A clean oil-water separation agent for polymer-containing produced fluid and a preparation method thereof

Abstract

The application discloses a kind of poly-containing produced liquid clean oil-water separating agent and preparation method thereof, it is related to sewage treatment technical field, comprising: S1, polyamide amine is dissolved in methanol solution, then dropwise added to the methanol solution containing polyethyleneimine, reaction 4~6d at room temperature in the dark, solvent is evaporated after reaction, and polyamide amine-polyethyleneimine copolymer (PAPE) is prepared;S2, hyperbranched polyether is reacted with propylene acyl chloride in the presence of triethylamine in tetrahydrofuran solution, solvent is evaporated after reaction, and hyperbranched polyether allyl ester is prepared;S3, hyperbranched polyether allyl ester and PAPE occur addition reaction in methanol solution, solvent is evaporated after reaction, and modified hyperbranched polyether is prepared.The oil-water separating agent prepared by the method of the application can realize efficient separation of oil and water after being added into poly-containing produced liquid or produced water, and does not react with anionic polyacrylamide in emulsion, so that the polymer can be retained in the aqueous phase, and the generation of poly-containing sludge is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the sewage treatment technical field, and particularly relates to a clean oil-water separation agent for poly-containing produced liquid and a preparation method thereof. BACKGROUND

[0002] Chemical flooding is a leading technology for tertiary oil recovery, which has been applied on a large scale in many oilfields in China. With the continuous expansion of the large-scale promotion of polymer flooding, many problems have been brought to the ground process. The existence of polyacrylamide greatly improves the emulsion stability and makes the emulsion type more complex. W / O (water-in-oil) type, O / W (oil-in-water) type and even W / O / W (water-in-oil-in-water) type emulsions are mixed. The cationic reverse demulsifier commonly used in oilfields makes polyacrylamide into solid phase after being destroyed, forming a large amount of polymer-containing sludge, which not only wastes the reagent resources, but also makes the sludge treatment system overburdened. Non-ionic demulsifier is concerned due to its low sludge production and no electrolyte influence.

[0003] Patent document CN105504306B discloses "application of a polyether hyperbranched polymer as a demulsifier", the center of the polyether hyperbranched polymer is a polyether structure, the end group contains hydrophilic hydroxyl and hydrophobic double bond, the demulsifier is prepared by ester exchange reaction of hyperbranched polyglycidol and glycidyl methacrylate, and the oil removal rate can reach 61% in 30 minutes.

[0004] Patent document CN105601941B discloses "application of a polyamide amine hyperbranched polymer as a demulsifier", the center of the polyamide amine hyperbranched polymer is ethylenediamine, the end group is amine group, and the skeleton contains a large number of hyperbranched structures, which has good hydrophilic performance and is suitable for oil-in-water emulsion. The oil removal rate can reach 68% in 30 minutes.

[0005] Patent document CN102899070B discloses "a binary flooding produced liquid comprehensive treatment agent and a preparation method", which comprises a demulsifier, a water purifying agent and a comprehensive treatment agent compounded by the demulsifier and the water purifying agent. The demulsifier and the water purifying agent are first synthesized, and then compounded to form a binary flooding produced liquid comprehensive treatment agent. Specifically, block polyether is synthesized by using phenylamine resin and propylene glycol as starting agent, and the binary flooding produced liquid comprehensive treatment agent is compounded after chain extension. The water content of the exported oil is reduced from 1.53% to 1.06%, and the oil content of the exported sewage is reduced to 21mg / L.

[0006] Patent document CN115368577A discloses "a hyperbranched polyether grafted polystyrene maleic anhydride oil and water synchronous demulsification water agent", comprising: (1) hyperbranched polyether reacts with p-toluenesulfonyl chloride to obtain hyperbranched polyether p-methyl benzene sulfonate intermediate, which further reacts with diamine to obtain hyperbranched amino-terminated polyether; (2) hyperbranched amino-terminated polyether reacts with polystyrene-maleic anhydride to obtain hyperbranched polyether grafted polystyrene maleic anhydride polymer, and finally an alkali treatment is carried out to obtain a hyperbranched polyether grafted polystyrene maleic anhydride oil and water synchronous demulsification water agent. The demulsification water agent has a dehydration rate of the polymer-containing produced liquid of Gudong Oil Production Plant of Shengli Oilfield of not less than 92.8%.

