Thickening agent as well as preparation method and application thereof

Abstract

The invention provides a thickening agent as well as a preparation method and application thereof. The thickening agent is a reaction product of an emulsion type polymer and a functional compound, and is an emulsion type thickening agent with a water-in-oil structure; in the thickening agent, the emulsion type polymer has higher molecular weight, so that the dosage of the thickening agent in a cross-linked acid system is reduced, and the injectivity of cross-linked acid further prepared from the thickening agent is improved; the thickening agent has a higher dissolution rate in acid and good high-temperature-resistant stability, can improve the tackifying and anti-shearing properties of cross-linked acid during subsequent preparation of the cross-linked acid, and meets the acidizing construction requirements at the temperature not higher than 160 DEG C.

Description

Technical Field

[0001] The present invention belongs to the technical field of oilfield chemistry, and particularly relates to a thickening agent, a preparation method thereof, and an application thereof. Background Art

[0002] Crosslinked acid is one of the important working fluids in acid fracturing construction. It refers to a system with an intermolecular three-dimensional network structure formed by a thickening agent through the action of a crosslinking agent in an acid solution. The formation of the crosslinked structure can effectively increase the viscosity of the acid solution system, enhance the temperature resistance, shear resistance, sand-carrying capacity, and rate retardation of the acid solution system, thereby achieving the purposes of reducing formation damage, increasing the acid release distance, realizing deep formation acidification, and increasing oil and gas production. During the on-site construction of crosslinked acid in oilfields, thickening agents mainly based on acrylamide polymers are generally in powder form, and they have the following problems: (1) The dissolution rate is slow, often requiring dissolution several hours or even several days in advance, increasing the construction process and time. On the other hand, the thickening agent degrades after being placed in the acid solution for a long time, and its performance deteriorates; (2) The dosage of the thickening agent in the crosslinked acid system is large. When the temperature is relatively low, the viscosity of the crosslinked acid system is large, and the injection performance is poor; (3) The intermolecular network structure of the crosslinked acid is damaged under shear conditions, and the viscosity drops sharply, affecting the use and promotion of the product. Summary of the Invention

[0003] One aspect of the present invention provides a thickening agent, which is a reaction product of an emulsion polymer and a functional compound;

[0004] The functional compound is a reaction product of a polyamine compound and a halogenated acid salt compound;

[0005] The emulsion polymer contains structural units derived from a first monomer, structural units derived from a second monomer, and structural units derived from a third monomer having a structure as shown in Formula I;

[0006]

[0007] Wherein, R1 is H or CH3, R2 is N or O, R3 is an alkyl group with 2 - 8 carbon atoms, and X is Cl or Br.

[0008] According to a specific embodiment of the present invention, in Formula I, R1 is H or CH3, R2 is N or O, R3 is an alkyl group with 3 - 4 carbon atoms, and X is Cl or Br.

[0009] According to a specific embodiment of the present invention, the mass ratio of the third monomer in the emulsion polymer to the aqueous solution of the functional compound is 1: (0.5 - 15);

[0010] Preferably, the mass ratio of the third monomer in the emulsion polymer to the aqueous solution of the functional compound is 1: (1 - 10);

[0011] Preferably, the mass ratio of the third monomer in the emulsion polymer to the aqueous solution of the functional compound is 1:(1 - 1.75);

[0012] Preferably, the concentration of the aqueous solution of the functional compound is 400 g / L.

[0013] According to a specific embodiment of the present invention, the mass ratio of the first monomer, the second monomer and the third monomer is 1:(0.01 - 0.5):(0.01 - 0.2); and / or

[0014] the mass ratio of the polyamine compound to the halogenated acid salt compound is 1:(0.5 - 5);

[0015] Preferably, the mass ratio of the first monomer, the second monomer and the third monomer is 1:(0.05 - 0.35):(0.01 - 0.1);

[0016] and / or

[0017] the mass ratio of the polyamine compound to the halogenated acid salt compound is 1:(1 - 3);

[0018] Preferably, the mass ratio of the first monomer, the second monomer and the third monomer is 1:(0.1 - 0.2):(0.016 - 0.06);

[0019] and / or

[0020] the mass ratio of the polyamine compound to the halogenated acid salt compound is 1:(1.8 - 2.3).

[0021] According to a specific embodiment of the present invention, the first monomer includes an acrylamide monomer and / or a monomer having the structure shown in Formula II, where n is 1 or 2;

[0022]

[0023] and / or

[0024] the second monomer includes at least one of an acrylic acid monomer, an unsaturated dibasic acid monomer, an acrylamidoalkylpropanesulfonic acid monomer and an alkenyl sulfonate monomer.

