Hydrophilic chain branched polymerizable functional monomer, macromolecular surfactant, and preparation method and application of hydrophilic chain branched polymerizable functional monomer and macromolecular surfactant

Abstract

The invention provides a hydrophilic chain branched polymerizable functional monomer, a macromolecular surfactant as well as a preparation method and application of the hydrophilic chain branched polymerizable functional monomer and the macromolecular surfactant. The molecular general formula of the hydrophilic chain branched polymerizable functional monomer is as shown in formula (I): in the formula (I), R1 is-(CH2CH2O) n-, and n is an integer in the range of 5-12; r2 is-(CH (CH3) CH2O) m-, and m is an integer from 5 to 15; r3 is-CtH2t + 1, and t is an integer from 1 to 4; r4 is-CyH2y-, and y is 1 or 2; wherein n < = m, and 4m + t + y < = 8n. The polymer surfactant prepared from the functional monomer can solve the chromatographic separation problem of polymer-surfactant binary flooding, and can ensure that the polymer surfactant has better interfacial activity and tackifying property under the condition of not changing the polymerization method of the polymer surfactant.

Description

Technical Field

[0001] This invention relates to the field of polymeric surfactants, and more specifically, to a hydrophilic branched polymerizable functional monomer, a polymeric surfactant, its preparation method, and its application. Background Technology

[0002] Long-term waterflooding creates dominant underground channels, rendering displacing agents ineffective and hindering the driving of residual underground oil in bipolar high-oil reservoirs. Traditional polymer flooding increases the viscosity of the displacing fluid to increase the swept volume, while traditional surfactant flooding reduces the interfacial tension between the displacing fluid and crude oil to improve washing efficiency. The simultaneous use of both is known as polymer-surfactant binary flooding, which can increase viscosity and reduce interfacial tension. However, in traditional binary flooding, the two displacing agents have very different structures and molecular weights, leading to chromatographic separation problems underground, which affects the efficiency of displacing fluid utilization.

[0003] To address the challenges of chromatographic separation, the design of surface-modifying agents (SMAs) was proposed, aiming to simultaneously enhance viscosity and reduce surface tension using a single chemical agent. However, during product development, it was discovered that commercially available functional monomers added during polymerization inevitably affect the product's water solubility. While adding more functional monomers increases interfacial activity, it also worsens the water solubility of the SMA, making it difficult to dissolve and ultimately causing the viscosity-enhancing properties to disappear. Conversely, without functional monomers, the product lacks oil-water interfacial activity. Even comonomers that generally do not affect or even enhance water solubility often negatively impact the product's oil-water interfacial activity. Balancing the product's viscosity-enhancing ability with its oil-water interfacial activity remains a significant challenge in SMA development. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this invention provides a hydrophilic branched polymerizable functional monomer, a polymeric surfactant, its preparation method, and its application.

[0005] To address the problem that existing surfactants cannot simultaneously improve interfacial activity and thickening properties, this invention designs a hydrophilic branched polymeric functional monomer. It is prepared through a multi-step reaction using raw materials including amino aldehydes, ethylene oxide, acid anhydrides, propylene, propylene oxide, and haloalkanes. By selecting the amounts of ethylene oxide and propylene oxide, the oil-water interfacial activity of the monomer can be controlled, effectively balancing the thickening performance and oil-water interfacial activity of the polymeric surfactant. When the monomer participates in the free radical polymerization of the polymeric surfactant, it ensures that the polymeric surfactant simultaneously possesses good interfacial activity and thickening properties without changing the polymerization method.

[0006] In preparing hydrophilic branched polymeric functional monomers, propylene is used as the allyl group to introduce a double bond. The carbon atom next to the double bond serves as the reaction center. Compared to ethylene, which has no reaction sites, propylene has the best reactivity and no steric hindrance. If the carbon chain is longer, an additional hydrophobic chain will appear, affecting the product structure and oil-water balance. Using a low-molecular-weight acid anhydride with good water solubility is beneficial for esterification reactions. Using an amino aldehyde ensures that no other sites (such as alcohol groups) are reacted during the reaction of the amino group. After the amino group reacts, it is protected, and then the aldehyde group is added to obtain an alcohol group that can further react, achieving a differentiated structure of hydrophilic / hydrophobic chains. If the carbon chain is too long, it will affect the oil-water balance of the product; therefore, a low-molecular-weight amino aldehyde is selected. Using haloalkanes with no more than 4 carbon atoms reduces the impact on the amount of other raw materials (mainly propylene oxide) used to ensure the oil-water balance.

[0007] The prepared hydrophilic branched polymeric functional monomers can participate in the polymerization of polymeric surfactants to obtain polymeric surfactants with hydrophilic side chain branching. The resulting polymeric surfactants have good water solubility and good thickening properties. The branched hydrophilic side chains can effectively maintain the interfacial tension of the product, preventing the situation where increasing the ethylene oxide chain length to ensure the product's hydrophilicity results in the polymeric surfactant becoming too hydrophilic and losing its interfacial activity. While solving the chromatographic separation problem of binary polymeric surfactants, the polymeric surfactants can be guaranteed to have both good interfacial activity and thickening properties without changing the polymerization method.

[0008] One objective of this invention is to provide a hydrophilic, branched, polymerizable functional monomer with the general molecular formula shown in formula (Ⅰ):

[0009]

[0010] In equation (Ⅰ), R1 is -(CH2CH2O) n - where n is an integer from 5 to 12; R2 is -(CH(CH3)CH2O) m -, m is an integer from 5 to 15; R3 is -C t H 2t+1 t is an integer from 1 to 4, such as t being any one of 1, 2, 3, or 4; R4 is -C y H 2y -, y is 1 or 2; where n≤m, 4m+t+y≤8n.

[0011] In a preferred embodiment of the present invention,

[0012] The hydrophilic branched polymerizable functional monomer is prepared from raw materials including amino aldehydes, ethylene oxide, acid anhydrides, propylene, propylene oxide, and haloalkanes.

[0013] Preferably,

[0014] The amino aldehyde is aminoacetaldehyde or 3-aminopropionaldehyde;

[0015] The acid anhydride is acetic anhydride or propionic anhydride; and / or,

[0016] The general formula of the haloalkanes is C t H 2t+1 X is one of Cl, Br, and I, and t is an integer from 1 to 4.

[0017] A second objective of this invention is to provide a method for preparing a hydrophilic, branched, polymerizable functional monomer, comprising:

[0018] (1) React amino aldehyde and ethylene oxide to obtain intermediate product 1;

[0019] (2) The intermediate product 1 obtained in step (1) is reacted with an acid anhydride to obtain intermediate product 2;

[0020] (3) React the intermediate product 2 obtained in step (2) with propylene to obtain intermediate product 3;

[0021] (4) The intermediate product 3 obtained in step (3) is reacted with propylene oxide to obtain intermediate product 4;

[0022] (5) The intermediate product 4 obtained in step (4) is reacted with a haloalkane to obtain intermediate product 5;

[0023] (6) Hydrolyze the intermediate product 5 obtained in step (5) to obtain the hydrophilic branched polymerizable functional monomer.

[0024] In a preferred embodiment of the present invention,

[0025] Step (1),

[0026] The molar ratio of the amino aldehyde to ethylene oxide is 1:(10-30), preferably 1:(11-25);

[0027] The reaction is carried out in an anhydrous protic solvent, preferably at least one of ethanol, methanol, and isopropanol;

[0028] The ratio of the amount of proton solvent to the total mass of the reaction raw materials is (0.1-10):1, preferably (0.5-3):1;

[0029] The reaction temperature is 30–60℃, preferably 40–50℃;

[0030] Maintain reflux during the reaction;

[0031] The reaction time is 3 to 12 hours, preferably 6 to 8 hours;

[0032] After the reaction is complete, unreacted ethylene oxide is removed, and the product is purified to obtain intermediate product 1.

[0033] For example, the reaction formula in step (1) can be:

[0034] In a preferred embodiment of the present invention,

[0035] Step (2),

[0036] The molar ratio of intermediate product 1 to acid anhydride is 1:(1-20), preferably 1:(5-10);

[0037] The reaction is carried out under the catalysis of an acidic substance; preferably, the acidic substance is concentrated sulfuric acid; and / or, the molar ratio of the acidic substance to intermediate product 1 is (0.1-0.5):1, more preferably (0.2-0.4):1;

[0038] The reaction temperature is 90–100℃;

[0039] Maintain reflux during the reaction;

[0040] After the reaction is complete, unreacted raw materials and by-products are removed, and the product is purified to obtain intermediate product 2.