[0007] With the development of chemical flooding exploitation technology, the emulsification stability effect of oil displacement agent is increasingly enhanced, and the original macromolecular demulsifier has insufficient demulsification effect in more complex emulsified systems such as ternary complex flooding, therefore, it is an important problem to be solved to develop a demulsifier which has good demulsification effect on complex stable emulsion and can effectively avoid the generation of polymer-containing sludge. SUMMARY

[0008] The present application aims to provide a polymer-containing produced liquid clean oil-water separation agent and a preparation method thereof, which improves the abundance of functional groups by copolymerization of various hyperbranched structures, has good demulsification effect on complex stable emulsion, and does not react with anionic polyacrylamide in emulsion, so that the polymer can remain in the water phase and the generation of polymer-containing sludge is avoided. In order to achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0009] The present application provides a preparation method of a polymer-containing produced liquid clean oil-water separation agent, which comprises the following steps:

[0010] Step S1, dissolving polyamide amine (PAMAM) in a methanol solution, then adding dropwise into a methanol solution containing polyethyleneimine (PEI), reacting at room temperature and avoiding light for 4-6 days, and then evaporating the solvent to obtain a polyamide amine-polyethyleneimine copolymer (PAPE);

[0011] Step S2, reacting hyperbranched polyether with propenyl chloride in the presence of triethylamine in a tetrahydrofuran solution, and then evaporating the solvent after the reaction to obtain a hyperbranched polyether allyl ester;

[0012] Step S3, addition reaction of the hyperbranched polyether allyl ester and the PAPE in a methanol solution, and then evaporating the solvent after the reaction to obtain a modified hyperbranched polyether.

[0013] Further, in step S1, the PAMAM is one of PAMAM G-1.5 or PAPAM G-2.5; wherein,

[0014] The PAMAM G-1.5 surface methyl ester group is 16;

[0015] The PAMAM G-2.5 surface methyl ester group is 32.

[0016] Further, the amount of PEI is 4-6 times the molar amount of PAMAM surface methyl ester group.

[0017] Further, in step S2, the mass ratio of the hyperbranched polyether to allyl chloride is 100:0.1-2.5; the amount of triethylamine is 0.1-2.5% of the mass of the hyperbranched polyether; and the mass concentration of the hyperbranched polyether in tetrahydrofuran is 10-50%.

[0018] Further, in step S2, the reaction conditions include:

[0019] The reaction temperature is 20-60℃, and the reaction time is 3-8h.

[0020] Further, in step S3, the mass ratio of the hyperbranched polyether allyl ester to PAPE is 1-10:1, and the mass concentration of the hyperbranched polyether allyl ester in methanol is 10-50%.

[0021] Further, in step S3, the reaction conditions include:

[0022] The reaction temperature is 20-60℃, and the reaction time is 4h-1d.

[0023] Further, the preparation method of the polyamidoamine (PAMAM) includes the following steps:

[0024] The polyethylene polyamine is added dropwise into an excessive amount of methyl methacrylate-containing methanol solution, the reaction temperature is controlled to be not more than 5℃ during the adding process, after the adding process, the mixed solution is automatically raised to room temperature, the reaction is carried out in the dark for 2d, the excessive solvent raw material is removed by evaporation, and PAPAM G-0.5 is obtained.

[0025] The PAPAM G-0.5 is dissolved in a methanol solution, and then added dropwise into an excessive amount of polyethylene polyamine solution, the reaction temperature is controlled to be not more than 5℃ during the adding process, the reaction is carried out in the dark at room temperature for 2d, and the excessive solvent raw material is removed by evaporation, and PAPAM G-0 is obtained.

[0026] The above steps are repeated, and the Michael addition reaction and the amidation reaction are repeated until the required PAMAM G-1.5 or PAPAM G-2.5 is obtained.

[0027] The present application also provides a clean oil-water separation agent for polymer-containing produced liquid, wherein the clean oil-water separation agent for polymer-containing produced liquid contains hyperbranched polyether (PMPO) and polyamidoamine-polyethyleneimine copolymer (PAPE) in the molecular structure.

[0028] The hyperbranched polyether is a phenolic amine resin polyether, and the initiator is one of a dihydric phenol or a polyhydric phenol;

[0029] The polyamidoamine-polyethyleneimine copolymer (PAPE) is a copolymerization product of polyamidoamine (PAMAM) and a small molecule branched polyethyleneimine (PEI), and the initiator is one of ethylenediamine, triethylenetetramine or tetraethylenepentamine.