[0025] According to a specific embodiment of the present invention, the acrylamide monomer is selected from at least one of acrylamide, methacrylamide, N,N - dimethylacrylamide and N,N - diethylacrylamide; and / or

[0026] the monomer having the structure shown in Formula II is selected from vinylpyrrolidone and / or vinylcaprolactam; and / or

[0027] The acrylic monomer is selected from acrylic acid and / or methacrylic acid; and / or

[0028] The unsaturated dibasic acid monomer is selected from at least one of maleic acid, itaconic acid and fumaric acid; and / or

[0029] The acrylamidoalkylpropanesulfonic acid monomer is 2-acrylamido-2-methylpropanesulfonic acid; and / or

[0030] The alkenyl sulfonate monomer is selected from styrene sulfonate and / or vinyl sulfonate.

[0031] According to a specific embodiment of the present invention, the first monomer includes acrylamide and / or N,N-dimethylacrylamide; and / or

[0032] The second monomer is selected from at least one of acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, sodium styrene sulfonate and itaconic acid.

[0033] According to a specific embodiment of the present invention, the polyamine compound is selected from at least one of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, hexylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine;

[0034] and / or

[0035] The halogenated acid salt compound is selected from at least one of sodium chloroacetate, sodium 2-chloroethylsulfonate, sodium 3-chloro-2-hydroxypropanesulfonate, sodium 3-chloropropanesulfonate, sodium bromoacetate, sodium 2-bromoethylsulfonate, sodium 3-bromo-2-hydroxypropanesulfonate and sodium 3-bromopropanesulfonate;

[0036] Preferably, the polyamine compound is selected from at least one of butylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine; and / or

[0037] The halogenated acid salt compound is selected from at least one of sodium chloroacetate, sodium 3-chloropropanesulfonate and sodium 3-chloro-2-hydroxypropanesulfonate.

[0038] According to a specific embodiment of the present invention, the molecular weight of the emulsion-type polymer is 1 million - 20 million.

[0039] According to a specific embodiment of the present invention, the emulsion-type polymer is prepared according to the following steps:

[0040] 1) Mix the non-ionic surfactant and white oil to obtain an oil phase;

[0041] 2) Mix the first monomer, the second monomer, the third monomer and water, and adjust the pH to obtain an aqueous phase;

[0042] 3) Add the aqueous phase to the oil phase to obtain a first reaction solution;

[0043] 4) React the first reaction solution under the action of an initiator to obtain the emulsion-type polymer.

[0044] According to a specific embodiment of the present invention, in step 1), the mass ratio of the non-ionic surfactant to the white oil is (1.01 - 1.3):(10 - 80); and / or

[0045] In step 2), the mass ratio of the first monomer, the second monomer, the third monomer to water is 1:(0.01 - 0.5):(0.01 - 0.2):(0.6 - 10); and / or

[0046] In step 3), the mass ratio of the oil phase to the aqueous phase is 1:(0.5 - 3); and / or

[0047] In step 4), the mass ratio of the total mass of the first monomer, the second monomer and the third monomer to the mass of the initiator is 1:(0.0005 - 0.017);

[0048] Preferably, the non-ionic surfactant includes sorbitan fatty acid ester surfactants (such as Span-80) and / or alkylphenol polyoxyethylene ether surfactants (such as OP-10); and / or

[0049] The initiator is at least one of persulfate, azobisisobutyramidine hydrochloride and sulfite;

[0050] Preferably, the mass ratio of the sorbitan fatty acid ester surfactant, the alkylphenol polyoxyethylene ether surfactant to the white oil is 1:(0.01 - 0.3):(10 - 80); and / or

[0051] The mass ratio of the total mass of the first monomer, the second monomer, the third monomer, persulfate, azobisisobutyramidine hydrochloride and sodium sulfite is 1:(0.0001 - 0.005):(0.0002 - 0.005):(0.0002 - 0.007);

[0052] Preferably, in step 1), the mass ratio of the non-ionic surfactant to the white oil is (1.05 - 1.35):(15 - 55); and / or

[0053] In step 2), the mass ratio of the first monomer, the second monomer, the third monomer to water is 1:(0.05 - 0.35):(0.01 - 0.1):(0.6 - 5); and / or

[0054] In step 3), the mass ratio of the oil phase to the aqueous phase is 1:(1 - 3); and / or

