Hyperbranched polyamido monomer, copolymer filtrate reducer and preparation method of hyperbranched polyamido monomer and copolymer filtrate reducer

Abstract

The invention provides a hyperbranched polyamido monomer, a copolymer filtrate reducer and a preparation method, the hyperbranched polyamido monomer takes acrylamide as a basic monomer, through catalysis of a UIO-66 type MOF catalyst, a branched side chain R is connected to a terminal amido of an amide group of the acrylamide, the branched side chain R is a nitrogen heterocyclic ring, and the hyperbranched polyamido monomer is a hyperbranched polyamido monomer. The preparation method comprises the following steps: mixing a hyperbranched multi-amino monomer, acrylamide, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid with water to obtain a mixed solution, and carrying out free radical aqueous solution polymerization in the mixed solution to obtain the copolymer filtrate reducer. The molecules of the filtrate reducer can form a supramolecular association body by virtue of the synergistic effect of hydrogen bonds formed between high-density amino groups and other polar groups in the structure of the filtrate reducer, so that the filtrate reduction performance of the filtrate reducer in a high-temperature and high-salt calcium environment can be ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas resource exploration, and in particular to a hyperbranched polyamine monomer, a copolymer fluid loss reducer and a preparation method thereof. Background Art

[0002] As the exploration and development of deep formation oil and gas resources continues to increase, the proportion of various deep wells and ultra-deep wells has increased year by year, resulting in the drilling fluid system facing the severe test of long-term high-temperature environment. At the same time, the salt-gypsum layer in some operating areas is relatively developed, which makes the drilling fluid extremely susceptible to salt and calcium invasion, aggravating the deterioration of system performance. In order to ensure the temperature and salt resistance of traditional deep well drilling fluid loss reducers, the usual solution is to introduce benzene rings, rigid large side groups and other related functional groups that can enhance the rigidity of the molecular chain into its molecular structure to improve its anti-degradation performance in high temperature and high salt and calcium environment, so as to maintain its polymer characteristics and exert its fluid loss reduction performance. However, the environmental protection of traditional fluid loss reducers is relatively low, and it is often difficult to achieve the non-toxic indicators of the treatment agent required in the SY / T7467-2020 Technical Specifications for Environmental Performance Evaluation of Drilling Fluids when used. Although the fluid loss reducers based on modified natural polymers can achieve the non-toxic indicators in the SY / T7467-2020 Technical Specifications for Environmental Performance Evaluation of Drilling Fluids, their temperature resistance is generally insufficient. Based on the above situation, it is imperative to develop temperature-resistant and salt-resistant filtration reducers that can meet the needs of deep well drilling and meet environmental protection performance standards. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the present invention provides a hyperbranched polyamine monomer, copolymer fluid loss reducer and a preparation method thereof. The fluid loss reducer contains rich amino functional groups. When the fluid loss reducer is fully hydrated in the drilling fluid, the fluid loss reducer molecules can form supramolecular associations by virtue of the synergistic effect of hydrogen bonds formed between the high-density amino groups and other polar groups in their structures, thereby ensuring the fluid loss reduction performance in a high-temperature, high-salt, and high-calcium environment.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a hyperbranched polyamine monomer, which takes acrylamide as a basic monomer, and is catalyzed by a UIO-66 type MOF catalyst, and a branched side chain R is connected to the terminal amine group of the amide group of acrylamide, and the branched side chain R is a nitrogen heterocycle, specifically including NH2, N(CH2CH2NH2)2 or N[CH2CH2N(CH2CH2NH2)2].

[0005] Further, its general structural formula is:

[0006]

[0007] The present invention provides a method for preparing a hyperbranched polyamine monomer, and the specific steps are as follows:

[0008] S1: preparing a UIO-66 type MOF catalyst aqueous solution under ice bath conditions;

[0009] S2 adds acrylamide aqueous solution to the UIO-66 type MOF catalyst solution, raises the temperature, and obtains a mixed solution A;

[0010] S3: adding an aziridine aqueous solution to the mixed solution A dropwise within 2 to 5 hours, cooling the mixture to obtain a mixed solution B;

[0011] S4 separates and extracts the mixed solution B to obtain a hyperbranched polyamine monomer G1.0;

[0012] Further, the hyperbranched polyamine monomer G1.0 obtained in S4 is used to replace the acrylamide in S2, and S3 and S4 are repeated to obtain the hyperbranched polyamine monomer G2.0;

[0013] The amount of the hyperbranched polyamine monomer G1.0 is 0.1 mol to 0.2 mol;

[0014] The hyperbranched polyamine monomer G1.0 in S2 is replaced by the hyperbranched polyamine monomer G2.0 obtained in S4, and S3 and S4 are repeated to obtain the hyperbranched polyamine monomer G3.0;

[0015] The usage of the hyperbranched polyamine monomer G2.0 is 0.05 mol to 0.1 mol.

[0016] Furthermore, the preparation method of the UIO-66 type MOF catalyst is as follows:

[0017] S1: dissolving 1-3 mmol of ZrCl4 and 1-3 mmol of terephthalic acid in N,N-dimethylformamide to obtain a mixed solution;

[0018] The S2 mixed solution is reacted at 100-150° C. for 12-36 hours to obtain a reactant;

[0019] S3: washing and filtering the reactants, drying the obtained solid at 80-120° C. for 4-12 hours, grinding, and obtaining a UIO-66 type MOF catalyst.

[0020] Furthermore, in S2, the content of acrylamide in the acrylamide aqueous solution is 0.1-0.3 mol; in S3, the content of aziridine in the aziridine aqueous solution is 0.2-0.4 mol; in S4, an excess of saturated NaCl deionized water solution is used for separation, the water layer is extracted with ethanol, and the extracts are combined into the organic layer.

[0021] The present invention provides a copolymer fluid loss reducer, which uses the hyperbranched polyamine monomer or the hyperbranched polyamine monomer prepared by the method as a raw material; the hyperbranched polyamine monomer, acrylamide, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid are mixed with water to obtain a mixed solution, and free radical aqueous solution polymerization is performed in the mixed solution to obtain the copolymer fluid loss reducer. The structure of the copolymer fluid loss reducer is as follows:

[0022]

[0023] Furthermore, the molar ratio of the hyperbranched polyamine monomer, acrylamide, acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid is 0.5-1.5:10-15:2-4:2-4; and the total concentration of the hyperbranched polyamine monomer in the mixed solution is 15wt%-30wt%.

