Polymer-containing produced liquid cleaning oil-water separating agent and preparation method thereof

Abstract

The invention discloses a polymer-containing produced liquid clean oil-water separating agent and a preparation method thereof, and relates to the technical field of sewage treatment.The preparation method comprises the steps that S1, polyamidoamine is dissolved in a methanol solution, then the solution is dropwise added into a methanol solution containing polyethyleneimine, a reaction is conducted at the room temperature in a dark place for 4-6 d, after the reaction is completed, a solvent is removed through evaporation, and a polyamidoamine solution is obtained; preparing a polyamidoamine-polyethyleneimine copolymer (PAPE); s2, enabling the hyperbranched polyether and allyl acyl chloride to react in a tetrahydrofuran solution in the presence of triethylamine, and evaporating to remove the solvent after the reaction is finished, so as to prepare hyperbranched polyether allyl ester; s3, the hyperbranched polyether allyl ester and PAPE are subjected to an addition reaction in a methanol solution, the solvent is removed through evaporation after the reaction is finished, and the modified hyperbranched polyether is prepared. After the oil-water separating agent prepared by the method disclosed by the invention is added into polymer-containing produced liquid or produced water, efficient separation of oil and water can be realized, the oil-water separating agent does not react with anionic polyacrylamide in an emulsion, a polymer can be retained in a water phase, and generation of polymer-containing sludge is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a clean oil-water separator for polymer-containing produced fluid and a preparation method thereof. Background Art

[0002] Chemical flooding, as the leading technology for tertiary oil recovery, has been applied on a large scale in many oil fields in my country. With the continuous expansion of the scale promotion of polymer flooding, many problems have been brought to the ground process. The presence of polyacrylamide has greatly improved the stability of the emulsion, and the emulsion type has become more complicated, with W / O (oil-in-water), O / W (water-in-oil-in-water) and even W / O / W (water-in-oil-in-water) emulsions mixed. The cationic reverse demulsifiers commonly used in oil fields destroy the polyacrylamide and enter the solid phase, forming a huge amount of polymer-containing sludge, which not only wastes chemical resources, but also makes the sludge treatment system overwhelmed. Non-ionic demulsifiers have attracted attention because they are not affected by electrolytes and have low sludge production.

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

[0004] Patent document CN105601941B discloses "the application of a polyamide-amine hyperbranched polymer as a demulsifier". The polyamide-amine hyperbranched polymer has ethylenediamine as its center and amine as its end group. Its skeleton contains a large number of hyperbranched structures and has good hydrophilic properties. It is suitable for oil-in-water emulsions and can achieve an oil removal rate of 68% in 30 minutes.

[0005] Patent document CN102899070B discloses "a comprehensive treatment agent for binary flooding produced fluid and its preparation method", including demulsifier, water purifier and a comprehensive treatment agent compounded with demulsifier and water purifier, first synthesizing demulsifier and water purifier, then compounding demulsifier and water purifier to compound into a comprehensive treatment agent for binary flooding produced fluid. Specifically, block polyether is synthesized with phenolamine resin and propylene glycol as initiators, respectively, and compounded into a comprehensive treatment agent for binary flooding produced fluid after chain extension, the water content of the externally transmitted oil is reduced from 1.53% to 1.06%, and the oil content of the externally transmitted sewage is reduced to 21mg / L.

[0006] Patent document CN115368577A discloses "a hyperbranched polyether grafted polystyrene maleic anhydride oil-water synchronous demulsification water clearing agent", comprising: (1) a hyperbranched polyether is reacted with p-toluenesulfonyl chloride to obtain a hyperbranched polyether p-toluenesulfonate intermediate, which is further reacted with a diamine to obtain a hyperbranched amino-terminated polyether; (2) a hyperbranched amino-terminated polyether is reacted with polystyrene-maleic anhydride to obtain a hyperbranched polyether grafted polystyrene maleic anhydride polymer, and finally an alkalization treatment is performed to obtain a hyperbranched polyether grafted polystyrene maleic anhydride oil-water synchronous demulsification water clearing agent. The demulsification water clearing agent has a dehydration rate of ≥92.8% for the polymer-containing produced liquid of the Gudong Oil Production Plant of Shengli Oilfield.