[0041] For example, the reaction formula in step (2) can be:

[0042]

[0043] In a preferred embodiment of the present invention,

[0044] Step (3),

[0045] The molar ratio of intermediate product 2 to propylene is 1:(1-5), preferably 1:(1.2-2);

[0046] To protect the tertiary amine in intermediate product 2, a sulfonic acid compound needs to be added before the reaction begins. Preferably, the sulfonic acid compound is at least one of methanesulfonic acid, ethanesulfonic acid, and benzenesulfonic acid, and / or the molar ratio of intermediate product 2 to the sulfonic acid compound is 1:(0.8-2), more preferably 1:(1-1.3).

[0047] The reaction is carried out under excitation light, which is near-ultraviolet-visible light, and the wavelength of the excitation light is 300-780 nm, preferably 345-465 nm;

[0048] The reaction is carried out in the presence of a catalyst, which is a combination of a metal catalyst, a photocatalyst, and a HAT catalyst.

[0049] Preferably,

[0050] The total molar amount of the catalyst is 0.1% to 0.2% of the molar amount of propylene;

[0051] Based on a total catalyst amount of 100% mol, the amount of the metal catalyst is 70-80 mol%, the amount of the photocatalyst is 5-10% mol%, and the amount of the HAT catalyst is 10-20 mol%.

[0052] The metal catalyst is at least one of gold (Au), silver (Ag), platinum (Pt), palladium (Pd), chromium (Cr), copper (Cu), chromium(II) chloride (CrCl2), cuprous(II) chloride (CuCl), and cuprous(II) bromide (CuBr), more preferably at least one of Cr, CrCl2, Cu, and CuBr.

[0053] The photocatalyst is at least one of the following: acridine salt (NSP-SA-NHS, NSP-DMAE-NHS, DMAE-NHS, Me-PhAcrMe, Me-DMAE-NHS) derivatives, heterocyclic naphthalene derivatives, heteroatom benzene derivatives, polytungstic acid derivatives, and iridium photosensitizers; the acridine salt is at least one of NSP-SA-NHS, NSP-DMAE-NHS, DMAE-NHS, Me-PhAcrMe, and Me-DMAE-NHS; more preferably, the photocatalyst is at least one of acridine fluoroborate (Mes-PhAcrMe2BF4), tetrabutylammonium decapolytungstate (TBADT), and difluorotolylbipyridine iridium hexafluorophosphate (Ir[dF(CF3)ppy]2(dtbpy)PF6);

[0054] The HAT catalyst is at least one of a thiol derivative and a polytungstic acid derivative, preferably at least one of dioxaphosphonium heterocyclic heptamyl thiol (TPI) and tetrabutylammonium decatungstate (TBADT).

[0055] Intermediate product 2 contains both aldehyde carbonyl and ester carbonyl groups. The reaction requires addition to the aldehyde carbonyl group without reacting with the ester carbonyl group. Based on this, the catalyst combination is further optimized, and the catalyst is selected from one of the following combinations:

[0056] (1)Cr / Cu / CrCl2 / CuBr+Ir[dF(CF3)ppy]2(dtbpy)PF6+TPI;

[0057] (2)Cr / Cu / CrCl2 / CuBr+Mes-PhAcrMe2BF4+TPI;

[0058] (3) Cr / Cu / CrCl2 / CuBr+TBADT;

[0059] An alkali metal salt is added to the reaction. Preferably, the amount of the alkali metal salt is 80-140% of the total molar amount of the catalyst; and / or, the alkali metal salt is at least one selected from Li2CO3, Na2CO3, K2CO3, Cs2CO3, K2HPO4, and Na2HPO4.

[0060] The reaction occurs in an organic solvent; preferably, the organic solvent is at least one of acetonitrile, toluene, dimethyl adipate, ethyl acetate, dichloromethane, dichloroethane, dichloropropane, and acetone, more preferably at least one of acetonitrile, dimethyl adipate, dichloromethane, and acetone; and / or, the molar ratio of the amount of the organic solvent to the total amount of the reaction raw materials in step (3) is (0.1 to 10):1, more preferably (0.5 to 2):1, such as 0.5:1, 1:1, 1.5:1, 2:1, or any two of the above values, for example (0.5 to 1):1;

[0061] The reaction temperature is 10–60°C, more preferably 20–50°C;

[0062] The reaction time is 12 to 72 hours, more preferably 20 to 48 hours;

[0063] After the reaction is complete, unreacted raw materials and solvents are removed, and the product is purified to obtain intermediate product 3.

[0064] For example, the reaction formula in step (3) can be:

[0065]

[0066] In a preferred embodiment of the present invention,

[0067] Step (4),

[0068] The molar ratio of intermediate product 3 to propylene oxide is 1:(5-20), preferably 1:(6-16);

[0069] The reaction involves the addition of propylene oxide in the presence of a polymerization inhibitor; preferably, the polymerization inhibitor is at least one selected from oxidizing polymerization inhibitors, phenolic polymerization inhibitors, phenolic resin polymerization inhibitors, nitrile polymerization inhibitors, and thioether polymerization inhibitors, more preferably at least one selected from oxygen, air, ethyl cyanoformate, ethyl cyanoacetate, and diallyl thioether; and / or, the molar percentage of the polymerization inhibitor to the total amount of reactants is 1–20% mol, preferably 3–8% mol;

[0070] The reaction is carried out in an anhydrous protic solvent; preferably, the protic solvent is at least one of ethanol and methanol; and / or, the mass ratio of the amount of the protic solvent to the total amount of the reaction raw materials in step (4) is (0.1-5):1, preferably (0.2-2):1, such as 0.2:1, 0.4:1, 0.8:1, 1.2:1, 1.6:1, 2:1 or any two of the above values, for example (0.4-0.8):1;

[0071] The reaction temperature is 30–60℃, preferably 40–50℃;

[0072] Maintain reflux during the reaction;

[0073] The reaction time is 3 to 12 hours, preferably 6 to 8 hours;

[0074] After the reaction is complete, unreacted propylene oxide is removed, and the product is purified to obtain intermediate product 4.

[0075] For example, the reaction formula in step (4) can be:

[0076]

[0077] In a preferred embodiment of the present invention,

[0078] Step (5),

[0079] The molar ratio of intermediate product 4 to haloalkanes is 1:(1-2), preferably 1:(1.1-1.2);

[0080] The reaction is carried out in the presence of a polymerization inhibitor; preferably, the polymerization inhibitor is at least one of an oxidizing polymerization inhibitor, a phenolic polymerization inhibitor, a phenolic resin polymerization inhibitor, a nitrile polymerization inhibitor, and a thioether polymerization inhibitor, more preferably at least one of oxygen, air, ethyl cyanoformate, ethyl cyanoacetate, and diallyl thioether; and / or, the molar percentage of the amount of the polymerization inhibitor to the total amount of the reaction raw materials in step (5) is 1 to 80% mol, preferably 20 to 60% mol;

[0081] The reaction is carried out under acid catalysis; preferably, the acid is at least one of sulfuric acid and phosphoric acid; and / or, the amount of acid used is 10 to 150% mol of the amount of intermediate product 4, preferably 40 to 100% mol.

[0082] The reaction temperature is 20–100℃, preferably 20–30℃;

[0083] The reaction time is 3 to 12 hours, preferably 6 to 8 hours;

[0084] The reaction is carried out in an organic solvent; preferably, the organic solvent is at least one of acetonitrile, toluene, dimethyl adipate, ethyl acetate, dimethylformamide, and dimethyl sulfoxide, more preferably at least one of ethyl acetate, dimethylformamide, and dimethyl sulfoxide; and / or, the mass ratio of the amount of the organic solvent to the total amount of the reaction raw materials in step (5) is (0.1-5):1, preferably (0.4-2):1, such as 0.4:1, 0.8:1, 1:1, 1.2:1, 1.6:1, 2:1 or any two of the above values, for example (0.4-1):1;

[0085] After the reaction is complete, unreacted raw materials and by-products are removed, and the product is purified to obtain intermediate product 5.

