Hyperbranched polymer anti-high temperature and high salt filtrate reducer, preparation method and application thereof

Abstract

The application discloses a hyperbranched polymer anti-high-temperature and high-salt fluid loss additive, a preparation method and application thereof. The additive is obtained by copolymerization of a tri-branched polyene monomer (1), a quaternary ammonium sulfonate alkene monomer (2), an alkene amide monomer and an alkene monomer containing a cyclic structure; in the formula (1), R and R' are selected from H, an alkyl group, an aryl group, NR"2, CH2OH, CH2NR"2, OH or SH, and X is selected from at least one of NH, O or S; R" is selected from H, an alkyl group or an aryl group; in the formula (2), R1 is selected from any one of formulas (a)-(c), n is an integer, R2 and R3 are selected from H, an alkyl group or an aryl group; in the formulas (a)-(c), L is (CH2) z , NH, O or S, x, y and z are greater than or equal to 0, and x, y and z are integers; R 1 and R 2 are selected from H, an alkyl group or an aryl group. The obtained hyperbranched polymer fluid loss additive has strong calcium salt resistance, is obviously superior to the same type of salt-resistant polymer fluid loss additive, and has temperature resistance up to 220 DEG C.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oilfield chemicals, in particular to a hyperbranched polymer high-temperature-resistant and high-salt-resistant fluid loss additive as well as a preparation method and application thereof. BACKGROUND

[0002] The performance of a drilling fluid is crucial to the components added in the drilling fluid, and the environmental protection index requirements are also increasingly high. Due to the structural limitations, the traditional drilling fluid has been unable to meet the increasingly high performance requirements. Therefore, molecular design has gradually become more and more important, which is an effective way to solve these problems, and can not only improve the performance of the drilling fluid, but also further meet the requirements of environmental protection.

[0003] Chinese patent CN111875758A discloses a nano-type high-temperature-resistant fluid loss additive, but it does not have salt resistance; Chinese patent CN114773539A discloses a high-temperature-resistant and high-salt-resistant micro-crosslinking hydrophobic association tackifying fluid loss additive, which has a temperature resistance of 200 DEG C, but can only resist 30% sodium chloride solution, and cannot well resist divalent calcium salt; Chinese patent CN113527575A discloses a pentaerythritol polyene monomer and a temperature-resistant fluid loss additive thereof, which has a temperature resistance of 200 DEG C, but has poor calcium salt resistance.

[0004] Therefore, it is of great significance to synthesize a new high-temperature-resistant and calcium salt-resistant fluid loss additive for oil and gas well development. SUMMARY

[0005] The present application aims to overcome the above technical deficiencies, and provides a hyperbranched polymer high-temperature-resistant and high-salt-resistant fluid loss additive as well as a preparation method and application thereof, which solves the technical problem that the existing fluid loss additive cannot simultaneously consider high-temperature resistance and high-salt (divalent salt) resistance.

[0006] In a first aspect, the present application provides a hyperbranched polymer high-temperature-resistant and high-salt-resistant fluid loss additive, which is obtained by copolymerization of a three-branched polyene monomer (1), a quaternary ammonium sulfonate alkene monomer (2), an alkene amide monomer and an alkene monomer containing a cyclic structure.

[0007]

[0008] In formula (1), R and R' are each selected from at least one of H, alkyl, aryl, NR''2, CH2OH, CH2NR''2, OH or SH, and X is selected from at least one of NH, O or S; R'' is selected from at least one of H, alkyl or aryl;

[0009] In formula (2), R1 is selected from any one of formula (a)-(c), n>0, and n is an integer; R2 and R3 are each selected from H, an alkyl group, or an aryl group;

[0010] ;

[0011] In formula (a)-(c), L is at least one of (CH2) z , NH, O, or S, x, y, z>0, and x, y, z are all integers; R 1 , R 2 are each selected from at least one of H, an alkyl group, or an aryl group.

[0012] In a second aspect, the present application provides a preparation method of a hyperbranched polymer high-temperature-resistant and high-salt-resistant fluid loss additive, including the following steps:

[0013] The tri-branched polyene monomer is added to part of the water and uniformly mixed to obtain a first mixed solution;

[0014] The quaternary ammonium sulfonate alkene monomer, the alkene amide monomer, and the alkene monomer containing a cyclic structure are dissolved into the remaining water, and the pH is adjusted to 7-8 to obtain a second mixed solution;

[0015] The first mixed solution and the second mixed solution are mixed and fully stirred under an inert atmosphere and a copolymerization reaction temperature to obtain a third mixed solution;

[0016] The initiator is added to the third mixed solution, and a copolymerization reaction is performed under an inert atmosphere; after the copolymerization reaction is completed, the reaction product is washed, dried, and crushed to obtain the hyperbranched polymer high-temperature-resistant and high-salt-resistant fluid loss additive.