[0007] With the development of chemical flooding technology, the emulsification stabilization effect of oil displacement agents has been increasingly enhanced. The demulsification effect of the original large molecular demulsifier is insufficient in more complex emulsification systems such as ternary composite flooding. Therefore, it is an important issue that needs to be urgently addressed to develop a demulsifier that has a good demulsification effect on complex stable emulsions and can effectively avoid the production of polymer-containing sludge. Summary of the invention

[0008] The purpose of the present invention is to provide a clean oil-water separation agent for polymer-containing produced fluid and a preparation method thereof, which improves the abundance of functional groups through copolymerization of multiple hyperbranched structures, has a good demulsification effect on complex stable emulsions, and does not react with anionic polyacrylamide in the emulsion. The polymer can be retained in the water phase to avoid the generation of polymer-containing sludge. To achieve the above purpose, the present invention provides the following technical solutions:

[0009] The present invention provides a method for preparing a clean oil-water separation agent for polymer-containing produced fluid, the method comprising the following steps:

[0010] Step S1, dissolving polyamidoamine (PAMAM) in a methanol solution, then adding dropwise to a methanol solution containing polyethyleneimine (PEI), reacting at room temperature in the dark for 4 to 6 days, and evaporating the solvent after the reaction to prepare a polyamidoamine-polyethyleneimine copolymer (PAPE);

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

[0012] Step S3: the hyperbranched polyether allyl ester and PAPE are subjected to an addition reaction in a methanol solution, and after the reaction is completed, the solvent is evaporated to prepare 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 number of methyl ester groups on the surface of PAMAM G-1.5 is 16;

[0015] The number of methyl ester groups on the surface of PAMAM G-2.5 is 32.

[0016] Furthermore, the amount of PEI used is 4 to 6 times the molar number of the methyl ester groups on the surface of PAMAM.

[0017] Furthermore, in step S2, the mass ratio of the hyperbranched polyether to allyl chloride is 100:0.1-2.5; the amount of triethylamine used 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°C and the reaction time is 3-8h.

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

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

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

[0023] Furthermore, the preparation method of the polyamidoamine (PAMAM) comprises the following steps:

[0024] Add polyethylene polyamine dropwise to an excess of methanol solution containing methyl acrylate, and control the reaction temperature to not exceed 5°C during the addition process. After the addition is completed, the mixed solution rises to room temperature on its own, and reacts for 2 days in the dark. The excess solvent raw material is evaporated to obtain PAPAM G-0.5;

[0025] Dissolve PAPAM G-0.5 in methanol solution, then add it dropwise to excess polyethylene polyamine solution, control the reaction temperature not to exceed 5°C during the addition process, react at room temperature in the dark for 2 days, evaporate excess solvent raw materials to obtain PAPAM G-0;

[0026] The above steps are repeated to obtain the desired PAMAMG-1.5 or PAPAM G-2.5 by repeating the Michael addition reaction and the amidation reaction.

[0027] The present invention also provides a clean oil-water separator for polymer-containing produced fluid, wherein the molecular structure of the clean oil-water separator for polymer-containing produced fluid contains hyperbranched polyether (PMPO) and polyamidoamine-polyethyleneimine copolymer (PAPE); wherein:

[0028] The hyperbranched polyether is a phenolamine resin polyether, and its 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 small molecule branched polyethyleneimine (PEI), and its initiator is one of ethylenediamine, triethylenetetramine or tetraethylenepentamine.

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

[0031] The molecular weight of the polyethyleneimine (PEI) is 600-1800 Da.

