Acid liquor gelling agent as well as preparation and application thereof

Abstract

The invention discloses an acid liquor gelling agent. The acid liquor gelling agent is polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-carboxylic acid olefin. The invention also discloses a preparation method and application thereof. The acid liquor gelling agent provided by the invention can be applied to carbonate rock acidification construction, has high temperature resistance and salt resistance, has good performance of retarding, filtrate loss reduction, crack formation and resistance reduction, and can effectively reduce secondary damage, effectively improve the flow conductivity of acid-etched cracks and the penetration distance of acid and achieve the purpose of deep acidification.

Description

Technical Field

[0001] The present invention relates to an acid gelator and its preparation and application. Background Art

[0002] During the oilfield development process, large-scale acid fracturing is required for carbonate reservoirs to achieve good development effects. Acid gelators are important additives in acidification and an important guarantee for acid fracturing operations. This type of gelator can effectively increase the viscosity of acid solution, reduce the frictional resistance, enhance the fracture-forming ability of acid solution, and achieve the purpose of acid fracturing. Acid gelators are high-value-added products and are highly targeted during use. They are mainly polyacrylamide-based products, but compared with conventional products, they need to meet extremely high salt and acid resistance characteristics.

[0003] Common acid gelators are solid particles. During on-site applications, there are difficulties in dissolution and dispersion, which affect the construction progress and reduce the construction effect. Therefore, on the basis of ensuring the viscosity and temperature resistance of acid solution, improving the dissolution ability has become an important research direction for acid gelators.

[0004] In the prior art, there are mainly two types of acid gelators: 1. Modifying conventional polyacrylamide to prepare modified polyacrylamide; 2. Using propionamide as the main monomer and adding different polymerization monomers to solve the dissolution problem under acid solution conditions. The synthesis methods in the prior art have low conversion efficiency, poor dispersion ability of the prepared acid gelators, are extremely prone to forming fisheyes, and are difficult to mix, bringing many inconveniences to on-site use. Summary of the Invention

[0005] In order to further improve the preparation efficiency of acid gelators and the dispersion ability of the prepared acid gelator products, and to enrich the selection space of acid gelators, the present invention is made.

[0006] As an aspect of the present invention, it relates to an acid gelator, which is polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-carboxylic acid olefin.

[0007] In specific embodiments, the polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-carboxylic acid olefin is polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-itaconic acid, polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-acrylic acid, or polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-butene-1,2,3-tricarboxylic acid.

[0008] In specific embodiments, in the polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-carboxylic acid olefin, acrylamide: acryloyloxyethyl trimethyl ammonium chloride: carboxylic acid olefin = 55-38: 35-52: 10-1, preferably acrylamide: acryloyloxyethyl trimethyl ammonium chloride: carboxylic acid olefin = 55-49: 50-40: 5-1.

[0009] As another aspect of the present invention, it relates to a method for preparing the above-mentioned polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin, and the method uses an azo initiator and a redox initiator simultaneously.

[0010] In a specific embodiment, the method includes:

[0011] (1) Dissolve acrylamide monomer, acryloyloxyethyltrimethylammonium chloride monomer, and carboxylic acid olefin monomer in deionized water, stir evenly, and prepare a reaction mother liquor.

[0012] (2) Under a nitrogen atmosphere, sequentially add a nitrogen initiator, an oxidation initiator, a reduction initiator, a chain transfer agent, and a complexing agent for polymerization reaction.

[0013] In a specific embodiment, the above method further includes:

[0014] (3) Dry and crush the polymer obtained from the polymerization reaction.

[0015] In a specific embodiment, the carboxylic acid olefin monomer is itaconic acid, acrylic acid, or 1,2,3-butenetricarboxylic acid, preferably itaconic acid; the azo initiator is azobisisobutyronitrile; the oxidizing agent is potassium persulfate or hydrogen peroxide; and the reducing initiator is potassium sulfite or sodium bisulfite.

[0016] As yet another aspect of the present invention, it relates to the application of the above-mentioned polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin in the process of oilfield development.

