CN115490800B

CN115490800B - Filtrate reducer and preparation method and application thereof

Info

Publication number: CN115490800B
Application number: CN202211194082.9A
Authority: CN
Inventors: 荣敏杰; 孙建波; 许永升; 于庆华; 荣帅帅
Original assignee: Shandong Nuoer Biological Technology Co Ltd
Current assignee: Shandong Nuoer Biological Technology Co Ltd
Priority date: 2022-09-28
Filing date: 2022-09-28
Publication date: 2024-02-13
Anticipated expiration: 2042-09-28
Also published as: CN115490800A

Abstract

The invention relates to a filtrate reducer, a preparation method and application thereof, and belongs to the technical field of oil and gas field development. The method comprises the following steps: uniformly mixing acrylamide, acryloylmorpholine, an enhanced monomer, a hydrolysis-resistant monomer, a cutting-lifting monomer, a structure regulator and water to obtain a mixed solution, introducing nitrogen into the mixed solution to remove oxygen, and then adding an initiator to initiate polymerization reaction to obtain a polymer gel block; granulating the polymer gel blocks to obtain polymer gel particles; uniformly mixing a modifier, potassium hydroxide, an activator and water to obtain a modified liquid, and then spraying polymeric colloidal particles with the modified liquid to perform a modification reaction to obtain the filtrate reducer. The filtrate reducer prepared by the invention can maintain the viscosity and the filtrate reducing performance in 30wt% calcium chloride aqueous solution, has stable rheological property, and can resist the temperature of more than 230 ℃.

Description

Filtrate reducer and preparation method and application thereof

Technical Field

The invention relates to the technical field of oil and gas field development, in particular to a filtrate reducer, a preparation method and application thereof.

Background

Shale gas is widely distributed in the global scope, and has great development potential. In recent years, research on shale gas development has been paid attention to as a clean energy source and a potential energy source for replacing natural gas. The exploration and development of domestic shale gas are still in an exploration stage, but the development in recent years is quite rapid, and the middle petrochemical industry and the middle petroleum industry at present respectively develop large-scale shale gas development work in areas such as Fuling and Weiyuan, and have obvious achievements.

Because shale gas reservoir develops cracks, has strong water sensitivity, easily generates problems of well collapse, well leakage and the like when drilling in a long horizontal section, and can also cause underground complex conditions if the lubricating and rock carrying capacities are insufficient. In view of the above, oil-based drilling fluids are commonly used at present to solve the problems, and the oil-based drilling fluids have the characteristics of strong inhibition, strong pollution resistance and good lubricating performance, and can meet the drilling requirements of shale gas horizontal wells. However, oil-based drilling fluids also have some disadvantages, such as environmental pollution problems, cost problems, etc., and especially now, the state is increasingly paying attention to environmental protection problems, and development of water-based drilling fluids with excellent performance for shale gas horizontal well drilling is a trend. Conventional dilute water-based drilling fluid cannot drill a shale layer due to the problems of relatively poor inhibition performance, unstable well wall and the like; the brine-based drilling fluid has strong pollution resistance, can effectively inhibit hydration of clay minerals in a reservoir, furthest reduces invasion of solid phases into the reservoir and is gradually concerned, but the high mineralization degree in the brine-based drilling fluid has very high requirements on additives therein, requires extremely high salt resistance of the additives, and has good rheological properties under high-temperature and high-minerality conditions.

However, few reports on a brine-based drilling fluid filtrate reducer are provided at present, and Chinese patent application CN202111418035.3 discloses a brine-based drilling fluid and a preparation method thereof, wherein the brine-based drilling fluid adopts a filtrate reducer of JHFR-HP, but has good rheological property and filtrate reducing performance only at 200 ℃, and the temperature resistance of the brine-based drilling fluid needs to be further improved; and the patent application directly adopts a commercially available filtrate reducer JHFR-HP, and the synthesis process of the filtrate reducer JHFR-HP is not clear.

Disclosure of Invention

The invention aims at meeting the requirements of a brine-based drilling fluid on a filtrate reducer, and provides the filtrate reducer for the brine-based drilling fluid, and a preparation method and application thereof. The filtrate reducer prepared by the invention can maintain the viscosity and the filtrate reducing performance in 30wt% calcium chloride aqueous solution, has stable rheological property, and can resist the temperature of more than 230 ℃.

The invention provides a preparation method of a filtrate reducer in a first aspect, which comprises the following steps:

(1) Uniformly mixing acrylamide, acryloylmorpholine, an enhanced monomer, a hydrolysis-resistant monomer, a cutting-lifting monomer, a structure regulator and water to obtain a mixed solution, introducing nitrogen into the mixed solution to remove oxygen, and then adding an initiator to initiate polymerization reaction to obtain a polymer gel block;

(2) Granulating the polymer gel block to obtain polymer gel particles;

(3) Uniformly mixing a modifier, potassium hydroxide, an activator and water to obtain a modified liquid, and then spraying the polymerized colloidal particles with the modified liquid to perform a modification reaction to obtain the filtrate reducer.

Preferably, the preparation method further comprises the steps of sequentially crushing, drying, grinding and sieving the filtrate reducer.