[0024] The present invention provides a method for preparing a copolymer fluid loss reducer, and the specific steps are as follows:

[0025] S1: adding a hyperbranched polyamine monomer, acrylamide, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid to excess water, adjusting the pH value to neutral, and obtaining a mixed solution;

[0026] S2 is stirred and heated to 40-60°C under a protective atmosphere, an initiator is added dropwise to the mixed solution, and the temperature is continued to rise to 50-80°C. After reacting for 4-8 hours, a crude reaction product is obtained;

[0027] S3: The crude reaction product is soaked in acetone, allowed to stand, and separated to obtain the insoluble part. The insoluble part is soaked in anhydrous ethanol, allowed to stand, and then filtered. The filter cake is dried and crushed to obtain a copolymer filtrate reducer.

[0028] Furthermore, in S2, the initiator is a mixed aqueous solution of ammonium persulfate and sodium bisulfite with a mass fraction of 0.1wt% to 0.4wt%, wherein the molar ratio of ammonium persulfate to sodium bisulfite is 1:1.

[0029] Compared with the prior art, the present invention has at least the following beneficial effects:

[0030] The invention provides a hyperbranched polyamine monomer. Acrylamide and nitrogen heterocycle are used as raw materials. Under the catalytic action of UIO-66 type MOF, the nucleophilicity of the N atom connected to the carbonyl group with strong electron-withdrawing property in the amide group of acrylamide is greatly enhanced, so that the acrylamide can undergo a nucleophilic addition reaction on the nitrogen heterocycle. The hyperbranched polyamine monomer containing two primary amine groups can be prepared by a one-step method.

[0031] Furthermore, by gradually adding more nitrogen heterocycles to the hyperbranched polyamine monomer containing two primary amine groups and performing iterative reactions, a series of polyamine monomers with high total amine values ​​and high primary amine group density can be prepared.

[0032] If appropriate functional groups that can form hydrogen bonds are introduced into the molecular structure of the fluid loss reducer, the treating agent molecules can form supramolecular associations by virtue of the hydrogen bonds between their functional groups after hydration in the drilling fluid, which helps them maintain polymer properties in a high temperature, high salt calcium environment, and thus maintain the performance of the drilling fluid. In order to enhance the hydrogen bonding effect between molecules, the relevant functional groups should be located at the ends of the molecular segments, which is not only conducive to the formation of hydrogen bonds, but also should ensure the functional group density, so as to enhance the overall strength of the hydrogen bonds. Based on this, the present invention uses the above-mentioned hyperbranched polyamine monomer in the preparation of the fluid loss reducer, and carries out a quaternary copolymerization reaction with three common olefin monomers to obtain a copolymer fluid loss reducer. When the fluid loss reducer is dissolved in water, the densely distributed primary amine groups in its molecular structure can simultaneously form hydrogen bonds with two nearby polar groups, and the copolymer polymer properties are ensured by the hydrogen bonding effect between molecules, thereby meeting the drilling operation requirements under a high temperature and high mineralization environment. At the same time, the biological toxicity of the filtrate reducer meets the non-toxic requirements in the SY / T 7467-2020 Technical Specifications for Environmental Performance Evaluation of Drilling Fluids, which is highly consistent with the relevant regulations on the development direction of the environmental performance of petrochemical products. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is the molecular structure of copolymer fluid loss reducer;

[0034] Figure 2 It is a schematic diagram of the structure of UIO-66 type MOF;

[0035] Figure 3 This is an electron microscope photo of the UIO-66 type MOF;

[0036] Figure 4 is the XRD pattern of UIO-66 type MOF;

[0037] Figure 5 It is the synthetic route of G1.0 hyperbranched polyamine monomer;

[0038] Figure 6 It is a G1.0 hyperbranched polyamine monomer. 1 H NMR spectrum;

[0039] Figure 7 It is the synthetic route of G2.0 hyperbranched polyamine monomer;

[0040] Figure 8 It is the synthetic route of G3.0 hyperbranched polyamine monomer;

[0041] Fig. 9 It is the molecular structure of G1.0 / AM / AA / AMPS copolymer fluid loss reducer;

[0042] Fig.10 It is a G1.0 / AM / AA / AMPS copolymer fluid loss reducer.1 H NMR spectrum;

[0043] Fig.11 It is the molecular structure of G2.0 / AM / AA / AMPS copolymer fluid loss reducer;

[0044] Fig.12 It is the molecular structure of G3.0 / AM / AA / AMPS copolymer fluid loss reducer;

[0045] Fig.13 These are the DSC curves of three homologous copolymer fluid loss reducers. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0047] The present invention provides a method for preparing a copolymer fluid loss reducer, and the specific steps are as follows:

[0048] 1. Preparation of UIO-66 MOF catalyst

[0049] S1: At room temperature, weigh 0.233-0.699 g (1-3 mmol) ZrCl4 and 0.166-0.498 g (1-3 mmol) terephthalic acid, dissolve in 10-30 mL N,N-dimethylformamide DMF, start stirring, stir for 0.5-2 h to fully dissolve, and obtain a mixed solution;

[0050] S2 transfers the mixed solution to a tetrafluoroethylene-lined reactor, reacts at 100-150° C. for 12-36 hours to obtain a reactant;

[0051] S3 After the reactants are naturally cooled to room temperature, they are washed with DMF and anhydrous methanol three times respectively, and after centrifugal filtration, the lower layer of solid is dried at 80-120°C for 4-12h and fully ground. The obtained milky white powder is the UIO-66 type MOF catalyst. Its structural diagram is shown in Figure 2 As shown;

[0052] See also Figure 3 and Figure 4 , Figure 3 This is a SEM electron microscope photo of UIO-66. Figure 3 It can be seen that the average particle size of UIO-66 particles is only about 100 nm, which is a typical nano-scale particle and presents a significant multi-angular configuration. Figure 4 This is the XRD picture of UIO-66. As can be seen from the figure, the XRD peak of UIO-66 is sharp, indicating that it has good crystallinity and presents a typical crystal structure.

[0053] 2. Preparation of hyperbranched polyamine monomers

[0054] S1: Pour the catalyst amount of UIO-66 powder into a beaker containing 30-100 mL of deionized water under ice bath conditions, vibrate with ultrasound until it is completely dispersed, and then pour it into a three-necked beaker;

[0055] After S2, 100-200 mL of deionized water pre-dissolved with 7.1-21.3 g (0.1-0.3 mol) of acrylamide was poured in, ultrasonic oscillation was maintained, and the temperature was slowly raised to 40-70°C;

[0056] S3 was followed by slowly dropping 50-100 mL of deionized water pre-dissolved with 8.64-17.28 g (0.2-0.4 mol) of aziridine. After the addition was completed within 2-5 h, the ultrasonic oscillation was removed and replaced with magnetic stirring. Stirring was continued under TLC control until the reaction was completed and the mixture was cooled to room temperature.