[0030] Further, the initiator is one of bisphenol AF, bisphenol S, and the EO / PO (ethylene oxide / propylene oxide) mass ratio is 1:1~4;

[0031] The polyethyleneimine (PEI) has a molecular weight of 600~1800 Da.

[0032] Technical effects and advantages of the present application:

[0033] The present application improves the abundance of functional groups by copolymerization of multiple hyperbranched structures, and has good demulsification effect on complex stable emulsion. After the oil-water separation agent prepared by the method of the present application is added into the polymer-containing produced liquid or produced water, efficient oil-water separation can be realized, and the oil-water separation agent does not react with anionic polyacrylamide in the emulsion, so that the polymer can remain in the water phase, thereby avoiding the generation of polymer-containing sludge.

[0034] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and obtained by the structure indicated in the specification and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 A flow chart of a preparation method of the polymer-containing produced liquid cleaning oil-water separation agent. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0037] To solve the problems in the prior art, the present application discloses a polymer-containing produced liquid cleaning oil-water separation agent, which is a modified hyperbranched polyether, and contains hyperbranched polyether (PMPO) and polyamidoamine-polyethyleneimine copolymer (PAPE) in the molecular structure; wherein,

[0038] The hyperbranched polyether is a phenolic amine resin polyether, the initiator of which is one of a binary phenol or a polyphenol, preferably one of bisphenol AF, bisphenol S, and the EO / PO (ethylene oxide / propylene oxide) mass ratio is 1:1-4, preferably 1:3-4;

[0039] The polyamidoamine-polyethyleneimine copolymer (PAPE) is a copolymer of polyamidoamine (PAMAM) and small molecule branched polyethyleneimine (PEI), preferably the polyamidoamine (PAMAM) is PAMAM G-1.5 or PAPAM G-2.5, preferably PAPAM G-2.5; specifically, the initiator thereof is one of ethylenediamine, triethylenetetramine or tetraethylenepentamine, preferably ethylenediamine; and the polyethyleneimine (PEI) has a molecular weight of 600-1800 Da.

[0040] The mass ratio of the hyperbranched polyether (PMPO) to the polyamidoamine-polyethyleneimine copolymer (PAPE) is 1-10:1.

[0041] The application further discloses a preparation method of the clean oil-water separation agent for the polymer-containing produced liquid. Figure 1 A flow chart of the preparation method of the clean oil-water separation agent for the polymer-containing produced liquid is shown in the figure. Figure 1 The method comprises the following steps.

[0042] Step S1, preparation of PAPAM G-0.5: the polyethylene polyamine is added dropwise into an excessive amount of methyl methacrylate-containing methanol solution, the reaction temperature is controlled to be not higher than 5 DEG C during the adding process, and after the adding process, the mixed solution is automatically raised to room temperature, and the reaction is carried out in the dark for 2 days; after the reaction is completed, the excessive solvent raw material is removed by evaporation, and PAPAM G-0.5 is prepared.

[0043] Step S2, preparation of PAPAM G-0: PAPAM G-0.5 is dissolved in a methanol solution, and then added dropwise into an excessive amount of polyethylene polyamine solution; the reaction temperature is controlled to be not higher than 5 DEG C during the adding process, and the reaction is carried out in the dark at room temperature for 2 days; after the reaction is completed, the excessive solvent raw material is removed by evaporation, and PAPAM G-0 is prepared.

[0044] Step S3, preparation of PAMAM G-1.5 or PAPAM G-2.5: the above steps are repeated, and the Michael addition reaction and the amidation reaction are repeated until the required PAMAM G-1.5 or PAPAM G-2.5 is obtained.

[0045] Step S4, preparation of PAPE: PAMAM G-1.5 or PAPAM G-2.5 is dissolved in methanol solution, then added dropwise into the methanol solution containing polyethyleneimine, and reacted at room temperature for 4-6 days in the dark. After the reaction is completed, the solvent is evaporated to prepare a polyamidoamine-polyethyleneimine copolymer (PAPE). The surface methyl ester group of PAMAM G-1.5 is 16, and the surface methyl ester group of PAMAM G-2.5 is 32. During the reaction, the amount of polyethyleneimine (PEI) is 4-6 times the molar amount of the surface methyl ester group of PAMAM, and is preferably 4 times.

