A CO2 chemical reaction thickening type surface agent for offshore CO2 drive heavy oil gas channeling control and a preparation method and application thereof

Abstract

The application belongs to the technical field of oil field chemistry, and discloses a CO2 chemical reaction viscosity-increasing type surfactant for offshore CO2 flooding heavy oil gas channeling control, and a preparation method and application thereof.The CO2 reaction viscosity-increasing type surfactant comprises structural units provided by formula (1), formula (2) and formula (3);in formula (1), R1, R2, R3, R4 and R5 are each one or more of H, F and C1-C4 alkyl alcohol, and at least one is F;in formula (2), R6, R7 and R8 are each one or more of H and C1-C4 alkyl;in formula (3), R is one or more of C 10 ‑C 16 alkyl; the CO2 reaction viscosity-increasing type surfactant has high CO2 gas channeling plugging strength, good chemical stability, and good heavy oil viscosity reduction performance.

Description

Technical Field

[0001] This invention belongs to the field of oilfield chemical technology, specifically relating to a CO2 chemical reaction thickening polymer for controlling gas channeling in offshore CO2-driven heavy oil, its preparation method, and its application. Background Technology

[0002] With the increasing global demand for crude oil and the gradual depletion of conventional crude oil, the rational exploitation of heavy oil has become particularly important. Globally, due to the long-term exploitation of conventional crude oil, offshore heavy oil resources account for a larger proportion of total oil reserves, exceeding 70% of the total remaining offshore oil reserves. Because CO2 has good miscibility with crude oil, effectively reducing crude oil viscosity, interfacial tension, volume expansion, and extraction of light hydrocarbons, offshore heavy oil CO2 flooding technology has become key to the efficient development of heavy oil reservoirs. However, compared with offshore heavy oil waterflooding, offshore heavy oil CO2 flooding faces the following challenges: ① Offshore heavy oil reservoirs are mostly loose sandstone reservoirs, characterized by loose rock cementation, high reservoir permeability, and severe heterogeneity. Furthermore, the large difference in the CO2 / heavy oil mobility ratio inevitably leads to cross-flow during CO2 injection, resulting in poor energy replenishment and low sweepability. ② Controlling gas channeling is the key to efficient CO2 oil displacement and storage, and the modifier is the core. However, due to the strong acidity of CO2 dissolved in water and the high injection intensity, conventional modifiers are "unsustainable and cannot control for long".

[0003] Therefore, there is an urgent need to develop efficient CO2 gas channeling control systems to improve CO2 oil displacement efficiency. CO2-responsive materials, due to their adaptable properties to environmental and spatial variations, have become a hot research topic in the field of gas channeling control. Among them, the most mature research areas include CO2-responsive thickening polymers or surfactants such as amino-based, amidine-based, guanidine-based, and nitrogen-containing azole heterocyclic polymers. These materials utilize the protonation reaction, counterion electrostatic shielding, and self-assembly effect of responsive polymers or surfactants with CO2. The polymer or surfactant aggregation morphology transforms from spherical to worm-like micelles. These worm-like micelles intertwine to form a highly viscoelastic three-dimensional network structure, effectively blocking gas channeling and thus expanding the CO2 sweep volume and improving oil displacement efficiency. However, CO2-sensitive thickening polymers / surfactants mainly block gas channeling through non-covalent physical association, making them susceptible to external factors such as water front intrusion dilution, charge shielding by high-salinity formation water, and residual oil dissolution, leading to system instability and uncontrollable gas channeling. Therefore, it is necessary to transform unstable non-covalent physical association viscosity enhancement into stable chemical covalent viscosity enhancement, that is, to transform from responsive viscosity enhancement into direct chemical reaction viscosity enhancement.

[0004] Therefore, given the unique characteristics of CO2 flooding and storage environments for heavy oil at sea, there is an urgent need for a CO2 reactive thickening and polymerization agent with good stability, high sealing strength, and excellent viscosity-reducing properties to improve the development efficiency of heavy oil reservoirs at sea. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies, such as low CO2-responsive thickening polymers or surfactants in blocking CO2 gas channeling and easy instability and failure. This invention provides a CO2 chemical reaction thickening polymer for controlling CO2 gas channeling in heavy oil at sea, along with its preparation method and application. This CO2-responsive thickening polymer has high CO2 gas channeling blocking strength, good chemical stability, and good viscosity-reducing performance in heavy oil.

[0006] To achieve the above objectives, the present invention provides a CO2 reactive thickening polymer surface agent, wherein the CO2 reactive thickening polymer surface agent comprises structural units provided by Lewis acid monomers represented by formula (1), structural units provided by Lewis base monomers represented by formula (2), structural units provided by hydrophilic monomers, and structural units provided by interfacial active monomers represented by formula (3).

[0007]

[0008] In formula (1), R1, R2, R3, R4 and R5 are the same or different, and each is one or more of H, F and C1-C4 alkyl alcohols, and at least one of them is F;

[0009]

[0010] In formula (2), R6, R7 and R8 may be the same or different, and each is one or more of H and C1-C4 alkyl groups;

[0011]

[0012] In equation (3), R is C 10 -C 16 One or more of the alkyl groups.

[0013] A second aspect of the present invention provides a method for preparing the aforementioned CO2 reactive thickening polymerizer, wherein the preparation method includes:

[0014] (F1) The Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer, the interfacial active monomer shown in formula (3) and the solvent are brought into contact and mixed to obtain a mixture;

[0015] (F2) The mixture is reacted with an initiator under an inert gas atmosphere;

[0016] (F3) The product obtained in step (F2) is contacted with an alcohol solvent and then subjected to precipitation, filtration and drying to obtain a CO2 reaction thickening agent.

[0017] A third aspect of the present invention provides an application of the aforementioned CO2 reactive thickening agent in the control of CO2 channeling in offshore heavy oil.

[0018] Through the above technical solution, the CO2 reactive thickening and surface-polymerizing agent of the present invention, after CO2 is introduced, can react with the surface-polymerizing agent to form stable covalent bonds, significantly increasing the viscosity of the system and thus achieving a sealing effect. Furthermore, it is not easily affected by external factors, has good chemical stability, high sealing strength, and can achieve long-term effective sealing. Simultaneously, the CO2 reactive thickening and surface-polymerizing agent can significantly reduce the viscosity of heavy oil and improve the washing efficiency of heavy oil. Attached Figure Description

[0019] Figure 1 It is the CO2 reactive thickening agent prepared in Example 1. 1 H NMR spectrum;

[0020] Figure 2 For the preparation of Lewis acid monomers in Example 1 1 H NMR spectrum;

[0021] Figure 3 For the preparation of Lewis acid monomers in Example 1 11 B NMR spectrum;

[0022] Figure 4 To prepare the Lewis base monomer of Example 6 1 H NMR spectrum;

[0023] Figure 5 To prepare the Lewis base monomer of Example 6 31 P NMR spectrum. Detailed Implementation

[0024] 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.

[0025] As mentioned above, the first aspect of the present invention provides a CO2 reactive thickening polymer surface agent, wherein the CO2 reactive thickening polymer surface agent includes structural units provided by Lewis acid monomers represented by formula (1), structural units provided by Lewis base monomers represented by formula (2), structural units provided by hydrophilic monomers, and structural units provided by interfacial active monomers represented by formula (3).

[0026]

[0027] In formula (1), R1, R2, R3, R4 and R5 are the same or different, and each is one or more of H, F and C1-C4 alkyl alcohols, and at least one of them is F;

[0028]

[0029] In formula (2), R6, R7 and R8 may be the same or different, and each is one or more of H and C1-C4 alkyl groups;

[0030]

[0031] In equation (3), R is C 10 -C 16 One or more of the alkyl groups.

[0032] According to the present invention, in formula (1), R1, R2, R3, R4 and R5 are the same or different, each being one or more of H, F, C1-C3 alkyl alcohols, and at least one of them is F.