[0017] In a third aspect, the present application provides an application of the hyperbranched polymer high-temperature-resistant and high-salt-resistant fluid loss additive; and the hyperbranched polymer high-temperature-resistant and high-salt-resistant fluid loss additive provided in the first aspect of the present application is used to prepare a drilling fluid.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] The tri-branched polyene monomer with good high-temperature resistance and the quaternary ammonium sulfonate alkene monomer with calcium salt resistance are used as core monomers, and other functional monomers are polymerized to obtain the hyperbranched polymer fluid loss additive; the hyperbranched polymer fluid loss additive has strong calcium salt resistance, is obviously superior to the same type of salt-resistant polymer fluid loss additive, has excellent temperature resistance, can resist a temperature of 220 DEG C, and has the advantages of high-temperature resistance and high-salt resistance. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is an infrared spectrum of the tri-branched polyene monomer 3-(3-allyloxy)-2-(allyloxy methyl)-2-methyl propoxy) propylene in Example 1;

[0021] Figure 2 High resolution mass spectrum of the trihyperbranched polyene monomer 3-(3-allyloxy)-2-(allyloxy methyl)-2-methylpropoxy) propene in Example 1. DETAILED DESCRIPTION

[0022] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0023] In a first aspect, the present application provides a hyperbranched polymer anti-high temperature and high salt filtrate reducer, which is obtained by copolymerization of a tri-branched polyene monomer (1), a quaternary ammonium sulfonate alkene monomer (2), an alkene amide monomer and an alkene monomer containing a cyclic structure.

[0024]

[0025] In formula (1), R and R' are each selected from at least one of H, alkyl, aryl, NR''2, CH2OH, CH2NR''2, OH or SH, and further, R and R' are each selected from at least one of H, CH3, Et, Ph, NR''2, CH2OH, CH2NR''2, OH or SH; X is selected from at least one of NH, O or S; R'' is selected from at least one of H, alkyl or aryl, and further, R'' is selected from at least one of H, CH3, Et, Ph;

[0026] In formula (2), R1 is selected from any one of formula (a)~(c), n≥0, and n is an integer; R2 and R3 are each selected from H, alkyl or aryl, and further, H, CH3, Et or Ph, etc.

[0027] ;

[0028] In formula (a)~(c), L is (CH2) z , NH, O or S, x, y, z≥0, and x, y, z are all integers; R 1 , R 2 are each selected from at least one of H, alkyl or aryl, and further, R 1 , R 2 are each selected from at least one of H, CH3, Et or Ph.

[0029] The present application puts the positive charge quaternary ammonium salt structure and the negative charge sulfonate structure in the same alkenyl monomer, which significantly improves the polymer performance. The unique structure of quaternary ammonium sulfonate makes the intramolecular salt formed by the positive and negative charges, and the sulfonic group is more in the negative ion state, which is more conducive to improving the salt resistance.

[0030] The hyperbranched polymer anti-high temperature and high salt fluid loss additive provided by the present application is a core monomer of temperature-resistant monomer tri-branched polyene monomer and quaternary ammonium sulfonate alkenyl monomer resistant to divalent salt (calcium salt), and is copolymerized with other functional monomers. The hyperbranched polymer has a highly branched three-dimensional structure, which is composed of a central core and gradually extending branched monomers. The hyperbranched polymer has more branched points and fewer molecular chain entanglements. The broken part of the branched chain has less effect on the performance of other branched chains at high temperature, so it has significant anti-high temperature performance. At the same time, the quaternary ammonium sulfonate structure introduced in the hyperbranched polymer is not sensitive to salt, especially resistant to divalent calcium salt, so as to ensure the salt resistance of the fluid loss additive; finally, the cyclic structure is introduced into the molecule, which enhances the rigidity of the polymer structure, and further improves the stability of the hyperbranched polymer fluid loss additive at high temperature.

[0031] In the embodiment, the tri-branched polyene monomer (1) is obtained by reaction of a substituted tri-branched terminal functional group compound (I), an allyl compound (II), 18-crown-6, tetrabutylammonium bromide (TBAB) and a base, and the specific reaction formula is as follows:

[0032] .

[0033] In formula (I), R is selected from at least one of H, alkyl, aryl, NR''2, CH2OH, CH2NR''2, OH or SH, and further, R is selected from at least one of H, CH3, Et, Ph, NR''2, CH2OH, CH2NR''2, OH or SH; X is selected from at least one of NH, O or S; R'' is selected from at least one of H, alkyl or aryl, and further, R'' is selected from at least one of H, CH3, Et, Ph.

[0034] In formula (II), R' is selected from at least one of H, alkyl, aryl, NR''2, CH2OH, CH2NR''2, OH or SH, and further, R' is selected from at least one of H, CH3, Et, Ph, NR''2, CH2OH, CH2NR''2, OH or SH; Y is selected from at least one of F, Cl, Br, I, OTs, OMs or OTf; R'' is selected from at least one of H, alkyl or aryl, and further, R'' is selected from at least one of H, CH3, Et, Ph.

[0035] The molar ratio of the substituted tri-branched end-functional compound (I) to the allyl compound (II) is 1:3-6.