Preferably, the structure modifier is prepared by the following steps:

(a) Adding concentrated sulfuric acid into 2-hydroxy propionic acid dropwise and reacting to obtain an intermediate A;

(b) Uniformly mixing the intermediate A, butanol amine and N, N-dimethylformamide and reacting to obtain an intermediate B;

(c) And uniformly mixing the intermediate B, 1, 2-dichloroethane and diethylamine, and then dropwise adding cinnamoyl chloride for reaction to obtain the structure regulator.

Preferably, in step (a), the mass fraction of the concentrated sulfuric acid is not less than 98%, the amount of the concentrated sulfuric acid is 4 to 6% by mass of the 2-hydroxypropionic acid, more preferably 5%, and/or the temperature of the reaction is 55 to 65 ℃, the time of the reaction is 2.5 to 4 hours, preferably 3 hours; and/or in step (b), the mass ratio of the intermediate a to the butanolamine is 8: (4-6) preferably 8:5, said N, N-dimethylformamide being used in an amount of 8-15%, preferably 10%, of the sum of the masses of said intermediate A and of butolamine, and/or said reaction being carried out at a temperature of 40-50℃for a time of 2.5-4 hours, preferably 3 hours.

Preferably, in step (c): the mass ratio of the intermediate B to the cinnamoyl chloride is 8: (4-6) is preferably 8:5; the 1, 2-dichloroethane is used in an amount of from 10 to 20% by mass, preferably 15% by mass, of the sum of the masses of the intermediate B and of cinnamoyl chloride; the dosage of the diethylamine is 1-5% of the sum of the mass of the intermediate B and the mass of the cinnamoyl chloride, preferably 3%; dropwise adding cinnamoyl chloride at the temperature of-5 to 5 ℃; and/or after the cinnamoyl chloride is added dropwise, controlling the reaction temperature to be 30-35 ℃ and reacting for 1.5-3 hours, preferably 2 hours, at 30-35 ℃.

Preferably, the reinforcing monomer is 3- (3-methoxy-4-methylphenyl) acrylic acid and/or 3- (4-methoxybenzoyl) acrylic acid; the hydrolysis-resistant monomer is vinyl trimethylsilane and/or 4-acetoxyl styrene; the stripping and cutting monomer is one or more of 2-phenoxyethyl acrylate, furfuryl alcohol methacrylate and 2-phenyl ethyl acrylate; the initiator comprises azo initiator and redox initiator, wherein the azo initiator is azodiisobutyronitrile and/or azodiisobutylamidine hydrochloride, the oxidant in the redox initiator is one or more of hydrogen peroxide, di-tert-butyl peroxide and tert-butyl hydroperoxide, the reducing agent in the redox initiator is sodium bisulphite, and preferably, the mass ratio of the azo initiator to the redox initiator is (1-3): (0.5-3); the modifier is hydroxylamine sulfate; and/or the activator is fatty alcohol polyoxyethylene ether.

Preferably, in the step (1), each raw material for preparing the polymer gel block comprises, by weight, 10-30 parts of acrylamide, 35-60 parts of acryloylmorpholine, 55-85 parts of a reinforcing monomer, 40-80 parts of a hydrolysis-resistant monomer, 25-45 parts of a stripping monomer, 1-5 parts of a structure regulator, 650-800 parts of water and 1.5-6 parts of an initiator; the particle size of the polymerized colloidal particles obtained in the step (2) is smaller than 0.5mm; and/or in the step (3), the mass ratio of the polymeric colloidal particles, the modifier, the potassium hydroxide, the activator and the water is 1000: (20-25): (5-10): (10-20): (40-60), preferably 1000:23:8:15:50.

Preferably, in the step (1), before introducing nitrogen to the mixed solution to remove oxygen, the pH of the mixed solution is adjusted to 6.5-7.0; in the step (1), the time for introducing nitrogen and removing oxygen is 40-80 min; in the step (1), an initiator is added at the temperature of 5-7 ℃ to initiate polymerization, and the time of the polymerization is 2-4 hours, preferably 3 hours; and/or in the step (3), the temperature of the modification reaction is 70-80 ℃, and the time of the modification reaction is 3-4 h.

The present invention provides in a second aspect a fluid loss additive obtainable by the process of the invention as described in the first aspect.

The present invention provides in a third aspect the use of a fluid loss additive made by the method of the invention described in the first aspect in a brine-based drilling fluid.

Compared with the prior art, the invention has at least the following beneficial effects:

(1) When the filter reducing agent is prepared, the monomer with a special structure is added, so that the sensitivity of a polymer molecular chain to salt is greatly reduced, the filter reducing agent has extremely high temperature resistance and salt resistance, and the filter reducing agent can have good rheological property and filter reducing property in 30 weight percent calcium chloride aqueous solution; according to the invention, the linear structure of the polymer is changed by adding the preferable structure regulator, so that the temperature resistance of the polymer is greatly improved; the rheological property of the drilling fluid is greatly improved by introducing the modification of the polymer by the stripping monomer, especially the dynamic shear force, the static shear force and the apparent viscosity of the brine-based drilling fluid are improved, and the rheological stability of the drilling fluid is higher under the conditions of high temperature and high salt.

(2) The filtrate reducer prepared by the invention is modified, when a shale reservoir is drilled, adsorption groups in the filtrate reducer are adsorbed on the surfaces of clay particles, meanwhile, the filtrate reducer can form a hydration film when being adsorbed on the surfaces of the clay, repulsive force among the clay particles is improved, dispersion of the clay particles can be maintained, and coagulation among the clay particles is prevented.