[0057] S4 is poured into an excess of saturated NaCl deionized water solution, separated, the aqueous layer is extracted with ethanol, the extracts are combined with the organic layer, and the process is repeated 3 times. After that, the water is removed with anhydrous MgSO4, and the residual ethanol is removed by vacuum rotary evaporation. The obtained orange-yellow viscous liquid is the hyperbranched polyamine monomer, and the structure is as follows:

[0058]

[0059] Wherein R=NH2 or N(CH2CH2NH2)2 or N[CH2CH2N(CH2CH2NH2)2]2.

[0060] Further, 33-66 g (0.1-0.2 mol) of the hyperbranched polyamine monomer G1.0 obtained in S4 is used to replace the acrylamide in S2, and S3 and S4 are repeated to obtain the hyperbranched polyamine monomer G2.0;

[0061] Furthermore, 33.7-67.4 g (0.05-0.1 mol) of the hyperbranched polyamine monomer G2.0 obtained in S4 is used to replace the hyperbranched polyamine monomer G1.0 in S2, and S3 and S4 are repeated to obtain the hyperbranched polyamine monomer G3.0.

[0062] Preferably, the amount of catalyst used is 0.02 to 0.04 g.

[0063] 3. Preparation of copolymer fluid loss reducer

[0064] S1. At room temperature, a hyperbranched polyamine monomer, acrylamide (AM), acrylic acid (AA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) are dissolved in excess deionized water in a ratio (molar ratio) of 0.5-1.5:10-15:2-4:2-4 (total concentration of the hyperbranched polyamine monomer is 15-30 wt%), stirred sufficiently until the raw materials are completely dissolved, and then adjusted to a neutral pH value with NaOH;

[0065] The S2 reaction system is poured into a three-necked flask, stirred and heated to 40-60°C under N2 atmosphere, and 5-15 mL of a deionized water solution of an initiator pre-dissolved with 0.1-0.4 wt% ammonium persulfate and sodium bisulfite (molar ratio of 1:1) is added dropwise, and the temperature is raised to 50-80°C after the addition is completed. The reaction is continued for 4-8 hours and then stopped. The obtained bright yellow viscous liquid is the crude product of the reaction;

[0066] S3 Take out the crude product and soak it in excess acetone, let it stand for 12 to 36 hours, then separate it with a Soxhlet extractor, take the insoluble part and soak it in excess anhydrous ethanol, let it stand for 4 to 12 hours, then filter it, vacuum dry the filter cake, and grind the light yellow powder obtained, which is the purified copolymer filtrate reducer, with a structure such as Figure 1 shown.

[0067] Example 1: Preparation of UIO-66 MOF

[0068] 1. Preparation of UIO-66 MOF

[0069] At room temperature, weigh 0.466g (2mmol) ZrCl4 and 0.332g (2mmol) terephthalic acid, dissolve in 15mL DMF, start stirring, stir for 0.5h to fully dissolve, transfer to a reactor lined with tetrafluoroethylene, and react at 120℃ for 24h. Take out the reactant and wait for it to cool naturally to room temperature, wash it with DMF and anhydrous methanol three times each, centrifuge and filter, dry the lower layer of solid at 110℃ for 8h, grind it thoroughly, and the obtained milky white powder is UIO-66 type MOF. Its structural diagram is as follows Figure 2 shown.

[0070] Structural characterization of UIO-66 type MOF

[0071] See also Figure 3 and Figure 4 . Figure 3 This is a SEM electron microscope photo of UIO-66. Figure 3 It can be seen that the average particle size of UIO-66 particles is only about 100 nm, which is a typical nano-scale particle and presents a significant multi-angular configuration. Figure 4 This is the XRD picture of UIO-66. As can be seen from the figure, the XRD peak of UIO-66 is sharp, indicating that it has good crystallinity and presents a typical crystal structure.

[0072] Example 2: Preparation of G1.0 hyperbranched polyamine monomer

[0073] 1. Preparation of G1.0 hyperbranched polyamine monomer

[0074] Under ice bath conditions, pour the catalyst amount of UIO-66 powder into a beaker containing 50 mL of deionized water, ultrasonically oscillate until it is completely dispersed, pour it into a three-necked beaker, and then pour in 100 mL of deionized water pre-dissolved with 7.1 g (0.1 mol) of acrylamide, maintain ultrasonic oscillation and slowly heat to 50°C, then slowly drop 75 mL of deionized water pre-dissolved with 10.8 g (0.25 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 3 hours, and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the water layer with ethanol, combine the extracts with the organic layer, repeat 3 times, remove water with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The orange-yellow viscous liquid obtained is the product G1.0 hyperbranched polyamine monomer (hereinafter referred to as G1.0). Its synthesis route is as follows Figure 5 shown.

[0075] 2. Structural characterization of G1.0 hyperbranched polyamine monomer

[0076] See also Figure 6 . Figure 6 It is a G1.0 hyperbranched polyamine monomer. 1 H NMR diagram, as shown in the figure, δ1.12 is the proton peak of -CH3 originally connected to the α,β unsaturated carbon-carbon double bond; δ1.53 is the proton peak of the primary amine -NH2; δ2.32 is the proton peak of -CH in the α,β unsaturated carbon-carbon double bond; δ3.19 is the proton peak of -CH2- introduced by aziridine, and δ4.73 is the proton peak of -CH2 in the α,β unsaturated carbon-carbon double bond. The analysis results show that the test product is consistent with the target product structure, indicating that the desired final product was successfully prepared.

[0077] Example 3: Preparation of G2.0 hyperbranched polyamine monomer

[0078] Under ice bath conditions, pour the catalyst amount of UIO-66 MOF powder into a beaker containing 75 mL of deionized water, ultrasonically oscillate until it is completely dispersed, pour it into a three-necked beaker, and then pour in 125 mL of deionized water pre-dissolved with 15.7 g (0.1 mol) of G1.0 hyperbranched polyamine monomer, maintain ultrasonic oscillation and slowly heat to 60°C, then slowly drop 100 mL of deionized water pre-dissolved with 21.6 g (0.5 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 3 hours and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the water layer with ethanol, combine the extracts with the organic layer, repeat 3 times, remove water with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The orange-yellow viscous liquid obtained is the product G2.0 hyperbranched polyamine monomer (hereinafter referred to as G2.0). Its synthesis route is as follows Figure 7 shown.