[0033] According to the present invention, preferably, the Lewis acid monomer is selected from one or more of formula (1-1), formula (1-2), formula (1-3), formula (1-4) and formula (1-5);

[0034]

[0035] That is, in this invention, the structure of formula (1-1) represents di(3,4,5-trifluorophenyl)(4-vinylphenyl)boron; the structure of formula (1-2) represents di(3,5-difluorophenyl)(4-vinylphenyl)boron; the structure of formula (1-3) represents dipentafluorophenyl(4-vinylphenyl)boron; the structure of formula (1-4) represents di(3-fluorophenyl)(4-vinylphenyl)boron; and the structure of formula (1-5) represents di[3,5-difluoro(4-hydroxymethyl)phenyl](4-vinylphenyl)boron.

[0036] According to the present invention, more preferably, the Lewis acid monomer is selected from one or more of dipentafluorophenyl(4-vinylphenyl)boron, di(3,5-difluorophenyl)(4-vinylphenyl)boron, and di(3,4,5-trifluorophenyl)(4-vinylphenyl)boron.

[0037] According to the present invention, in formula (2), R6, R7 and R8 are the same or different, and each is one or more of H, C1-C3 alkyl groups.

[0038] According to the present invention, preferably, the Lewis base monomer is selected from one or more of formula (2-1), formula (2-2), formula (2-3), formula (2-4) and formula (2-5);

[0039]

[0040] That is, in this invention, the structure of formula (2-1) represents dimethyltrimethyl(4-vinylphenyl)phosphine; the structure of formula (2-2) represents diphenyl(4-vinylphenyl)phosphine; the structure of formula (2-3) represents di(2,4,6-triethylphenyl)(4-vinylphenyl)phosphine; the structure of formula (2-4) represents di(2,4,6-triisopropylphenyl)(4-vinylphenyl)phosphine; and the structure of formula (2-5) represents di(2,4,6-tritert-butylphenyl)(4-vinylphenyl)phosphine.

[0041] According to the present invention, more preferably, the Lewis base monomer is selected from one or more of dimestrimethyl(4-vinylphenyl)phosphine, di(2,4,6-triethylphenyl)(4-vinylphenyl)phosphine, and di(2,4,6-triisopropylphenyl)(4-vinylphenyl)phosphine.

[0042] According to the present invention, the purity of the Lewis acid monomer is 82-98%, preferably 82.06-97.88%, and more preferably 90-98%.

[0043] According to the present invention, the purity of the Lewis base monomer is 80-99%, preferably 80.3-98.82%, and more preferably 92.38-98.82%.

[0044] According to the present invention, the hydrophilic monomer is selected from one or more of acrylamide, N-vinylamide, acrylic acid, and methacrylic acid.

[0045] According to the present invention, in equation (3), R is C 10 -C 16 One or more of the alkyl groups.

[0046] According to the present invention, the molar ratio of the structural unit provided by the Lewis acid monomer shown in formula (1), the structural unit provided by the Lewis base monomer shown in formula (2), the structural unit provided by the hydrophilic monomer, and the structural unit provided by the interfacial active monomer shown in formula (3) is 1:(0.4-2.5):(10-100):(0.5-10), preferably 1:(0.5-2):(25-80):(0.7-6), more preferably 1:(0.7-1.5):(30-70):(1-4), and even more preferably 1:(0.8-1.3):(40-60):(1.5-3);

[0047] According to the present invention, the number average molecular weight of the CO2 reactive thickening agent is 100,000-2,000,000, preferably 500,000-1,500,000, more preferably 800,000-1,200,000, and even more preferably 900,000-1,100,000.

[0048] In this invention, the preparation of the Lewis acid monomer represented by formula (1) includes:

[0049] (S1) Under nitrogen protection, a solution containing a compound with the structure shown in formula (S-1) is added dropwise to a solution containing a boron halide compound and an anhydrous solvent to carry out the first reaction;

[0050]

[0051] In the structures shown in equations (S-1) and (S-2), X is a halogen.

[0052] Among them, R1, R2, R3, R4 and R5 may be the same or different, and each is one or more of H, F and C1-C4 alkyl alcohols, and at least one of them is F;

[0053] (S2) A solution containing the compound with the structure shown in formula (S-2) is added dropwise to the reaction solution after step (S1) to carry out a second reaction, thereby preparing a Lewis acid monomer.

[0054] According to the present invention, the inventors have discovered that all reaction processes must be carried out under anhydrous and oxygen-free conditions. In the method for preparing Lewis acid monomers of the present invention, the raw materials (S-1) and (S-2) used are both Grignard reagents, which react violently with water to generate flammable hydrocarbons RH and Mg(OH)X (where R represents a hydrocarbon group and X represents a halogen), leading to impure products or reaction failure. Therefore, anhydrous conditions are required. On the other hand, the presence of oxygen will cause boron to be oxidized, resulting in impure products and a decrease in yield. Therefore, oxygen-free conditions are also required.

[0055] According to the present invention, the anhydrous solvent is anhydrous tetrahydrofuran and / or anhydrous diethyl ether; in the present invention, the solvent needs to be anhydrous before use to prevent the influence of water on the reaction process.

[0056] Specifically, the method for processing anhydrous tetrahydrofuran can be as follows: add shredded sodium blocks to tetrahydrofuran, reflux under moisture-free conditions to remove water and peroxides, then distill, collect the distillate, and obtain anhydrous tetrahydrofuran.

[0057] Similarly, the treatment method for anhydrous diethyl ether can be as follows: add shredded sodium blocks to tetrahydrofuran, reflux under moisture-free conditions to remove water and peroxides, then distill, collect the fraction, and obtain anhydrous diethyl ether.

[0058] According to the present invention, the total weight ratio of the anhydrous solvent to the compound with the structure shown in formula (S-1), the boron halide compound to the compound with the structure shown in formula (S-2) is (100-500):100, preferably (150-400):100.

[0059] According to the present invention, X in the structures shown in formula (S-1) and formula (S-2) is selected from one or more of Cl, Br, F and I.

[0060] According to the present invention, preferably, the compound with the structure shown in formula (S-1) is selected from one or more of pentafluorophenyl magnesium bromide, pentafluorophenyl magnesium chloride, 3,5-difluorophenyl magnesium bromide and 3,4,5-trifluorophenyl magnesium chloride.

[0061] According to the present invention, preferably, the compound with the structure shown in formula (S-2) is magnesium p-styrene bromide and / or magnesium p-styrene chloride.

[0062] According to the present invention, preferably, the boron halide is selected from one or more of BCl3, BBr3, BF3 and BI3.

[0063] According to the present invention, the molar ratio of the compound with the structure shown in formula (S-1), the boron halide compound and the compound with the structure shown in formula (S-2) is 1:(0.1-1.5):(0.05-1.5), preferably 1:(0.2-1.5):(0.1-1.5), and more preferably 1:(0.3-0.7):(0.2-0.6).

[0064] In this invention, the concentration of the solution containing the compound with the structure shown in formula (S-1) in the solution described in step (S1) is 1 mol / L to 4 mol / L; in addition, in this invention, the solvent in the solution containing the compound with the structure shown in formula (S-1) is not particularly limited, and can be tetrahydrofuran or diethyl ether, preferably diethyl ether, that is, a diethyl ether solution containing the compound with the structure shown in formula (S-1).

[0065] In this invention, the concentration of the solution containing the compound with the structure shown in formula (S-2) in the solution described in step (S2) is 1 mol / L to 3 mol / L; in addition, in this invention, the solvent in the solution containing the compound with the structure shown in formula (S-2) is not particularly limited, and can be tetrahydrofuran or diethyl ether, preferably diethyl ether, that is, a diethyl ether solution containing the compound with the structure shown in formula (S-2).

[0066] According to the present invention, in step (S1), the first reaction conditions include: a temperature of -10°C to 15°C and a time of 1-6 hours; preferably, a temperature of -5°C to 5°C and a time of 2-4 hours.