[0055] In step 4), the mass ratio of the total mass of the first monomer, the second monomer and the third monomer to the mass of the initiator is 1:(0.00085 - 0.013);

[0056] Preferably, the mass ratio of the sorbitan fatty acid ester surfactant, the alkylphenol polyoxyethylene ether surfactant and the white oil is 1:(0.05 - 0.25):(15 - 55); and / or

[0057] The mass ratio of the total mass of the first monomer, the second monomer, the third monomer, persulfate, azobisisobutyramidine hydrochloride and sodium sulfite is 1:(0.0002 - 0.003):(0.0003 - 0.005):(0.00035 - 0.005);

[0058] Preferably, in step 1), the mass ratio of the non-ionic surfactant to the white oil is (1.1 - 1.2):(24 - 36);

[0059] and / or

[0060] In step 2), the mass ratio of the first monomer, the second monomer, the third monomer and water is 1:(0.1 - 0.2):(0.016 - 0.06):(1.6 - 2.3); and / or

[0061] In step 3), the mass ratio of the oil phase to the water phase is 1:(1.3 - 2.1); and / or

[0062] In step 4), the mass ratio of the total mass of the first monomer, the second monomer and the third monomer to the mass of the initiator is 1:(0.0012 - 0.0015);

[0063] Preferably, the mass ratio of the sorbitan fatty acid ester surfactant, the alkylphenol polyoxyethylene ether surfactant and the white oil is 1:(0.1 - 0.2):(24 - 36); and / or

[0064] The mass ratio of the total mass of the first monomer, the second monomer, the third monomer, persulfate, azobisisobutyramidine hydrochloride and sodium sulfite is 1:(0.0002 - 0.0004):(0.0005 - 0.00075):(0.0004 - 0.0006).

[0065] According to a specific embodiment of the present invention, in step 2), the pH is adjusted to 7 - 8.5; and / or

[0066] In step 4), the reaction conditions are to react at 10 - 50 °C for 0.5 - 10 h;

[0067] Preferably, the conditions for the reaction are to react at 10 - 35°C for 1 - 5 h;

[0068] Preferably, in step 2), the pH is adjusted to 7.8; and / or

[0069] In step 4), the conditions for the reaction are to react at 15 - 25°C for 3 - 3.5 h.

[0070] According to a specific embodiment of the present invention, the functional compound is prepared according to the following steps:

[0071] a. Mix the polyamine compound, the halogenated acid salt compound and acetone to obtain a second reaction solution;

[0072] b. React the second reaction solution under alkaline conditions to obtain the functional compound.

[0073] According to a specific embodiment of the present invention, in step b, an alkali is added to create an alkaline environment;

[0074] Preferably, the mass ratio of the polyamine compound, the halogenated acid salt compound, the alkali and acetone is 1:(0.5 - 5):(1 - 8):(3 - 25);

[0075] Preferably, the mass ratio of the polyamine compound, the halogenated acid salt compound, the alkali and acetone is 1:(1 - 3):(1.5 - 5):(5 - 20);

[0076] Preferably, the mass ratio of the polyamine compound, the halogenated acid salt compound, the alkali and acetone is 1:(1.8 - 2.3):(2 - 2.2):(10 - 15).

[0077] According to a specific embodiment of the present invention, the alkali is preferably a carbonate (such as potassium carbonate and / or sodium carbonate).

[0078] According to a specific embodiment of the present invention, in step b, the conditions for the reaction are to react at 30 - 60°C for 6 - 48 h;

[0079] Preferably, the conditions for the reaction are to react at 40 - 60°C for 6 - 24 h;

[0080] Preferably, the conditions for the reaction are to react at 45°C for 20 h.

[0081] According to a specific embodiment of the present invention, the product obtained from the reaction in step b is purified to obtain the functional compound;

[0082] Preferably, the purification is achieved by removing the volatile components from the product through vacuum distillation; and / or

[0083] The temperature of the vacuum distillation is 50°C.

[0084] The second aspect of the present invention provides a method for preparing the thickening agent as described in the first aspect of the present invention, which includes the following steps:

[0085] A. Formulate the functional compound into an aqueous solution of the functional compound;

[0086] B. Add the aqueous solution of the functional compound to the emulsion polymer and react to obtain the thickening agent.

[0087] According to a specific embodiment of the present invention, the mass ratio of the third monomer in the emulsion polymer to the mass of the aqueous solution of the functional compound is 1:(0.5 - 15);

[0088] Preferably, the mass ratio of the third monomer in the emulsion polymer to the mass of the aqueous solution of the functional compound is 1:(1 - 10);

[0089] Preferably, the mass ratio of the third monomer in the emulsion polymer to the mass of the aqueous solution of the functional compound is 1:(1 - 1.75);

[0090] Preferably, the concentration of the aqueous solution of the functional compound is 400 g / L.