(3) The filtrate reducer prepared by the invention can maintain the viscosity and the filtrate reducing performance in 30wt% calcium chloride aqueous solution, has stable rheological property, has a dynamic shear force of more than 20Pa, a phi 6/phi 3 of more than 12/9 and a filtrate loss of less than 5mL in brine-based drilling fluid.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below in connection with the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

(1) Uniformly mixing acrylamide, acryloylmorpholine (alias: 4-acryloylmorpholine), a reinforcing monomer, a hydrolysis-resistant monomer, a cutting-lifting monomer, a structure regulator and water to obtain a mixed solution, introducing nitrogen into the mixed solution to remove oxygen, and then adding an initiator to initiate polymerization reaction to obtain a polymer gel block;

(2) Granulating the polymer gel block to obtain polymer gel particles; the present invention does not specifically limit the operation of carrying out the granulation, and the granulation is carried out by a conventional operation, and preferably, the granulation is carried out in a granulator; preferably, the polymer colloidal particles with the particle size smaller than 0.5mm are obtained through granulation;

(3) Uniformly mixing a modifier, potassium hydroxide, an activator and water to obtain a modified liquid, and then spraying the polymerized colloidal particles with the modified liquid to perform a modification reaction to obtain a filtrate reducer; in the invention, specifically, for example, a modifier, potassium hydroxide, an activator and water are fully dissolved to obtain a uniformly mixed modified liquid, the modified liquid is uniformly sprayed on the surface of the polymer colloidal particle and fully mixed, and the polymer colloidal particle sprayed with the modified liquid is subjected to modification reaction for 3-4 hours at 70-80 ℃ to obtain the filtrate reducer; the water in the step (1) and the step (3) of the invention can be deionized water, for example; in the invention, the activator is added to promote the modification of the polymer by the modifier and increase the permeability of the modifier.

When the filtrate reducer is prepared, monomers with special structures (comprising acryloylmorpholine, an enhanced monomer, a hydrolysis-resistant monomer, a structure regulator and the like) are added, so that the sensitivity of a polymer molecular chain to salt is greatly reduced, the filtrate reducer has extremely high temperature resistance and salt resistance, and the filtrate reducer can have good rheological property and filtrate reduction property in 30wt% calcium chloride aqueous solution; according to the invention, the modification of the polymer by introducing the stripping monomer greatly improves the rheological property of the drilling fluid, especially improves the dynamic shear force, static shear force and apparent viscosity of the brine-based drilling fluid, and has stronger rheological stability under the conditions of high temperature and high salt; the filtrate reducer prepared by the invention is modified, when a shale reservoir is drilled, adsorption groups in the filtrate reducer are adsorbed on the surfaces of clay particles, meanwhile, the filtrate reducer can form a hydration film when being adsorbed on the surfaces of the clay, repulsive force among the clay particles is improved, dispersion of the clay particles can be maintained, and coagulation among the clay particles is prevented.

According to some preferred embodiments, the preparation method further comprises the steps of sequentially crushing, drying, grinding and sieving the filtrate reducer; the conditions of crushing, drying, grinding and sieving are not particularly limited, and conventional operation is adopted.

According to some preferred embodiments, the structure-modifying agent is prepared by the steps of:

(a) Adding concentrated sulfuric acid into 2-hydroxy propionic acid dropwise and reacting to obtain an intermediate A; the speed of dropwise adding the concentrated sulfuric acid is not particularly required, the concentrated sulfuric acid is slowly dropwise added, and preferably, the time of dropwise adding the concentrated sulfuric acid is 0.5-1.5 h, more preferably 1h;

(b) Uniformly mixing an intermediate A, butanol amine (alias: 2-amino-1-butanol) and N, N-dimethylformamide, and reacting to obtain an intermediate B;

(c) Uniformly mixing an intermediate B, 1, 2-dichloroethane and diethylamine (alias: aminodiethyl), and then dropwise adding cinnamoyl chloride for reaction to obtain a structure regulator; in the invention, in the step (c), 1, 2-dichloroethane is used as a solvent, and diethylamine is added, so that diethylamine hydrochloride can be produced in the reaction process, and chloride ions in the reaction can be combined, thereby facilitating the reaction.

The structure regulator prepared in the steps (a) to (c) is preferably added, the linear structure of the polymer can be changed, and compared with the conventional structure regulator, the temperature resistance of the polymer is greatly improved, so that the filtrate reducer can effectively maintain the viscosity and the filtrate reduction performance at high temperature and high mineralization degree, and has high dynamic shear force, high phi 6/phi 3 and low filtrate loss in brine-based drilling fluid.