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

[0033] The present invention improves the abundance of functional groups through copolymerization of multiple hyperbranched structures, and has a good demulsification effect on complex stable emulsions. After the oil-water separator prepared by the method of the present invention is added to polymer-containing produced fluid or produced water, efficient oil-water separation can be achieved, and the oil-water separator does not react with anionic polyacrylamide in the emulsion, and the polymer can be retained in the water phase, thereby avoiding the generation of polymer-containing sludge.

[0034] Other features and advantages of the present invention will be described in the following description, and partly become obvious from the description, or be understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention is a flow chart of a method for preparing a clean oil-water separation agent for polymer-containing produced fluid. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In order to solve the deficiencies of the prior art, the present invention discloses a clean oil-water separator for polymer-containing produced fluid, wherein the clean oil-water separator for polymer-containing produced fluid is a modified hyperbranched polyether, and its molecular structure contains hyperbranched polyether (PMPO) and polyamidoamine-polyethyleneimine copolymer (PAPE); wherein,

[0038] The hyperbranched polyether is a phenolamine resin polyether, the initiator of which is one of diphenol or polyphenol, preferably one of bisphenol AF and 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 copolymerization product 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, its initiator is one of ethylenediamine, triethylenetetramine or tetraethylenepentamine, preferably ethylenediamine; the molecular weight of the polyethyleneimine (PEI) is 600 to 1800 Da.

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

[0041] The present invention also discloses a method for preparing a clean oil-water separation agent for polymer-containing produced fluid. Figure 1 The flow chart of the preparation method of a clean oil-water separation agent for polymer-containing produced fluid of the present invention is as follows: Figure 1 As shown, the method comprises the following steps:

[0042] Step S1, preparation of PAPAM G-0.5: polyethylene polyamine is added dropwise to an excess methanol solution containing methyl acrylate, and the reaction temperature is controlled not to exceed 5°C during the addition process. After the addition is completed, the mixed solution rises to room temperature on its own, and the mixture is reacted in the dark for 2 days. After the reaction is completed, the excess solvent raw material is evaporated to prepare PAPAM G-0.5.

[0043] Step S2, preparation of PAPAM G-0: PAPAM G-0.5 was dissolved in a methanol solution, and then added dropwise to an excess polyethylene polyamine solution. The reaction temperature was controlled not to exceed 5° C. during the addition process, and the reaction was carried out at room temperature in the dark for 2 days. After the reaction was completed, the excess solvent raw material was evaporated to prepare PAPAM G-0.

[0044] Step S3, preparation of PAMAM G-1.5 or PAPAM G-2.5: Repeat the above steps, by repeating the Michael addition reaction and the amidation reaction, until the desired 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 a methanol solution, and then added dropwise to a methanol solution containing polyethyleneimine, and reacted at room temperature in the dark for 4 to 6 days. After the reaction, the solvent is evaporated to prepare a polyamidoamine-polyethyleneimine copolymer (PAPE). PAMAM G-1.5 has 16 methyl ester groups on the surface, and PAMAM G-2.5 has 32. During the reaction, the amount of polyethyleneimine (PEI) used is 4 to 6 times the molar number of the methyl ester groups on the surface of PAMAM, preferably 4 times.

[0046] Step S5, preparation of hyperbranched polyether allyl ester: hyperbranched polyether and propylene acid chloride react in tetrahydrofuran solution in the presence of triethylamine, and after the reaction, the solvent is evaporated to prepare hyperbranched polyether allyl ester. The mass ratio of hyperbranched polyether to propylene acid chloride is 100:0.1-2.5, the amount of triethylamine used is 0.1-2.5% of the mass of hyperbranched polyether, the mass concentration of hyperbranched polyether in tetrahydrofuran is 10-50%, the temperature of the reaction of hyperbranched polyether and propylene acid 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 undergo addition reaction in a methanol solution, and after the reaction is completed, the solvent is evaporated to prepare a modified hyperbranched polyether. The mass ratio of the hyperbranched polyether allyl ester to PAPE is 1 to 10:1, the mass concentration of the hyperbranched polyether allyl ester dissolved in methanol is 10 to 50%, the temperature of the reaction of the hyperbranched polyether allyl ester and PAPE is 20 to 60°C, and the reaction time is 4 hours to 1 day.