[0067] According to the present invention, in step (S2), the second reaction conditions include: first reacting at a temperature of -10°C to 10°C for 1-4 hours, and then reacting at 20-35°C for 8-16 hours; more preferably, first reacting at a temperature of 0-5°C for 1-2 hours, and then reacting at 20-35°C for 12-15 hours.

[0068] In this invention, in step (S1), preferably, the reaction is carried out under stirring conditions, with a stirring rate of 200-800 rpm, more preferably, with a stirring rate of 400-500 rpm.

[0069] In this invention, in step (S2), preferably, the reaction is carried out under stirring conditions, with a stirring rate of 300-800 rpm, more preferably, with a stirring rate of 400-600 rpm.

[0070] In this invention, more preferably, in step (S1), a solution containing a compound with the structure shown in formula (S-1) is added dropwise to a solution containing a boron halide compound and an anhydrous solvent to carry out a first reaction; wherein, the dropping rate can be 0.5-2 drops / second. In this invention, the advantage of using the dropping method is that the reaction rate can be effectively controlled, the reaction process can be avoided from being too violent, the generation of side reaction products can be reduced, and the purity and yield of the product can be improved.

[0071] In this invention, more preferably, in step (S2), a solution containing a compound with the structure shown in formula (S-2) is added dropwise to the reaction solution after step (S1) to carry out a second reaction; wherein, the dropping rate can be 0.5-2 drops / second. In this invention, the advantage of using the dropping method is that it can effectively control the reaction rate, avoid the reaction process from being too violent, reduce the generation of by-products, and improve the purity and yield of the product.

[0072] According to the present invention, the preparation method further includes: further separating and purifying the crude product mixture after step (S2); preferably, the separation and purification method includes: removing the solvent from the crude product mixture after step (S2) under vacuum, and then cutting the obtained residue and sublimating it to obtain Lewis acid monomer.

[0073] According to the present invention, the method for removing the solvent under vacuum employs vacuum distillation; preferably, the conditions for vacuum distillation include: a temperature of 120-150°C and a pressure of -0.1 MPa to 1 × 10⁻⁶ MPa. -7 MPa.

[0074] According to the present invention, the obtained residue is shredded and then sublimated, preferably by vacuum sublimation; preferably, the conditions for vacuum sublimation include: a temperature of 120-150°C and a pressure of -0.1-1×10⁻⁶. -7 MPa.

[0075] In this invention, the preparation of the Lewis base monomer represented by formula (2) includes:

[0076] (J1) Under nitrogen protection, a solution containing a compound with the structure shown in formula (J-1) is added dropwise to a solution containing a phosphorus halide compound and an anhydrous solvent to carry out a first reaction;

[0077]

[0078] In the structures shown in equations (J-1) and (J-2), X is a halogen.

[0079] Among them, R1, R2 and R3 may be the same or different, and each is one or more of H and C1-C4 alkyl groups;

[0080] (J2) A solution containing the compound with the structure shown in formula (J-2) is added dropwise to the reaction solution after step (J1) to carry out a second reaction, thereby preparing a Lewis base monomer.

[0081] According to the present invention, the inventors have discovered that all reaction processes must be carried out under anhydrous and oxygen-free conditions. In the reaction for synthesizing Lewis base monomers, the raw materials (J-1) and (J-2) are both Grignard reagents, which react violently with water to generate flammable hydrocarbons RH and Mg(OH)X (where R represents a hydrocarbon group and X represents a halogen), leading to impure products or reaction failure. Therefore, anhydrous conditions are required. Furthermore, the presence of oxygen will cause phosphorus to be oxidized, resulting in impure products and decreased yield. Therefore, oxygen-free conditions are also required.

[0082] According to the present invention, the anhydrous solvent is anhydrous tetrahydrofuran and / or anhydrous diethyl ether; in the present invention, the solvent needs to be anhydrous before use to prevent the influence of water on the reaction process.

[0083] Specifically, the method for processing anhydrous tetrahydrofuran can be as follows: add shredded sodium blocks to tetrahydrofuran, reflux under moisture-free conditions to remove water and peroxides, then distill, collect the distillate, and obtain anhydrous tetrahydrofuran.

[0084] Similarly, the treatment method for anhydrous diethyl ether can be as follows: add shredded sodium blocks to tetrahydrofuran, reflux under moisture-free conditions to remove water and peroxides, then distill, collect the fraction, and obtain anhydrous diethyl ether.

[0085] According to the present invention, the total weight ratio of the anhydrous solvent to the compound with the structure shown in formula (J-1), the phosphorus halide compound to the compound with the structure shown in formula (J-2) is (100-500):100, preferably (150-400):100.

[0086] According to the present invention, X in the structures shown in formula (J-1) and formula (J-2) is selected from one or more of Cl, Br, F and I.

[0087] According to the present invention, preferably, the compound with the structure shown in formula (J-1) is selected from one or more of mesitylene magnesium chloride, mesitylene magnesium bromide, 2,4,6-triethylphenyl magnesium chloride, 2,4,6-triisopropylphenyl magnesium bromide and 2,4,6-tritert-butylphenyl magnesium bromide.

[0088] According to the present invention, preferably, the compound with the structure shown in formula (J-2) is magnesium p-styrene bromide and / or magnesium p-styrene chloride.

[0089] According to the present invention, preferably, the phosphorus halide compound is selected from one or more of PCl3, PBr3, PF3 and PI3.

[0090] According to the present invention, the molar ratio of the compound with the structure shown in formula (J-1), the phosphorus halide compound and the compound with the structure shown in formula (J-2) is 1:(0.1-2):(0.05-2), preferably 1:(0.2-1):(0.1-0.8), more preferably 1:(0.2-0.6):(0.1-0.5), and even more preferably 1:(0.4-0.6):(0.3-0.5).

[0091] In this invention, the concentration of the solution containing the compound with the structure shown in formula (J-1) in the solution described in step (J1) is 0.5 mol / L to 4 mol / L. In addition, in this invention, there is no particular limitation on the solvent in the solution containing the compound with the structure shown in formula (J-1), but tetrahydrofuran or diethyl ether is preferred as the solvent, that is, a tetrahydrofuran solution containing the compound with the structure shown in formula (J-1) or a diethyl ether solution containing the compound with the structure shown in formula (J-1).

[0092] In this invention, the concentration of the solution containing the compound with the structure shown in formula (J-2) in the solution described in step (J2) is 0.5 mol / L to 2 mol / L. In addition, in this invention, there is no particular limitation on the solvent in the solution containing the compound with the structure shown in formula (J-2), but tetrahydrofuran or diethyl ether is preferred as the solvent, that is, a tetrahydrofuran solution containing the compound with the structure shown in formula (J-2) or a diethyl ether solution containing the compound with the structure shown in formula (J-2).

[0093] According to the present invention, in step (J1), the first reaction conditions include: a temperature of 0-25°C and a time of 10-16h; preferably, a temperature of 0-10°C and a time of 12-14h.

[0094] According to the present invention, in step (J2), the second reaction conditions include: a temperature of 0-35°C and a time of 10-18h; preferably, a temperature of 0-15°C and a time of 13-16h.

[0095] In this invention, in step (J1), preferably, the first reaction is carried out under stirring conditions, with a stirring rate of 200-700 rpm, more preferably, with a stirring rate of 300-400 rpm.

[0096] In this invention, in step (J2), preferably, the second reaction is carried out under stirring conditions, with a stirring rate of 300-700 rpm, more preferably, with a stirring rate of 400-500 rpm.

[0097] In this invention, more preferably, in step (J1), a solution containing a compound with the structure shown in formula (J-1) is added dropwise to a solution containing a phosphorus halide compound and an anhydrous solvent to carry out a first reaction; wherein, the dropping rate can be 0.5-2 drops / second. In this invention, the advantage of using the dropping method is that it can effectively control the reaction rate, avoid the reaction process from being too violent, reduce the generation of by-products, and improve the purity and yield of the product.

