reaction duration is 1 to 8 hours.

24. The method for preparing a polymer plugging agent according to claim 23, wherein: The amount of the initiator added is 0.5% to 1.5% of the total mass of the three monomers; In step A4, the reaction time is 2 to 6 hours; The emulsifier in step A1 is a mixture of one or two polysorbate nonionic surfactants with an HLB range of 3 to 9, or sodium di(2-ethylhexyl)sulfosuccinate.

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