According to some preferred embodiments, in step (a), the mass fraction of the concentrated sulfuric acid is not less than 98%, the amount of the concentrated sulfuric acid is 4-6% (e.g. 4%, 4.5%, 5%, 5.5% or 6%) of the mass of the 2-hydroxypropionic acid, more preferably 5%, and/or the temperature of the reaction is 55-65 ℃ (e.g. 55 ℃, 60 ℃ or 65 ℃), the time of the reaction is 2.5-4 hours (e.g. 2.5, 3, 3.5 or 4 hours), preferably 3 hours; and/or in step (b), the mass ratio of the intermediate a to the butanolamine is 8: (4-6) (e.g., 8:4, 8:4.5, 8:5, 8:5.5, or 8:6) is preferably 8:5, the amount of said N, N-dimethylformamide is 8-15% (e.g., 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%) of the sum of the masses of said intermediate a and butolamine is preferably 10%, and/or the temperature of said reaction is 40-50 ℃ (e.g., 40 ℃, 45 ℃, or 50 ℃) and the time of said reaction is 2.5-4 hours (e.g., 2.5, 3, 3.5, or 4 hours) is preferably 3 hours.

According to some preferred embodiments, in step (c): the mass ratio of the intermediate B to the cinnamoyl chloride is 8: (4-6) (e.g., 8:4, 8:4.5, 8:5, 8:5.5, or 8:6) is preferably 8:5; the 1, 2-dichloroethane is used in an amount of 10 to 20% (e.g. 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%) of the sum of the masses of the intermediate B and cinnamoyl chloride, preferably 15%; the amount of diethylamine is 1 to 5% (e.g. 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%) of the sum of the masses of intermediate B and cinnamoyl chloride, preferably 3%; the method is characterized in that the cinnamoyl chloride is dropwise added at-5 ℃ (such as-5 ℃, -4 ℃, -3 ℃, -2 ℃, -1 ℃, 0 ℃, 1 ℃,2 ℃, 3 ℃, 4 ℃ or 5 ℃), the speed of dropwise adding the cinnamoyl chloride is not particularly limited, and the cinnamoyl chloride is slowly dropwise added, preferably, the time of dropwise adding the cinnamoyl chloride is 1.5-2.5 h; and/or after the cinnamoyl chloride is added dropwise, the reaction temperature is controlled to be 30-35 ℃ (e.g. 30 ℃ or 35 ℃), and the reaction is carried out at 30-35 ℃ for 1.5-3 hours (e.g. 1.5, 2, 2.5 or 3 hours), preferably 2 hours.

According to some specific embodiments, step (a) is: adding 2-hydroxy propionic acid into a three-neck flask with a stirrer, a condenser pipe and a thermometer, starting a water bath to control the temperature to 55-65 ℃, dropwise adding concentrated sulfuric acid accounting for 5% of the total mass of the 2-hydroxy propionic acid, continuously reacting for 3 hours, cooling to room temperature after the reaction is finished, and performing rotary evaporation by a rotary evaporator to evaporate a solvent to obtain a yellowish transparent liquid, namely an intermediate A; in the present invention, the concentrated sulfuric acid is preferably an aqueous sulfuric acid solution having a mass fraction of not less than 98%.

According to some specific embodiments, step (b) is: adding an intermediate A, butanol amine and N, N-dimethylformamide into a three-neck flask with a stirrer, a condenser pipe and a thermometer, starting a water bath to control the temperature to 40-50 ℃ and performing constant-temperature reaction for 3 hours; after the reaction is finished, yellow transparent liquid is obtained, rotary evaporation is carried out by a rotary evaporator, and solvent is evaporated to obtain yellow liquid, namely an intermediate B; wherein the mass ratio of the intermediate A to the butanol amine is preferably 8:5, and the dosage of the N, N-dimethylformamide is 10% of the sum of the mass of the intermediate A and the butanol amine.

According to some specific embodiments, step (c) is: adding an intermediate B,1, 2-dichloroethane and diethylamine into a three-neck flask with a stirrer, a condenser and a thermometer, uniformly mixing, starting to control the temperature, slowly dropwise adding cinnamoyl chloride at the temperature of-5-5 ℃, controlling the temperature to 30-35 ℃ after the dropwise adding is completed for about 2 hours, continuing to react for 2 hours to complete the reaction, filtering, and performing rotary evaporation by using a rotary evaporator to evaporate the solvent to obtain brown liquid, namely the structure regulator; wherein the mass ratio of the intermediate B to the cinnamoyl chloride is preferably 8:5, the amount of the 1, 2-dichloroethane is 15% of the sum of the mass of the intermediate B and the mass of the cinnamoyl chloride, and the amount of the diethylamine is 3% of the sum of the mass of the intermediate B and the mass of the cinnamoyl chloride.

According to some preferred embodiments, the reinforcing monomer is 3- (3-methoxy-4-methylphenyl) acrylic acid (CAS number: 209287-19-4) and/or 3- (4-methoxybenzoyl) acrylic acid (CAS number: 5711-41-1); the invention preferably introduces special reinforcing monomers of 3- (3-methoxy-4-methylphenyl) acrylic acid and/or 3- (4-methoxybenzoyl) acrylic acid into the molecular chain, so that the sensitivity of the polymer molecular chain to salt is greatly reduced, the filtrate reducer has extremely high temperature resistance and salt resistance, and the filtrate reducer can have better rheological property and filtrate reduction property in 30 weight percent calcium chloride aqueous solution; the hydrolysis-resistant monomer is vinyl trimethylsilane and/or 4-acetoxyl styrene; the stripping and cutting monomer is one or more of 2-phenoxyethyl acrylate, furfuryl alcohol methacrylate and 2-phenyl ethyl acrylate; the initiator comprises azo initiator and redox initiator, wherein the azo initiator is azodiisobutyronitrile and/or azodiisobutylamidine hydrochloride, the oxidant in the redox initiator is one or more of hydrogen peroxide, di-tert-butyl peroxide and tert-butyl hydroperoxide, the reducing agent in the redox initiator is sodium bisulphite, and preferably, the mass ratio of the azo initiator to the redox initiator is (1-3): (0.5-3), wherein the mass ratio of the oxidant to the reducing agent is 1: (0.8-1.2); the modifier is hydroxylamine sulfate; and/or the activator is fatty alcohol polyoxyethylene ether; the fatty alcohol-polyoxyethylene ether is not particularly limited, and products which can be directly purchased in the market can be adopted, and specifically, the fatty alcohol-polyoxyethylene ether AEO-7 and the fatty alcohol-polyoxyethylene ether AEO-9 can be adopted.