[0036] The molar ratio of the substituted tri-branched end-functional compound (I) to 18-crown-6 is 1:2-6.

[0037] The molar ratio of the substituted tri-branched end-functional compound (I) to tetrabutylammonium bromide is 1:3-6.

[0038] The base is at least one of Na2CO3, NaHCO3, K2CO3, Cs2CO3, KOH, CsOH, KH2PO4, K2HPO4, K3PO4, NaOH. Further, the molar ratio of the substituted tri-branched end-functional compound to the base is 1:3-6.

[0039] In the reaction of the substituted tri-branched end-functional compound (I), the allyl compound (II), 18-crown-6, tetrabutylammonium bromide and the base, the reaction temperature is 20-60°C, further 40-50°C; the reaction time is 3-6 h, further 4-5 h.

[0040] After the reaction of the substituted tri-branched end-functional compound (I), the allyl compound (II), 18-crown-6, tetrabutylammonium bromide and the base is completed, the reaction mixture is extracted with dichloromethane, the solvent is removed by a rotary evaporator, and then column chromatography is performed with petroleum ether to obtain the tri-branched polyene monomer.

[0041] The tri-branched polyene monomer (1) is obtained by reacting the substituted tri-branched end-functional compound (I), the allyl compound (II), 18-crown-6, tetrabutylammonium bromide and the base under solvent-free conditions.

[0042] In this embodiment, the quaternary ammonium sulfonate alkenyl monomer is obtained by reacting a sulfonate compound with a leaving group and an amine compound with an end alkenyl group.

[0043] The sulfonate compound with a leaving group is one or more of sodium methylsulfonate, sodium bromomethylsulfonate, sodium 2-chloroethylsulfonate, sodium 2-bromoethylsulfonate, sodium 3-chloropropane sulfonate, sodium 3-chloro-2-hydroxypropane sulfonate, sodium 3-bromopropane sulfonate, sodium 2-hydroxy-3-iodopropane sulfonate, sodium 4-chloro-1-hydroxybutane sulfonate, sodium 4-bromobutane-1-sulfonate, sodium 4-iodobutane-1-sulfonate, and sodium 5-bromo-1-pentanesulfonate.

[0044] The amine compound with terminal alkenyl group is one or more of N,N-dimethyl-4-vinylaniline, N,N-dimethyl-4-vinylphenylethylamine, N,N-dimethyl-2-(4-vinylphenyl)ethan-1-amine, N,N-dimethyl-3-(4-vinylphenyl)propan-1-amine, N,N-dimethylprop-1-en-1-amine, N,N-dimethylbut-3-en-1-amine, N,N-dimethylpent-4-en-1-amine, 1-propenyloxy-N,N-dimethylmethanamine, 1-allyl-N,N-dimethylpiperidin-4-amine, N,N-dimethylacrylamide, N,N-diethylacrylamide, 1-dimethylaminobut-3-en-2-one, 5-dimethylaminopent-1-en-3-one, 6-dimethylaminohex-1-en-3-one, 7-dimethylaminohept-1-en-3-one, dimethylaminomethyl acrylate, 2-(dimethylamino)ethyl acrylate, 2-(diethylamino)ethyl acrylate, 3-(dimethylamino)propyl acrylate, and 4-(dimethylamino)butyl acrylate.

[0045] The molar ratio of the sulfonate compound with leaving group to the amine compound with terminal alkenyl group is 1: (0.5-2).

[0046] The preparation process of the quaternary ammonium sulfonate alkenyl monomer specifically includes: slowly adding an aqueous solution of the sulfonate compound with leaving group to an ethanol solution of the amine compound with terminal alkenyl group, controlling the pH value of the system to be 8-10 during the adding process, continuing to stir and reflux after the adding process is completed, removing the solvent by distillation under reduced pressure after the reaction is completed, recrystallizing the crude product with ethanol, and obtaining the quaternary ammonium sulfonate alkenyl monomer after suction filtration and vacuum drying.

[0047] In the embodiment, the alkenyl amide monomer is one or more of acrylamide, methacrylamide, ethyl acrylamide, vinyl methyl acetamide, isobutyl acrylamide, N,N-dimethyl acrylamide, N,N-diethyl acrylamide, and N-phenyl acrylamide.

[0048] In some specific embodiments of the present application, the alkenyl amide monomer is a mixture of acrylamide, methacrylamide, ethyl acrylamide, vinyl methyl acetamide, isobutyl acrylamide, N,N-dimethyl acrylamide, N,N-diethyl acrylamide, and N-phenyl acrylamide in a mass ratio of 1:1:1:1:1:1:1:1. Because the reactivity of different monomers is different, the molecular weight distribution range of the product obtained by compounding multiple monomers is more extensive, and the product has better filtration loss reduction effect and application prospect, and can better meet the needs of different regions and different environments.

[0049] In the embodiment, the cyclic structure containing olefin monomer is one or more of N-vinylvalerolactam, N-vinylcaprolactam, N-vinylpyrrolidone, 3-acetyl-N-vinylpyrrolidone, N-acryloylmorpholine, 2-propenylphenol.