[0079] Since G2.0 is a homologue of G1.0 and its molecular structure characterization is similar to the latter, it will not be analyzed separately.

[0080] Example 4: Preparation of G3.0 hyperbranched polyamine monomer

[0081] Under ice bath conditions, pour the catalyst amount of UIO-66 MOF powder into a beaker containing 75 mL of deionized water, ultrasonically oscillate until it is completely dispersed, pour it into a three-necked beaker, and then pour in 150 mL of deionized water pre-dissolved with 33.7 g (0.05 mol) of G2.0 hyperbranched polyamine monomer, maintain ultrasonic oscillation and slowly heat to 60°C, then slowly drop 100 mL of deionized water pre-dissolved with 21.6 g (0.5 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 3 hours and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the water layer with ethanol, combine the extracts with the organic layer, repeat 3 times, remove water with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The dark yellow viscous liquid obtained is the product G3.0 hyperbranched polyamine monomer (hereinafter referred to as G3.0). Its synthesis route is as follows Figure 8 shown.

[0082] Since G3.0 is a homologue of G1.0 and its molecular structure characterization is similar to the latter, it will not be analyzed separately.

[0083] Example 5: Biological toxicity evaluation of three hyperbranched polyamine monomers

[0084] The biological toxicity of three hyperbranched polyamine monomers was evaluated using a DXY-3 intelligent biological toxicity tester. The experimental results are shown in Table 1.

[0085] Table 1 E of three hyperbranched polyamine monomers C50 Numeric

[0086] Polyamine monomer type <![CDATA[EC 50 ]]> G1.0 48800 G2.0 52500 G3.0 53400

[0087] As shown in Table 1, the EC values ​​of the three hyperbranched polyamine monomers are 50 The values ​​are significantly higher than the biological non-toxicity evaluation standard in SY / T 7467-2020 Technical Specification for Environmental Performance Evaluation of Drilling Fluids (EC 50 ≥30000), indicating that they are all biological non-toxic treatment agents.

[0088] Example 6: Preparation of G1.0 / AM / AA / AMPS copolymer fluid loss reducer

[0089] 1. Preparation of G1.0 / AM / AA / AMPS copolymer fluid loss reducer

[0090] At room temperature, G1.0 polyamine monomer, acrylamide (AM), acrylic acid (AA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) were dissolved in excess deionized water (total monomer concentration was 25wt%) in a ratio of 1:10:3:2 (molar ratio). After fully stirring until the raw materials were completely dissolved, the pH was adjusted to neutral with NaOH, and the reaction system was poured into a three-necked flask. Under a N2 atmosphere, the mixture was stirred and heated to 45°C. 10 mL of an initiator deionized water solution pre-dissolved with 0.3wt% ammonium persulfate and sodium bisulfite (molar ratio of 1:1) was added dropwise. After the addition was completed, the temperature was raised to 70°C, and the reaction was stopped after continuing for 6 hours. The resulting bright yellow viscous liquid was the crude product of the reaction. Take out the crude product and soak it in excess acetone, let it stand for 24 hours, then separate it with a Soxhlet extractor, take the insoluble part and soak it in excess anhydrous ethanol, let it stand for 8 hours, then filter it, vacuum dry the filter cake, and grind the light yellow powder obtained, which is the purified G1.0 / AM / AA / AMPS copolymer filtrate reducer product. The reaction equation is as follows Fig. 9 shown.

[0091] 2. Structural characterization of G1.0 / AM / AA / AMPS copolymer fluid loss reducer

[0092] See also Fig.10 . Fig.10 It is a G1.0 / AM / AA / AMPS copolymer fluid loss reducer. 1 H NMR graph shows that the test product contains the proton characteristic peaks of all monomers involved in the copolymerization reaction, and a significant proton peak of -CH2- in the C-C main chain appears at δ4.71. The analysis results show that the test product is consistent with the target product structure, and the desired copolymer was successfully prepared.

[0093] Example 7: Preparation of G2.0 / AM / AA / AMPS copolymer fluid loss reducer

[0094] At room temperature, G2.0 polyamine monomer, AM, AA and AMPS were dissolved in excess deionized water (total monomer concentration was 25wt%) in a ratio of 1:10:3:2 (molar ratio), and the raw materials were fully stirred until they were completely dissolved, and then the pH was adjusted to neutral with NaOH, and the reaction system was poured into a three-necked flask, stirred and heated to 45°C under N2 atmosphere, and 10mL of initiator deionized water solution pre-dissolved with 0.3wt% ammonium persulfate and sodium bisulfite (molar ratio of 1:1) was added dropwise, and the temperature was raised to 70°C after the addition was completed, and the reaction was continued for 6 hours before stopping the reaction. The obtained bright yellow viscous liquid was the crude product of the reaction. The crude product was taken out and soaked in excess acetone, and separated by a Soxhlet extractor after standing for 24 hours, and the insoluble part was soaked in excess anhydrous ethanol, and filtered after standing for 8 hours, and the filter cake was vacuum dried, and the light yellow powder obtained by crushing was the purified G2.0 / AM / AA / AMPS copolymer filtrate reducer finished product. The reaction equation is as follows Fig.11 shown.

[0095] Since G2.0 / AM / AA / AMPS is a homologue of G1.0 / AM / AA / AMPS and its molecular structure characterization is similar to that of the latter, it will not be analyzed separately.

[0096] Example 8: Preparation of G3.0 / AM / AA / AMPS copolymer fluid loss reducer

[0097] At room temperature, G3.0 polyamine monomer, AM, AA and AMPS were dissolved in excess deionized water (total monomer concentration was 25wt%) in a ratio of 1:10:3:2 (molar ratio), and after fully stirring until the raw materials were completely dissolved, NaOH was used to adjust the pH to neutral, and the reaction system was poured into a three-necked flask, stirred and heated to 45°C under N2 atmosphere, and 10mL of initiator deionized water solution pre-dissolved with 0.3wt% ammonium persulfate and sodium bisulfite (molar ratio of 1:1) was added dropwise, and the temperature was raised to 70°C after the addition was completed, and the reaction was continued for 8h before stopping the reaction. The obtained bright yellow viscous liquid was the crude product of the reaction. The crude product was taken out and soaked in excess acetone, and separated by a Soxhlet extractor after standing for 24h, and the insoluble part was soaked in excess anhydrous ethanol, and filtered after standing for 8h, and the filter cake was vacuum dried, and the bright yellow powder obtained by crushing was the purified G3.0 / AM / AA / AMPS copolymer filtrate reducer finished product. The reaction equation is as follows Fig.12 shown.