[0017] The acid gelling agent provided by the present invention can be applied to carbonate acidification construction, has high temperature resistance and salt resistance, and has good performance in retarding, filtrate reduction, fracture formation, and drag reduction. It can effectively reduce secondary damage, effectively improve the conductivity of acid-etched fractures and the penetration distance of acid, and achieve the purpose of deep acidification. Specific Embodiments

[0018] Example 1

[0019] (1) Prepare a reaction mother liquor: Dissolve 55 g of acrylamide monomer, 43.75 g of acryloyloxyethyltrimethylammonium chloride monomer (80% aqueous solution, effective ingredient is 35 g), and 10 g of itaconic acid in 191.02 g of deionized water, stir evenly, then add Na2CO3 to adjust the pH value of the solution to 12, stir evenly to obtain a reaction mother liquor, and place the mother liquor into a polymerization device.

[0020] (2) When the temperature of the reaction mother liquor is 8 °C, under a nitrogen atmosphere, 0.05 g of azobisisobutyramidine hydrochloride (azo initiator), 0.07 g of potassium persulfate (oxidative initiator), 0.07 g of sodium sulfite (reductive initiator), 0.03 g of sodium formate (chain transfer agent), and 0.01 g of sodium dimethylidene phosphate (complexing agent) are added in sequence. The temperature is raised to 60 °C in a water bath, and a polymerization reaction is carried out for 4 hours;

[0021] (3) Take out the polymer obtained from the polymerization reaction, granulate it, dry it at 60 °C for 5 hours, and pulverize it to obtain the acid gelator. The obtained acid gelator is composed of polyacrylamide-acryloyloxyethyltrimethylammonium chloride-itaconic acid, which is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin. Among them, acrylamide:acryloyloxyethyltrimethylammonium chloride:itaconic acid = 55:35:10.

[0022] In this example, the azo initiator accounts for 0.05% of the total mass of the monomers used; the oxidative initiator accounts for 0.07% of the total mass of the monomers used; the reductive initiator accounts for 0.07% of the total mass of the monomers used; the chain transfer agent accounts for 0.03% of the total mass of the monomers used; the complexing agent accounts for 0.01% of the total mass of the monomers used.

[0023] Example 2

[0024] (1) Prepare the reaction mother liquor: Dissolve 50 g of acrylamide monomer, 56.25 g of acryloyloxyethyltrimethylammonium chloride monomer (80% aqueous solution, effective ingredient is 45 g), and 5 g of itaconic acid in 188.50 g of deionized water, stir evenly, then add Na2CO3 to adjust the pH value of the solution to pH = 12, stir evenly to obtain the reaction mother liquor, and place the mother liquor in the polymerization device;

[0025] (2) When the temperature of the reaction mother liquor is 8 °C, under a nitrogen atmosphere, 0.07 g of azobisisobutyronitrile (azo initiator), 0.07 g of potassium persulfate (oxidative initiator), 0.07 g of sodium bisulfite (reductive initiator), 0.03 g of sodium formate (chain transfer agent), and 0.01 g of ethylenediaminetetraacetic acid (complexing agent) are added in sequence. The temperature is raised to 60 °C in a water bath, and a polymerization reaction is carried out for 4 hours;

[0026] (3) Take out the polymer obtained from the polymerization reaction, granulate it, dry it at 60 °C for 5 hours, and pulverize it to obtain the acid gelator. The obtained acid gelator is composed of polyacrylamide-acryloyloxyethyltrimethylammonium chloride-itaconic acid, which is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin. Among them, acrylamide:acryloyloxyethyltrimethylammonium chloride:itaconic acid = 50:45:5.

[0027] In this example, the azo initiator accounts for 0.07% of the total mass of the monomers used; the oxidation initiator accounts for 0.07% of the total mass of the monomers used; the reduction initiator accounts for 0.07% of the total mass of the monomers used; the chain transfer agent accounts for 0.03% of the total mass of the monomers used; the complexing agent accounts for 0.01% of the total mass of the monomers used.

[0028] Example 3

[0029] (1) Prepare the reaction mother liquor: Dissolve 59.5 g of acrylamide monomer, 50.0 g of acryloyloxyethyltrimethylammonium chloride monomer (80% aqueous solution, effective ingredient is 40.0 g), and 0.5 g of itaconic acid in 189.74 g of deionized water, stir evenly, then add Na2CO3 to adjust the pH value of the solution to pH 10, stir evenly to obtain the reaction mother liquor, and place the mother liquor into the polymerization device;