[0048] Embodiment 1:

[0049] Example 1 of the present invention discloses a method for preparing a polymer-containing produced fluid clean oil-water separation agent-1#, the method comprising the following steps:

[0050] Step S1, 15g of ethylenediamine was dissolved in 100mL of methanol, 430g of methyl acrylate was added to a three-necked flask containing 300mL of methanol and stirred on ice water, ethylenediamine was added dropwise to methyl acrylate, and the reaction temperature was controlled not to exceed 5°C during the addition process. After the addition was completed, the mixed solution was automatically warmed to room temperature, and the reaction was stirred in the dark for 48h. After the reaction was completed, the excess methyl acrylate and methanol were evaporated to prepare PAMAM G-0.5.

[0051] Step S2, 80g PAMAM G-0.5 was dissolved in 200mL methanol, 240g ethylenediamine was added to a three-necked flask containing 200mL methanol and stirred evenly on ice water. Under stirring, PAMAM G-0.5 was added dropwise to the ethylenediamine solution, the reaction mixture was heated to room temperature by itself, stirred in the dark for 2d, the excess raw materials and solvent were evaporated, the methanol solution of PAMAM was added dropwise to tetrahydrofuran / ether (2:1, v / v), stirred, sonicated, and centrifuged for purification to prepare PAMAM G-0.

[0052] Step S3, 52g PAMAM G-0 was dissolved in 200mL methanol, 344g was added to a three-necked flask containing 300mL methanol and stirred on ice water, ethylenediamine was added dropwise to methyl acrylate, and the reaction temperature was controlled not to exceed 5°C during the addition process. After the addition, the mixed solution was automatically warmed to room temperature, and the reaction was stirred in the dark for 48h. After the reaction was completed, the excess methyl acrylate and methanol were removed by rotary evaporation to prepare PAMAM G-1.5.

[0053] Step S4, dissolve 21 g of PAMAM G-1.5 in 30 mL of methanol, dissolve 22 g of polyethyleneimine (PEI-1800) in 30 mL of methanol, add the PAMAM G-1.5 solution dropwise to the PEI-1800 solution, stir vigorously, react at room temperature in the dark for 4 d, and evaporate the solvent to prepare a polyamidoamine-polyethyleneimine copolymer (PAPE-1).

[0054] Step S5, taking 100 g of bisphenol AF phenolamine resin hyperbranched polyether with EO / PO=1:1, 0.5 g of allyl chloride and 0.5 g of triethylamine, dissolving them in 100 g of tetrahydrofuran, reacting at 40° C. for 5 h, and removing the solvent tetrahydrofuran by rotary evaporation to prepare hyperbranched polyether allyl ester.

[0055] Step S6, taking 100 g of hyperbranched polyether allyl ester and 100 g of PAPE-1 and dissolving them in 200 g of methanol, reacting them at 20° C. for 1 day, and evaporating the methanol to prepare a clean oil-water separation agent-1# for polymer-containing produced liquid.

[0056] Example 2

[0057] Embodiment 2 of the present invention discloses a method for preparing a polymer-containing produced liquid clean oil-water separation agent-2#, the method comprising the following steps:

[0058] Step S1, dissolve 29g of PAMAM G-1.5 described in Example 1 in 100mL of methanol, add 480g of ethylenediamine into a three-necked flask containing 400mL of methanol and stir evenly on ice water. Under stirring, add PAMAM G-1.5 dropwise into the ethylenediamine solution, the reaction mixture rises to room temperature by itself, stirs and reacts for 2d in a dark environment, evaporates excess raw materials and solvent, adds the methanol solution of PAMAM dropwise into tetrahydrofuran / ether (2:1, v / v), stirs, sonicates, and centrifuges for purification to prepare PAMAM G-1.