According to some preferred embodiments, in step (1), each raw material for preparing the polymer rubber block comprises 10-30 parts (such as 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 parts) of acrylamide, 35-60 parts (such as 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 5, 3, 54, 55, 56, 57, 58, 59 or 60 parts) of acryloamide, 55-85 parts (such as 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83 84 or 85 parts), 40-80 parts (e.g., 40, 42, 45, 48, 50, 52, 55, 58, 60, 62, 65, 68, 70, 72, 75, 78, or 80 parts) of hydrolysis-resistant monomer, 25-45 parts (e.g., 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, or 45 parts) of cleavage-resistant monomer, 1-5 parts (e.g., 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 parts) of structure-modifying agent, 650-800 parts (e.g., 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 790, or 800 parts) of water, and 1.5-6 parts (e.g., 1.5, 2, 2.5, 3, 3.5, 4.5, 5, or 6 parts) of initiator; in the invention, the raw materials for preparing the polymer gel block preferably comprise, by weight, 10-30 parts of acrylamide, 35-60 parts of acryloylmorpholine, 55-85 parts of a reinforcing monomer, 40-80 parts of a hydrolysis-resistant monomer, 25-45 parts of a cutting-off monomer, 1-5 parts of a structure regulator, 650-800 parts of water and 1.5-6 parts of an initiator, so that the temperature resistance and salt resistance of the filtrate reducer are improved, the filtrate reducer can have better rheological property and filtrate reducer performance in 30wt% calcium chloride aqueous solution, especially the dynamic shear force, static shear force and apparent viscosity of brine-based drilling fluid are improved, and the rheological stability of the brine-based drilling fluid is stronger and the filtrate reducer is better under the conditions of high temperature and high salt.

In the present invention, "parts" refers to "parts by weight", and in the specific examples and comparative examples, the unit of parts by weight may be unified as, for example, the unit of weight such as "g" or "kg".

According to some preferred embodiments, the particle size of the polymeric colloidal particles obtained in step (2) is less than 0.5mm.

According to some preferred embodiments, in step (3), the mass ratio of polymeric colloidal particles, modifier, potassium hydroxide, activator to water is 1000: (20-25): (5-10):

(10-20): (40-60), preferably 1000:23:8:15:50, so that the modification effect of the polymer colloidal particles is better ensured, the proper amount of the activator can better promote the modification of the polymer by the modifier and increase the permeability of the modifier, and the potassium hydroxide can provide an alkaline modification environment and also help the modification of the polymer by the modifier, and if the amount of the alkali is excessive, the polymer is hydrolyzed in the modification process.

According to some preferred embodiments, in step (1), the pH of the mixed liquor is adjusted to 6.5-7.0 prior to introducing nitrogen into the mixed liquor to remove oxygen; in the present invention, for example, the pH of the mixed solution may be adjusted to 6.5 to 7.0 by using ammonia water, the amount of the ammonia water is not particularly limited, and the pH of the mixed solution may be adjusted to a target range, and in the present invention, the volume concentration (i.e., volume percentage concentration) of the ammonia water to be used is preferably, for example, 25%; in the step (1), the time for introducing nitrogen and removing oxygen is 40-80 min (for example, 40, 45, 50, 55, 60, 65, 70, 75 or 80 min); in the step (1), an initiator is added at the temperature of 5-7 ℃ to initiate polymerization, and the time of the polymerization is 2-4 hours, preferably 3 hours; in the step (1), the initiation temperature of the polymerization reaction is 5-7 ℃; in the invention, after the polymerization reaction is initiated at the temperature of 5-7 ℃, the temperature of a reaction system naturally rises, the reaction system carries out the natural temperature rising polymerization reaction, and the reaction time is 2-4 h; and/or in step (3), the temperature of the modification reaction is 70 to 80 ℃ (e.g. 70 ℃, 75 ℃ or 80 ℃), and the time of the modification reaction is 3 to 4 hours (e.g. 3, 3.5 or 4 hours).

In the present invention, the occurrence of "and/or" between a plurality of technical features means that the technical features are connected in "and/or" relation, and that any one of the technical features may be represented, or any combination of two or more of the technical features may be represented.