[0091] According to a specific embodiment of the present invention, in step B, the reaction conditions are reacting at 40 - 80°C for 0.5 - 6 h;

[0092] Preferably, the reaction conditions are reacting at 40 - 65°C for 1 - 3 h;

[0093] Preferably, the reaction conditions are reacting at 50 - 60°C for 1 - 2 h.

[0094] The application of the thickening agent according to the first aspect of the present invention or the thickening agent prepared by the method according to the second aspect of the present invention in formulating crosslinked acid.

[0095] The beneficial effects of the present invention:

[0096] Aiming at the problems of slow dissolution rate, large dosage, poor injection performance of the powder thickener used in the prior art, and poor shear resistance of the crosslinked acid prepared therefrom, the present invention provides a thickener, a preparation method thereof and an application. The thickener is a reaction product of an emulsion-type polymer and a functional compound, and is an emulsion-type thickener having a water-in-oil structure. By designing the structure of the monomer, the inventors make the emulsion-type polymer have a relatively high molecular weight, which is beneficial to reducing the dosage of the thickener, and further improving the injectability of the crosslinked acid prepared from the thickener; compared with the powder-type thickener, the thickener provided by the present invention is a water-in-oil emulsion-type emulsifier, which has a higher dissolution rate in acid, can realize on-line mixing of the medicament, and simplifies the construction process on site; various groups are introduced into the thickener by adding a functional compound, and it has good high-temperature stability, and can improve the viscosity increase and shear resistance of the crosslinked acid when preparing the crosslinked acid subsequently. At 120 °C, 140 °C, and 160 °C, the apparent viscosities of the crosslinked acids prepared from the thickener provided by the present invention can reach 120 mPa·s, 105 mPa·s, and 87 mPa·s respectively, which can meet the requirements of acidification construction at temperatures not higher than 160 °C. Detailed Embodiments

[0097] The present invention will be further described below in conjunction with embodiments, but the embodiments of the present invention are only exemplary descriptions, and in no case do they constitute a limitation to the present invention.

[0098] Unless otherwise specified, the experimental methods used in the following experimental evaluations are all conventional methods.

[0099] The crosslinked acid agents used in the following experimental evaluations, including crosslinking agent (PCA-1), corrosion inhibitor (PHT-2), corrosion inhibitor synergist (PHTA-2), high-temperature stabilizer (PTR), and iron ion stabilizer (PFAA), are all purchased from Puyang Lutong Petrochemical Co., Ltd. Other materials, reagents, etc., unless otherwise specified, can be obtained from commercial channels.

[0100] The third monomer used in the following embodiments is purchased from Zhangjiagang Renda Chemical Co., Ltd. Other materials, reagents, etc., unless otherwise specified, can be obtained from commercial channels.

[0101] Preparation of Emulsion-Type Polymer

[0102] Example 1

[0103] 1) Dissolve 5 g of sorbitan oleate (Span-80) and 1 g of octylphenol polyoxyethylene ether (OP-10) in 120 g of white oil to obtain an oil phase;

[0104] 2) Dissolve 90 g of the first monomer acrylamide, 13 g of the second monomer 2-acrylamido-2-methylpropanesulfonic acid, 5 g of the second monomer acrylic acid, and 2 g of the third monomer (in formula I, R1 is H, R2 is N, R3 is CH2CH2CH2, and X is Cl) in 150 g of deionized water, and adjust the pH of the solution to 7.8 with NaOH to obtain an aqueous phase;

[0105] 3) Slowly drop 100 g of the aqueous phase into 75 g of the oil phase, and stir rapidly while dropping to facilitate emulsification of the system. After dropping, purge with N2 to remove oxygen for 30 min under stirring to obtain a first reaction solution;

[0106] 4) Control the temperature of the first reaction solution at 15 °C, add 25 mg of ammonium persulfate, 75 mg of 2,2'-azobis(2-methylpropionamidine) dihydrochloride, and 45 mg of sodium sulfite, and carry out a polymerization reaction for 3 h to obtain an emulsion-type polymer with a molecular weight of 1 million - 20 million.

[0107] Comparative Example 1

[0108] Remove the third monomer in step 2) of Example 1, and keep the others the same as in Example 1 to obtain an emulsion-type polymer with a molecular weight of 1 million - 20 million.