[0059] Step S2, 15g of PAMAM G-1 was dissolved in 100mL of methanol, 430g of methyl acrylate was added to a three-necked flask containing 300mL of methanol and stirred on ice water, ethylenediamine was added dropwise to the methyl acrylate, and the reaction temperature was controlled not to exceed 5°C during the addition process. After the addition was completed, the mixed solution was automatically warmed to room temperature, and the reaction was stirred in the dark for 48h. After the reaction was completed, the excess methyl acrylate and methanol were evaporated to prepare PAMAM G-2.5.

[0060] Step S3, dissolving 23 g of PAMAM G-2.5 in 30 mL of methanol, dissolving 23 g of polyethyleneimine (PEI-1800) in 30 mL of methanol, adding the PAMAM G-1.5 solution dropwise to the PEI solution, stirring vigorously, reacting at room temperature in the dark for 6 d, and evaporating the solvent to prepare a polyamidoamine-polyethyleneimine copolymer (PAPE-2).

[0061] Step S4, taking 100 g of bisphenol S phenolamine resin hyperbranched polyether with EO / PO=1:3, 0.5 g of allyl chloride and 0.5 g of triethylamine, dissolving them in 100 g of tetrahydrofuran, reacting at 60° C. for 3 h, and removing the solvent tetrahydrofuran by rotary evaporation to prepare hyperbranched polyether allyl ester.

[0062] Step S5, taking 100 g of hyperbranched polyether allyl ester and 20 g of PAPE-2 and dissolving them in 100 mL of methanol, reacting at 30° C. for 12 h, and evaporating the methanol to prepare a clean oil-water separation agent-2# for polymer-containing produced liquid.

[0063] Example 3

[0064] Embodiment 3 of the present invention discloses a method for preparing a polymer-containing produced liquid clean oil-water separation agent-3#, the method comprising the following steps:

[0065] Step S1, taking 100 g of bisphenol AF phenolamine resin hyperbranched polyether with EO / PO=1:4, 0.5 g of allyl chloride and 0.5 g of triethylamine, dissolving them in 100 g of tetrahydrofuran, reacting at 20°C for 8 h, and removing the solvent tetrahydrofuran by rotary evaporation to prepare hyperbranched polyether allyl ester.

[0066] Step S2, take 100g of hyperbranched polyether allyl ester and 100g of PAPE-210g described in Example 2, dissolve them in 100mL of methanol, react at 60°C for 4h, and after evaporating methanol, prepare a clean oil-water separation agent-3# for polymer-containing produced liquid.

[0067] Example 4

[0068] The oil-water separator described in Examples 1-3 was used to conduct a bottle test demulsification test on the simulated ASP flooding produced fluid. The emulsion was prepared by 1:9 of purified crude oil and pure water, and contained 500 mg / L of partially hydrolyzed polyacrylamide, 400 mg / L of surfactant ORS-41, and 400 mg / L of NaOH. The demulsified oil-water interface was clear, no sludge was generated, and the dehydration rate was shown in Table 1 below.

[0069] Table 1 Dehydration rate results of the oil-water separation agent prepared in Examples 1-3

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

[0071] Example 5

[0072] The oil-water separator described in Examples 1-3 was used to conduct a bottle test demulsification test on simulated ASP flooding produced water. The simulated liquid contained 1500 mg / L oil, 300 mg / L partially hydrolyzed polyacrylamide, 150 mg / L surfactant ORS-4, and 50 mg / L NaOH. The demulsified oil-water interface was clear, no sludge was generated, and the oil content of the water phase after demulsification for 30 minutes was shown in Table 2 below.