[0086] For example, the reaction formula in step (5) can be:

[0087]

[0088] In a preferred embodiment of the present invention,

[0089] Step (6),

[0090] The reaction is carried out in a mixed solvent consisting of water and an organic solvent; preferably, the mass ratio of water to organic solvent in the mixed solvent is 1:(1-5), more preferably 1:(1-3); and / or, the organic solvent is at least one of methanol, ethanol, isopropanol, n-propanol, and n-butanol, more preferably one of methanol, ethanol, and isopropanol; and / or, the mass ratio of intermediate product 5 to the mixed solvent is 1:(1-10), preferably 1:(1-5), such as 1:1, 1:2, 1:3, 1:4, 1:5 or any two of the above values, for example 1:(1-2);

[0091] The reaction is carried out in the presence of a polymerization inhibitor; preferably, the polymerization inhibitor is at least one selected from oxidative polymerization inhibitors, phenolic polymerization inhibitors, phenolic resin polymerization inhibitors, nitrile polymerization inhibitors, and thioether polymerization inhibitors, more preferably at least one selected from oxygen, air, ethyl cyanoformate, ethyl cyanoacetate, and diallyl thioether; and / or, the molar ratio of the amount of the polymerization inhibitor to the amount of intermediate product 5 is (0.1-5):1, preferably (0.5-2):1;

[0092] The reaction is carried out under the catalysis of a base; preferably, the base is at least one of LiOH, NaOH, and KOH; and / or, the molar ratio of the amount of base to the amount of intermediate product 5 is (1-10):1, preferably (2-4):1;

[0093] The reaction temperature is 50–80℃, preferably 60–65℃;

[0094] After the reaction is complete, byproduct salts, polymerization inhibitors, unreacted alkalis and solvents are removed, and the purified product is the hydrophilic branched polymerizable functional monomer.

[0095] For example, the reaction formula in step (6) can be:

[0096]

[0097] The third objective of this invention is to provide a polymeric surfactant obtained by copolymerization of an aqueous solution of a polymeric monomer, wherein the polymeric monomer includes the hydrophilic branched polymerizable functional monomer as described in claim 1 or 2, or the hydrophilic branched polymerizable functional monomer obtained by the preparation method described in any one of claims 3 to 9.

[0098] Preferably,

[0099] Based on a total of 100 parts by weight of the polymeric monomer aqueous solution, the polymeric monomer aqueous solution includes 40-50 parts by weight of polymeric monomer and 50-60 parts by weight of water; more preferably, the water is deionized water.

[0100] In a preferred embodiment of the present invention,

[0101] With a total mass of 100 wt% for the polymeric monomers, the polymeric monomers comprise:

[0102] 0.1–5 wt% of hydrophilic branched polymerizable functional monomers; preferably 1–3 wt%.

[0103] Nonionic monomers 95–99.9 wt%; preferably 97–99 wt%;

[0104] Preferably,

[0105] The nonionic monomer is at least one of acrylamide, methacrylamide, ethylacrylamide, N'N-dimethylacrylamide, N'N-diethylacrylamide, and tert-butylacrylamide.

[0106] In a preferred embodiment of the present invention,

[0107] When copolymerizing the monomer aqueous solution, initiator I, initiator II, and initiator III also need to be added; preferably,

[0108] The total mass of the initiator is 0.03 to 0.5 wt% of the total mass of the polymerizing monomers, more preferably 0.04 to 0.1 wt%; and / or,

[0109] The mass ratio of initiator I, initiator II, and initiator III is 1:(0.5–2):(0.5–5), more preferably 1:(0.5–1):(0.5–3); and / or,

[0110] The initiator I is an oxidizing initiator, more preferably one of sodium persulfate, ammonium persulfate, and potassium persulfate; and / or,

[0111] The initiator II is a reducing initiator, more preferably one of sodium thiosulfate, sodium sulfite, sodium bisulfite, potassium sulfite, and potassium bisulfite; and / or,

[0112] The initiator III is a water-soluble azo initiator, more preferably one of azobisisobutyramidine hydrochloride, azobisisobutyramidine imidazoline hydrochloride, and azobisisobutyramidal acid.

[0113] The fourth objective of this invention is to provide a method for preparing a polymeric surfactant, comprising:

[0114] An initiator is added to an aqueous solution of the polymeric monomer, and the reaction is carried out under a protective gas atmosphere to obtain the polymeric surfactant.

[0115] Preferably,

[0116] First, add aqueous solutions of initiator II and initiator III to the aqueous solution of the polymer monomer, cool down to the initiation temperature, and then add an aqueous solution of initiator I dropwise to carry out the reaction.

[0117] The initiation temperature is 0–10°C, preferably 2–5°C; and / or,

[0118] The maximum reaction temperature is controlled at 30–80°C, preferably 50–60°C; and / or,

[0119] The reaction time is 2–8 hours, preferably 4–6 hours; and / or,

[0120] After the reaction is complete, the mixture is granulated, dried, and pulverized.

[0121] The fifth objective of this invention is to provide an application of a polymeric surfactant in oil production; preferably, the polymeric surfactant is dissolved in injection water that matches the target formation to obtain a solution with a concentration of 0.1 to 0.5 wt%, which is then applied in enhanced oil recovery operations.

[0122] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0123] Existing surfactant technologies suffer from the problem that interfacial activity and thickening properties cannot be improved simultaneously. This invention designs the structure of a hydrophilic branched functional monomer and develops a synthetic route for this functional monomer. According to the monomer synthesis route provided by this invention, the oil-water interfacial activity of the monomer can be controlled during monomer synthesis by selecting the amounts of ethylene oxide and propylene oxide. This functional monomer can participate in the polymerization of polymeric surfactants to obtain hydrophilic branched polymeric surfactants. The obtained polymeric surfactants have good water solubility and good thickening properties. The branched hydrophilic side chains can effectively maintain the interfacial tension of the product, preventing the loss of interfacial activity of the polymeric surfactant due to the need to increase ethylene oxide to ensure the polymeric surfactant. While solving the chromatographic separation problem of binary polymeric surfactant flooding, this invention ensures that the polymeric surfactant has both good interfacial activity and thickening properties without changing the polymerization method of the polymeric surfactant. Attached Figure Description

[0124] Figure 1 The hydrophilic branched polymerizable functional monomer prepared in Example 1 1 H-NMR spectrum;

[0125] Figure 2 The hydrophilic branched polymerizable functional monomer prepared in Example 2 1 H-NMR spectrum;

[0126] Figure 3 This is a schematic diagram of the oil displacement experimental apparatus in an embodiment of the present invention. Detailed Implementation

[0127] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0128] The specific embodiments of the present invention will be described in detail below. However, it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims in the appendix.

[0129] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0130] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application’s filing, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0131] All raw materials used in the examples are commercially available.

[0132] Test method:

[0133] Solubility: Simulated brine matching the mineralization of the target formation, 1% concentration of polymeric surfactant, stirred at 700 rpm at room temperature for 1 hour, the solution condition was observed by lifting with a glass every 15 minutes until the total stirring time was 2 hours.

[0134] Viscosity: Using a rotational rheometer or rotational viscometer, at the target formation temperature and a shear rate of 7.34 s⁻¹. -1 The viscosity of solutions with polymeric surfactant concentrations of 0.1%, 0.2%, and 0.5% was tested.

[0135] Interfacial tension: Using an interfacial rheometer, the interfacial tension between a 0.2% polymeric surfactant solution and the target crude oil was measured at the target formation temperature and a rotation speed of 8000 rpm. The interfacial tension was recorded every 10 minutes until the difference between three consecutive records was less than 1 × 10⁻⁶. -3 mN / m, with a total test duration not exceeding 8 hours.

[0136] Oil displacement experiment:

[0137] An oil displacement experiment was conducted using a 0.2% polymeric surfactant solution at the target formation temperature and an injection rate of 0.5 mL / min.