[0046] Step S5, preparation of hyperbranched polyether allyl ester: hyperbranched polyether is reacted with allyl chloride in the presence of triethylamine in tetrahydrofuran solution. After the reaction is completed, the solvent is evaporated to prepare a hyperbranched polyether allyl ester. The mass ratio of hyperbranched polyether to allyl chloride is 100:0.1-2.5, the amount of triethylamine is 0.1-2.5% of the mass of hyperbranched polyether, the mass concentration of hyperbranched polyether in tetrahydrofuran is 10-50%, and the reaction temperature of hyperbranched polyether with allyl chloride is 20-60°C, and the reaction time is 3-8h.

[0047] Step S6, preparation of modified hyperbranched polyether: hyperbranched polyether allyl ester and PAPE are added in methanol solution to react, and after the reaction is completed, the solvent is evaporated to prepare a modified hyperbranched polyether. The mass ratio of hyperbranched polyether allyl ester to PAPE is 1-10:1, the mass concentration of hyperbranched polyether allyl ester in methanol is 10-50%, the reaction temperature of hyperbranched polyether allyl ester with PAPE is 20-60°C, and the reaction time is 4h-1d.

[0048] Example 1:

[0049] Example 1 of the present application discloses a preparation method of a polyacrylamide oil-water separation agent-1# for produced liquid containing polyacrylamide. The method comprises the following steps:

[0050] Step S1, 15g of ethylenediamine is dissolved in 100mL of methanol, 430g of methyl acrylate is added to a three-necked flask containing 300mL of methanol and stirred on ice water, and the ethylenediamine is added dropwise into the methyl acrylate. During the addition, the reaction temperature is controlled to be not more than 5°C, and after the addition is completed, the mixed solution is allowed to rise to room temperature, and is stirred in the dark for 48h. After the reaction is completed, the excess methyl acrylate and methanol are evaporated to prepare PAMAM G-0.5.

[0051] Step S2, 80g PAMAM G-0.5 was dissolved in 200mL methanol, 240g ethylenediamine was added into a three-neck flask containing 200mL methanol and stirred uniformly on ice water. Under the condition of stirring, PAMAM G-0.5 was added dropwise into the ethylenediamine solution, the reaction mixture was allowed to rise to room temperature, and the reaction was carried out in the dark for 2d. The excess raw materials and solvents were removed by evaporation, and the methanol solution of PAMAM was added dropwise into tetrahydrofuran / ethyl ether (2:1, v / v), stirred, ultrasonicated, and centrifuged to purify, thereby obtaining PAMAM G-0.

[0052] Step S3, 52g PAMAM G-0 was dissolved in 200mL methanol, 344g was added into a three-neck flask containing 300mL methanol and stirred uniformly on ice water. The ethylenediamine was added dropwise into methyl acrylate, and the reaction temperature was controlled to be not more than 5℃ during the addition. After the addition was completed, the mixed solution was allowed to rise to room temperature, and the reaction was carried out in the dark for 48h. After the reaction was completed, the excess methyl acrylate and methanol were removed by rotary evaporation, thereby obtaining PAMAM G-1.5.

[0053] Step S4, 21g PAMAM G-1.5 was dissolved in 30mL methanol, and 22g polyethyleneimine (PEI-1800) was dissolved in 30mL methanol. The PAMAM G-1.5 solution was added dropwise into the PEI-1800 solution, and stirred vigorously. The reaction was carried out in the dark at room temperature for 4d. After the solvent was removed by evaporation, a polyamidoamine-polyethyleneimine copolymer (PAPE-1) was prepared.

[0054] Step S5, 100g of hyperbranched polyether 100g of hyperbranched polyether allyl ester was prepared by dissolving 100g of hyperbranched polyether, 0.5g of allyl chloride and 0.5g of triethylamine in 100g of tetrahydrofuran and reacting at 40℃ for 5h. The solvent tetrahydrofuran was removed by rotary evaporation.

[0055] Step S6, 100g of hyperbranched polyether allyl ester was dissolved in 200g of methanol, and 100g of PAPE-1 was dissolved in 200g of methanol. The reaction was carried out at 20℃ for 1d. After the methanol was removed by evaporation, a poly-based produced fluid cleaning oil-water separation agent-1# was prepared.

[0056] Example 2

[0057] The example 2 of the present application discloses a preparation method of a poly-based produced fluid cleaning oil-water separation agent-2#, which comprises the following steps:

[0058] Step S1, 23 g of PAMAM G-1.5 was dissolved in 100 mL of methanol, 480 g of ethylenediamine was added to a three-necked flask containing 400 mL of methanol and stirred uniformly on ice water. Under the condition of stirring, PAMAM G-1.5 was added dropwise to the ethylenediamine solution, the reaction mixture was allowed to rise to room temperature, and the reaction was carried out in the dark for 2 d. The excess raw materials and solvents were removed by evaporation, and the methanol solution of PAMAM was added dropwise to tetrahydrofuran / ethyl ether (2:1, v / v), stirred, ultrasonicated, and centrifuged to purify, to obtain PAMAM G-1.5.