[0098] In this invention, more preferably, in step (J2), a solution containing a compound with the structure shown in formula (J-2) is added dropwise to the reaction solution after step (J1) to carry out a second reaction; wherein, the dropping rate can be 0.5-2 drops / second. In this invention, the advantage of using the dropping method is that it can effectively control the reaction rate, avoid the reaction process from being too violent, reduce the generation of by-products, and improve the purity and yield of the product.

[0099] According to the present invention, the preparation method further includes: further separating and purifying the crude product mixture after step (J2); preferably, the separation and purification method includes:

[0100] (i) The crude product mixture after step (J2) is contacted with a saturated salt solution and then extracted with diethyl ether to collect the organic phase;

[0101] (ii) The organic phase is dried, distilled, concentrated, and precipitated to obtain a crude product;

[0102] (iii) The crude product is subjected to chromatography to prepare Lewis base monomers.

[0103] According to the present invention, in step (i), the salt solution may be one of NaCl, NH4Cl, MgCl2, and CaCl2, preferably NaCl or NH4Cl.

[0104] According to the present invention, in step (i), the weight ratio of the crude product mixture, the saturated salt solution and the diethyl ether is 1:(0.5-2):(1-4), preferably 1:(0.5-2):(1.5-4), and more preferably 1:(0.5-1.5):(1-3).

[0105] In this invention, in step (ii), the distillation concentration is carried out by rotary evaporation; preferably, the conditions for rotary evaporation include: a temperature of 25-40°C and a pressure of -0.08 MPa to -0.1 MPa.

[0106] According to the present invention, the viscous oily liquid obtained after distillation and concentration is contacted with an alcohol solvent for precipitation treatment; in the present invention, in step (ii), the alcohol solvent may be one of methanol, isopropanol, n-butanol, and isobutanol, preferably methanol.

[0107] According to the present invention, preferably, the weight ratio of the viscous oily liquid to the alcohol solvent is 1:(2-4).

[0108] In this invention, in step (iii), the packing material of the chromatography column can be one of silica gel, alumina, or ion exchange resin, preferably alumina.

[0109] A second aspect of the present invention provides a method for preparing the aforementioned CO2 reactive thickening polymerizer, wherein the preparation method includes:

[0110] (F1) The Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer, the interfacial active monomer shown in formula (3) and the solvent are brought into contact and mixed to obtain a mixture;

[0111] (F2) The mixture is reacted with an initiator under an inert gas atmosphere;

[0112] (F3) The product obtained in step (F2) is contacted with an alcohol solvent and then subjected to precipitation, filtration and drying to obtain a CO2 reaction thickening agent.

[0113] According to the present invention, the molar ratio of the Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer and the surfactant monomer shown in formula (3) is 1:(0.5-2):(20-100):(1-10), preferably 1:(0.6-1.5):(30-80):(1-6), more preferably 1:(0.7-1.3):(40-70):(2-5), and even more preferably 1:(0.8-1.2):(50-70):(2-3).

[0114] According to the present invention, the amount of the initiator is 0.1-0.8% by weight, preferably 0.2-0.5% by weight, based on the total weight of the Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer and the surfactant monomer shown in formula (3).

[0115] According to the present invention, the solvent may be selected from solvents that do not inhibit or slow down the polymerization reaction; preferably, the solvent is selected from at least two of toluene, chloroform, dimethyl sulfoxide, N,N-dimethylformamide and cyclohexane.

[0116] According to the present invention, the Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer and the interfacial active monomer shown in formula (3) have the same or different concentrations in the solvent, each of which is 10-30 wt%, for example, 10 wt%, 12 wt%, 15 wt%, 17.5 wt%, 20 wt%, 25 wt%, 30 wt%, and any range of any two of the above values.

[0117] According to the present invention, the initiator is selected from one or more of azo initiators, organic peroxide initiators, inorganic peroxide initiators and oil-soluble redox initiators, with azo initiators being preferred.

[0118] Specifically, the initiator is selected from one or more of azobisisobutyrazoline hydrochloride, azobisisobutyronitrile, azobisisobutyronitrile, azobiscarboxyethyl-2-isobutylamidine hydrate, azobismethylN-2-hydroxybutylacrylamide, azobiscyclohexylformitrile, and azobisisovalerate, preferably azobisisobutyronitrile.

[0119] According to the present invention, in step (F2), the reaction conditions include: a reaction temperature of 40-100°C and a reaction time of 12-28h; preferably, the reaction temperature is 60-80°C and the reaction time is 16-24h.

[0120] In this invention, preferably, the free radical polymerization reaction is carried out under stirring conditions, with a stirring rate of 100-500 rpm, more preferably, with a stirring rate of 200-400 rpm.

[0121] According to the present invention, the separation and purification method is not particularly limited in the preparation of the CO2 reactive thickening polymer. The reactants obtained from the free radical polymerization reaction can be obtained by precipitation, filtration, and drying. For example, the reactants obtained from the free radical polymerization reaction can be precipitated in an alcohol solvent, filtered, and then vacuum dried to constant weight to obtain the CO2 reactive thickening polymer.

[0122] Preferably, the alcohol solvent is selected from one or more of methanol, ethanol, isopropanol, and n-butanol, more preferably methanol; preferably, the drying conditions are vacuum drying at 30-50°C, more preferably vacuum drying at 40°C.

[0123] A third aspect of the present invention provides an application of the aforementioned CO2 reactive thickening agent in the control of CO2 channeling in offshore heavy oil.

[0124] In this invention, the heavy oil from the sea originates from the Bohai Oilfield.

[0125] The present invention will be described in detail below through embodiments.

[0126] In the following examples and comparative examples:

[0127] 1 ¹H NMR spectral parameters were determined by proton nuclear magnetic resonance spectroscopy; polymer molecular weight was determined by gel permeation chromatography; viscosity parameters were determined using an Anton Paar MCR 72 rheometer according to the test procedure specified in standard GB / T 16321-2008; and the plugging rate was determined by core physical simulation flow experiment. All reagents used were commercially available products from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0128] Preparation Example 1

[0129] This preparation example relates to the Lewis acid prepared according to the present invention.

[0130] (S1) Under nitrogen protection at 0℃, a 2 mol / L solution of pentafluorophenyl magnesium bromide in diethyl ether was added dropwise to a boron trifluoride diethyl ether solution at a dropping rate of 0.5 drops / second, and then the reaction was continued at 0℃ and a stirring rate of 400 rpm for 3 h.

[0131] (S2) At 0°C and a stirring speed of 500 rpm, magnesium ethyl ether solution of p-styrene bromide was added dropwise to the mixture from step (S1) at a dropping rate of 0.5 drops / second. After the addition was complete, the reaction mixture was stirred at 0°C for 2 hours, and then the mixture was stirred at room temperature for 14 hours to obtain a crude product mixture containing the target product; wherein the concentration of magnesium ethyl ether solution of p-styrene bromide was 2 mol / L.

[0132] The molar ratio of magnesium pentafluorophenyl bromide, boron trifluoride, and magnesium p-styrene bromide is 1:0.4:0.4.

[0133] (S3) The crude product mixture obtained in step (S2) is subjected to vacuum distillation (25℃, -0.08MPa), and the residue is then shredded and sublimated (130℃, 1×10⁻⁶ MPa). -7 (MPa) yields the Lewis acid monomer dipentafluorophenyl(4-vinylphenyl)boron, the structure of which is shown below:

[0134]

[0135] The yield and purity of the prepared Lewis acid monomers are shown in Table 1.

[0136] Figure 2 For the preparation of Lewis acid monomers in Example 1 1 H NMR spectrum, from Figure 2 The nuclear magnetic resonance (NMR) spectrum shows that the chemical shifts on the horizontal axis from 7.49 to 7.81 (m, 4H) ppm indicate the presence of peak a (H on the styrene group); the chemical shift from 6.91 (d, 1H) ppm indicates the presence of peak b (H on -CH=C-); and the chemical shifts from 5.42 to 5.97 (d, 2H) ppm indicate the presence of peak c (H on -C=CH2).