[0138] Figure 3 This is a schematic diagram of the oil displacement experimental apparatus in an embodiment of the present invention;

[0139] The sand-filled pipe is 30cm long and 3.8cm in diameter. It is filled with quartz sand with a permeability of 1000mD and a porosity of 30%. Before the experiment, the target formation crude oil was diluted with saturated kerosene in the sand-filled pipe. The mass ratio of crude oil to kerosene was 1:10. Tank 1 contains simulated brine, and tank 2 contains the test liquid. Pressure measuring point A measures the pressure at the inlet of the test sample, and pressure measuring point B measures the pressure at the tail end of the sand-filled pipe. The pressure readings are shown in pressure gauges A and B, respectively.

[0140] The effluent was collected during the experiment, and the recovery rate was calculated.

[0141] Example 1

[0142] Synthesis of hydrophilic branched polymerizable functional monomers:

[0143] 50 g of methanol was added to a 100 mL round-bottom flask equipped with a reflux condenser. Then, 2.9 g (0.05 mol) of aminoacetaldehyde and 24.2 g (0.55 mol) of ethylene oxide were added. A constant temperature water bath was turned on and set to 40 °C. After reaching the temperature, the flask containing the reaction solution was placed in the water bath and the reflux condenser was attached. The mixture was stirred and kept reacting for 6 hours. After stopping the reaction, unreacted ethylene oxide was removed, and the product was purified to obtain intermediate 1, whose structural formula is as follows:

[0144]

[0145] 21 g (0.2 mol) of acetic anhydride was added to a 100 mL round-bottom flask equipped with a reflux condenser, followed by 20 g (0.04 mol) of intermediate product 1, and the mixture was thoroughly stirred. A constant temperature water bath was turned on and set to 90 °C. After reaching the temperature, the flask containing the reaction solution was placed in the water bath and fitted with a reflux condenser. Stirring was started, and 1 g (0.01 mol) of concentrated sulfuric acid was added dropwise. The reaction was maintained for 6 hours. After the reaction was completed, unreacted raw materials and by-products were removed, and intermediate product 2 was obtained after purification. Its structural formula is as follows:

[0146]

[0147] Add 20g of dimethyl adipate to a 100mL colorless glass isothermal reactor equipped with a reflux condenser, and then add 3.8×10⁻⁶ ppm of the condenser. -5 mol Na2CO3, 3.3×10 -5 mol CrCl2, 3.6 × 10 -6 mol Ir[dF(CF3)ppy]2(dtbpy)PF6, 7.2×10 -6 1 mol TPI was mixed thoroughly, and then 20 g (0.034 mol) of intermediate product 2 and 3.3 g (0.034 mol) of methanesulfonic acid were added and mixed thoroughly. Then, 1.8 g (0.043 mol) of propylene (approximately 1.0 L under standard atmospheric pressure) was introduced. A constant temperature water bath was turned on and the temperature was set to 20°C. After reaching the temperature, the light source was set to 345 nm to irradiate the reactor to initiate the reaction, and the reaction was maintained for 20 hours. After the reaction was completed, unreacted raw materials and by-products were removed, and intermediate product 3 was obtained after purification. Its structural formula is as follows:

[0148]

[0149] Add 20g of methanol and 2g (0.0175mol) of diallyl sulfide to a 100mL round-bottom beaker and mix well. Then add 20g (0.032mol) of intermediate product 3 and mix well. Turn on the constant temperature water bath and set the temperature to 40℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution into the water bath. Add 11.2g (0.193mol) of propylene oxide dropwise to the round-bottom beaker while stirring, and maintain the reaction for 6 hours. After the reaction is completed, remove the unreacted raw materials and by-products to obtain intermediate product 4, whose structural formula is as follows:

[0150]

[0151] Add 20g of dimethyl sulfoxide and 2g (0.0175mol) of diallyl sulfide to a 100mL round-bottom beaker and mix well. Then add 20g (0.023mol) of intermediate product 4 and mix well. Turn on the constant temperature water bath and set the temperature to 20℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution into the water bath. While stirring, add 1.3g (0.026mol) of CH3Cl dropwise, followed by 1g (0.01mol) of phosphoric acid dropwise. Maintain the reaction for 6 hours. After the reaction is complete, remove the unreacted raw materials and by-products to obtain intermediate product 5, whose structural formula is as follows:

[0152]

[0153] Add 15g of deionized water and 25g of methanol to a 100mL round-bottom beaker, then add 2g (0.0175mol) of diallyl sulfide and 2g (0.05mol) of NaOH. Mix well, then add 20g (0.023mol) of intermediate product 5 and mix well. Turn on the constant temperature water bath and set the temperature to 60℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution into the water bath and maintain the reaction for 6 hours. After the reaction is completed, remove the hydrolysis byproduct sodium acetate, polymerization inhibitor, unreacted alkali, and solvent to obtain the final product, whose structural formula is as follows:

[0154]

[0155] The product of Example 1 1 H-NMR spectrum as follows Figure 1 As shown, the chemical shift at 5.37 represents two H atoms, which are H atoms at the -OH end caps of the two ethoxy chains; the one H atom at chemical shift 5.75 and the two H atoms at chemical shift 5.20 represent H atoms at the C atoms of the double bond; the chemical shifts between 3 and 4 represent H atoms at the C atoms connected to O; the chemical shift near 1 represents a methyl group; the chemical shifts of other H atoms are also shown in the diagram. 1 The corresponding peak positions were located on the H-NMR spectrum. By integrating the peaks, the number of H atoms at each chemical shift could be obtained, confirming the structure as described above.

[0156] Example 2

[0157] Synthesis of hydrophilic branched polymerizable functional monomers:

[0158] 50 g of ethanol was added to a 100 mL round-bottom flask equipped with a reflux condenser, followed by 4.3 g (0.073 mol) of aminoacetaldehyde and 54.5 g (1.237 mol) of ethylene oxide. A constant temperature water bath was turned on and set to 50 °C. After reaching the temperature, the flask containing the reaction solution was placed in the water bath and the reflux condenser was attached. The mixture was stirred and kept in the reaction for 8 hours. After stopping the reaction, unreacted ethylene oxide was removed, and the product was purified to obtain intermediate 1, whose structural formula is as follows:

[0159]

[0160] 39 g (0.382 mol) of acetic anhydride was added to a 100 mL round-bottom flask equipped with a reflux condenser, followed by 30 g (0.041 mol) of intermediate product 1, and the mixture was thoroughly stirred. A constant temperature water bath was turned on and set to 100 °C. After reaching the temperature, the flask containing the reaction solution was placed in the water bath and fitted with a reflux condenser. Stirring was started, and 1 g (0.01 mol) of concentrated sulfuric acid was added dropwise, maintaining the reaction for 4 hours. After the reaction was completed, unreacted raw materials and by-products were removed, and intermediate product 2 was obtained after purification. Its structural formula is as follows:

[0161]

[0162] Add 30g of dimethyl adipate to a 100mL colorless glass isothermal reactor equipped with a reflux condenser, and then add 7.2×10⁻⁶ ppm of the condenser. -5 mol K2CO3, 4.2×10 -5 mol CuBr, 5.2 × 10 -6 mol Mes-PhAcrMe2BF4, 6.4×10 -6 mol TPI was mixed thoroughly, and then 30g (0.037mol) of intermediate product 2 and 5g (0.045mol) of ethanesulfonic acid were added and mixed thoroughly. Then, 1.9g (0.045mol) of propylene (approximately 1.0L at standard atmospheric pressure) was introduced. A constant temperature water bath was turned on and the temperature was set to 20℃. After reaching the temperature, the light source was set to 380nm to irradiate the reactor to initiate the reaction, and the reaction was maintained for 40 hours. After the reaction was completed, unreacted raw materials and by-products were removed, and intermediate product 3 was obtained after purification. Its structural formula is as follows:

[0163]

[0164] Add 30g of ethanol and 3g (0.027mol) of ethyl cyanoacetate to a 100mL round-bottom beaker and mix well. Then add 30g (0.034mol) of intermediate product 3 and mix well. Turn on the constant temperature water bath and set the temperature to 50℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution into the water bath. Add 30g (0.517mol) of propylene oxide dropwise to the round-bottom beaker while stirring, and maintain the reaction for 8 hours. After the reaction is completed, remove the unreacted raw materials and by-products to obtain intermediate product 4, whose structural formula is as follows:

[0165]