[0073] Table 2 Oil content of water phase of oil-water separation agent prepared in Example 1-3 after demulsification for 30 min

[0074]

[0075] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a clean oil-water separation agent for polymer-containing produced fluid, characterized in that: The method comprises the following steps: Step S1, dissolving polyamidoamine (PAMAM) in a methanol solution, then adding dropwise to a methanol solution containing polyethyleneimine (PEI), reacting at room temperature in the dark for 4 to 6 days, and evaporating the solvent after the reaction to prepare a polyamidoamine-polyethyleneimine copolymer (PAPE); Step S2, reacting a hyperbranched polyether with acryloyl chloride in a tetrahydrofuran solution in the presence of triethylamine, and evaporating the solvent after the reaction to prepare a hyperbranched polyether allyl ester; Step S3: the hyperbranched polyether allyl ester and PAPE are subjected to an addition reaction in a methanol solution, and after the reaction is completed, the solvent is evaporated to prepare a modified hyperbranched polyether.

2. The method for preparing a clean oil-water separation agent for polymer-containing produced fluid according to claim 1, characterized in that: In step S1, the PAMAM is one of PAMAM G-1.5 and PAPAM G-2.5; wherein, The number of methyl ester groups on the surface of PAMAM G-1.5 is 16; The number of methyl ester groups on the surface of PAMAM G-2.5 is 32.

3. The method for preparing a clean oil-water separation agent for polymer-containing produced fluid according to claim 2, characterized in that: The amount of PEI used is 4 to 6 times the molar number of the methyl ester groups on the surface of PAMAM.

4. The method for preparing a clean oil-water separation agent for polymer-containing produced fluid according to claim 1, characterized in that: In step S2, the mass ratio of the hyperbranched polyether to allyl chloride is 100:0.1-2.5; the amount of triethylamine used 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%.

5. The method for preparing a clean oil-water separation agent for polymer-containing produced fluid according to claim 4, characterized in that: In step S2, the reaction conditions include: The reaction temperature is 20-60°C and the reaction time is 3-8h.

6. The method for preparing a clean oil-water separation agent for polymer-containing produced fluid according to claim 1, characterized in that: 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 dissolved in methanol is 10-50%.

7. The method for preparing a clean oil-water separation agent for polymer-containing produced fluid according to claim 6, characterized in that: In step S3, the reaction conditions include: The reaction temperature is 20-60°C, and the reaction time is 4h-1d.

8. The method for preparing a clean oil-water separation agent for polymer-containing produced fluid according to claim 2, characterized in that: The preparation method of the polyamidoamine (PAMAM) comprises the following steps: Add polyethylene polyamine dropwise to an excess of methanol solution containing methyl acrylate, and control the reaction temperature to not exceed 5°C during the addition process. After the addition is completed, the mixed solution rises to room temperature on its own, and reacts for 2 days in the dark. The excess solvent raw material is evaporated to obtain PAPAM G-0.5; Dissolve PAPAM G-0.5 in methanol solution, then add it dropwise to excess polyethylene polyamine solution, control the reaction temperature not to exceed 5°C during the addition process, react at room temperature in the dark for 2 days, evaporate excess solvent raw materials to obtain PAPAMG-0; The above steps are repeated to repeat the Michael addition reaction and the amidation reaction until the desired PAMAM G-1.5 or PAPAM G-2.5 is obtained.

9. A polymer-containing produced fluid clean oil-water separation agent, prepared by the method according to any one of claims 1 to 8, characterized in that: The molecular structure of the clean oil-water separation agent for polymer-containing produced fluid contains hyperbranched polyether (PMPO) and polyamidoamine-polyethyleneimine copolymer (PAPE); wherein, The hyperbranched polyether is a phenolamine resin polyether, and its initiator is one of a dihydric phenol or a polyhydric phenol; The polyamidoamine-polyethyleneimine copolymer (PAPE) is a copolymerization product of polyamidoamine (PAMAM) and small molecule branched polyethyleneimine (PEI), and its initiator is one of ethylenediamine, triethylenetetramine or tetraethylenepentamine.

10. The clean oil-water separation agent for polymer-containing produced fluid according to claim 9, characterized in that: The initiator is one of bisphenol AF and bisphenol S, and the mass ratio of EO / PO (ethylene oxide / propylene oxide) is 1:1-4; The molecular weight of the polyethyleneimine (PEI) is 600-1800 Da.

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