[0030] (2) When the temperature of the reaction mother liquor is 10 °C, under a nitrogen atmosphere, sequentially add 0.08 g of azobisisobutyronitrile (azo initiator), 0.07 g of potassium persulfate (oxidation initiator), 0.07 g of sodium bisulfite (reduction initiator), 0.03 g of sodium formate (chain transfer agent), and 0.01 g of ethylenediaminetetraacetic acid (complexing agent), heat up to 60 °C in a water bath, and carry out the polymerization reaction for 4 hours;

[0031] (3) Take out the polymer obtained from the polymerization reaction, granulate it, dry it at 60 °C for 5 hours, and pulverize it to obtain the acid gel agent. The components of the obtained acid gel agent are polyacrylamide-acryloyloxyethyltrimethylammonium chloride-itaconic acid, which is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin. Among them, acrylamide:acryloyloxyethyltrimethylammonium chloride:itaconic acid = 59.5:40:0.5.

[0032] In this example, the azo initiator accounts for 0.08% of the total mass of the monomers used; the oxidation initiator accounts for 0.07% of the total mass of the monomers used; the reduction initiator accounts for 0.07% of the total mass of the monomers used; the chain transfer agent accounts for 0.03% of the total mass of the monomers used; the complexing agent accounts for 0.01% of the total mass of the monomers used.

[0033] Example 4

[0034] (1) Prepare the reaction mother liquor: Dissolve 35.0 g of acrylamide monomer, 62.5 g of acryloyloxyethyltrimethylammonium chloride monomer (80% aqueous solution, effective ingredient is 50.0 g), and 15.0 g of itaconic acid in 187.25 g of deionized water, stir evenly, then add Na2CO3 to adjust the pH value of the solution to pH 11, stir evenly to obtain the reaction mother liquor, and place the mother liquor into the polymerization device;

[0035] (2) When the temperature of the reaction mother liquor is 11 °C, under a nitrogen atmosphere, 0.07 g of azobisisobutyronitrile (azo initiator), 0.07 g of sodium persulfate (oxidative initiator), 0.07 g of sodium bisulfite (reductive initiator), 0.03 g of sodium formate (chain transfer agent), and 0.01 g of pentasodium nitrilotriacetate (complexing agent) are added in sequence. The temperature is raised to 60 °C in a water bath, and the polymerization reaction is carried out for 4 hours;

[0036] (3) The polymer obtained from the polymerization reaction is taken out for granulation, dried at 60 °C for 5 hours, and pulverized to obtain the acid gelator. The composition of the obtained acid gelator is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-itaconic acid, which is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin. Among them, polyacrylamide: acryloyloxyethyltrimethylammonium chloride: itaconic acid = 35:50:15.

[0037] In this example, the azo initiator accounts for 0.07% of the total mass of the monomers used; the oxidative initiator accounts for 0.07% of the total mass of the monomers used; the reductive initiator accounts for 0.07% of the total mass of the monomers used; the chain transfer agent accounts for 0.03% of the total mass of the monomers used; the complexing agent accounts for 0.01% of the total mass of the monomers used.

[0038] Example 5

[0039] (1) Prepare the reaction mother liquor: Dissolve 55.0 g of acrylamide monomer, 50.0 g of acryloyloxyethyltrimethylammonium chloride monomer (80% aqueous solution, effective ingredient is 40.0 g), and 5.0 g of itaconic acid in 189.75 g of deionized water, stir evenly, then add Na2CO3 to adjust the pH value of the solution to pH 11, stir evenly to obtain the reaction mother liquor, and place the mother liquor in the polymerization device;

[0040] (2) When the temperature of the reaction mother liquor is 8 °C, under a nitrogen atmosphere, 0.07 g of azobisisobutyronitrile (azo initiator), 0.07 g of potassium persulfate (oxidative initiator), 0.07 g of potassium bisulfite (reductive initiator), 0.03 g of sodium formate (chain transfer agent), and 0.01 g of ethylenediaminetetraacetic acid (complexing agent) are added in sequence. The temperature is raised to 60 °C in a water bath, and the polymerization reaction is carried out for 4 hours;

[0041] (3) The polymer obtained from the polymerization reaction is taken out for granulation, dried at 60 °C for 5 hours, and pulverized to obtain the acid gelator. The composition of the obtained acid gelator is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-itaconic acid, which is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin. Among them, acrylamide: acryloyloxyethyltrimethylammonium chloride: itaconic acid = 55:40:5.