[0166] Add 20g of ethyl acetate and 3g (0.027mol) of ethyl cyanoacetate to a 100mL round-bottom beaker and mix well. Then add 40g (0.023mol) of intermediate product 4 and mix well. Turn on the constant temperature water bath and set the temperature to 30℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution into the water bath. While stirring, add 2.6g (0.027mol) of CH3Br dropwise, followed by 2g (0.02mol) of sulfuric acid dropwise. Maintain the reaction for 8 hours. After the reaction is complete, remove the unreacted raw materials and by-products to obtain intermediate product 5, whose structural formula is as follows:

[0167]

[0168] Add 15g of deionized water and 15g of isopropanol to a 100mL round-bottom beaker, then add 3g (0.027mol) of ethyl cyanoacetate and 3g (0.053mol) of KOH. Mix well, then add 30g (0.017mol) of intermediate product 5 and mix well. Turn on the constant temperature water bath and set the temperature to 65℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution into the water bath and maintain the reaction for 8 hours. After the reaction is completed, remove the hydrolysis byproduct potassium acetate, polymerization inhibitor, unreacted alkali, and solvent to obtain the final product, whose structural formula is as follows:

[0169]

[0170] The product of Example 2 1 H-NMR spectrum as follows Figure 2 As shown, the chemical shift at 5.37 represents two H atoms, which are H atoms at the -OH end caps of the two ethoxy chains; the one H atom at chemical shift 5.75 and the two H atoms at chemical shift 5.20 represent H atoms at the C atoms of the double bond; the chemical shifts near 3 and 4 represent H atoms at the C atoms connected to O; the chemical shifts of other H atoms are also... 1 The corresponding peak positions were located on the H-NMR spectrum. By integrating the peaks, the number of H atoms at each chemical shift could be obtained, confirming the structure as described above.

[0171] Example 3

[0172] Synthesis of hydrophilic branched polymerizable functional monomers:

[0173] 50 g of methanol was added to a 100 mL round-bottom flask equipped with a reflux condenser, followed by 3.6 g (0.05 mol) of 3-aminopropionaldehyde and 55 g (1.25 mol) of ethylene oxide. A constant temperature water bath was turned on and set to 50 °C. After reaching the temperature, the flask containing the reaction solution was placed in the water bath and the reflux condenser was attached. The mixture was stirred and kept in the reaction for 6 hours. After stopping the reaction, unreacted ethylene oxide was removed, and the product was purified to obtain intermediate 1, whose structural formula is as follows:

[0174]

[0175] 21 g (0.2 mol) of acetic anhydride was added to a 100 mL round-bottom flask equipped with a reflux condenser, followed by 45 g (0.04 mol) of intermediate product 1, and the mixture was thoroughly stirred. A constant temperature water bath was turned on and set to 90 °C. After reaching the temperature, the flask containing the reaction solution was placed in the water bath and fitted with a reflux condenser. Stirring was started, and 1 g (0.01 mol) of concentrated sulfuric acid was added dropwise, maintaining the reaction for 6 hours. After the reaction was completed, unreacted raw materials and by-products were removed, and intermediate product 2 was obtained after purification. Its structural formula is as follows:

[0176]

[0177] Add 20g of dimethyl adipate to a 100mL colorless glass isothermal reactor equipped with a reflux condenser, and then add 4.75×10⁻⁶ ppm of the condenser. -5 mol Na2CO3, 3.3×10 -5 mol CrCl2, 4.0 × 10 -6 molIr[dF(CF3)ppy]2(dtbpy)PF6, 8.0×10 -6 0.030 mol) TPI was mixed thoroughly, and then 36 g (0.030 mol) of intermediate product 2 and 3.3 g (0.034 mol) of methanesulfonic acid were added and mixed thoroughly. Then, 1.8 g (0.043 mol) of propylene (approximately 1.0 L under standard atmospheric pressure) was introduced. A constant temperature water bath was turned on and the temperature was set to 20°C. After reaching the temperature, the light source was set to 345 nm to irradiate the reactor to initiate the reaction, and the reaction was maintained for 20 hours. After the reaction was completed, unreacted raw materials and by-products were removed, and intermediate product 3 was obtained after purification. Its structural formula is as follows:

[0178]

[0179] Add 20g of methanol and 2g (0.0175mol) of diallyl sulfide to a 100mL round-bottom beaker and mix well. Then add 25g (0.020mol) of intermediate product 3 and mix well. Turn on the constant temperature water bath and set the temperature to 40℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution into the water bath. Add 18g (0.31mol) of propylene oxide dropwise to the round-bottom beaker with stirring and maintain the reaction for 6 hours. After the reaction is completed, remove the unreacted raw materials and by-products to obtain intermediate product 4, whose structural formula is as follows:

[0180]

[0181] Add 20g of dimethyl sulfoxide and 0.5g (0.0044mol) of diallyl sulfide to a 100mL round-bottom beaker and mix well. Then add 22g (0.010mol) of intermediate product 4 and mix well. Turn on the constant temperature water bath and set the temperature to 20℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution into the water bath. While stirring, add 0.6g (0.012mol) of CH3Cl dropwise, followed by 0.5g (0.005mol) of phosphoric acid dropwise. Maintain the reaction for 6 hours. After the reaction is complete, remove the unreacted raw materials and by-products to obtain intermediate product 5, whose structural formula is as follows:

[0182]

[0183] Add 8g of deionized water and 24g of methanol to a 100mL round-bottom beaker, then add 1.2g (0.0105mol) of diallyl sulfide and 1g (0.025mol) of NaOH. Mix well, then add 22g (0.010mol) of intermediate product 5 and mix well. Turn on the constant temperature water bath and set the temperature to 60℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution into the water bath and maintain the reaction for 6 hours. After the reaction is completed, remove the hydrolysis byproduct sodium acetate, polymerization inhibitor, unreacted alkali, and solvent to obtain the final product, whose structural formula is as follows:

[0184]

[0185] Example 4

[0186] Synthesis of hydrophilic branched polymerizable functional monomers:

[0187] 50 g of ethanol was added to a 100 mL round-bottom flask equipped with a reflux condenser, followed by 4.3 g (0.073 mol) of aminoacetaldehyde and 54.5 g (1.237 mol) of ethylene oxide. A constant temperature water bath was turned on and set to 40 °C. After reaching the temperature, the flask containing the reaction solution was placed in the water bath and the reflux condenser was attached. The mixture was stirred and kept in the reaction for 8 hours. After stopping the reaction, unreacted ethylene oxide was removed, and the product was purified to obtain intermediate 1, whose structural formula is as follows:

[0188]

[0189] 39 g (0.382 mol) of acetic anhydride was added to a 100 mL round-bottom flask equipped with a reflux condenser, followed by 30 g (0.041 mol) of intermediate product 1, and the mixture was thoroughly stirred. A constant temperature water bath was turned on and set to 100 °C. After reaching the temperature, the flask containing the reaction solution was placed in the water bath and fitted with a reflux condenser. Stirring was started, and 1 g (0.01 mol) of concentrated sulfuric acid was added dropwise, maintaining the reaction for 4 hours. After the reaction was completed, unreacted raw materials and by-products were removed, and intermediate product 2 was obtained after purification. Its structural formula is as follows:

[0190]

[0191] Add 30g of dimethyl adipate to a 100mL colorless glass isothermal reactor equipped with a reflux condenser, and then add 7.2×10⁻⁶ ppm of the condenser. -5 mol K2CO3, 4.2×10 -5 mol CuBr, 5.2 × 10 -6 mol Mes-PhAcrMe2BF4, 6.4×10 - 6 mol TPI was mixed thoroughly, and then 30g (0.037mol) of intermediate product 2 and 5g (0.045mol) of ethanesulfonic acid were added and mixed thoroughly. Then, 3g (0.071mol) of propylene (approximately 1.0L at standard atmospheric pressure) was introduced. A constant temperature water bath was turned on and the temperature was set to 20℃. After reaching the temperature, the light source was set to 380nm to irradiate the reactor to initiate the reaction, and the reaction was maintained for 40 hours. After the reaction was completed, unreacted raw materials and by-products were removed, and intermediate product 3 was obtained after purification. Its structural formula is as follows:

[0192]