According to some specific embodiments, the preparation of the fluid loss additive according to the present invention comprises the following steps:

(1) polymer gel block preparation

The preparation of the polymer gel block of the filtrate reducer for the brine-based drilling fluid comprises the following raw materials in parts by weight: 10-30 parts of acrylamide, 35-60 parts of acryloylmorpholine, 55-85 parts of reinforcing monomer, 40-80 parts of hydrolysis-resistant monomer, 25-45 parts of stripping monomer, 1-5 parts of structure regulator, 0-45 parts of ammonia water, 650-800 parts of water, 1-3 parts of high-temperature initiator (azo initiator) and 0.5-3 parts of low-temperature initiator (redox initiator). The preparation method comprises the following steps: and (3) fully and uniformly mixing acrylamide, acryloylmorpholine, a reinforcing monomer, a hydrolysis-resistant monomer, a cutting monomer, a structure regulator and water, regulating the pH value to 6.5-7.0 by ammonia water, transferring into a reaction kettle, introducing nitrogen to remove oxygen for 60min, adding a high-temperature initiator and a low-temperature initiator at 5-7 ℃ to initiate polymerization, and reacting for 3h to obtain the polymer gel block.

(2) Modification of polymeric glue blocks

The polymer gel block of the filtrate reducer for the brine-based drilling fluid is modified by adopting the following raw materials: the water-based adhesive comprises polymeric colloidal particles, potassium hydroxide, a modifier, water and an activator, wherein the mass ratio of the polymeric colloidal particles, the modifier, the potassium hydroxide, the activator to the water is 1000:23:8:15:50. The preparation method comprises the following steps: granulating the polymer gel block into polymer gel particles with the granularity (particle size) smaller than 0.5mm in a granulator, fully dissolving a modifier, potassium hydroxide, water and an activator to obtain uniformly mixed modified liquid, uniformly spraying the modified liquid on the surface of the polymer gel particles, fully mixing, pressing the polymer gel particles into a closed tank with a certain heat preservation temperature for modification reaction, and sequentially crushing, drying, grinding and screening after modification is finished to obtain the filtrate reducer for brine-based drilling fluid.

The invention will be further illustrated by way of example, but the scope of the invention is not limited to these examples.

The following examples 1 to 5 and comparative examples 1 to 8 were prepared using the structure-modifying agents:

(1) 500 parts of 2-hydroxy propionic acid is added into a three-neck flask with a stirrer, a condenser pipe and a thermometer, the temperature of a water bath is started to be 60 ℃, 25 parts of 98% by mass of concentrated sulfuric acid is dropwise added in 1h, the reaction is continued for 3h (including 1h of dropwise adding of the concentrated sulfuric acid and 2h of continuous reaction after the dropwise adding is completed), the reaction is cooled to room temperature after the completion, rotary evaporation is carried out by a rotary evaporator, and the solvent is distilled off, so that an intermediate A is obtained.

(2) 240 parts of intermediate A, 150 parts of butanol amine and 39 parts of N, N-dimethylformamide are added into a three-neck flask with a stirrer, a condenser pipe and a thermometer, and are uniformly mixed, a water bath is started to control the temperature to 45 ℃ and the constant temperature reaction is carried out for 3 hours; after the reaction, rotary evaporation was performed by using a rotary evaporator, and the solvent was distilled off to obtain intermediate B.

(3) 320 parts of intermediate B,78 parts of 1, 2-dichloroethane and 15.6 parts of diethylamine are added into a three-neck flask with a stirrer, a condenser and a thermometer, the temperature is controlled at 0 ℃ by opening, 200 parts of cinnamoyl chloride is dropwise added within 2 hours, the temperature is controlled at 30 ℃ after the dropwise addition is finished, the reaction is continued for 2 hours, the filtration is carried out after the reaction is finished, the rotary evaporation is carried out by a rotary evaporator, and the solvent is distilled out, so that the structural regulator is obtained.

Example 1

(1) Polymer gel block preparation

The raw materials for preparing the polymer gel block comprise: 10 parts of acrylamide, 35 parts of acryloylmorpholine, 55 parts of 3- (3-methoxy-4-methylphenyl) acrylic acid, 40 parts of vinyltrimethylsilane, 25 parts of 2-phenoxyethyl acrylate, 3 parts of a structure regulator, 800 parts of water, 1 part of azodiisobutyronitrile, 0.5 part of hydrogen peroxide and 0.5 part of sodium bisulfite. The preparation method comprises the following steps: fully and uniformly mixing acrylamide, acryloylmorpholine, 3- (3-methoxy-4-methylphenyl) acrylic acid, vinyltrimethylsilane, 2-phenoxyethyl acrylate, a structure regulator and water to obtain a mixed solution, regulating the pH value of the mixed solution to 6.6 by using ammonia water with the volume concentration of 25%, transferring the mixed solution into a reaction kettle, introducing nitrogen to deoxidize for 60min, adding azodiisobutyronitrile, hydrogen peroxide and sodium bisulphite to initiate polymerization reaction at the temperature of 5 ℃, and reacting for 3h to obtain the polymer gel.

(2) Polymer slab modification

Modification of the polymer gel block: granulating the polymer gel block into polymer gel particles with the average granularity of 0.4mm in a granulator, uniformly mixing hydroxylamine sulfate, fatty alcohol polyoxyethylene ether AEO-9 and potassium hydroxide in water to obtain modified liquid, uniformly spraying the modified liquid on the surfaces of the polymer gel particles, fully mixing, carrying out modification reaction on the polymer gel particles sprayed with the modified liquid at 70 ℃ for 3 hours, and after modification, sequentially carrying out crushing, drying, grinding and screening to obtain the filtrate reducer; wherein the mass ratio of the polymerized colloidal particles, the hydroxylamine sulfate, the potassium hydroxide, the fatty alcohol polyoxyethylene ether AEO-9 and the water is 1000:23:8:15:50.