[0098] Since G3.0 / AM / AA / AMPS is a homologue of G1.0 / AM / AA / AMPS and its molecular structure characterization is similar to that of the latter, it will not be analyzed separately.

[0099] Example 9: DSC Spectrum Analysis of Three Homologous Copolymer Fluid Loss Control Agents

[0100] The thermogravimetric curves of the three copolymer fluid loss reducers prepared in the same series were analyzed using a differential thermal-thermogravimetric simultaneous analyzer. Fig.13 .

[0101] from Fig.13 It can be seen that the DSC curves of the three copolymer fluid loss reducers of the same series all show two glass transition temperatures in the range of -150 to 150 °C, namely, T g1 and T g2 , where T g1 It appears near -125℃, which should belong to the main chain of the polymer, so it does not change with the change of the hydrogen bond crosslinking degree between the molecular segments, while Tg2 appears in the range of 20-30℃ and increases with the increase of the generation number of the polyamine monomer, indicating that the copolymer fluid loss reducer formed by introducing three polyamine monomers does form a hydrogen bond synergistic effect after hydration, and the hydrogen bond crosslinking points formed increase with the increase of the number of primary amine groups in the polyamine monomer, so the restriction on the thermal motion of the copolymer molecular segments is also more significant, which is manifested as T g2 of gradual increase.

[0102] Example 10: Performance of three homologous copolymer fluid loss reducers in drilling fluids

[0103] According to the method in the petroleum and natural gas industry standard "SY / T 5241-1991 Evaluation Procedure for Fluid Loss Reducers for Water-Based Drilling Fluids", a base slurry with a bentonite content of 4% was first prepared, and then the required treatment agents were added in sequence to form a benchmark water-based drilling fluid system for evaluation. Its specific composition is: 4% bentonite + 7% KCl + 3% SMP-3 fluid loss reducer + 0.2% KPAM coating agent + 4% ShaleSeaL plugging agent. 2% of commercial polymer fluid loss reducers DSP-1 and DSP-2 and three homemade copolymer fluid loss reducers were added to the system, and after sealed curing at room temperature for 24 hours, 10% NaCl, 2.0% CaCl2 and 0.5% CaSO4 were added to form a high-temperature, high-salt calcium drilling fluid environment simulating the downhole. The evaluation method in the petroleum and natural gas industry standard "SY / T 5241-1991 Evaluation Procedure for Fluid Loss Reducers for Water-Based Drilling Fluids" was also used to compare and evaluate the effects of commercial fluid loss reducers and homemade copolymer fluid loss reducers on drilling fluid performance. The experimental results are shown in Table 2.

[0104] Table 2 Effects of commercially available and homemade fluid loss reducers on drilling fluid properties

[0105]

[0106]

[0107] As can be seen from Table 2, the rheological and filtration properties of the drilling fluid system with the copolymer filtrate reducer formed by the two hyperbranched polyamine monomers G1.0 and G2.0 before aging are comparable to those of the system with the commercial filtrate reducers DSP-1 and DSP-2. After aging at 180°C, the apparent viscosity, plastic viscosity and dynamic shear force of the drilling fluid system with the two homemade filtrate reducers are greater than those of the system with the commercial filtrate reducer, while the API and HTHP filtration losses of the former are significantly lower than those of the latter, indicating that the homemade copolymer filtrate reducer can indeed form supramolecular association complexes after hydration by virtue of the rich amino functional groups in its molecular structure, and can maintain its own polymer characteristics in a high temperature, high salt and calcium environment, thereby ensuring the rheological and filtration properties of the drilling fluid system in the medium. At the same time, it can be seen from Table 1 that the apparent viscosity, plastic viscosity and dynamic shear force of the drilling fluid system with the addition of G3.0 / AM / AA / AMPS copolymer fluid loss reducer before aging are slightly greater than those of the system with the addition of two commercially available fluid loss reducers, but its fluid loss is basically equivalent to the latter, while the rheological and fluid loss properties of the system with the addition of the former after aging are inferior to those of the latter. Combined with the DSC analysis results in Example 8, it can be inferred that although the copolymer fluid loss reducer based on G3.0 has the largest density of amino functional groups in its molecular structure, and the hydrogen bond synergy formed after hydration is also the strongest, making the polymer have extremely strong temperature and salt resistance, too many and dense hydrogen bond cross-linking points also severely limit the freedom of movement of the polymer main chain, making it difficult to capture bentonite particles in the drilling fluid to play a protective role, resulting in the particles agglomerating and settling due to high temperature and salt calcium, which is manifested as a decrease in viscosity and an increase in fluid loss of the drilling fluid system. It can be seen that the fluid loss reduction performance of the copolymer first increases and then decreases with the increase of its amino functional group density, and the fluid loss reduction performance of G2.0 / AM / AA / AMPS copolymer is the best.

[0108] Example 11: Biotoxicity evaluation of three homemade copolymer fluid loss reducers

[0109] The biological toxicity of three homemade copolymer fluid loss reducers was evaluated using the DXY-3 intelligent biological toxicity tester. The experimental results are shown in Table 3.

[0110] Table 3 E of three hyperbranched polyamine monomers C50 Numeric

[0111]

[0112]

[0113] As shown in Table 3, the EC values ​​of the three self-made copolymer fluid loss reducers are 50 The value also significantly exceeds the evaluation standard of biological non-toxicity in SY / T 7467-2020 Technical Specification for Environmental Performance Evaluation of Drilling Fluids (EC 50≥30000), indicating that they are all biological non-toxic treatment agents.

[0114] Example 12

[0115] The present invention provides a method for preparing a copolymer fluid loss reducer, and the specific steps are as follows:

[0116] 1. Preparation of UIO-66 MOF

[0117] At room temperature, 0.233g (1mmol) ZrCl4 and 0.166g (1mmol) terephthalic acid were weighed and dissolved in 10mL DMF, and stirred for 2h to fully dissolve, and then transferred to a reactor lined with tetrafluoroethylene and reacted at 100°C for 12h. The reactants were taken out and cooled to room temperature naturally, and then washed with DMF and anhydrous methanol three times each. After centrifugal filtration, the lower layer of solid was dried at 80°C for 12h and fully ground. The obtained milky white powder was UIO-66 type MOF.