[0050] In some embodiments of the present application, the cyclic structure containing olefin monomer is a mixture of N-vinylvalerolactam, N-vinylcaprolactam, N-vinylpyrrolidone, 3-acetyl-N-vinylpyrrolidone, N-acryloylmorpholine, 2-propenylphenol in a mass ratio of 1:1:1:1:1:1. Due to the different reactivity of different monomers, the molecular weight distribution range of the product obtained by compounding multiple monomers is more extensive, and it has better fluid loss reduction effect and application prospect, and can better meet the needs of different regions and different environments.

[0051] In the embodiment, the raw material of the hyperbranched polymer high-temperature resistant and high-salt resistant fluid loss additive further comprises an initiator. The initiator is a compound that can easily decompose into free radicals and has a weak bond in the molecular structure. The present application does not limit the type of initiator used, and those skilled in the art can select it according to the actual situation. In some preferred embodiments of the present application, the initiator is an oxidation-reduction initiator. Further, the oxidation-reduction initiator is ammonium persulfate and sodium bisulfite, and the mass ratio of ammonium persulfate to sodium bisulfite is 1-5:1. Further, the amount of initiator added is 0.1%-1% of the total weight of the reaction mixture.

[0052] In the embodiment, the raw material monomer of the hyperbranched polymer high-temperature resistant and high-salt resistant fluid loss additive is composed of 0.5%-10% of the three-branched polyene monomer, 10%-70% of the alkenyl amide monomer, 1%-40% of the quaternary ammonium sulfonate alkene monomer, and 1%-40% of the cyclic structure containing olefin monomer.

[0053] In some embodiments of the present application, the raw material monomer of the hyperbranched polymer high-temperature resistant and high-salt resistant fluid loss additive is composed of 2%-5% of the three-branched polyene monomer, 50%-65% of the alkenyl amide monomer, 15%-25% of the quaternary ammonium sulfonate alkene monomer, and 15%-25% of the cyclic structure containing olefin monomer.

[0054] In the embodiment, the temperature of the copolymerization reaction is 40-65 ℃, and the time of the copolymerization reaction is 2-6 h.

[0055] In a second aspect, the present application provides a preparation method of a hyperbranched polymer high-temperature resistant and high-salt resistant fluid loss additive, comprising the following steps:

[0056] S1, adding the three-branched polyene monomer into part of the water and mixing uniformly to obtain a first mixed solution;

[0057] S2, dissolve the quaternary ammonium sulfonate alkylene monomer, alkylene amide monomer and alkylene monomer containing a cyclic structure into the remaining water, and adjust the pH to 7-8 to obtain a second mixed solution;

[0058] S3, mix the first mixed solution and the second mixed solution under an inert atmosphere and at a copolymerization reaction temperature, and fully stir to obtain a third mixed solution;

[0059] S4, add an initiator to the third mixed solution and perform a copolymerization reaction under an inert atmosphere, and after the copolymerization reaction is completed, wash, dry and crush the reaction product to obtain the hyperbranched polymer high-temperature-resistant and high-salt-resistant fluid loss additive; wherein the temperature of the copolymerization reaction is 40-65 ℃, and the time of the copolymerization reaction is 2-6 h.

[0060] In this embodiment, the mass ratio of the total mass of the raw monomers of the hyperbranched polymer high-temperature-resistant and high-salt-resistant fluid loss additive to the mass of water is (0.1-1):1.

[0061] The kind of base used for adjusting the pH is not limited in the present application, and those skilled in the art can select according to the actual situation. In some specific embodiments of the present application, the base used in the process of adjusting the pH is a 10%-30% sodium hydroxide solution.

[0062] In this embodiment, the first mixed solution and the second mixed solution are mixed and fully stirred for 0.1-1 h after mixing.

[0063] In this embodiment, the inert atmosphere is nitrogen or helium, etc.

[0064] In a third aspect, the present application provides an application of the hyperbranched polymer high-temperature-resistant and high-salt-resistant fluid loss additive. The hyperbranched polymer high-temperature-resistant and high-salt-resistant fluid loss additive provided by the first aspect of the present application is used for preparing a drilling fluid.

[0065] Example 1

[0066] (1) Preparation of tri-branched polyene monomer : 1,1,1-tris(hydroxymethyl)ethane 6 g, tetrabutylammonium bromide 4.8 g, 18-crown-6 5.2 g and sodium hydroxide 10 g were added into a reaction container, then allyl bromide 36 g was slowly added into the reaction container (the dropping time was about half an hour), after the dropping was completed, the reaction was carried out at 40 ℃ for 4.5 h, and the reaction was stopped. The reaction product was extracted with dichloromethane, a rotary evaporator was used to remove the solvent, then petroleum ether was used for column chromatography to achieve the purpose of separation and purification, and finally the colorless oily liquid obtained was the hyperbranched polyene monomer.