[0137] Figure 3 For the preparation of Lewis acid monomers in Example 1 11 B NMR spectrum, from Figure 3 It can be seen that the peak value of B (boron group) appears at 74.3 (br) ppm.

[0138] Preparation Example 2

[0139] This preparation example relates to the Lewis acid prepared according to the present invention.

[0140] Lewis acids were prepared using the same method as in Preparation Example 1, except that “magnesium pentafluorophenyl bromide” was replaced with “magnesium 3,5-difluorophenyl bromide”.

[0141] The resulting Lewis acid monomer was bis(3,5-difluorophenyl)(4-vinylphenyl)boron, with the structure shown below. The yield and purity are shown in Table 1.

[0142]

[0143] Preparation Example 3

[0144] This preparation example relates to the Lewis acid prepared according to the present invention.

[0145] Lewis acids were prepared using the same method as in Preparation Example 1, except that “pentafluorophenyl magnesium bromide” was replaced with “3,4,5-trifluorophenyl magnesium bromide”.

[0146] The resulting Lewis acid monomer was bis(3,4,5-trifluorophenyl)(4-vinylphenyl)boron, with the structure shown below. The yield and purity are shown in Table 1.

[0147]

[0148] Preparation Example 4

[0149] This preparation example relates to the Lewis acid prepared according to the present invention.

[0150] Lewis acids were prepared using the same method as in Preparation Example 1, except that “pentafluorophenyl magnesium bromide” was replaced with “3-fluorophenyl magnesium bromide”.

[0151] The resulting Lewis acid monomer was bis(3-fluorophenyl)(4-vinylphenyl)boron, with the structure shown below. The yield and purity are shown in Table 1.

[0152]

[0153] Preparation Example 5

[0154] This preparation example relates to the Lewis acid prepared according to the present invention.

[0155] Lewis acids were prepared using the same method as in Preparation Example 1, except that “magnesium pentafluorophenyl bromide” was replaced with “4-methoxy-3,5-difluorophenyl magnesium bromide”.

[0156] The resulting Lewis acid monomer was bis[3,5-difluoro(4-hydroxymethyl)phenyl](4-vinylphenyl)boron, with the structure shown below. The yield and purity are shown in Table 1.

[0157]

[0158] Table 1

[0159]

[0160]

[0161] Preparation Example 6

[0162] This preparation example is intended to illustrate the Lewis base prepared according to the present invention.

[0163] (J1) Under nitrogen protection, phosphorus trichloride was dissolved in anhydrous tetrahydrofuran, and then a mesitylene magnesium bromide tetrahydrofuran solution was slowly added dropwise at a rate of 1 drop / second. The reaction was carried out at 0°C and a stirring rate of 400 rpm for 12 h. The concentration of the mesitylene magnesium bromide tetrahydrofuran solution was 1 mol / L.

[0164] (J2) At 0°C and a stirring speed of 500 rpm, a magnesium tetrahydrofuran solution of p-styrene bromide was slowly added dropwise to the mixture from step (J1) at a dropping rate of 1 drop / second. After the addition was complete, the reaction mixture was stirred at 0°C for 15 h to obtain a crude product mixture containing the target product; wherein the concentration of the magnesium tetrahydrofuran solution of p-styrene bromide was 1 mol / L.

[0165] The molar ratio of methyltrimethylbenzene magnesium bromide, phosphorus trichloride, and p-styrene magnesium bromide is 1:0.5:0.5.

[0166] (J3) Add saturated NaCl solution to the crude product mixture obtained in step (J2), then extract with diethyl ether, collect the organic phase and dry it with anhydrous magnesium sulfate, then perform rotary evaporation (30℃, -0.08MPa), add the concentrated liquid to methanol to obtain the crude product.

[0167] The weight ratio of the crude product mixture, saturated NaCl solution, and diethyl ether was 1:0.5:1.5; the weight ratio of the concentrated liquid to methanol was 1:3.

[0168] (J4) The crude product obtained in step (J3) was passed through a neutral alumina chromatography column to obtain the Lewis base monomer ditrimethyl(4-vinylphenyl)phosphine, the structure of which is shown below:

[0169]

[0170] The yield and purity of the prepared Lewis base monomers are shown in Table 2.

[0171] Figure 4 To prepare the Lewis base monomer of Example 6 1 H NMR spectrum, from Figure 4The nuclear magnetic resonance (NMR) spectra show the following peaks: a (H on the benzene ring of the mesitylene group) at chemical shifts of 7.17–7.35 ppm (m, 4H); b (H on the benzene ring of the styrene group) at chemical shift 6.85 ppm (m, 4H); c (H on -C=CH-) at chemical shift 6.64 ppm (d, 1H); d (H on CH2=C-) at chemical shifts of 5.28–5.75 ppm (d, 2H); and e (H on -CH3 group) at chemical shifts of 2.10–2.24 ppm (s, 18H).

[0172] Figure 5 To prepare the Lewis base monomer of Example 6 31 p NMR spectrum, from Figure 5 It can be seen that the P (phosphine group) peak appears at -22.1(s)ppm.

[0173] Preparation Example 7

[0174] This preparatory example illustrates the preparation of Lewis base monomers.

[0175] Lewis bases were prepared using the same method as in Preparation Example 6, except that "mestrimethylbenzene magnesium chloride" was replaced with "2,4,6-triethylphenyl magnesium chloride".

[0176] The resulting Lewis base monomer was bis(2,4,6-triethylphenyl)(4-vinylphenyl)phosphine, with the structure shown below. The yield and purity are shown in Table 2.

[0177]

[0178] Preparation Example 8

[0179] This preparatory example illustrates the preparation of Lewis base monomers.

[0180] Lewis bases were prepared using the same method as in Preparation Example 6, except that “mesotrimethylammonium chloride” was replaced with “2,4,6-triisopropylphenylmagnesium chloride”.

[0181] The resulting Lewis base monomer was bis(2,4,6-triisopropylphenyl)(4-vinylphenyl)phosphine, the structure of which is shown below. The yield and purity are shown in Table 2.

[0182]

[0183] Preparation Example 9

[0184] This preparatory example illustrates the preparation of Lewis base monomers.

[0185] Lewis bases were prepared using the same method as in Preparation Example 6, except that "metrimethylammonium chloride" was replaced with "phenylmagnesium chloride".

[0186] The Lewis base monomer prepared was diphenyl(4-vinylphenyl)phosphine, the structure of which is shown below. The yield and purity are shown in Table 2.

[0187]

[0188] Preparation Example 10

[0189] This preparatory example illustrates the preparation of Lewis base monomers.

[0190] Lewis bases were prepared using the same method as in Preparation Example 6, except that "mestrimethylbenzene magnesium chloride" was replaced with "2,4,6-tritert-butylphenyl magnesium chloride".

[0191] The resulting Lewis base monomer was bis(2,4,6-tri-tert-butylphenyl)(4-vinylphenyl)phosphine, the structure of which is shown below. The yield and purity are shown in Table 2.

[0192]

[0193] Table 2

[0194]

[0195]

[0196] Example 1

[0197] This embodiment illustrates the CO2 reactive thickening agent prepared using the method of the present invention.

[0198] (1) In a reactor equipped with a temperature control device and a reflux condenser, dipentafluorophenyl(4-vinylphenyl)boron prepared in Preparation Example 1, ditrimethylmethyl(4-vinylphenyl)phosphine prepared in Preparation Example 6, acrylamide, and C were sequentially added. 14 Sodium alkenyl sulfonate was added to a mixed solvent of toluene and dimethyl sulfoxide and stirred.

[0199] Among them, dipentafluorophenyl(4-vinylphenyl)boron, dimetrimethyl(4-vinylphenyl)phosphine, acrylamide and C 14 The molar ratio of sodium alkenyl sulfonate is 1:1:60:2, the concentration of the monomer mixture in the mixed solvent is 15wt%, and the volume ratio of toluene to dimethyl sulfoxide is 2:3.