[0118] 2. Preparation of G1.0 hyperbranched polyamine monomer

[0119] Under ice bath conditions, pour the catalyst amount of UIO-66 powder into a beaker containing 30 mL of deionized water, ultrasonically oscillate until it is completely dispersed, pour it into a three-necked beaker, and then pour in 200 mL of deionized water pre-dissolved with 21.3 g (0.3 mol) of acrylamide, maintain ultrasonic oscillation and slowly raise the temperature to 70°C, then slowly add 50 mL of deionized water pre-dissolved with 8.64 g (0.2 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 2 h, and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the aqueous layer with ethanol, combine the extracts with the organic layer, repeat 3 times, remove water with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The obtained orange-yellow viscous liquid is the product G1.0 hyperbranched polyamine monomer.

[0120] 3. Preparation of G1.0 / AM / AA / AMPS copolymer fluid loss reducer

[0121] At room temperature, G1.0 polyamine monomer, acrylamide (AM), acrylic acid (AA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) were dissolved in excess deionized water (total monomer concentration was 15wt%) in a ratio of 0.5:15:4:3 (molar ratio). After fully stirring until the raw materials were completely dissolved, the pH was adjusted to neutral with NaOH, and the reaction system was poured into a three-necked flask. Under a N2 atmosphere, the mixture was stirred and heated to 60°C. 15 mL of an initiator deionized water solution pre-dissolved with 0.4wt% ammonium persulfate and sodium bisulfite (molar ratio of 1:1) was added dropwise. After the addition was completed, the temperature was raised to 70°C, and the reaction was stopped after continuing for 8 hours. The resulting bright yellow viscous liquid was the crude product of the reaction. Take out the crude finished product and soak it in excess acetone. After standing for 36 hours, separate it with a Soxhlet extractor. Take the insoluble part and soak it in excess anhydrous ethanol. After standing for 12 hours, filter it and vacuum dry the filter cake. The light yellow powder obtained by crushing is the purified G1.0 / AM / AA / AMPS copolymer filtrate reducer finished product.

[0122] Embodiment 13

[0123] The present invention provides a method for preparing a copolymer fluid loss reducer, and the specific steps are as follows:

[0124] 1. Preparation of UIO-66 MOF

[0125] At room temperature, 0.699g (3mmol) ZrCl4 and 0.498g (3mmol) terephthalic acid were weighed and dissolved in 30mL DMF, and stirred for 0.5h to fully dissolve, and then transferred to a reactor lined with tetrafluoroethylene and reacted at 150°C for 36h. The reactants were taken out and cooled to room temperature naturally, and then washed with DMF and anhydrous methanol three times each. After centrifugal filtration, the lower layer of solid was dried at 120°C for 4h and fully ground. The obtained milky white powder was UIO-66 type MOF.

[0126] 2. Preparation of G1.0 hyperbranched polyamine monomer

[0127] Under ice bath conditions, pour the catalyst amount of UIO-66 powder into a beaker containing 100 mL of deionized water, ultrasonically oscillate until it is completely dispersed, pour it into a three-necked beaker, and then pour 150 mL of deionized water pre-dissolved with 14.2 g (0.2 mol) of acrylamide, maintain ultrasonic oscillation and slowly raise the temperature to 40°C, then slowly add 100 mL of deionized water pre-dissolved with 13 g (0.3 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 5 h, and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the aqueous layer with ethanol, combine the extracts with the organic layer, repeat 3 times, remove water with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The obtained orange-yellow viscous liquid is the product G1.0 hyperbranched polyamine monomer.

[0128] 3. Preparation of G2.0 hyperbranched polyamine monomer

[0129] Under ice bath conditions, pour the catalyst amount of UIO-66 MOF powder into a beaker containing 100 mL of deionized water, ultrasonically oscillate until it is completely dispersed, pour it into a three-necked beaker, and then pour in 150 mL of deionized water pre-dissolved with 31.4 g (0.2 mol) of G1.0 hyperbranched polyamine monomer, maintain ultrasonic oscillation and slowly heat to 40°C, then slowly drop 100 mL of deionized water pre-dissolved with 13 g (0.3 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 5 h and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the water layer with ethanol, combine the extracts with the organic layer, repeat 3 times, remove water with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The orange-yellow viscous liquid obtained is the product G2.0 hyperbranched polyamine monomer

[0130] 4. Preparation of G2.0 / AM / AA / AMPS copolymer fluid loss reducer

[0131] At room temperature, G2.0 polyamine monomer, AM, AA and AMPS were dissolved in excess deionized water (total monomer concentration was 30wt%) in a ratio of 1.5:13:2:4 (molar ratio). After fully stirring until the raw materials were completely dissolved, the pH was adjusted to neutral with NaOH, and the reaction system was poured into a three-necked flask. Under a N2 atmosphere, the mixture was stirred and heated to 40°C. 5 mL of a deionized water solution of an initiator pre-dissolved with 0.1wt% ammonium persulfate and sodium bisulfite (molar ratio of 1:1) was added dropwise. After the addition was completed, the temperature was raised to 50°C, and the reaction was continued for 4 hours before stopping. The resulting bright yellow viscous liquid was the crude product of the reaction. Take out the crude finished product and soak it in excess acetone. After standing for 12 hours, separate it with a Soxhlet extractor. Take the insoluble part and soak it in excess anhydrous ethanol. After standing for 48 hours, filter it and vacuum dry the filter cake. The light yellow powder obtained by crushing is the purified G2.0 / AM / AA / AMPS copolymer filtrate reducer finished product.

[0132] Embodiment 14

[0133] The present invention provides a method for preparing a copolymer fluid loss reducer, and the specific steps are as follows:

[0134] 1. Preparation of UIO-66 MOF

[0135] At room temperature, 0.699g (3mmol) ZrCl4 and 0.498g (3mmol) terephthalic acid were weighed and dissolved in 30mL DMF, and stirred for 0.5h to fully dissolve, and then transferred to a reactor lined with tetrafluoroethylene and reacted at 150°C for 36h. The reactants were taken out and cooled to room temperature naturally, and then washed with DMF and anhydrous methanol three times each. After centrifugal filtration, the lower layer of solid was dried at 120°C for 4h and fully ground. The obtained milky white powder was UIO-66 type MOF.

[0136] 2. Preparation of G1.0 hyperbranched polyamine monomer

[0137] Under ice bath conditions, pour the catalyst amount of UIO-66 powder into a beaker containing 100 mL of deionized water, ultrasonically oscillate until it is completely dispersed, pour it into a three-necked beaker, and then pour 150 mL of deionized water pre-dissolved with 14.2 g (0.2 mol) of acrylamide, maintain ultrasonic oscillation and slowly raise the temperature to 40°C, then slowly add 100 mL of deionized water pre-dissolved with 13 g (0.3 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 5 h, and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the aqueous layer with ethanol, combine the extracts with the organic layer, repeat 3 times, remove water with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The obtained orange-yellow viscous liquid is the product G1.0 hyperbranched polyamine monomer.