[0067] (2) Preparation of quaternary ammonium sulfonate olefin monomer :

[0068] N,N-dimethyl-4-vinylphenyl ethylamine 80 g was added to 250 mL of ethanol, heated to 80°C with stirring, and a reflux device was installed. 2-chloroethyl sulfonate sodium 90 g was dissolved in 200 mL of water to prepare an aqueous solution. The aqueous solution was added to a dropping funnel and slowly added to the above ethanol mixed solution, while adding a sodium hydroxide solution to maintain the pH of the system at 8-10, and all was added within 1 hour. After the addition was completed, the stirring reaction was continued under reflux for 5 hours. After the reaction was completed, the solvent ethanol and water were removed by distillation under reduced pressure, and the crude product was recrystallized with ethanol, filtered, and dried under vacuum to obtain the product.

[0069] (3) Synthesis of hyperbranched polymer anti-high temperature and high salt filtrate reducer using tri-branched polyene monomer

[0070] (3A) Three branched polyene monomers, quaternary ammonium sulfonate alkene monomers, alkene amide monomers, cyclic structure containing alkene monomers, and water were weighed according to the weight of each component; wherein,

[0071] Three branched polyene monomers: 15 g;

[0072] Quaternary ammonium sulfonate alkene monomers: 66 g;

[0073] Alkene amide monomers: acrylamide 21 g, methacrylamide 21 g, ethyl acrylamide 21 g, vinyl methyl acetamide 21 g, isobutyl acrylamide 21 g, N,N-dimethyl acrylamide 21 g, N,N-diethyl acrylamide 21 g, N-phenyl acrylamide 21 g;

[0074] Cyclic structure containing alkene monomers: N-vinyl valerolactam 11 g, N-vinyl caprolactam 11 g, N-vinyl pyrrolidone 11 g, 3-acetyl-N-vinyl pyrrolidone 11 g, N-acryloyl morpholine 11 g, 2-propenyl phenol 11 g;

[0075] Water: 664 g.

[0076] (3B) Three branched polyene monomers and 300 g of deionized water were added to a three-necked flask, N2 was introduced to remove oxygen in the reaction system, and the temperature was raised to 60°C; the above alkene amide monomers, cyclic structure containing alkene monomers, and quaternary ammonium sulfonate alkene monomers were dissolved in 364 g of deionized water, neutralized to pH 7-8 with a prepared 20% sodium hydroxide solution, and added to the three-necked flask; after stirring for 30 minutes, 1.55 g of initiator ammonium persulfate and sodium bisulfite were added, nitrogen was continuously introduced, and the reaction was carried out for 4 h to obtain a gel-like compound; the product was washed with anhydrous ethanol, dried, crushed, and a white powdery copolymer was obtained.

[0077] Example 2

[0078] (1) Preparation of tri-branched polyene monomer: 1,1,1-tris(aminomethyl)propane 9 g, tetrabutylammonium bromide 7.2 g, 18-crown-6 10.4 g, and sodium hydroxide 15 g were put into a reaction vessel, and then allyl bromide 45 g was slowly added dropwise to the reaction vessel (the dropping time was about half an hour), and after the dropping was completed, the reaction was performed at 40°C for 4.5 h, and then the reaction was stopped. The reaction product was extracted with dichloromethane, and then the solvent was removed by a rotary evaporator, and then column chromatography was performed with petroleum ether to achieve the purpose of separation and purification, and then a colorless oily liquid was obtained as the branched polyene monomer.

[0079] (2) Preparation of quaternary ammonium sulfonate olefin monomer :

[0080] N,N-dimethylacryl-1-amine 45 g was put into 200 mL of ethanol, and then the mixture was stirred and heated to 80°C, and then a reflux device was installed. Sodium 2-chloroethyl sulfonate 85 g was dissolved in 200 mL of water to prepare an aqueous solution. The aqueous solution was put into a dropping funnel, and then the aqueous solution was slowly added dropwise to the ethanol mixture, and then a sodium hydroxide solution was added dropwise to maintain the pH value of the system at 8-10, and then the dropping was completed within 1 h, and then the stirring and reflux were continued for 5 h after the dropping was completed, and then the solvent ethanol and water were removed by distillation under reduced pressure, and then the crude product was recrystallized with ethanol, and then the product was obtained by suction filtration and vacuum drying.

[0081] (3) Synthesis of hyperbranched polymer anti-high temperature and high salt filtrate reducer using tri-branched polyene monomer :

[0082] (3A) The branched polyene monomer, the quaternary ammonium sulfonate alkylene monomer, the alkylene amide monomer, the alkylene monomer containing a cyclic structure, and water were weighed according to the weight of each component; wherein,

[0083] The branched polyene monomer: 18 g;

[0084] The quaternary ammonium sulfonate alkylene monomer: 84 g;

[0085] The alkylene amide monomer: acrylamide 32 g, methacrylamide 32 g, ethyl acrylamide 32 g, vinyl methyl acetamide 32 g, isobutyl acrylamide 32 g, N,N-dimethyl acrylamide 32 g, N,N-diethyl acrylamide 32 g, and N-phenyl acrylamide 32 g;

[0086] The alkylene monomer containing a cyclic structure: N-vinyl pyrrolidone 14 g, N-vinyl valerolactam 14 g, N-vinyl caprolactam 14 g, 3-acetyl-N-vinyl pyrrolidone 14 g, N-acryloyl morpholine 14 g, and 2-propenyl phenol 14 g;

[0087] Water: 526 g.