[0109] Example 2

[0110] Adjust the dosage of OP-10 in step 1) of Example 1 to 0.5 g and the dosage of white oil to 180 g, and keep the others the same as in Example 1 to prepare an emulsion-type polymer with a molecular weight of 1 million - 20 million.

[0111] Example 3

[0112] Adjust the type and dosage of the first monomer in step 2) of Example 1 to a mixture of 75 g of acrylamide and 15 g of N,N-dimethylacrylamide, and keep the others the same as in Example 1 to prepare an emulsion-type polymer with a molecular weight of 1 million - 20 million.

[0113] Example 4

[0114] Adjust the type and dosage of the second monomer in step 2) of Example 1 to a mixture of 7 g of sodium styrenesulfonate and 3 g of itaconic acid, and keep the others the same as in Example 1 to prepare an emulsion-type polymer with a molecular weight of 1 million - 20 million.

[0115] Example 5

[0116] Adjust the type and dosage of the third monomer in step 2) of Example 1 to 1.5 g of the third monomer (in formula I, R1 is H, R2 is O, R3 is CH2CH2CH2, and X is Br), and keep the others the same as in Example 1 to prepare an emulsion-type polymer with a molecular weight of 1 million - 20 million.

[0117] Example 6

[0118] Adjust the type and dosage of the third monomer in step 2) of Example 1 to 5 g of the third monomer (in formula I, R1 is CH3, R2 is N, R3 is CH2CH2CH2CH2, and X is Cl), and the others are the same as in Example 1, to prepare an emulsion-type polymer with a molecular weight of 1 million - 20 million.

[0119] Example 7

[0120] Adjust the dosage of deionized water in step 2) of Example 1 to 200 g, and the others are the same as in Example 1, to prepare an emulsion-type polymer with a molecular weight of 1 million - 20 million.

[0121] Example 8

[0122] Adjust the dosage of the aqueous phase in step 3) of Example 1 to 135 g and the dosage of the oil phase to 65 g, and the others are the same as in Example 1, to prepare an emulsion-type polymer with a molecular weight of 1 million - 20 million.

[0123] Example 9

[0124] Adjust the dosage of ammonium persulfate in step 3) of Example 1 to 45 mg, the dosage of azodiisobutyramidine hydrochloride to 55 mg, and the dosage of sodium sulfite to 60 mg, and the others are the same as in Example 1, to prepare an emulsion-type polymer with a molecular weight of 1 million - 20 million.

[0125] Example 10

[0126] Adjust the temperature in step 3) of Example 1 to 25 °C and the polymerization reaction time to 3.5 h, and the others are the same as in Example 1, to prepare an emulsion-type polymer with a molecular weight of 1 million - 20 million.

[0127] Preparation of functional compound

[0128] Example 11

[0129] a. Add 20 g of triethylenetetramine, 10 g of sodium chloroacetate, 26 g of 3-chloro-2-hydroxypropanesulfonic acid sodium, and 200 g of acetone to a single-necked flask equipped with magnetic stirring and a spherical condenser, and stir to mix the raw materials evenly to obtain a second reaction solution;

[0130] b. Add 44 g of sodium carbonate to the second reaction solution, stir evenly, control the temperature at 45 °C, react for 20 h under magnetic stirring, filter the product, and distill off the volatile components under reduced pressure at 50 °C to obtain the functional compound.

[0131] Example 12

[0132] In Example 11, step a, replace 20 g of triethylenetetramine with a mixture of 15 g of tetraethylenepentamine and 5 g of butanediamine, and keep other conditions the same as in Example 11 to prepare a functional compound.

[0133] Example 13

[0134] In Example 11, step a, replace 20 g of triethylenetetramine with a mixture of 10 g of diethylenetriamine and 10 g of pentaethylenehexamine, and keep other conditions the same as in Example 11 to prepare a functional compound.

[0135] Example 14

[0136] In Example 11, step a, replace “10 g of sodium chloroacetate, 26 g of 3-chloro-2-hydroxypropanesulfonic acid sodium salt” with a mixture of “15 g of sodium chloroacetate and 30 g of 3-chloro-2-hydroxypropanesulfonic acid sodium salt”, and keep other conditions the same as in Example 11 to prepare a functional compound.

[0137] Example 15

[0138] In Example 11, step a, replace “10 g of sodium chloroacetate, 26 g of 3-chloro-2-hydroxypropanesulfonic acid sodium salt” with a mixture of “8 g of sodium chloroacetate and 32 g of 3-chloropropanesulfonic acid sodium salt”, and keep other conditions the same as in Example 11 to prepare a functional compound.