[0193] Add 30g of ethanol and 3g (0.027mol) of ethyl cyanoacetate to a 100mL round-bottom beaker and mix well. Then add 30g (0.034mol) of intermediate product 3 and mix well. Turn on the constant temperature water bath and set the temperature to 50℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution into the water bath. Add 30g (0.517mol) of propylene oxide dropwise to the round-bottom beaker while stirring, and maintain the reaction for 8 hours. After the reaction is completed, remove the unreacted raw materials and by-products to obtain intermediate product 4, whose structural formula is as follows:

[0194]

[0195] Add 20g of ethyl acetate and 3g (0.027mol) of ethyl cyanoacetate to a 100mL round-bottom beaker and mix well. Then add 40g (0.023mol) of intermediate product 4 and mix well. Turn on the constant temperature water bath and set the temperature to 30℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution into the water bath. While stirring, add 4.6g (0.027mol) of C3H7I dropwise, followed by 2g (0.02mol) of sulfuric acid dropwise. Maintain the reaction for 8 minutes. After the reaction is complete, remove the unreacted raw materials and by-products to obtain intermediate product 5, whose structural formula is as follows:

[0196]

[0197] Add 10g of deionized water and 20g of ethanol to a 100mL round-bottom beaker, then add 3g (0.027mol) of ethyl cyanoacetate and 3g (0.053mol) of KOH, mix well, and then add 30g (0.017mol) of intermediate product 5 and mix well. Turn on the constant temperature water bath and set the temperature to 65℃. After reaching the temperature, place the round-bottom beaker containing the reaction solution in the water bath and maintain the reaction for 8 hours. After the reaction is completed, remove the hydrolysis byproduct potassium acetate, polymerization inhibitor, unreacted alkali, and solvent, and purify to obtain the final product, the structure of which is as follows:

[0198]

[0199] Application Example 1

[0200] Synthesis of polymeric surfactants:

[0201] The hydrophilic branched polymerizable functional monomer synthesized in Example 1 was used.

[0202] Weigh 100g of deionized water into a 500mL beaker, add 97g of acrylamide and 3g of functional monomer, stir well, and adjust the pH to 8.2 with 30wt% NaOH solution to obtain the monomer solution.

[0203] Weigh 40g of deionized water into a 100mL beaker, add 10g of ammonium persulfate, and dissolve thoroughly to obtain initiator I solution; weigh 40g of deionized water into a 100mL beaker, add 10g of sodium thiosulfate, and dissolve thoroughly to obtain initiator II solution; weigh 40g of deionized water into a 100mL beaker, add 10g of azobisisobutyramidine hydrochloride, and dissolve thoroughly to obtain initiator III solution.

[0204] After cooling the monomer solution to below 5°C, pour it into a 0.5L insulated reactor. Add 0.1g of initiator II solution and 0.2g of initiator III solution, and purge with nitrogen gas. While maintaining nitrogen purging, add 0.2g of initiator I solution dropwise over 1 minute. Continue purging with nitrogen gas for 30 minutes, then remove the nitrogen gas, seal the insulated reactor, and continue the reaction. The maximum reaction temperature is controlled at 60°C, and the reaction is maintained for 4 hours to obtain the polymeric surfactant gel.

[0205] The gel was granulated, dried in a vacuum oven at 120°C for 1 hour, and then pulverized to obtain a dry powder of polymeric surfactant.

[0206] Application Example 2

[0207] Synthesis of polymeric surfactants:

[0208] The hydrophilic branched polymerizable functional monomer synthesized in Example 2 was used.

[0209] Weigh 120g of deionized water into a 500mL beaker, add 79g of acrylamide and 1g of functional monomer, stir well, and adjust the pH to 8.1 with 30wt% NaOH solution to obtain the monomer solution.

[0210] Weigh 40g of deionized water into a 100mL beaker, add 10g of ammonium persulfate, and dissolve thoroughly to obtain initiator I solution; weigh 40g of deionized water into a 100mL beaker, add 10g of sodium thiosulfate, and dissolve thoroughly to obtain initiator II solution; weigh 40g of deionized water into a 100mL beaker, add 10g of azobisisobutyramidine hydrochloride, and dissolve thoroughly to obtain initiator III solution.

[0211] After cooling the monomer solution to below 5°C, pour it into a 0.5L insulated reactor. Add 0.1g of initiator II solution and 0.2g of initiator III solution, and purge with nitrogen gas. While maintaining nitrogen purging, add 0.1g of initiator I solution dropwise over 1 minute. Continue purging with nitrogen gas for 30 minutes, then remove the nitrogen gas, seal the insulated reactor, and continue the reaction. The maximum reaction temperature is controlled at 55°C, and the reaction is maintained for 6 hours to obtain the polymeric surfactant gel.

[0212] The gel was granulated, dried in a vacuum oven at 120°C for 1 hour, and then pulverized to obtain a dry powder of polymeric surfactant.

[0213] Application Example 3

[0214] Synthesis of polymeric surfactants:

[0215] The hydrophilic branched polymerizable functional monomer synthesized in Example 3 was used.

[0216] Weigh 100g of deionized water into a 500mL beaker, add 97g of acrylamide and 3g of functional monomer, stir well, and adjust the pH to 8.2 with 30wt% NaOH solution to obtain the monomer solution.

[0217] Weigh 40g of deionized water into a 100mL beaker, add 10g of ammonium persulfate, and dissolve thoroughly to obtain initiator I solution; weigh 40g of deionized water into a 100mL beaker, add 10g of sodium thiosulfate, and dissolve thoroughly to obtain initiator II solution; weigh 40g of deionized water into a 100mL beaker, add 10g of azobisisobutyramidine hydrochloride, and dissolve thoroughly to obtain initiator III solution.

[0218] After cooling the monomer solution to below 5°C, pour it into a 0.5L insulated reactor. Add 0.1g of initiator II solution and 0.2g of initiator III solution, and purge with nitrogen gas. While maintaining nitrogen purging, add 0.2g of initiator I solution dropwise over 1 minute. Continue purging with nitrogen gas for 30 minutes, then remove the nitrogen gas, seal the insulated reactor, and continue the reaction. The maximum reaction temperature is controlled at 60°C, and the reaction is maintained for 4 hours to obtain the polymeric surfactant gel.

[0219] The gel was granulated, dried in a vacuum oven at 120°C for 1 hour, and then pulverized to obtain a dry powder of polymeric surfactant.

[0220] Comparative Example 1

[0221] Weigh 100g of deionized water into a 500mL beaker, add 97g of acrylamide and 3g of CH2=CH-CH2-N-[(CH2CH2O)5-(CH2(CH3)CH2O)3-H]2, stir well, and adjust the pH to 8.3 with 30wt% NaOH solution to obtain the monomer solution.

[0222] Weigh 40g of deionized water into a 100mL beaker, add 10g of ammonium persulfate, and dissolve evenly to obtain initiator I solution; weigh 40g of deionized water into a 100mL beaker, add 10g of sodium thiosulfate, and dissolve evenly to obtain initiator II solution; weigh 40g of deionized water into a 100mL beaker, add 10g of azobisisobutyramidine hydrochloride, and dissolve evenly to obtain initiator III solution.

[0223] After cooling the monomer solution to below 5°C, pour it into a 0.5L insulated reactor. Add 0.1g of initiator II solution and 0.2g of initiator III solution, and purge with nitrogen gas. While maintaining nitrogen purging, add 0.2g of initiator I solution dropwise over 1 minute. Continue purging with nitrogen gas for 30 minutes, then remove the nitrogen gas, seal the insulated reactor, and continue the reaction. The maximum reaction temperature is controlled at 60°C, and the reaction is maintained for 4 hours to obtain the polymeric surfactant gel.

[0224] The gel was granulated, dried in a vacuum oven at 120°C for 1 hour, and then pulverized to obtain a dry powder of polymeric surfactant.

[0225] A simulated saline solution with a total mineralization of 121633 mg / L and a total calcium and magnesium ion concentration of 315.94 mg / L was prepared and tested in accordance with Examples 1-3 and Comparative Example 1. The specific test results are shown in Table 1.