[0200] (2) After passing nitrogen gas for 30 minutes, the initiator azobisisobutyronitrile was added to the above mixture, the temperature was raised to 62°C, and the mixture was stirred at a stirring rate of 300 rpm for 24 hours.

[0201] The amount of azobisisobutyronitrile used is 0.5% by weight of the total weight of the monomer mixture.

[0202] (3) Add methanol to the above reactants, precipitate the solid, filter it, and then vacuum dry it at 40°C to constant weight to obtain CO2 reaction thickening agent. The parameters are characterized as shown in Table 3.

[0203] The volume ratio of methanol to toluene and dimethyl sulfoxide in the mixed solvent is 2:1.

[0204] Figure 1 The CO2 reactive thickening agent prepared in Example 1 1 H NMR spectrum, from Figure 1 The nuclear magnetic resonance (NMR) spectra show that: the chemical shifts on the horizontal axis from 1.22 to 2.75 ppm indicate the presence of ad (H on -CH3, -CH2-, and -CH-); the chemical shift from 6.99 ppm indicates the presence of e (H on the benzene ring of the mesitylene group); the chemical shifts from 7.17 to 7.38 ppm indicate the presence of f (H on the benzene ring connected to P); and the chemical shifts from 7.56 to 7.78 ppm indicate the presence of g (H on the benzene ring connected to B).

[0205] Example 2

[0206] This embodiment illustrates the CO2 reactive thickening agent prepared using the method of the present invention.

[0207] (1) In a reactor equipped with a temperature control device and a reflux condenser, dipentafluorophenyl(4-vinylphenyl)boron prepared in Preparation Example 1, ditrimethylmethyl(4-vinylphenyl)phosphine prepared in Preparation Example 6, acrylamide, and C were sequentially added. 16 Sodium alkenyl sulfonate was added to a mixed solvent of chloroform and dimethyl sulfoxide and stirred.

[0208] Among them, dipentafluorophenyl(4-vinylphenyl)boron, dimetrimethyl(4-vinylphenyl)phosphine, acrylamide and C 16 The molar ratio of sodium alkenyl sulfonate is 1:0.8:50:3, the concentration of the monomer mixture in the mixed solvent is 20wt%, and the volume ratio of chloroform to dimethyl sulfoxide is 1:3.

[0209] (2) After passing nitrogen gas for 30 minutes, the initiator azobisisobutyrazoline hydrochloride was added to the above mixture, the temperature was raised to 60°C, and the mixture was stirred at a stirring rate of 400 rpm for 20 hours.

[0210] The amount of azobisisobutyrazoline hydrochloride used is 0.3% by weight of the total weight of the monomer mixture.

[0211] (3) Add methanol to the above reactants, precipitate the solid, filter it, and then vacuum dry it at 30°C to constant weight to obtain CO2 reaction thickening agent. The parameters are characterized as shown in Table 3.

[0212] The volume ratio of methanol to chloroform and dimethyl sulfoxide in the mixed solvent is 1:1.

[0213] Example 3

[0214] This embodiment illustrates the CO2 reactive thickening agent prepared using the method of the present invention.

[0215] (1) In a reactor equipped with a temperature control device and a reflux condenser, dipentafluorophenyl(4-vinylphenyl)boron prepared in Preparation Example 1, dimethyltrimethylyl(4-vinylphenyl)phosphine prepared in Preparation Example 6, acrylic acid and C were sequentially added. 16 Sodium alkenyl sulfonate was added to a mixed solvent of toluene and N,N-dimethylformamide and mixed and stirred.

[0216] Among them, dipentafluorophenyl(4-vinylphenyl)boron, dimetrimethyl(4-vinylphenyl)phosphine, acrylic acid and C 16 The molar ratio of sodium alkenyl sulfonate is 1:1.2:70:2, the concentration of the monomer mixture in the mixed solvent is 25 wt%, and the volume ratio of toluene to N,N-dimethylformamide is 1:2.

[0217] (2) After passing nitrogen gas for 60 min, the initiator azobisisobutyronitrile was added to the above mixture, the temperature was raised to 70℃, and the mixture was stirred at a stirring rate of 200 rpm for 16 h.

[0218] The amount of azobisisobutyronitrile used is 0.5% by weight of the total weight of the monomer mixture.

[0219] (3) Add ethanol to the above reactants, precipitate the solid, filter it, and then vacuum dry it at 40°C to constant weight to obtain CO2 reaction thickening agent. The parameters are characterized as shown in Table 3.

[0220] The volume ratio of ethanol to toluene and N,N-dimethylformamide in the mixed solvent is 3:1.

[0221] Example 4

[0222] This embodiment illustrates the CO2 reactive thickening agent prepared using the method of the present invention.

[0223] (1) In a reactor equipped with a temperature control device and a reflux condenser, dipentafluorophenyl(4-vinylphenyl)boron prepared in Preparation Example 1, ditrimethylmethyl(4-vinylphenyl)phosphine prepared in Preparation Example 6, methacrylic acid and C were sequentially added. 14 Sodium alkenyl sulfonate was added to a mixed solvent of cyclohexane and dimethyl sulfoxide and stirred.

[0224] Among them, dipentafluorophenyl(4-vinylphenyl)boron, dimetrimethyl(4-vinylphenyl)phosphine, methacrylic acid and C 14 The molar ratio of sodium alkenyl sulfonate is 1:0.6:40:1, the concentration of the monomer mixture in the mixed solvent is 10wt%, and the volume ratio of cyclohexane to dimethyl sulfoxide is 1:1.

[0225] (2) After passing argon gas for 30 minutes, add the initiator azoisobutyl cyanoformamide to the above mixture, heat to 80°C, and stir at a stirring rate of 500 rpm for 28 hours.

[0226] The amount of azoisobutyl cyanoformamide used is 0.2% by weight of the total weight of the monomer mixture.

[0227] (3) Add ethanol to the above reactants, precipitate the solid, filter it, and then vacuum dry it at 50°C to constant weight to obtain CO2 reaction thickening agent. The parameters are characterized as shown in Table 3.

[0228] The volume ratio of ethanol to the mixed solvent of cyclohexane and dimethyl sulfoxide is 3:1.

[0229] Example 5

[0230] This embodiment illustrates the CO2 reactive thickening agent prepared using the method of the present invention.

[0231] (1) In a reactor equipped with a temperature control device and a reflux condenser, dipentafluorophenyl(4-vinylphenyl)boron prepared in Preparation Example 1, ditrimethylmethyl(4-vinylphenyl)phosphine prepared in Preparation Example 6, N-vinylamide and C were sequentially added. 16 Sodium alkenyl sulfonate was added to a mixed solvent of toluene and dimethyl sulfoxide and stirred.

[0232] Among them, dipentafluorophenyl(4-vinylphenyl)boron, dimetrimethyl(4-vinylphenyl)phosphine, N-vinylamide and C 16 The molar ratio of sodium alkenyl sulfonate is 1:1.8:80:4, the concentration of the monomer mixture in the mixed solvent is 30wt%, and the volume ratio of toluene to dimethyl sulfoxide is 1:2.

[0233] (2) After passing nitrogen gas for 45 minutes, the initiator azodimethyl N-2-hydroxybutylacrylamide was added to the above mixture, the temperature was raised to 50°C, and the mixture was stirred at a stirring rate of 400 rpm for 12 hours.

[0234] The amount of azodimethyl N-2-hydroxybutylacrylamide used is 0.6% by weight of the total weight of the monomer mixture.

[0235] (3) Isopropanol was added to the above reactants, the solid was precipitated and filtered, and then vacuum dried at 50°C to constant weight to obtain CO2 reaction thickening agent. The parameters are shown in Table 3.

[0236] The volume ratio of isopropanol to the mixed solvent of toluene and dimethyl sulfoxide is 1:2.

[0237] Example 6

[0238] This embodiment illustrates the CO2 reactive thickening agent prepared using the method of the present invention.