Example 2

(1) Polymer gel block preparation

The raw materials for preparing the polymer gel block comprise: 20 parts of acrylamide, 50 parts of acryloylmorpholine, 70 parts of 3- (4-methoxybenzoyl) acrylic acid, 60 parts of 4-acetoxystyrene, 35 parts of furfuryl methacrylate, 2 parts of a structure regulator, 725 parts of water, 2 parts of azo diisobutyl amidine hydrochloride, 1 part of di-tert-butyl peroxide and 1 part of sodium bisulphite. The preparation method comprises the following steps: fully and uniformly mixing acrylamide, acryloylmorpholine, 3- (4-methoxybenzoyl) acrylic acid, 4-acetoxystyrene, furfuryl methacrylate, a structure regulator and water to obtain a mixed solution, regulating the pH value of the mixed solution to 6.8 by using ammonia water with the volume concentration of 25%, transferring the mixed solution into a reaction kettle, introducing nitrogen to deoxidize for 60min, adding azo diisobutylamidine hydrochloride, di-tert-butyl peroxide and sodium bisulphite to initiate polymerization reaction at the temperature of 6 ℃, and reacting for 3h to obtain the polymer gel.

(2) Polymer slab modification

Modification of the polymer gel block: granulating the polymer gel block into polymer gel particles with the average granularity of 0.4mm in a granulator, uniformly mixing hydroxylamine sulfate, fatty alcohol polyoxyethylene ether AEO-9 and potassium hydroxide in water to obtain modified liquid, uniformly spraying the modified liquid on the surfaces of the polymer gel particles, fully mixing, carrying out modification reaction on the polymer gel particles sprayed with the modified liquid at the temperature of 75 ℃ for 3.5 hours, and after modification, sequentially carrying out crushing, drying, grinding and screening to obtain the filtrate reducer; wherein the mass ratio of the polymerized colloidal particles, the hydroxylamine sulfate, the potassium hydroxide, the fatty alcohol polyoxyethylene ether AEO-9 and the water is 1000:23:8:15:50.

Example 3

(1) Polymer gel block preparation

The raw materials for preparing the polymer gel block comprise: 30 parts of acrylamide, 60 parts of acryloylmorpholine, 85 parts of 3- (4-methoxybenzoyl) acrylic acid, 80 parts of vinyltrimethylsilane, 45 parts of ethyl 2-phenylacrylate, 4 parts of a structure regulator, 650 parts of water, 3 parts of azobisisobutyronitrile, 1.5 parts of tert-butyl hydroperoxide and 1.5 parts of sodium bisulfite. The preparation method comprises the following steps: fully and uniformly mixing acrylamide, acryloylmorpholine, 3- (4-methoxybenzoyl) acrylic acid, vinyl trimethylsilane, ethyl 2-phenylacrylate, a structure regulator and water to obtain a mixed solution, regulating the pH value of the mixed solution to 7.0 by using ammonia water with the volume concentration of 25%, transferring the mixed solution into a reaction kettle, introducing nitrogen to deoxidize for 60min, adding azodiisobutyronitrile, tert-butyl hydroperoxide and sodium bisulphite to initiate polymerization reaction at the temperature of 7 ℃, and reacting for 3h to obtain the polymer gel.

(2) Polymer slab modification

Modification of the polymer gel block: granulating the polymer gel block into polymer gel particles with the average granularity of 0.4mm in a granulator, uniformly mixing hydroxylamine sulfate, fatty alcohol polyoxyethylene ether AEO-9 and potassium hydroxide in water to obtain modified liquid, uniformly spraying the modified liquid on the surfaces of the polymer gel particles, fully mixing, carrying out modification reaction on the polymer gel particles sprayed with the modified liquid at 80 ℃ for 4 hours, and sequentially carrying out crushing, drying, grinding and screening after modification is finished to obtain the filtrate reducer; wherein the mass ratio of the polymerized colloidal particles, the hydroxylamine sulfate, the potassium hydroxide, the fatty alcohol polyoxyethylene ether AEO-9 and the water is 1000:23:8:15:50.

Example 4

Example 4 is substantially the same as example 1 except that:

(1) polymer gel block preparation

The raw materials for preparing the polymer gel block comprise: 40 parts of acrylamide, 35 parts of acryloylmorpholine, 40 parts of 3- (3-methoxy-4-methylphenyl) acrylic acid, 30 parts of vinyltrimethylsilane, 20 parts of 2-phenoxyethyl acrylate, 3 parts of a structure regulator, 800 parts of water, 1 part of azodiisobutyronitrile, 0.5 part of hydrogen peroxide and 0.5 part of sodium bisulfite. The preparation method comprises the following steps: fully and uniformly mixing acrylamide, acryloylmorpholine, 3- (3-methoxy-4-methylphenyl) acrylic acid, vinyltrimethylsilane, 2-phenoxyethyl acrylate, a structure regulator and water to obtain a mixed solution, regulating the pH value of the mixed solution to 6.6 by using ammonia water with the volume concentration of 25%, transferring the mixed solution into a reaction kettle, introducing nitrogen to deoxidize for 60min, adding azodiisobutyronitrile, hydrogen peroxide and sodium bisulphite to initiate polymerization reaction at the temperature of 5 ℃, and reacting for 3h to obtain the polymer gel.