[0042] In this example, the azo initiator accounts for 0.07% of the total mass of the monomers used; the oxidation initiator accounts for 0.07% of the total mass of the monomers used; the reduction initiator accounts for 0.07% of the total mass of the monomers used; the chain transfer agent accounts for 0.03% of the total mass of the monomers used; the complexing agent accounts for 0.01% of the total mass of the monomers used.

[0043] Example 6

[0044] (1) Prepare the reaction mother liquor: Dissolve 55.0 g of acrylamide monomer, 43.75 g of acryloyloxyethyltrimethylammonium chloride monomer (80% aqueous solution, with an effective component of 35.0 g), and 10.0 g of acrylic acid in 191.08 g of deionized water, stir evenly, then add Na2CO3 to adjust the pH value of the solution to pH = 12, stir evenly to obtain the reaction mother liquor, and place the mother liquor into the polymerization device;

[0045] (2) When the temperature of the reaction mother liquor is 12 °C, under a nitrogen atmosphere, sequentially add 0.07 g of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (azo initiator), 0.03 g of hydrogen peroxide (oxidation initiator), 0.03 g of sodium bisulfite (reduction initiator), 0.03 g of sodium formate (chain transfer agent), and 0.01 g of pentasodium triethylenetetraminepentaacetate (complexing agent), raise the temperature to 60 °C in a water bath, and carry out the polymerization reaction for 4 hours;

[0046] (3) Take out the polymer obtained from the polymerization reaction, granulate it, dry it at 60 °C for 5 hours, and pulverize it to obtain the acid gel agent. The composition of the obtained acid gel agent is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-acrylic acid, which is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin, where acrylamide:acryloyloxyethyltrimethylammonium chloride:acrylic acid = 55:35:10.

[0047] In this example, the azo initiator accounts for 0.07% of the total mass of the monomers used; the oxidation initiator accounts for 0.03% of the total mass of the monomers used; the reduction initiator accounts for 0.03% of the total mass of the monomers used; the chain transfer agent accounts for 0.03% of the total mass of the monomers used; the complexing agent accounts for 0.01% of the total mass of the monomers used.

[0048] Example 7

[0049] (1) Prepare the reaction mother liquor: Dissolve 49.0 g of acrylamide monomer, 62.50 g of acryloyloxyethyltrimethylammonium chloride monomer (80% aqueous solution, with an effective component of 50.0 g), and 1.0 g of acrylic acid in 187.29 g of deionized water, stir evenly, then add Na2CO3 to adjust the pH value of the solution to pH = 10, stir evenly to obtain the reaction mother liquor, and place the mother liquor into the polymerization device;

[0050] (2) When the temperature of the reaction mother liquor is 10 °C, under a nitrogen atmosphere, 0.11 g of azobisisobutyronitrile (azo initiator), 0.03 g of potassium persulfate (oxidative initiator), 0.03 g of sodium bisulfite (reductive initiator), 0.03 g of sodium formate (chain transfer agent), and 0.01 g of pentasodium nitrilotriacetate (complexing agent) are added in sequence. The temperature is raised to 60 °C in a water bath, and the polymerization reaction is carried out for 4 hours;

[0051] (3) The polymer obtained from the polymerization reaction is taken out for granulation, dried at 60 °C for 5 hours, and pulverized to obtain the acid gelator. The components of the obtained acid gelator are polyacrylamide-acryloyloxyethyltrimethylammonium chloride-acrylic acid, which is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin. Among them, acrylamide:acryloyloxyethyltrimethylammonium chloride:acrylic acid = 49:50:1.

[0052] In this example, the azo initiator accounts for 0.11% of the total mass of the monomers used; the oxidative initiator accounts for 0.03% of the total mass of the monomers used; the reductive initiator accounts for 0.03% of the total mass of the monomers used; the chain transfer agent accounts for 0.03% of the total mass of the monomers used; the complexing agent accounts for 0.01% of the total mass of the monomers used.