[0226] Table 1

[0227]

[0228] As shown in Table 1:

[0229] Compared to the polymeric surfactant synthesized from the functional monomers of Comparative Example 1, the polymeric surfactant synthesized from the functional monomers of Example 1 exhibits better solubility. Solutions measured at concentrations of 0.1 wt%, 0.2 wt%, and 0.5 wt% show higher viscosity and lower interfacial tension. Testing revealed that water flooding was performed before sample injection, followed by a change of sample solution after stabilization. Compared to water flooding, the recovery rate of Application Example 1 increased by 21.6%, while the recovery rate of Comparative Example 1 increased by 3.1%. The recovery rate of Application Example 1 was approximately seven times higher than that of Comparative Example 1. This demonstrates that the polymeric surfactant prepared by this invention can simultaneously improve interfacial activity and viscosity, solving the problem in existing polymeric surfactants where interfacial activity and viscosity cannot be improved simultaneously. Furthermore, the obtained polymeric surfactant exhibits excellent water solubility. This demonstrates that the functional monomers prepared by this invention can ensure that the polymeric surfactant simultaneously possesses good interfacial activity and viscosity without changing the polymerization method, solving the chromatographic separation problem of binary polymeric surfactant flooding.

[0230] Examples 1-3 were prepared by a multi-step reaction using raw materials including amino aldehydes, ethylene oxide, acid anhydrides, propylene, propylene oxide, and haloalkanes. The oil-water interfacial activity of the monomers was controlled by adjusting the amounts of ethylene oxide and propylene oxide, resulting in hydrophilic branched polymeric functional monomers that participated in the polymerization of polymeric surfactants. The hydrophilic side-chain branched polymeric surfactants used in Examples 1-3 were obtained, which were completely soluble in water within 2 hours. The viscosity at 0.1 wt% concentration was 7.4–8.7 mPa·s, at 0.2 wt% concentration it was 9.1–12.1 mPa·s, and at 0.5 wt% concentration it was 19.6–26.8 mPa·s, exhibiting good thickening ability. At a 0.2 wt% concentration, the interfacial tension was (1.7–3.1) × 10⁻⁶. -2 The mN / m ratio achieved a good technical effect.

Claims

1. A hydrophilic, branched, polymerizable functional monomer, with the general molecular formula shown in formula (Ⅰ): In equation (Ⅰ), R1 is -(CH2CH2O) n - where n is an integer from 5 to 12; R2 is -(CH(CH3)CH2O) m -, m is an integer from 5 to 15; R3 is -C t H 2t+1 t is an integer from 1 to 4; R4 is -C y H 2y -, where y is 1 or 2; where, n≤m, 4m+t+y≤8n.

2. The hydrophilic branched polymerizable functional monomer as described in claim 1, characterized in that: The hydrophilic branched polymerizable functional monomer is prepared from raw materials including amino aldehydes, ethylene oxide, acid anhydrides, propylene, propylene oxide, and haloalkanes. Preferably, The amino aldehyde is aminoacetaldehyde or 3-aminopropionaldehyde; and / or, The acid anhydride is acetic anhydride or propionic anhydride; and / or, The general formula of the haloalkanes is C t H 2t+1 X is one of Cl, Br, and I, and t is an integer from 1 to 4.

3. A method for preparing a hydrophilic branched polymerizable functional monomer as described in claim 1 or 2, comprising: (1) React amino aldehyde and ethylene oxide to obtain intermediate product 1; (2) The intermediate product 1 obtained in step (1) is reacted with an acid anhydride to obtain intermediate product 2; (3) React the intermediate product 2 obtained in step (2) with propylene to obtain intermediate product 3; (4) The intermediate product 3 obtained in step (3) is reacted with propylene oxide to obtain intermediate product 4; (5) The intermediate product 4 obtained in step (4) is reacted with a haloalkane to obtain intermediate product 5; (6) Hydrolyze the intermediate product 5 obtained in step (5) to obtain the hydrophilic branched polymerizable functional monomer.

4. The method for preparing the hydrophilic branched polymerizable functional monomer as described in claim 3, characterized in that: Step (1), The molar ratio of the amino aldehyde to ethylene oxide is 1:(10-30), preferably 1:(11-25); and / or, The reaction is carried out in an anhydrous protic solvent, preferably at least one of ethanol, methanol, and isopropanol; and / or, The ratio of the amount of proton solvent to the total mass of the reaction raw materials is (0.1–10):1, preferably (0.5–3):1; and / or, The reaction temperature is 30–60°C, preferably 40–50°C; and / or, Maintain reflux during the reaction; and / or, The reaction time is 3–12 hours, preferably 6–8 hours; and / or, After the reaction is complete, unreacted ethylene oxide is removed, and the product is purified to obtain intermediate product 1.

5. The method for preparing the hydrophilic branched polymerizable functional monomer as described in claim 3, characterized in that: Step (2), The molar ratio of intermediate product 1 to acid anhydride is 1:(1-20), preferably 1:(5-10); and / or, The reaction is carried out under the catalysis of an acidic substance; preferably, the acidic substance is concentrated sulfuric acid; and / or, the molar ratio of the acidic substance to intermediate product 1 is (0.1–0.5):1, more preferably (0.2–0.4):1; and / or, The reaction temperature is 90–100℃; and / or, Maintain reflux during the reaction; and / or, After the reaction is complete, unreacted raw materials and by-products are removed, and the product is purified to obtain intermediate product 2.

6. The method for preparing the hydrophilic branched polymerizable functional monomer as described in claim 3, characterized in that: Step (3), The molar ratio of intermediate product 2 to propylene is 1:(1-5), preferably 1:(1.2-2); and / or, A sulfonic acid compound is added before the reaction begins. Preferably, the sulfonic acid compound is at least one of methanesulfonic acid, ethanesulfonic acid, and benzenesulfonic acid. And / or, the molar ratio of intermediate product 2 to the sulfonic acid compound is 1:(0.8–2), more preferably 1:(1–1.3); and / or, The reaction is carried out under excitation light, which is near-ultraviolet-visible light with a wavelength of 300–780 nm, preferably 345–465 nm; and / or, The reaction is carried out in the presence of a catalyst, which is a combination of a metal catalyst, a photocatalyst, and a HAT catalyst. Preferably, The total molar amount of the catalyst is 0.1% to 0.2% of the molar amount of propylene; and / or, Based on a total catalyst content of 100% mol, the amount of the metal catalyst is 70-80 mol%, the amount of the photocatalyst is 5-10% mol%, and the amount of the HAT catalyst is 10-20 mol%; and / or, The metal catalyst is at least one selected from gold, silver, platinum, palladium, chromium, copper, chromium chloride, cuprous chloride, and cuprous bromide, more preferably at least one selected from chromium, chromium chloride, copper, and cuprous chloride; and / or, The photocatalyst is at least one selected from acridine salt derivative, heterocyclic naphthalene derivative, heteroatom benzene derivative, polytungstic acid derivative, and iridium photosensitizer; the acridine salt is at least one selected from NSP-SA-NHS, NSP-DMAE-NHS, DMAE-NHS, Me-PhAcrMe, and Me-DMAE-NHS; more preferably, the photocatalyst is at least one selected from acridine fluoroborate, tetrabutylammonium decapolytungstate, and difluorotolylbipyridine iridium hexafluorophosphate; and / or, The HAT catalyst is at least one of a thiol derivative and a polytungstic acid derivative, preferably at least one of a dioxaphosphazene-heptanthiol and tetrabutylammonium decapolytungsticate. More preferably, the catalyst is selected from one of the following combinations: (1)Cr / Cu / CrCl2 / CuBr+Ir[dF(CF3)ppy]2(dtbpy)PF6+TPI; (2)Cr / Cu / CrCl2 / CuBr+Mes-PhAcrMe2BF4+TPI; (3) Cr / Cu / CrCl2 / CuBr+TBADT; and / or, An alkali metal salt is added to the reaction; preferably, the amount of the alkali metal salt is 80-140% of the total molar amount of the catalyst; and / or, the alkali metal salt is at least one selected from Li₂CO₃, Na₂CO₃, K₂CO₃, Cs₂CO₃, K₂HPO₄, and Na₂HPO₄; and / or, The reaction occurs in an organic solvent; preferably, the organic solvent is at least one of acetonitrile, toluene, dimethyl adipate, ethyl acetate, dichloromethane, dichloroethane, dichloropropane, and acetone, more preferably at least one of acetonitrile, dimethyl adipate, dichloromethane, and acetone; and / or, the molar ratio of the amount of the organic solvent to the total amount of the reaction raw materials in step (3) is (0.1–10):1, more preferably (0.5–2):1; and / or, The reaction temperature is 10–60°C, more preferably 20–50°C; and / or, The reaction time is 12–72 hours, more preferably 20–48 hours; and / or, After the reaction is complete, unreacted raw materials and solvents are removed, and the product is purified to obtain intermediate product 3.