[0139] Example 16

[0140] In Example 11, step b, replace 44 g of sodium carbonate with 40 g of potassium carbonate, and keep other conditions the same as in Example 11 to prepare a functional compound.

[0141] Example 17

[0142] In Example 11, step a, adjust the addition amount of acetone to 300 g, and keep other conditions the same as in Example 11 to prepare a functional compound.

[0143] Preparation of thickener

[0144] Example 18

[0145] A. Prepare an aqueous solution of the functional compound prepared in Example 11 with a concentration of 400 g / L.

[0146] B. Slowly drop 3.5 g of the aqueous solution of the functional compound into the emulsion polymer prepared in Example 1 (where the amount of the third monomer is 2 g), while quickly stirring during the dropping process. After the dropping is completed, control the temperature at 50 °C and react for 2 h to obtain a thickener, which is an emulsion-type thickener with a water-in-oil structure.

[0147] Example 19

[0148] A. Prepare an aqueous solution of the functional compound prepared in Example 12 with a concentration of 400 g / L;

[0149] B. Slowly add 3.5 g of the aqueous solution of the functional compound dropwise to the emulsion-type polymer prepared in Example 1 (where the amount of the third monomer is 2 g), and stir rapidly while adding. After the addition is complete, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0150] Example 20

[0151] A. Prepare an aqueous solution of the functional compound prepared in Example 13 with a concentration of 400 g / L;

[0152] B. Slowly add 3.5 g of the aqueous solution of the functional compound dropwise to the emulsion-type polymer prepared in Example 1 (where the amount of the third monomer is 2 g), and stir rapidly while adding. After the addition is complete, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0153] Example 21

[0154] A. Prepare an aqueous solution of the functional compound prepared in Example 14 with a concentration of 400 g / L;

[0155] B. Slowly add 3.5 g of the aqueous solution of the functional compound dropwise to the emulsion-type polymer prepared in Example 1 (where the amount of the third monomer is 2 g), and stir rapidly while adding. After the addition is complete, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0156] Example 22

[0157] A. Prepare an aqueous solution of the functional compound prepared in Example 15 with a concentration of 400 g / L;

[0158] B. Slowly add 3.5 g of the aqueous solution of the functional compound dropwise to the emulsion-type polymer prepared in Example 1 (where the amount of the third monomer is 2 g), and stir rapidly while adding. After the addition is complete, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0159] Example 23

[0160] A. Prepare an aqueous solution of the functional compound prepared in Example 16 with a concentration of 400 g / L;

[0161] B. Slowly add 3.5 g of the functional compound aqueous solution dropwise into the emulsion polymer prepared in Example 1 (where the amount of the third monomer is 2 g), and stir rapidly while adding. After the addition is complete, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0162] Example 24

[0163] A. Prepare an aqueous solution of the functional compound with a concentration of 400 g / L from the functional compound prepared in Example 17;

[0164] B. Slowly add 3.5 g of the functional compound aqueous solution dropwise into the emulsion polymer prepared in Example 1 (where the amount of the third monomer is 2 g), and stir rapidly while adding. After the addition is complete, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0165] Example 25

[0166] A. Prepare an aqueous solution of the functional compound with a concentration of 400 g / L from the functional compound prepared in Example 11;

[0167] B. Slowly add 3.5 g of the functional compound aqueous solution dropwise into the emulsion polymer prepared in Example 2 (where the amount of the third monomer is 2 g), and stir rapidly while adding. After the addition is complete, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0168] Example 26

[0169] A. Prepare an aqueous solution of the functional compound with a concentration of 400 g / L from the functional compound prepared in Example 11;

[0170] B. Slowly add 3.5 g of the functional compound aqueous solution dropwise into the emulsion polymer prepared in Example 3 (where the amount of the third monomer is 2 g), and stir rapidly while adding. After the addition is complete, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0171] Example 27

[0172] A. Prepare an aqueous solution of the functional compound with a concentration of 400 g / L from the functional compound prepared in Example 11;

[0173] B. Slowly add 3.5 g of the functional compound aqueous solution dropwise into the emulsion polymer prepared in Example 4 (where the amount of the third monomer is 2 g), and stir rapidly while adding. After the addition is complete, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0174] Example 28

[0175] A. Prepare an aqueous solution of the functional compound prepared in Example 11 with a concentration of 400 g / L;

[0176] B. Slowly drop 3.5 g of the aqueous solution of the functional compound into the emulsion polymer prepared in Example 5 (where the amount of the third monomer is 1.5 g), and stir rapidly while dropping. After dropping, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0177] Example 29