[0059] Step S2, 15 g of PAMAM G-1 was dissolved in 100 mL of methanol, 430 g of methyl acrylate was added to a three-necked flask containing 300 mL of methanol and stirred on ice water. Ethylenediamine was added dropwise to methyl acrylate, and the reaction temperature was controlled to be not more than 5°C during the addition. After the addition was completed, the mixed solution was allowed to rise to room temperature, and the reaction was carried out in the dark for 48 h. After the reaction was completed, the excess methyl acrylate and methanol were removed by evaporation, to obtain PAMAM G-2.5.

[0060] Step S3, 23 g of PAMAM G-2.5 was dissolved in 30 mL of methanol, and 23 g of polyethyleneimine (PEI-1800) was dissolved in 30 mL of methanol. The PAMAM G-1.5 solution was added dropwise to the PEI solution, and the reaction was carried out at room temperature in the dark for 6 d. After the solvent was removed by evaporation, polyamidoamine-polyethyleneimine copolymer (PAPE-2) was obtained.

[0061] Step S4, 100 g of hyperbranched polyether of bisphenol S phenylamine resin with EO / PO=1:3, 0.5 g of allyl chloride and 0.5 g of triethylamine were dissolved in 100 g of tetrahydrofuran, and the reaction was carried out at 60°C for 3 h. The solvent tetrahydrofuran was removed by rotary evaporation, to obtain hyperbranched polyether allyl ester.

[0062] Step S5, 100 g of hyperbranched polyether allyl ester and 20 g of PAPE-2 were dissolved in 100 mL of methanol, and the reaction was carried out at 30°C for 12 h. After the methanol was removed by evaporation, poly-based produced fluid cleaning oil-water separating agent-2# was obtained.

[0063] Example 3

[0064] The example 3 of the present application discloses a preparation method of poly-based produced fluid cleaning oil-water separating agent-3#, which comprises the following steps:

[0065] Step S1, 100 g of hyperbranched polyether of bisphenol AF phenylamine resin with EO / PO=1:4, 0.5 g of allyl chloride and 0.5 g of triethylamine were dissolved in 100 g of tetrahydrofuran, and the reaction was carried out at 20°C for 8 h. The solvent tetrahydrofuran was removed by rotary evaporation, to obtain hyperbranched polyether allyl ester.

[0066] Step S2, 100 g of the hyperbranched polyether allyl ester and 100 g of PAPE-2 described in Example 2 were dissolved in 100 mL of methanol, and reacted at 60°C for 4 h. After removing the methanol by evaporation, a polyacrylamide-containing produced fluid cleaning oil-water separation agent-3# was prepared.

[0067] Example 4

[0068] The oil-water separation agents described in Examples 1-3 were used to carry out bottle test demulsification experiments on simulated ternary complex flooding produced fluid. The polyacrylamide-containing emulsion was prepared by mixing purified crude oil and pure water at a ratio of 1:9, containing 500 mg / L of partially hydrolyzed polyacrylamide, 400 mg / L of surfactant ORS-4, and 400 mg / L of NaOH. The oil-water interface was clear after demulsification, and no sludge was produced. The dehydration rates are shown in Table 1.

[0069] Table 1 Dehydration rates of the oil-water separation agents prepared in Examples 1-3

[0070] Medicament Medicament concentration Dehydration rate (30 min) (%) Polymer retention rate (%) Polymer-containing produced fluid clean oil-water separation agent-1 40 mg / L 93.26 95.78 Polymer-containing produced fluid clean oil-water separation agent-2 40 mg / L 94.32 95.92 Polymer-containing produced fluid clean oil-water separation agent-3 40 mg / L 96.67 96.43

[0071] Example 5

[0072] The oil-water separation agents described in Examples 1-3 were used to carry out bottle test demulsification experiments on simulated ternary complex flooding produced fluid. The simulated fluid contained 1500 mg / L of oil, 300 mg / L of partially hydrolyzed polyacrylamide, 50 mg / L of surfactant ORS-4, and 50 mg / L of NaOH. The oil-water interface was clear after demulsification, and no sludge was produced. The oil content in the water phase after 30 min of demulsification is shown in Table 2.