[0088] (3B) In a three-necked flask, add the three-branched polyene monomer and 300 g of deionized water, introduce N2 to remove oxygen in the reaction system, and heat to 60 °C; then dissolve the above-mentioned alkenyl amide monomer, the cyclic structure-containing olefin monomer and the quaternary ammonium sulfonate alkene monomer in 226 g of deionized water, neutralize the pH to 7-8 with the prepared 20% sodium hydroxide solution, and add to the three-necked flask; after stirring for 30 minutes, add 2.25 g of each of the initiators ammonium persulfate and sodium bisulfite, continue to introduce nitrogen, and react for 4 h to obtain a gel-like compound; the product is washed with anhydrous ethanol, dried, crushed, and a white powdery copolymer is obtained.

[0089] Example 3

[0090] (1) Preparation of tri-branched polyene monomer : Add 1,1,1-tris(hydroxymethyl)ethane 8 g, tetrabutylammonium bromide 4.9 g, 18-crown-6 3.9 g and sodium hydroxide 13 g into a reaction container, then slowly drop allyl bromide 42 g into the reaction container (the dropping time is about half an hour), after the dropping is completed, react at 40 °C for 4.5 h, and stop the reaction. The reaction product is extracted with dichloromethane, the solvent is removed by a rotary evaporator, then column chromatography is performed with petroleum ether to achieve the purpose of separation and purification, and finally the colorless oily liquid obtained is the three-branched polyene monomer.

[0091] (2) Preparation of quaternary ammonium sulfonate olefin monomer :

[0092] Add 2-(dimethylamino)ethyl acrylate 74 g into 200 mL of ethanol, stir and heat to 80 °C, and install a reflux device. Dissolve sodium 3-bromopropyl sulfonate 115 g in 300 mL of water to prepare an aqueous solution. Add the above-mentioned aqueous solution to a dropping funnel, and slowly drop it into the above-mentioned ethanol mixed solution, while adding a sodium hydroxide solution to maintain the pH value of the system at 8-10, drop all within 1 hour, after the dropping is completed, continue to stir and reflux for 8 hours, after the reaction is completed, remove the solvent ethanol and water by distillation under reduced pressure, recrystallize the crude product with ethanol, and after suction filtration and vacuum drying, the product is obtained.

[0093] (3) Synthesis of hyperbranched polymer anti-high temperature and high salt filtrate reducer using tri-branched polyene monomer Preparation of tri-branched polyene monomer Preparation of quaternary ammonium sulfonate olefin monomer Synthesis of hyperbranched polymer anti-high temperature and high salt filtrate reducer using tri-branched polyene monomer :

[0094] (3A) The three-branched polyene monomer, the quaternary ammonium sulfonate alkene monomer, the alkenyl amide monomer, the cyclic structure-containing olefin monomer and water are weighed according to the weight of each component; wherein,

[0095] The three-branched polyene monomer: 16 g;

[0096] The quaternary ammonium sulfonate alkene monomer: 78 g;

[0097] Alkenyl amide monomers: acrylamide 28 g, methacrylamide 28 g, ethyl acrylamide 28 g, vinyl methyl acetamide 28 g, isobutyl acrylamide 28 g, N,N-dimethyl acrylamide 28 g, N,N-diethyl acrylamide 28 g, N-phenyl acrylamide 28 g;

[0098] Olefins containing cyclic structure monomers: N-vinyl valerolactam 13 g, N-vinyl caprolactam 13 g, 3-acetyl-N-vinyl pyrrolidone 13 g, N-acryloyl morpholine 13 g, N-vinyl pyrrolidone 13 g, 2-propenyl phenol 13 g;

[0099] Water: 576 g.

[0100] (3B) In a three-necked flask, three branched polyene monomers and 300 g of deionized water were added, N2 was introduced to remove oxygen in the reaction system, and the temperature was raised to 60 °C; the above-mentioned alkenyl amide monomers, olefins containing cyclic structure monomers and quaternary ammonium sulfonate alkenyl monomers were dissolved in 276 g of deionized water, neutralized to pH 7-8 with a prepared 20% sodium hydroxide solution, and added to the three-necked flask; after stirring for 30 min, 1.35 g of initiator ammonium persulfate and sodium bisulfite were added, nitrogen was continuously introduced, and the reaction was carried out for 4 h to obtain a gel-like compound; the product was washed with anhydrous ethanol, dried, crushed, and a white powdery copolymer was obtained.