[0053] Example 8

[0054] (1) Prepare the reaction mother liquor: Dissolve 38.0 g of acrylamide monomer, 65.0 g of acryloyloxyethyltrimethylammonium chloride monomer (80% aqueous solution, effective component is 35.0 g), and 10.0 g of 1,2,3-butene tricarboxylic acid in 186.87 g of deionized water, stir evenly, then add Na2CO3 to adjust the pH value of the solution to 11, stir evenly to obtain the reaction mother liquor, and place the mother liquor into the polymerization device;

[0055] (2) When the temperature of the reaction mother liquor is 10 °C, under a nitrogen atmosphere, 0.05 g of azodiisobutyronitrile (azo initiator), 0.02 g of potassium persulfate (oxidative initiator), 0.03 g of sodium bisulfite (reductive initiator), 0.02 g of sodium formate (chain transfer agent), and 0.01 g of pentasodium nitrilotriacetate (complexing agent) are added in sequence. The temperature is raised to 60 °C in a water bath, and the polymerization reaction is carried out for 4 hours;

[0056] (3) The polymer obtained from the polymerization reaction is taken out for granulation, dried at 60 °C for 5 hours, and pulverized to obtain the acid gelator. The components of the obtained acid gelator are polyacrylamide-acryloyloxyethyltrimethylammonium chloride-1,2,3-butene tricarboxylic acid, which is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin. Among them, acrylamide:acryloyloxyethyltrimethylammonium chloride:1,2,3-butene tricarboxylic acid = 55:35:10.

[0057] In this example, the azo initiator accounts for 0.05% of the total mass of the monomers used; the oxidation initiator accounts for 0.02% of the total mass of the monomers used; the reduction initiator accounts for 0.03% of the total mass of the monomers used; the chain transfer agent accounts for 0.02% of the total mass of the monomers used; the complexing agent accounts for 0.01% of the total mass of the monomers used.

[0058] Example 9

[0059] (1) Prepare the reaction mother liquor: Dissolve 49.0 g of acrylamide monomer, 62.50 g of acryloyloxyethyltrimethylammonium chloride monomer (80% aqueous solution, with an effective component of 50.0 g), and 1.0 g of butene-1,2,3-tricarboxylate in 187.26 g of deionized water, stir evenly, then add Na2CO3 to adjust the pH value of the solution to 11, stir evenly to obtain the reaction mother liquor, and place the mother liquor into the polymerization device;

[0060] (2) When the temperature of the reaction mother liquor is 9 °C, under a nitrogen atmosphere, sequentially add 0.07 g of azobisisobutyronitrile (azo initiator), 0.07 g of potassium persulfate (oxidation initiator), 0.07 g of potassium sulfite (reduction initiator), 0.02 g of sodium formate (chain transfer agent), and 0.01 g of sodium dimethylenephosphonate (complexing agent), raise the temperature to 60 °C in a water bath, and carry out the polymerization reaction for 4 hours;

[0061] (3) Take out the polymer obtained from the polymerization reaction, granulate it, dry it at 60 °C for 5 hours, and pulverize it to obtain the acid gel agent. The components of the obtained acid gel agent are polyacrylamide-acryloyloxyethyltrimethylammonium chloride-butene-1,2,3-tricarboxylate, which is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin. Among them, acrylamide:acryloyloxyethyltrimethylammonium chloride:butene-1,2,3-tricarboxylate = 49:50:1.

[0062] In this example, the azo initiator accounts for 0.07% of the total mass of the monomers used; the oxidation initiator accounts for 0.07% of the total mass of the monomers used; the reduction initiator accounts for 0.07% of the total mass of the monomers used; the chain transfer agent accounts for 0.02% of the total mass of the monomers used; the complexing agent accounts for 0.01% of the total mass of the monomers used.

[0063] Verify the implementation effects of the acid gel agents prepared in the above examples.

[0064] The verification method is as follows: 1. Observe the polymerization state of the product: including whether there is precipitation in the polymerization liquid, whether the polymerization liquid is uniform, and whether there is a phenomenon of explosive polymerization into lumps; 2. Observe the dispersion state of the obtained acid gel agent added to the acid, whether it dissolves in the acid, whether it is difficult to disperse, and the state after dissolving in the acid; 3. Measure the acid viscosity (write clearly the measurement method) to see if it meets the requirements of the conventional acid field construction viscosity.

[0065] The verification results are shown in Table 1.