[0178] A. Prepare an aqueous solution of the functional compound prepared in Example 11 with a concentration of 400 g / L;

[0179] B. Slowly drop 5 g of the aqueous solution of the functional compound into the emulsion polymer prepared in Example 6 (where the amount of the third monomer is 2 g), and stir rapidly while dropping. After dropping, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0180] Example 30

[0181] A. Prepare an aqueous solution of the functional compound prepared in Example 11 with a concentration of 400 g / L;

[0182] B. Slowly drop 3.5 g of the aqueous solution of the functional compound into the emulsion polymer prepared in Example 7 (where the amount of the third monomer is 2 g), and stir rapidly while dropping. After dropping, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0183] Example 31

[0184] A. Prepare an aqueous solution of the functional compound prepared in Example 11 with a concentration of 400 g / L;

[0185] B. Slowly drop 3.5 g of the aqueous solution of the functional compound into the emulsion polymer prepared in Example 8 (where the amount of the third monomer is 2 g), and stir rapidly while dropping. After dropping, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0186] Example 32

[0187] A. Prepare an aqueous solution of the functional compound prepared in Example 11 with a concentration of 400 g / L;

[0188] B. Slowly drop 3.5 g of the functional compound aqueous solution into the emulsion-type polymer prepared in Example 9 (where the amount of the third monomer is 2 g), and stir rapidly while dropping. After dropping, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0189] Example 33

[0190] A. Prepare an aqueous solution of the functional compound prepared in Example 11 with a concentration of 400 g / L;

[0191] B. Slowly drop 3.5 g of the functional compound aqueous solution into the emulsion-type polymer prepared in Example 10 (where the amount of the third monomer is 2 g), and stir rapidly while dropping. After dropping, control the temperature at 50 °C and react for 2 h to obtain a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0192] Example 34

[0193] Adjust the addition amount of the functional compound aqueous solution in Step B of Example 18 to 2 g, and keep the others the same as in Example 18 to prepare a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0194] Example 35

[0195] Adjust the reaction temperature in Step B of Example 18 to 60 °C and the reaction time to 1 h, and keep the others the same as in Example 18 to prepare a thickening agent, which is an emulsion-type thickening agent with a water-in-oil structure.

[0196] Comparative Example 2

[0197] Use the emulsion-type polymer prepared in Comparative Example 1 as the thickening agent.

[0198] Comparative Example 3

[0199] The thickening agent PEJ-3 of Puyang Lutong Petrochemical Co., Ltd.

[0200] Experimental evaluation

[0201] Prepare crosslinked acids from the thickening agents prepared in Examples 18 to 35, the thickening agent prepared in Comparative Example 2, and the thickening agent PEJ-3 provided in Comparative Example 3 respectively, and then according to SY / T 5107-2016 "Evaluation Method for Performance of Water-Based Fracturing Fluids", at a high temperature of 120 to 160 °C for 170 s -1 Shear for 90 min and then measure the apparent viscosity to evaluate the high-temperature stability of the thickening agent and the viscosity increasing and shear resistance properties of the prepared crosslinked acid at high temperature. The test temperatures are 120 °C, 140 °C, and 160 °C respectively;

[0202] The crosslinked acid formulation is as follows: 400 g of hydrochloric acid (20%) + 8 g of thickening agent + 12 g of crosslinking agent PCA-1 + 8 g of corrosion inhibitor PHT-2 + 4 g of corrosion inhibitor synergist PHTA-2 + 10 g of high-temperature stabilizer PTR + 6 g of iron ion stabilizer PFAA; among them, the thickening agent is the thickening agent prepared or provided in any one of Examples 18 to 35 and Comparative Examples 2 and 3.

[0203] The measurement results are shown in Table 1.

[0204] Table 1. Apparent viscosity of crosslinked acid

[0205]

[0206]

[0207] It can be seen from the data in the table that the crosslinked acid prepared with the thickening agent prepared in Examples 18 to 35 has good viscosity increasing and shear resistance properties at high temperatures of 120 to 160 °C. At 120 °C, 140 °C, and 160 °C, the apparent viscosities of the crosslinked acid can reach 120 mPa·s, 105 mPa·s, and 87 mPa·s in sequence, indicating that the thickening agent provided by the present invention has good high-temperature stability and can meet the requirements of acidizing construction not higher than 160 °C. The thickening agent provided by Comparative Example 2 does not add functional compounds and only uses the emulsion-type polymer prepared in Comparative Example 1 without adding the third monomer as the thickening agent. The apparent viscosity of the further prepared crosslinked acid at 120 to 160 °C is lower than that of the crosslinked acid prepared with the thickening agent provided in Examples 18 to 35; Comparative Example 3 provides a generally commercially available thickening agent. Although the apparent viscosity of the crosslinked acid prepared with it is slightly higher than that of the crosslinked acid prepared with the thickening agent provided by Comparative Example 1, it is still lower than that of the crosslinked acid prepared with the thickening agent provided in Examples 18 to 35, which also proves the improvement of the thickening agent provided by the present invention in enhancing the high-temperature shear resistance performance of crosslinked acid.