[0101] Comparative Example 1

[0102] Comparative Example 1 is a hyperbranched polymer fluid loss additive synthesized according to the method of Example 1 of patent CN113527575A.

[0103] Test group

[0104] In 400 mL of distilled water, 16 g of bentonite was added, stirred at a speed of 10,000 r / min for 30 min, and then sealed and maintained at room temperature for 24 h to obtain a fresh water base slurry.

[0105] In the fresh water base slurry, 120 g of sodium chloride and 20 g of calcium chloride were added to prepare a salt water base slurry.

[0106] 5 portions of the salt water base slurry were taken, 1 portion was used as a blank sample without adding any chemical agent, and the other 4 portions were added with 5.6 g of the hyperbranched polymer fluid loss additives synthesized in Examples 1-3 and Comparative Example 1 respectively at a stirring speed of 10,000 r / min, and then stirred for another 30 min. The API filtration amount and HTHP (150 °C) filtration amount of the samples after aging at 220 °C for 16 h were measured.

[0107] Table 1

[0108]

[0109] As can be seen from Table 1, when the amount of the hyperbranched polymer fluid loss additive synthesized in the three embodiments is 1%, the normal temperature fluid loss in the composite brine base slurry is about 9 mL, and the high temperature and high pressure fluid loss is about 22 mL, which can effectively control the fluid loss of the drilling fluid, and has the ability of resisting high temperature and divalent salt (calcium salt). At the same time, although the system of Comparative Example 1 also contains hyperbranched polymer, sulfonate, amide bond and cyclic structure, the ability of resisting high temperature and composite salt of the obtained polymer fluid loss additive is significantly lower than that of Examples 1-3, which shows that the system of the present application is more conducive to improving the temperature resistance and salt tolerance of the obtained fluid loss additive.

[0110] The specific embodiments of the application described above do not constitute a limitation on the protection scope of the application. Any various other corresponding changes and modifications made according to the technical concept of the application shall be included in the protection scope of the claims of the application.

Claims

1. A hyperbranched polymer anti-high temperature and high salt filtrate reducer, characterized in that, The hyperbranched polymer anti-high temperature and high salt filtrate reducer is obtained by copolymerization of a tri-branched polyene monomer (1), a quaternary ammonium sulfonate olefin monomer (2), an olefin amide monomer and an olefin monomer containing a cyclic structure. ； In formula (1), R and R' are at least one of H, alkyl, aryl, NR''2, CH2OH, CH2NR''2, OH or SH, and X is at least one of NH, O or S; R'' is at least one of H, alkyl or aryl; In formula (2), R1 is any one of formula (a)-(c), n is an integer greater than or equal to 0, and R2 and R3 are H, alkyl or aryl; ； In formulae (a) to (c), L is at least one of (CH2) z , NH, O or S, x, y, z > 0, and x, y, z are each an integer; R 1 , R 2 are each selected from at least one of H, an alkyl group or an aryl group. The olefin amide monomer is one or more of acrylamide, methacrylamide, ethyl acrylamide, vinyl methyl acetamide, isobutyl acrylamide, N,N-dimethyl acrylamide, N,N-diethyl acrylamide and N-phenyl acrylamide. The olefin monomer containing a cyclic structure is one or more of N-vinyl valerolactam, N-vinyl caprolactam, N-vinyl pyrrolidone, 3-acetyl-N-vinyl pyrrolidone, N-acryloyl morpholine and 2-propenyl phenol. The raw material monomers of the hyperbranched polymer anti-high temperature and high salt filtrate reducer are composed of 0.5-10% of the tri-branched polyene monomer, 10-70% of the olefin amide monomer, 1-40% of the quaternary ammonium sulfonate olefin monomer and 1-40% of the olefin monomer containing a cyclic structure.

2. The hyperbranched polymer fluid loss additive of claim 1, wherein, In formula (1), R, R' are selected from at least one of H, CH3, Et, Ph, NR"2, CH2OH, CH2NR"2, OH or SH, R" is selected from at least one of H, CH3, Et, Ph; in formula (2), R2, R3 are selected from at least one of H, CH3, Et or Ph; in formula (a)-(c), R 1 , R 2 are selected from at least one of H, CH3, Et or Ph.

3. The hyperbranched polymer fluid loss additive of claim 1, wherein, The tri-branched polyene monomer (1) is obtained by reaction of a substituted tri-branched terminal functional group compound (I), an allyl compound (II), 18-crown-6, tetrabutylammonium bromide and a base, and the specific reaction formula is as follows: ； The molar ratio of the substituted tri-branched terminal functional group compound (I) to the allyl compound (II) is 1:3-6, the molar ratio of the substituted tri-branched terminal functional group compound (I) to 18-crown-6 is 1:2-6, the molar ratio of the substituted tri-branched terminal functional group compound (I) to tetrabutylammonium bromide is 1:3-6, the base is at least one of Na2CO3, NaHCO3, K2CO3, Cs2CO3, KOH, CsOH, KH2PO4, K2HPO4, K3PO4 and NaOH, the molar ratio of the substituted tri-branched terminal functional group compound to the base is 1:3-6, and the reaction temperature is 20-60°C and the reaction time is 3-6 h in the reaction of the substituted tri-branched terminal functional group compound (I), the allyl compound (II), 18-crown-6, tetrabutylammonium bromide and the base.