[0138] 3. Preparation of G2.0 hyperbranched polyamine monomer

[0139] Under ice bath conditions, pour the catalyst amount of UIO-66 MOF powder into a beaker containing 100 mL of deionized water, ultrasonically oscillate until it is completely dispersed, pour it into a three-necked beaker, and then pour in 150 mL of deionized water pre-dissolved with 0.15 mol G1.0 hyperbranched polyamine monomer, maintain ultrasonic oscillation and slowly heat to 40°C, then slowly add 100 mL of deionized water pre-dissolved with 13 g (0.3 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 5 h, and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the water layer with ethanol, combine the extracts with the organic layer, repeat 3 times, dehydrate with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The obtained orange-yellow viscous liquid is the product G2.0 hyperbranched polyamine monomer.

[0140] 4. Preparation of G3.0 hyperbranched polyamine monomers

[0141] Under ice bath conditions, pour the catalyst amount of UIO-66 MOF powder into a beaker containing 75 mL of deionized water, ultrasonically vibrate until it is completely dispersed, pour it into a three-necked beaker, and then pour 150 mL of deionized water pre-dissolved with 0.1 mol of G2.0 hyperbranched polyamine monomer, maintain ultrasonic oscillation and slowly heat to 60 ° C, then slowly drop 100 mL of deionized water pre-dissolved with 21.6 g (0.5 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 3 h and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the water layer with ethanol, combine the extracts with the organic layer, repeat 3 times, remove water with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The obtained dark yellow viscous liquid is the product G3.0 hyperbranched polyamine monomer.

[0142] 4. Preparation of G3.0 / AM / AA / AMPS copolymer fluid loss reducer

[0143] At room temperature, G3.0 polyamine monomer, AM, AA and AMPS were dissolved in excess deionized water (total monomer concentration was 30wt%) in a ratio of 1.5:13:2:4 (molar ratio). After sufficient stirring until the raw materials were completely dissolved, the pH was adjusted to neutral with NaOH, and the reaction system was poured into a three-necked flask. Under a N2 atmosphere, the mixture was stirred and heated to 40°C. 5 mL of an initiator deionized water solution pre-dissolved with 0.1wt% ammonium persulfate and sodium bisulfite (molar ratio of 1:1) was added dropwise. After the addition was completed, the temperature was raised to 50°C, and the reaction was continued for 4 hours before stopping. The resulting bright yellow viscous liquid was the crude product of the reaction. Take out the crude finished product and soak it in excess acetone. After standing for 12 hours, separate it with a Soxhlet extractor. Take the insoluble part and soak it in excess anhydrous ethanol. After standing for 48 hours, filter it and vacuum dry the filter cake. The light yellow powder obtained by crushing is the purified G3.0 / AM / AA / AMPS copolymer filtrate reducer finished product.

[0144] Embodiment 15

[0145] The present invention provides a method for preparing a copolymer fluid loss reducer, and the specific steps are as follows:

[0146] 1. Preparation of UIO-66 MOF

[0147] At room temperature, 0.699g (3mmol) ZrCl4 and 0.498g (3mmol) terephthalic acid were weighed and dissolved in 30mL DMF, and stirred for 0.5h to fully dissolve, and then transferred to a reactor lined with tetrafluoroethylene and reacted at 150°C for 36h. The reactants were taken out and cooled to room temperature naturally, and then washed with DMF and anhydrous methanol three times each. After centrifugal filtration, the lower layer of solid was dried at 120°C for 4h and fully ground. The obtained milky white powder was UIO-66 type MOF.

[0148] 2. Preparation of G1.0 hyperbranched polyamine monomer

[0149] Under ice bath conditions, pour the catalyst amount of UIO-66 powder into a beaker containing 100 mL of deionized water, ultrasonically oscillate until it is completely dispersed, pour it into a three-necked beaker, and then pour 150 mL of deionized water pre-dissolved with 14.2 g (0.2 mol) of acrylamide, maintain ultrasonic oscillation and slowly raise the temperature to 40°C, then slowly add 100 mL of deionized water pre-dissolved with 13 g (0.3 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 5 h, and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the aqueous layer with ethanol, combine the extracts with the organic layer, repeat 3 times, remove water with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The obtained orange-yellow viscous liquid is the product G1.0 hyperbranched polyamine monomer.

[0150] 3. Preparation of G2.0 hyperbranched polyamine monomer

[0151] Under ice bath conditions, pour the catalyst amount of UIO-66 MOF powder into a beaker containing 100 mL of deionized water, ultrasonically oscillate until it is completely dispersed, pour it into a three-necked beaker, and then pour in 150 mL of deionized water pre-dissolved with 0.15 mol of G1.0 hyperbranched polyamine monomer, maintain ultrasonic oscillation and slowly heat to 40°C, then slowly add 100 mL of deionized water pre-dissolved with 13 g (0.3 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 5 h, and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the aqueous layer with ethanol, combine the extracts with the organic layer, repeat 3 times, remove water with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The obtained orange-yellow viscous liquid is the product G2.0 hyperbranched polyamine monomer.

[0152] 4. Preparation of G3.0 hyperbranched polyamine monomers

[0153] Under ice bath conditions, pour the catalyst amount of UIO-66 MOF powder into a beaker containing 75 mL of deionized water, ultrasonically vibrate until it is completely dispersed, pour it into a three-necked beaker, and then pour 150 mL of deionized water pre-dissolved with 0.08 mol of G2.0 hyperbranched polyamine monomer, maintain ultrasonic oscillation and slowly heat to 60 ° C, then slowly drop 100 mL of deionized water pre-dissolved with 21.6 g (0.5 mol) of aziridine, remove ultrasonic oscillation after the addition is completed within 3 h and switch to magnetic stirring, continue stirring under TLC control until the reaction is completed, cool to room temperature, pour in excess saturated NaCl deionized water solution, separate the liquids, extract the water layer with ethanol, combine the extracts with the organic layer, repeat 3 times, remove water with anhydrous MgSO4, and remove residual ethanol by vacuum rotary evaporation. The dark yellow viscous liquid obtained is the product G3.0 hyperbranched polyamine monomer.