7. The method for preparing the hydrophilic branched polymerizable functional monomer as described in claim 3, characterized in that: Step (4), The molar ratio of intermediate product 3 to propylene oxide is 1:(5-20), preferably 1:(6-16); and / or, The reaction is carried out in the presence of a polymerization inhibitor; preferably, the polymerization inhibitor is at least one of oxidizing polymerization inhibitors, phenolic polymerization inhibitors, phenolic resin polymerization inhibitors, nitrile polymerization inhibitors, and sulfide polymerization inhibitors, more preferably at least one of oxygen, air, ethyl cyanoformate, ethyl cyanoacetate, and diallyl sulfide; and / or, the molar percentage of the polymerization inhibitor to the total amount of reaction raw materials in step (4) is 1 to 20% mol, preferably 3 to 8% mol; and / or, The reaction is carried out in an anhydrous proton solvent; preferably, the proton solvent is at least one of ethanol and methanol; and / or, the mass ratio of the amount of the proton solvent to the total amount of the reaction raw materials in step (4) is (0.1-5):1, preferably (0.2-2):1; and / or, The reaction temperature is 30–60°C, preferably 40–50°C; and / or, Maintain reflux during the reaction; and / or, The reaction time is 3–12 hours, preferably 6–8 hours; and / or, After the reaction is complete, unreacted propylene oxide is removed, and the product is purified to obtain intermediate product 4.

8. The method for preparing the hydrophilic branched polymerizable functional monomer as described in claim 3, characterized in that: Step (5), The molar ratio of intermediate product 4 to haloalkane is 1:(1-2), preferably 1:(1.1-1.2); and / or, The reaction is carried out in the presence of a polymerization inhibitor; preferably, the polymerization inhibitor is at least one of oxidizing polymerization inhibitors, phenolic polymerization inhibitors, phenolic resin polymerization inhibitors, nitrile polymerization inhibitors, and sulfide polymerization inhibitors, more preferably at least one of oxygen, air, ethyl cyanoformate, ethyl cyanoacetate, and diallyl sulfide; and / or, the molar percentage of the polymerization inhibitor to the total amount of reaction raw materials in step (5) is 1–80% mol, preferably 20–60% mol; and / or, The reaction is carried out under acid catalysis; preferably, the acid is at least one of sulfuric acid and phosphoric acid; and / or, the amount of acid used is 10-150% mol, preferably 40-100% mol, of the amount of intermediate product 4; and / or, The reaction temperature is 20–100°C, preferably 20–30°C; and / or, The reaction time is 3–12 hours, preferably 6–8 hours; and / or, The reaction is carried out in an organic solvent; preferably, the organic solvent is at least one of acetonitrile, toluene, dimethyl adipate, ethyl acetate, dimethylformamide, and dimethyl sulfoxide, more preferably at least one of ethyl acetate, dimethylformamide, and dimethyl sulfoxide; and / or, the mass ratio of the amount of the organic solvent to the total amount of the reaction raw materials in step (5) is (0.1-5):1, preferably (0.4-2):1; and / or, After the reaction is complete, unreacted raw materials and by-products are removed, and the product is purified to obtain intermediate product 5.

9. The method for preparing the hydrophilic branched polymerizable functional monomer as described in claim 3, characterized in that: Step (6), The reaction is carried out in a mixed solvent consisting of water and an organic solvent; preferably, the mass ratio of water to organic solvent in the mixed solvent is 1:(1-5), more preferably 1:(1-3); and / or, the organic solvent is at least one of methanol, ethanol, isopropanol, n-propanol, and n-butanol, more preferably one of methanol, ethanol, and isopropanol; and / or, the mass ratio of intermediate 5 to the mixed solvent is 1:(1-10), preferably 1:(1-5); and / or, The reaction is carried out in the presence of a polymerization inhibitor; preferably, the polymerization inhibitor is at least one selected from oxidative polymerization inhibitors, phenolic polymerization inhibitors, phenolic resin polymerization inhibitors, nitrile polymerization inhibitors, and thioether polymerization inhibitors, more preferably at least one selected from oxygen, air, ethyl cyanoformate, ethyl cyanoacetate, and diallyl thioether; and / or, the molar ratio of the polymerization inhibitor to the intermediate product 5 is (0.1–5):1, preferably (0.5–2):1; and / or, The reaction is carried out under the catalysis of a base; preferably, the base is at least one selected from LiOH, NaOH, and KOH; and / or, the molar ratio of the base to the intermediate product 5 is (2-10):1, preferably (2-4):1; and / or, The reaction temperature is 50–80°C, preferably 60–65°C; and / or, After the reaction is complete, byproduct salts, polymerization inhibitors, unreacted alkalis and solvents are removed, and the purified product is the hydrophilic branched polymerizable functional monomer.

10. A polymeric surfactant, obtained by copolymerization of an aqueous solution of a polymeric monomer, wherein the polymeric monomer comprises the hydrophilic branched polymerizable functional monomer as described in claim 1 or 2, or the hydrophilic branched polymerizable functional monomer obtained by the preparation method described in any one of claims 3 to 9; Preferably, Based on a total of 100 parts by weight of the polymeric monomer aqueous solution, the polymeric monomer aqueous solution includes 40-50 parts by weight of polymeric monomer and 50-60 parts by weight of water; more preferably, the water is deionized water.

11. The polymeric surfactant as described in claim 10, characterized in that: With a total mass of 100 wt% for the polymeric monomers, the polymeric monomers comprise: 0.1–5 wt% of hydrophilic branched polymerizable functional monomers; preferably 1–3 wt%. Nonionic monomers 95–99.9 wt%; preferably 97–99 wt%; Preferably, The nonionic monomer is at least one of acrylamide, methacrylamide, ethylacrylamide, N'N-dimethylacrylamide, N'N-diethylacrylamide, and tert-butylacrylamide.

12. The polymeric surfactant as described in claim 10, characterized in that: When copolymerizing the monomer aqueous solution, initiator I, initiator II, and initiator III also need to be added; preferably, The total mass of the initiator is 0.03 to 0.5 wt% of the total mass of the polymerizing monomers, more preferably 0.04 to 0.1 wt%; and / or, The mass ratio of initiator I, initiator II, and initiator III is 1:(0.5–2):(0.5–5), more preferably 1:(0.5–1):(0.5–3); and / or, The initiator I is an oxidizing initiator, more preferably one of sodium persulfate, ammonium persulfate, and potassium persulfate; and / or, The initiator II is a reducing initiator, more preferably one of sodium thiosulfate, sodium sulfite, sodium bisulfite, potassium sulfite, and potassium bisulfite; and / or, The initiator III is a water-soluble azo initiator, more preferably one of azobisisobutyramidine hydrochloride, azobisisobutyramidine imidazoline hydrochloride, and azobisisobutyramidal acid.

13. A method for preparing a polymeric surfactant as described in any one of claims 10 to 12, comprising: An initiator is added to an aqueous solution of the polymeric monomer, and the reaction is carried out under a protective gas atmosphere to obtain the polymeric surfactant. Preferably, First, add aqueous solutions of initiator II and initiator III to the aqueous solution of the polymer monomer, cool down to the initiation temperature, and then add the aqueous solution of initiator I dropwise to carry out the reaction. The initiation temperature is 0–10°C, preferably 2–5°C; and / or, The maximum reaction temperature is controlled at 30–80°C, preferably 50–60°C; and / or, The reaction time is 2–8 hours, preferably 4–6 hours; and / or, After the reaction is complete, the mixture is granulated, dried, and pulverized.

14. The application of a polymeric surfactant as described in any one of claims 10 to 12 or a polymeric surfactant obtained by the preparation method described in claim 13 in oil production; preferably, the polymeric surfactant is dissolved in injection water that matches the target formation to obtain a solution with a concentration of 0.1 to 0.5 wt%, which is then applied in enhanced oil recovery operations.

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