[0239] The CO2 reactive thickening polymer was prepared using the same method as in Example 1, except that "dipentafluorophenyl(4-vinylphenyl)boron" was replaced with "di(3,5-difluorophenyl)(4-vinylphenyl)boron prepared in Preparation Example 2", and "dimethyltrimethylyl(4-vinylphenyl)phosphine" was replaced with "di(2,4,6-triethylphenyl)(4-vinylphenyl)phosphine prepared in Preparation Example 7".

[0240] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0241] Example 7

[0242] This embodiment illustrates the CO2 reactive thickening agent prepared using the method of the present invention.

[0243] The CO2 reactive thickening polymer was prepared using the same method as in Example 1, except that "dipentafluorophenyl(4-vinylphenyl)boron" was replaced with "di(3,4,5-trifluorophenyl)(4-vinylphenyl)boron prepared in Preparation Example 3", and "di-trimethylmethyl(4-vinylphenyl)phosphine" was replaced with "di(2,4,6-triisopropylphenyl)(4-vinylphenyl)phosphine prepared in Preparation Example 8".

[0244] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0245] Example 8

[0246] This embodiment illustrates the CO2 reactive thickening agent prepared using the method of the present invention.

[0247] The CO2 reactive thickening polymer was prepared using the same method as in Example 1, except that "dipentafluorophenyl(4-vinylphenyl)boron" was replaced with "di(3-fluorophenyl)(4-vinylphenyl)boron prepared in Preparation Example 4", and "dimethyltrimethylyl(4-vinylphenyl)phosphine" was replaced with "diphenyl(4-vinylphenyl)phosphine prepared in Preparation Example 9".

[0248] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0249] Example 9

[0250] This embodiment illustrates the CO2 reactive thickening agent prepared using the method of the present invention.

[0251] The CO2 reactive thickening polymer was prepared using the same method as in Example 1, except that "dipentafluorophenyl(4-vinylphenyl)boron" was replaced with "di[3,5-difluoro(4-hydroxymethyl)phenyl](4-vinylphenyl)boron prepared in Preparation Example 5", and "dimethyltrimethylyl(4-vinylphenyl)phosphine" was replaced with "di(2,4,6-tritert-butylphenyl)(4-vinylphenyl)phosphine prepared in Preparation Example 10".

[0252] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0253] Example 10

[0254] This embodiment illustrates the CO2 reactive thickening agent prepared using the method of the present invention.

[0255] The CO2 reactive thickening polymer was prepared using the same method as in Example 1, except that the "mixed solvent of toluene and dimethyl sulfoxide" was replaced with "dimethyl sulfoxide as a single solvent".

[0256] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0257] Comparative Example 1

[0258] The CO2 reactive thickening polymer was prepared using the same method as in Example 1, except that the Lewis acid monomer dipentafluorophenyl (4-vinylphenyl)boron was not added.

[0259] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0260] Comparative Example 2

[0261] The CO2 reactive thickening agent was prepared using the same method as in Example 1, except that the Lewis base monomer dimethyltrimethyl(4-vinylphenyl)phosphine was not added.

[0262] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0263] Comparative Example 3

[0264] The CO2 reactive thickening agent was prepared using the same method as in Example 1, except that the surfactant monomer C was not added. 14 Sodium alkenyl sulfonate.

[0265] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0266] Comparative Example 4

[0267] The CO2 reactive thickening agent was prepared using the same method as in Example 1, except that the reaction temperature was set to 0°C.

[0268] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0269] Comparative Example 5

[0270] The CO2 reactive thickening agent was prepared using the same method as in Example 1, except that no inert gas was introduced.

[0271] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0272] Comparative Example 6

[0273] The CO2-reactive thickening polymer was prepared using the same method as in Example 1, except that: dipentafluorophenyl(4-vinylphenyl)boron, dimethyltrimethyl(4-vinylphenyl)phosphine, acrylamide, and C... 14 The molar ratio of sodium alkenyl sulfonate was changed from "1:1:60:2" to "1:20:60:2".

[0274] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0275] Comparative Example 7

[0276] The CO2-reactive thickening polymer was prepared using the same method as in Example 1, except that: dipentafluorophenyl(4-vinylphenyl)boron, dimethyltrimethyl(4-vinylphenyl)phosphine, acrylamide, and C... 14 The molar ratio of sodium alkenyl sulfonate was changed from "1:1:60:2" to "1:1:2:2".

[0277] The CO2-reactive thickening polymer was successfully prepared, and its parameters are shown in Table 3.

[0278] Table 3

[0279]

[0280]

[0281] Test case

[0282] 1. CO2 reaction thickening performance test

[0283] 0.5 g of the CO2 reactive thickening polymerizers prepared in Examples 1-10 and Comparative Examples 1-7 were added to 50 mL of water, respectively. After stirring at 10000 r / min for 30 min, different polymer solutions were obtained. Anton Paar MCR 72 rheometer was used to measure the polymers at 25 °C for 10 s. -1 The initial viscosity of each polymer solution was determined at the shear rate. Then, CO2 was introduced into each polymer solution at a flow rate of 100 mL / min for 20 min. After the CO2 introduction was completed, the solution was allowed to stand for 2 h, and then subjected to a 10-second test at 25 °C. -1 The final viscosity of each polymer solution was determined at the shear rate. The test results of the viscosity of different polymer solutions before and after CO2 introduction are shown in Table 4.

[0284] Table 4

[0285]

[0286]

[0287] As can be seen from Table 4, the CO2-reactive thickening polymers prepared in Examples 1-10 showed significant thickening effects after CO2 was introduced. However, in Comparative Examples 1 and 2, the CO2-reactive thickening polymers showed virtually no thickening effect after CO2 was introduced in the absence of Lewis acid monomers or Lewis base monomers. This indicates that the polymers only react with CO2 when both Lewis acid and base monomers are present, causing cross-linking between polymer chains and thus increasing the viscosity of the solution.

[0288] 2. Blocking performance test

[0289] CO2 gas drive was performed at an injection pressure of 3.5 MPa. After gas channeling stabilized, the gas drive was stopped. Then, the CO2 reactive viscosifier was injected into the simulated core fractures at a rate of 0.5 PV. After the CO2 reactive viscosifier system stabilized, CO2 injection continued, and the gas velocity at the core fractures before and after plugging was measured. The core was then placed at 50℃ for 3 months, and the gas velocity at the core fractures was measured again. The plugging rate was calculated, and the results are shown in Table 5, which presents the CO2 reactive viscosifier gas channeling plugging test results.

[0290] The formula for calculating the blocking rate is: Blocking rate (%) = (Flow velocity before blocking - Flow velocity after blocking) / Flow velocity before blocking × 100%.

[0291] Table 5

[0292]

[0293]

[0294] As shown in Table 5, the CO2 reactive thickening agent prepared by the method of the present invention, under preferred conditions, exhibits a CO2 gas channeling blocking rate of over 91%. After being placed at 50°C for 3 months, the blocking rate remains essentially unchanged, indicating that the CO2 reactive thickening agent prepared by the method of the present invention possesses excellent gas channeling blocking performance and chemical stability. In contrast, Comparative Examples 1-7, which did not employ the method of the present invention, show a significantly lower blocking rate compared to the examples.

[0295] 3. Heavy oil viscosity reduction performance test

[0296] 0.5g of the CO2 reactive thickening polymerizers prepared in Examples 1-10 and Comparative Examples 1-7 were added to 50mL of water, respectively. After stirring at 10000r / min for 30min, different polymer solutions were obtained. These solutions were then added to glass reagent bottles along with heavy oil at an oil-to-water ratio of 1:1. The bottles were sealed and aged in a 50℃ constant temperature oven for 3h. After aging, the reagent bottles were inverted four times to mix the oil and water phases and form a homogeneous emulsion. The emulsion was then analyzed using an Anton Paar MCR 72 rheometer at 25℃ for 10s. -1 The viscosity of heavy oil and emulsion was measured at the shear rate, and the viscosity reduction rate was calculated. The results are shown in Table 6, which shows the viscosity reduction test results of heavy oil with CO2 reaction thickening agent.