4. The hyperbranched polymer fluid loss additive of claim 1, wherein, The quaternary ammonium sulfonate olefin monomer is obtained by reaction of a sulfonate compound with a leaving group and an amine compound with a terminal olefin group, wherein The leaving group-containing sulfonate compound is one or more of sodium chloromethanesulfonate, sodium bromomethylsulfonate, sodium 2-chloroethylsulfonate, sodium 2-bromoethylsulfonate, sodium 3-chloropropane sulfonate, sodium 3-chloro-2-hydroxypropane sulfonate, sodium 3-bromopropane sulfonate, sodium 2-hydroxy-3-iodopropane sulfonate, sodium 4-chloro-1-hydroxybutane sulfonate, sodium 4-bromobutane-1-sulfonate, sodium 4-iodobutane-1-sulfonate, and sodium 5-bromo-1-pentanesulfonate; The terminal alkenyl-containing amine compound is one or more of N,N-dimethyl-4-vinylaniline, N,N-dimethyl-4-vinylphenylethylamine, N,N-dimethyl-2-(4-vinylphenyl)ethan-1-amine, N,N-dimethyl-3-(4-vinylphenyl)propan-1-amine, N,N-dimethylprop-2-en-1-amine, N,N-dimethylbut-3-en-1-amine, N,N-dimethylpent-4-en-1-amine, 1-propenyloxy-N,N-dimethylmethanamine, 1-allyl-N,N-dimethylpiperidin-4-amine, N,N-dimethylacrylamide, N,N-diethylacrylamide, 1-dimethylaminobut-3-en-2-one, 5-dimethylaminopent-1-en-3-one, 6-dimethylaminohex-1-en-3-one, 7-dimethylaminohept-1-en-3-one, dimethylaminomethyl acrylate, 2-(dimethylamino)ethyl acrylate, 2-(diethylamino)ethyl acrylate, 3-(dimethylamino)propyl acrylate, and 4-(dimethylamino)butyl acrylate.

5. The hyperbranched polymer fluid loss additive of claim 4, wherein the hyperbranched polymer fluid loss additive is resistant to high temperature and high salt. The molar ratio of the leaving group-containing sulfonate compound to the terminal alkenyl-containing amine compound is 1:(0.5-2).

6. The hyperbranched polymer fluid loss additive of claim 4, wherein the hyperbranched polymer fluid loss additive is resistant to high temperature and high salt. The preparation process of the quaternary ammonium sulfonate alkenyl monomer specifically comprises: slowly adding an aqueous solution of the leaving group-containing sulfonate compound to an ethanol solution of the terminal alkenyl-containing amine compound, controlling the pH value of the system to be 8-10 during the adding process, continuing to stir and reflux after the adding process is completed, removing the solvent by distillation under reduced pressure after the reaction is completed, recrystallizing the crude product with ethanol, and obtaining the quaternary ammonium sulfonate alkenyl monomer after suction filtration and vacuum drying.

7. The hyperbranched polymer fluid loss additive of claim 1, wherein the hyperbranched polymer fluid loss additive is resistant to high temperature and high salt. The raw material of the hyperbranched polymer anti-high-temperature and high-salt fluid loss additive further comprises an initiator; the initiator is ammonium persulfate and sodium bisulfite with a mass ratio of 1-5:1, and the addition amount of the initiator is 0.1%-1% of the total weight of the reaction mixture.

8. The hyperbranched polymer fluid loss additive of claim 1, wherein, The temperature of the copolymerization reaction is 40-65 ℃, and the time of the copolymerization reaction is 2-6 h.

9. A method for preparing the hyperbranched polymer anti-high temperature and high salt filtrate reducer according to any one of claims 1-8, characterized in that, The method comprises the following steps: adding three branched polyene monomers into part of water, mixing uniformly to obtain a first mixed solution; dissolving the quaternary ammonium sulfonate alkenyl monomer, the alkenyl amide monomer, and the olefin monomer containing a cyclic structure into the remaining water and adjusting the pH value to 7-8 to obtain a second mixed solution; mixing the first mixed solution and the second mixed solution under an inert atmosphere and at a copolymerization reaction temperature, and fully stirring to obtain a third mixed solution; adding an initiator to the third mixed solution and performing a copolymerization reaction under an inert atmosphere, washing, drying, and crushing the reaction product after the copolymerization reaction is completed to obtain the hyperbranched polymer anti-high-temperature and high-salt fluid loss additive.

10. The use of the hyperbranched polymer of any one of claims 1-8 as a high temperature resistant and high salt resistant fluid loss additive. The hyperbranched polymer anti-high-temperature and high-salt filtrate reducer is used for preparing a drilling fluid.

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