[0066] Table 1

[0067] Aggregation state Degree of acid solution dispersion Viscosity of acid solution Example 1 Uniform polymerization Uniform dispersion 33 Example 2 Uniform polymerization Uniform dispersion 57 Example 3 Violent polymerization Poor dispersion ability 18 Example 4 Violent polymerization Poor dispersion ability 15 Example 5 Uniform polymerization Uniform dispersion 45 Example 6 Uniform polymerization Uniform dispersion 36 Example 7 Uniform polymerization Uniform dispersion 45 Example 8 Uniform polymerization Uniform dispersion 39 Example 9 Uniform polymerization Uniform dispersion 48

[0068] The above examples show that the selection of the type and dosage of the polymerization monomer and the type and dosage of the initiator will both affect the implementation effect of the final acid gelator. Except for Examples 3 and 4, the viscosities of the acid gelators prepared in other examples can all achieve a good viscosity-raising effect. Among them, the effects of Examples 2, 5, 7, and 9 have obvious advantages over Examples 1 and 6, and Example 2 is the best. It can be seen from this that the simultaneous use of azo initiators and redox initiators helps to prepare a better acidification gelator. The prepared acid gelator has a relatively uniform polymerization liquid, a higher degree of acid dispersion, and a higher acid viscosity. Especially when the carboxylic acid olefin monomer selected is itaconic acid, the azo initiator selected is azobisisobutyronitrile, the oxidant selected is potassium persulfate, and the reducing initiator selected is sodium bisulfite, the prepared acidification gelator has the optimal molecular weight and the best dispersion ability, and the product has a strong dispersion ability, the highest viscosity, and the best effect. The high-efficiency acid gelator prepared in Example 2 shows the properties of fast dispersion and high viscosity.

[0069] Based on the above examples, it can be known that the prepared acid gelator is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin. Among them, based on Examples 2, 5, 7, and 9, when polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic acid olefin is polyacrylamide-acryloyloxyethyltrimethylammonium chloride-itaconic acid, polyacrylamide-acryloyloxyethyltrimethylammonium chloride-acrylic acid, polyacrylamide-acryloyloxyethyltrimethylammonium chloride-1,2,3-tricarboxylic acid butene, the implementation effect of the acid gelator is better. Especially when acrylamide:acryloyloxyethyltrimethylammonium chloride:carboxylic acid olefin = 55-38:35-52:10-1, the acid viscosity is greater than 30 mPa·s. Preferably, when acrylamide:acryloyloxyethyltrimethylammonium chloride:carboxylic acid olefin = 55-49:50-40:5-1, the implementation effect of the acid gelator is better, and the viscosity is above 40 mPa·s.

Claims

1. An acid gelator, characterized in that, The acid gelling agent is polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-carboxylic acid olefin.

2. The acid gelling agent according to claim 1, characterized in that, The polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-carboxylic acid olefin is polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-itaconic acid, polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-acrylic acid or polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-butene 1,2,3-tricarboxylic acid.

3. The acid gelling agent according to claim 1, characterized in that, In the polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-carboxylic acid olefin, acrylamide: acryloyloxyethyl trimethyl ammonium chloride: carboxylic acid olefin = 55-38: 35-52: 10-1.

4. The acid gelling agent according to claim 3, characterized in that, In the polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-carboxylic acid olefin, acrylamide: acryloyloxyethyl trimethyl ammonium chloride: carboxylic acid olefin = 55-49: 50-49: 5-1.

5. A method for preparing the polyacrylamide-acryloyloxyethyltrimethylammonium chloride-carboxylic olefin according to any one of claims 1-4, characterized in that, The method uses an azo initiator and a redox initiator simultaneously.

6. The method according to claim 5, characterized in that The method includes: (1) Dissolve acrylamide monomer, acryloyloxyethyl trimethyl ammonium chloride monomer and carboxylic acid olefin monomer in deionized water, stir evenly to prepare a reaction mother liquor; (2) Under a nitrogen atmosphere, sequentially add a nitrogen initiator, an oxidation initiator, a reduction initiator, a chain transfer agent and a complexing agent for polymerization reaction.

7. The method according to claim 6, characterized in that, The method further includes: (3) Dry and crush the polymer obtained from the polymerization reaction.

8. The method according to claim 6, characterized in that, The carboxylic acid olefin monomer is itaconic acid, acrylic acid or butene 1,2,3-tricarboxylic acid.

9. The method according to claim 6, wherein The azo initiator is azodiisobutyronitrile, the oxidant is potassium persulfate or hydrogen peroxide, and the reduction initiator is potassium sulfite or sodium bisulfite.

10. Use of the polyacrylamide-acryloyloxyethyl trimethyl ammonium chloride-carboxylic acid olefin according to any one of claims 1-5 in the process of oilfield development.