[0297] The viscosity reduction rate is calculated using the following formula: Viscosity reduction rate (%) = (Heavy oil viscosity - Emulsion viscosity) / Heavy oil viscosity × 100%.

[0298] Table 6

[0299]

[0300]

[0301] As shown in Table 6, the CO2 reactive thickening polymer prepared by the method of the present invention, under preferred conditions, achieves a viscosity reduction rate of over 90% for heavy oil, indicating its excellent viscosity-reducing ability for heavy oil. In contrast, Comparative Example 3, due to the absence of added surfactant monomers, resulted in a product that essentially lacked emulsifying and viscosity-reducing capabilities.

[0302] 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 CO2 reactive thickening and polymerization agent, characterized in that, The CO2 reaction thickening polymerizer includes structural units provided by Lewis acid monomers as shown in formula (1), structural units provided by Lewis base monomers as shown in formula (2), structural units provided by hydrophilic monomers, and structural units provided by interfacial active monomers as shown in formula (3). In formula (1), R1, R2, R3, R4 and R5 are the same or different, and each is one or more of H, F and C1-C4 alkyl alcohols, and at least one of them is F; In formula (2), R6, R7 and R8 may be the same or different, and each is one or more of H and C1-C4 alkyl groups; In equation (3), R is C 10 -C 16 One or more of the alkyl groups.

2. The CO2 reactive thickening and polymerization agent according to claim 1, wherein, In formula (1), R1, R2, R3, R4 and R5 are the same or different, and each is one or more of H, F and C1-C3 alkyl alcohols, and at least one of them is F.

3. The CO2 reactive thickening and polymerization agent according to claim 2, wherein, The Lewis acid monomer is selected from one or more of formulas (1-1), (1-2), (1-3), (1-4), and (1-5); 4. The CO2 reactive thickening and polymerizing agent according to claim 3, wherein, The Lewis acid monomer is selected from one or more of dipentafluorophenyl(4-vinylphenyl)boron, di(3,5-difluorophenyl)(4-vinylphenyl)boron, and di(3,4,5-trifluorophenyl)(4-vinylphenyl)boron.

5. The CO2 reactive thickening and polymerization agent according to claim 1, wherein, In formula (2), R6, R7 and R8 may be the same or different, and each is one or more of H, C1-C3 alkyl groups.

6. The CO2 reactive thickening and polymerization agent according to claim 5, wherein, The Lewis base monomer is selected from one or more of formulas (2-1), (2-2), (2-3), (2-4), and (2-5); 7. The CO2 reactive thickening and polymerizing agent according to claim 6, wherein, The Lewis base monomer is selected from one or more of dimethyltrimethyl(4-vinylphenyl)phosphine, di(2,4,6-triethylphenyl)(4-vinylphenyl)phosphine, and di(2,4,6-triisopropylphenyl)(4-vinylphenyl)phosphine.

8. The CO2 reactive thickening and polymerization agent according to claim 1, wherein, The purity of the Lewis acid monomer is 82-98%; And / or, the purity of the Lewis base monomer is 80-99%.

9. The CO2 reactive thickening agent according to claim 8, wherein, The purity of the Lewis acid monomer is 82.06-97.88%; And / or, the purity of the Lewis base monomer is 80.3-98.82%.

10. The CO2 reactive thickening and polymerization agent according to claim 9, wherein, The purity of the Lewis acid monomer is 90-98%; And / or, the purity of the Lewis base monomer is 92.38-98.82%.

11. The CO2 reactive thickening and polymerization agent according to claim 1, wherein, The hydrophilic monomer is selected from one or more of acrylamide, N-vinylamide, acrylic acid, and methacrylic acid; And / or, in equation (3), R is C 10 -C 16 One or more of the alkyl groups.

12. The CO2 reactive thickening and polymerizing agent according to any one of claims 1-11, wherein, The molar ratio of the structural units provided by the Lewis acid monomer shown in formula (1), the structural units provided by the Lewis base monomer shown in formula (2), the structural units provided by the hydrophilic monomer, and the structural units provided by the interfacial active monomer shown in formula (3) is 1:(0.4-2.5):(10-100):(0.5-10); And / or, the number average molecular weight of the CO2 reactive thickening agent is 100,000 to 2,000,000.

13. The CO2 reactive thickening agent according to claim 12, wherein, The molar ratio of the structural units provided by the Lewis acid monomer shown in formula (1), the structural units provided by the Lewis base monomer shown in formula (2), the structural units provided by the hydrophilic monomer, and the structural units provided by the interfacial active monomer shown in formula (3) is 1:(0.5-2):(25-80):(0.7-6); And / or, the number average molecular weight of the CO2 reactive thickening agent is 500,000 to 1,500,000.

14. The CO2 reactive thickening agent according to claim 13, wherein, The molar ratio of the structural units provided by the Lewis acid monomer shown in formula (1), the structural units provided by the Lewis base monomer shown in formula (2), the structural units provided by the hydrophilic monomer, and the structural units provided by the interfacial active monomer shown in formula (3) is 1:(0.7-1.5):(30-70):(1-4); And / or, the number average molecular weight of the CO2 reactive thickening agent is 800,000 to 1,200,000.

15. The CO2 reactive thickening and polymerizing agent according to claim 14, wherein, The molar ratio of the structural units provided by the Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer, and the interfacial active monomer shown in formula (3) is 1:(0.8-1.3):(40-60):(1.5-3); And / or, the number average molecular weight of the CO2 reactive thickening agent is 900,000 to 1,100,000.

16. A method for preparing a CO2 reactive thickening agent according to any one of claims 1-15, characterized in that, The preparation method includes: (F1) The Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer, the interfacial active monomer shown in formula (3) and the solvent are brought into contact and mixed to obtain a mixture; (F2) The mixture is reacted with an initiator under an inert gas atmosphere; (F3) The product obtained in step (F2) is contacted with an alcohol solvent and then subjected to precipitation, filtration and drying to obtain a CO2 reaction thickening agent.

17. The preparation method according to claim 16, wherein, The molar ratio of the Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer and the interfacial active monomer shown in formula (3) is 1:(0.5-2):(20-100):(1-10).

18. The preparation method according to claim 17, wherein, The molar ratio of the Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer and the surfactant monomer shown in formula (3) is 1:(0.6-1.5):(30-80):(1-6).

19. The preparation method according to claim 18, wherein, The molar ratio of the Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer and the surfactant monomer shown in formula (3) is 1:(0.7-1.3):(40-70):(2-5).

20. The preparation method according to claim 19, wherein, The molar ratio of the Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer and the surfactant monomer shown in formula (3) is 1:(0.8-1.2):(50-70):(2-3).

21. The preparation method according to claim 16, wherein, Based on the total weight of the Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer and the interfacial active monomer shown in formula (3), the amount of the initiator is 0.1-0.8% by weight. And / or, the solvent is selected from at least two of toluene, chloroform, dimethyl sulfoxide, N,N-dimethylformamide and cyclohexane; And / or, the Lewis acid monomers of formula (1), Lewis base monomers of formula (2), hydrophilic monomers and interfacial active monomers of formula (3) are in the same or different concentrations in the solvent, each being 10-30 wt%.

22. The preparation method according to claim 21, wherein, Based on the total weight of the Lewis acid monomer shown in formula (1), the Lewis base monomer shown in formula (2), the hydrophilic monomer, and the surfactant monomer shown in formula (3), the amount of the initiator is 0.2-0.5% by weight.

23. The preparation method according to claim 16, wherein, In step (F2), the reaction conditions include: a reaction temperature of 40-100°C and a reaction time of 12-28 h.

24. The preparation method according to claim 23, wherein, In step (F2), the reaction conditions include: a reaction temperature of 60-80°C and a reaction time of 16-24 hours.

25. The application of the CO2 reactive thickening agent according to any one of claims 1-15 in the control of CO2 channeling in offshore heavy oil.

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