[0208] Although the present invention has been described with reference to specific embodiments, those skilled in the art should understand that various changes can be made without departing from the true spirit and scope of the present invention. In addition, various changes can be made to the main body, spirit, and scope of the present invention to adapt to specific situations, materials, material compositions, and methods. All these changes are included within the scope of the claims of the present invention.

Claims

1. A thickening agent which is a reaction product of an emulsion polymer and a functional compound; The functional compound is a reaction product of a polyamine compound and a halogenated acid salt compound; The emulsion polymer contains structural units derived from a first monomer, structural units derived from a second monomer, and structural units derived from a third monomer having a structure as shown in Formula I; Among them, R1 is H or CH3, R2 is N or O, R3 is an alkyl group with 2 - 8 carbon atoms, and X is Cl or Br.

2. The thickening agent according to claim 1, wherein The mass ratio of the third monomer in the emulsion polymer to the mass of the aqueous solution of the functional compound is 1:(0.5 - 15).

3. The thickener according to claim 1 or 2, characterized in that, The mass ratio of the first monomer, the second monomer, and the third monomer is 1:(0.01 - 0.5):(0.01 - 0.2); and / or The mass ratio of the polyamine compound to the halogenated acid salt compound is 1:(0.5 - 5).

4. The thickening agent according to any one of claims 1 to 3, characterized in that The first monomer includes an acrylamide monomer and / or a monomer having a structure as shown in Formula II, where n is 1 or 2; and / or The second monomer includes at least one of an acrylic acid monomer, an unsaturated dibasic acid monomer, an acrylamidoalkylpropanesulfonic acid monomer, and an alkenyl sulfonate monomer.

5. The thickening agent according to claim 4, characterized in that, The acrylamide monomer is selected from at least one of acrylamide, methacrylamide, N,N - dimethylacrylamide, and N,N - diethylacrylamide; and / or The monomer having a structure as shown in Formula II is selected from vinylpyrrolidone and / or vinylcaprolactam; and / or The acrylic acid monomer is selected from acrylic acid and / or methacrylic acid; and / or The unsaturated dibasic acid monomer is selected from at least one of maleic acid, itaconic acid, and fumaric acid; and / or The acrylamidoalkylpropanesulfonic acid monomer is 2 - acrylamido - 2 - methylpropanesulfonic acid; and / or The alkenyl sulfonate monomer is selected from styrene sulfonate and / or vinyl sulfonate.

6. The thickening agent according to any one of claims 1 to 5, characterized in that, The polyamine compound is selected from at least one of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, hexylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine; and / or The halogenated acid salt compound is selected from at least one of sodium chloroacetate, sodium 2 - chloroethylsulfonate, sodium 3 - chloro - 2 - hydroxypropanesulfonate, sodium 3 - chloropropanesulfonate, sodium bromoacetate, sodium 2 - bromoethylsulfonate, sodium 3 - bromo - 2 - hydroxypropanesulfonate, and sodium 3 - bromopropanesulfonate.

7. The thickening agent according to any one of claims 1 to 6, characterized in that, The molecular weight of the emulsion polymer is 1 million - 20 million.

8. A method for preparing the thickening agent according to any one of claims 1 to 7, which comprises the following steps: A. Formulate the functional compound into an aqueous solution of the functional compound; B. Add the aqueous solution of the functional compound to the emulsion polymer and react to obtain the thickening agent.

9. The method according to claim 8, wherein The mass ratio of the third monomer in the emulsion polymer to the mass of the aqueous solution of the functional compound is 1:(0.5 - 15).

10. The method according to claim 8 or 9, characterized in that In step B, the reaction conditions are to react at 40 - 80 °C for 0.5 - 6 h.

11. Use of the thickening agent according to any one of claims 1 to 7 or the thickening agent prepared by the method according to any one of claims 8 to 10 in formulating crosslinked acid.

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