[0154] 4. Preparation of G3.0 / AM / AA / AMPS copolymer fluid loss reducer

[0155] At room temperature, G3.0 polyamine monomer, AM, AA and AMPS were dissolved in excess deionized water (total monomer concentration was 30wt%) in a ratio of 1.5:13:2:4 (molar ratio). After sufficient stirring until the raw materials were completely dissolved, the pH was adjusted to neutral with NaOH, and the reaction system was poured into a three-necked flask. Under a N2 atmosphere, the mixture was stirred and heated to 40°C. 5 mL of an initiator deionized water solution pre-dissolved with 0.1wt% ammonium persulfate and sodium bisulfite (molar ratio of 1:1) was added dropwise. After the addition was completed, the temperature was raised to 50°C, and the reaction was continued for 4 hours before stopping. The resulting bright yellow viscous liquid was the crude product of the reaction. Take out the crude finished product and soak it in excess acetone. After standing for 12 hours, separate it with a Soxhlet extractor. Take the insoluble part and soak it in excess anhydrous ethanol. After standing for 48 hours, filter it and vacuum dry the filter cake. The light yellow powder obtained by crushing is the purified G3.0 / AM / AA / AMPS copolymer filtrate reducer finished product.

[0156] In summary, the fluid loss reducer of the present invention uses the homemade UIO-66 type MOF as a catalyst to make acrylamide (AM) and aziridine (AZ) undergo iterative addition reaction to successively prepare G1.0, G2.0 and G3.0 hyperbranched polyamine monomers, which are used as raw materials to undergo a quaternary copolymerization reaction with acrylamide (AM), acrylic acid (AA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) to prepare a series of fluid loss reducers rich in amino functional groups. The preparation method is simple to operate, mild in conditions, high in yield, and low in toxicity and environmentally friendly. When the fluid loss reducer is dissolved in water, it can form a supramolecular association based on hydrogen bond synergy by virtue of the abundant primary amine groups in its molecular structure, which is beneficial for it to maintain polymer properties in a long-term high temperature and high mineralization environment.

Claims

1. A hyperbranched polyamine monomer, characterized in that: Taking acrylamide as the basic monomer, through the catalysis of UIO-66 type MOF catalyst, the terminal amine group of the amide group of acrylamide is connected with a branched side chain R, and the branched side chain R is a nitrogen heterocycle, specifically including NH2, N(CH2CH2NH2)2 or N[CH2CH2N(CH2CH2NH2)2].

2. A hyperbranched polyamine monomer according to claim 1, characterized in that: Its general structural formula is:

3. The method for preparing a hyperbranched polyamine monomer according to claim 1, characterized in that: The specific steps are as follows: S1: preparing a UIO-66 type MOF catalyst aqueous solution under ice bath conditions; S2 adds acrylamide aqueous solution to the UIO-66 type MOF catalyst solution, raises the temperature, and obtains a mixed solution A; S3: adding an aziridine aqueous solution to the mixed solution A dropwise within 2 to 5 hours, cooling the mixture to obtain a mixed solution B; S4 separates and extracts the mixed solution B to obtain a hyperbranched polyamine monomer G1.

0.

4. The method for preparing a hyperbranched polyamine monomer according to claim 3, characterized in that: Substituting the acrylamide in S2 with the hyperbranched polyamine monomer G1.0 obtained in S4, repeating S3 and S4 to obtain the hyperbranched polyamine monomer G2.0; The amount of the hyperbranched polyamine monomer G1.0 is 0.1 mol to 0.2 mol; The hyperbranched polyamine monomer G1.0 in S2 is replaced by the hyperbranched polyamine monomer G2.0 obtained in S4, and S3 and S4 are repeated to obtain the hyperbranched polyamine monomer G3.0; The usage of the hyperbranched polyamine monomer G2.0 is 0.05 mol to 0.1 mol.

5. The method for preparing a hyperbranched polyamine monomer according to claim 3, characterized in that: The preparation method of the UIO-66 type MOF catalyst is as follows: S1: dissolving 1-3 mmol of ZrCl4 and 1-3 mmol of terephthalic acid in N,N-dimethylformamide to obtain a mixed solution; The S2 mixed solution is reacted at 100-150° C. for 12-36 hours to obtain a reactant; S3: washing and filtering the reactants, drying the obtained solid at 80-120° C. for 4-12 hours, grinding, and obtaining a UIO-66 type MOF catalyst.

6. The method for preparing a hyperbranched polyamine monomer according to claim 3, characterized in that: In S2, the content of acrylamide in the acrylamide aqueous solution is 0.1-0.3 mol; in S3, the content of aziridine in the aziridine aqueous solution is 0.2-0.4 mol; in S4, excess saturated NaCl deionized water solution is used for separation, ethanol is used to extract the water layer, and the extracts are combined into the organic layer.

7. A copolymer fluid loss reducer, characterized in that: The hyperbranched polyamine monomer described in any one of claims 1 to 2 or the hyperbranched polyamine monomer prepared by the method described in any one of claims 3 to 6 is used as a raw material; the hyperbranched polyamine monomer, acrylamide, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid are mixed with water to obtain a mixed solution, and free radical aqueous solution polymerization is performed in the mixed solution to obtain a copolymer fluid loss reducer. The structure of the copolymer fluid loss reducer is as follows:

8. A copolymer fluid loss reducer according to claim 7, characterized in that: The molar ratio of the hyperbranched polyamine monomer, acrylamide, acrylic acid and 2-acrylamide-2-methylpropane sulfonic acid is 0.5-1.5:10-15:2-4:2-4; and the total concentration of the hyperbranched polyamine monomer in the mixed solution is 15wt%-30wt%.

9. The method for preparing a copolymer fluid loss reducer according to claim 8, characterized in that: The specific steps are as follows: S1: adding a hyperbranched polyamine monomer, acrylamide, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid to excess water, adjusting the pH value to neutral, and obtaining a mixed solution; S2 is stirred and heated to 40-60°C under a protective atmosphere, an initiator is added dropwise to the mixed solution, and the temperature is continued to rise to 50-80°C. After reacting for 4-8 hours, a crude reaction product is obtained; S3: The crude reaction product is soaked in acetone, allowed to stand, and separated to obtain the insoluble part. The insoluble part is soaked in anhydrous ethanol, allowed to stand, and then filtered. The filter cake is dried and crushed to obtain a copolymer filtrate reducer.

10. The method for preparing a copolymer fluid loss reducer according to claim 9, characterized in that: In S2, the initiator is a mixed aqueous solution of ammonium persulfate and sodium bisulfite with a mass fraction of 0.1wt% to 0.4wt%, wherein the molar ratio of ammonium persulfate to sodium bisulfite is 1:1.

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