[0073] Table 2 Oil content in the water phase after 30 min of demulsification of the oil-water separation agents prepared in Examples 1-3

[0074]

[0075] Finally, it should be noted that the above-described only preferred embodiments of the present application, and not for limiting the present application, although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still can be modified to the technical solutions recorded in the foregoing embodiments, or equivalent replacement of some of the technical features, any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application, should be included in the protection scope of the present application.

Claims

1. A method for preparing a clean oil-water separation agent for use in a polyacrylamide-containing produced fluid, characterized by, The method comprises the following steps: Step S1, dissolving polyamidoamine (PAMAM) in a methanol solution, then adding dropwise into a methanol solution containing small molecule branched polyethyleneimine (PEI), reacting at room temperature for 4-6 days in the dark, and evaporating the solvent after the reaction to obtain polyamidoamine-polyethyleneimine copolymer (PAPE); Step S2, reacting hyperbranched polyether with allyl chloride in the presence of triethylamine in tetrahydrofuran solution, evaporating the solvent after the reaction to obtain hyperbranched polyether allyl ester; Step S3, hyperbranched polyether allyl ester and PAPE are added in methanol solution to occur addition reaction, evaporating the solvent after the reaction to obtain modified hyperbranched polyether; The PAMAM is one of PAMAM G-1.5 or PAMAM G-2.5; wherein, The PAMAM G-1.5 surface methyl ester group is 16; The PAMAM G-2.5 surface methyl ester group is 32; The amount of PEI is 4-6 times the molar number of PAMAM surface methyl ester group; The mass ratio of hyperbranched polyether to allyl chloride is 100:0.1-2.5; The mass ratio of hyperbranched polyether allyl ester to PAPE is 1-10:

1.

2. A method of preparing a clean oil-water separation agent for a polyacrylamide-containing produced fluid according to claim 1, characterized by, In step S2, the amount of triethylamine is 0.1-2.5% of the mass of hyperbranched polyether; the mass concentration of hyperbranched polyether in tetrahydrofuran is 10-50%.

3. A method of preparing a clean oil-water separation agent for use with a polymeric produced fluid according to claim 2, wherein, In step S2, the reaction conditions include: The reaction temperature is 20-60℃, and the reaction time is 3-8h.

4. The method of claim 1, wherein the method is characterized by: In step S3, the mass concentration of hyperbranched polyether allyl ester in methanol is 10-50%.

5. A method of preparing a clean oil-water separation agent for use with a polymeric produced fluid according to claim 4, characterized in that, In step S3, the reaction conditions include: The reaction temperature is 20-60℃, and the reaction time is 4h-1d.

6. The method of claim 1, wherein the method is characterized by: The preparation method of the polyamidoamine (PAMAM) comprises the following steps: The polyethylene polyamine is added dropwise into an excess of methyl methacrylate-containing methanol solution, the reaction temperature is controlled to be not more than 5℃ during the adding process, the mixed solution is then raised to room temperature after the adding process, and the reaction is carried out in the dark for 2 days, and then the excess solvent raw material is evaporated to obtain PAPAM G-0.5; PAPAM G-0.5 is dissolved in a methanol solution, then added dropwise into an excess of polyethylene polyamine solution, the reaction temperature is controlled to be not more than 5℃ during the adding process, and the reaction is carried out in the dark at room temperature for 2 days, and then the excess solvent raw material is evaporated to obtain PAPAM G-0; The above steps are repeated to obtain the required PAMAM G-1.5 or PAMAM G-2.5 through repeated Michael addition reaction and amidation reaction.

7. A clean oil-water separation agent for a polymer-containing produced fluid, prepared by the method according to any one of claims 1 to 6, characterized in that, The molecular structure of the polyacrylamide-containing produced fluid cleaning oil-water separation agent contains hyperbranched polyether (PMPO) and polyamidoamine-polyethyleneimine copolymer (PAPE); wherein, The hyperbranched polyether is a phenolic amine resin polyether, and the initiator is one of a binary phenol or a polyphenol; The initiator of the polyamidoamine is one of ethylenediamine, triethylenetetramine or tetraethylenepentamine.

8. The polyacrylamide-containing produced fluid cleaning oil-water separation agent according to claim 7, wherein, The initiator of the hyperbranched polyether is one of bisphenol AF and bisphenol S, and the EO / PO (ethylene oxide / propylene oxide) mass ratio is 1:1-4. The polyethyleneimine (PEI) has a molecular weight of 600-1800 Da.

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