Example 5

Example 5 is substantially the same as example 1 except that:

(2) polymer slab modification

Modification of the polymer gel block: granulating the polymer gel block into polymer gel particles with the average granularity of 0.4mm in a granulator, fully dissolving hydroxylamine sulfate, fatty alcohol polyoxyethylene ether AEO-9 and potassium hydroxide in water to obtain uniformly mixed modified liquid, uniformly spraying the modified liquid on the surfaces of the polymer gel particles, fully mixing, carrying out modification reaction on the polymer gel particles sprayed with the modified liquid at 70 ℃ for 3 hours, and sequentially carrying out crushing, drying, grinding and screening after modification is finished to obtain the filtrate reducer; wherein the mass ratio of the polymerized colloidal particles, the hydroxylamine sulfate, the potassium hydroxide, the fatty alcohol polyoxyethylene ether AEO-9 and the water is 1000:10:2:5:79.

Comparative example 1

Comparative example 1 is substantially the same as example 1 except that:

in step (1), no acryloylmorpholine was added, and the amount of acryloylmorpholine was replaced with acrylamide, i.e., 45 parts of acrylamide was added.

Comparative example 2

Comparative example 2 is substantially the same as example 1 except that:

in step (1), the reinforcing monomer 3- (3-methoxy-4-methylphenyl) acrylic acid was not added, and the amount of 3- (3-methoxy-4-methylphenyl) acrylic acid was replaced with acrylamide, that is, 65 parts of acrylamide was added.

Comparative example 3

Comparative example 3 is substantially the same as example 1 except that:

in step (1), the hydrolysis-resistant monomer vinyltrimethylsilane was not added, and the amount of vinyltrimethylsilane was replaced with acrylamide, i.e., 50 parts of acrylamide was added.

Comparative example 4

Comparative example 4 is substantially the same as example 1 except that:

in the step (1), the 2-phenoxyethyl acrylate as a cleavage monomer was not added, and the amount of 2-phenoxyethyl acrylate was replaced with acrylamide, that is, 35 parts of acrylamide was added.

Comparative example 5

Comparative example 5 is substantially the same as example 1 except that:

in step (2), the polymer gel mass is granulated in a granulator into polymer gel particles having an average particle size of 1 mm.

Comparative example 6

Comparative example 6 is substantially the same as example 1 except that:

(2) polymer slab modification

Modification of the polymer gel block: granulating the polymer gel block into polymer gel particles with the average granularity of 0.4mm in a granulator, uniformly mixing hydroxylamine sulfate and fatty alcohol polyoxyethylene ether AEO-9 in water to obtain modified liquid, uniformly spraying the modified liquid on the surfaces of the polymer gel particles, fully mixing, carrying out modification reaction on the polymer gel particles sprayed with the modified liquid at 70 ℃ for 3 hours, and sequentially carrying out crushing, drying, grinding and screening after modification is finished to obtain the filtrate reducer; wherein the mass ratio of the polymerized colloidal particles, the hydroxylamine sulfate, the fatty alcohol polyoxyethylene ether AEO-9 and the water is 1000:23:15:58.

Comparative example 7

Comparative example 7 is substantially the same as example 1 except that:

(2) polymer slab modification

Modification of the polymer gel block: granulating the polymer gel block into polymer gel particles with the average granularity of 0.4mm in a granulator, uniformly mixing hydroxylamine sulfate and potassium hydroxide in water to obtain modified liquid, uniformly spraying the modified liquid on the surfaces of the polymer gel particles, fully mixing, carrying out modification reaction on the polymer gel particles sprayed with the modified liquid at 70 ℃ for 3 hours, and after modification, sequentially carrying out crushing, drying, grinding and screening to obtain the filtrate reducer; wherein the mass ratio of the polymerized colloidal particles to the hydroxylamine sulfate to the potassium hydroxide to the water is 1000:23:8:65.

Comparative example 8

The preparation method comprises the following steps of: 10 parts of acrylamide, 35 parts of acryloylmorpholine, 55 parts of 3- (3-methoxy-4-methylphenyl) acrylic acid, 40 parts of vinyltrimethylsilane, 25 parts of 2-phenoxyethyl acrylate, 3 parts of a structure regulator, 800 parts of water, 1 part of azodiisobutyronitrile, 0.5 part of hydrogen peroxide and 0.5 part of sodium bisulfite. The preparation method comprises the following steps: fully and uniformly mixing acrylamide, acryloylmorpholine, 3- (3-methoxy-4-methylphenyl) acrylic acid, vinyltrimethylsilane, 2-phenoxyethyl acrylate, a structure regulator and water to obtain a mixed solution, regulating the pH value of the mixed solution to 6.6 by using ammonia water with the volume concentration of 25%, transferring the mixed solution into a reaction kettle, introducing nitrogen to remove oxygen for 60min, adding azodiisobutyronitrile, hydrogen peroxide and sodium bisulphite to initiate polymerization reaction at the temperature of 5 ℃, and reacting for 3h to obtain a polymer gel; and then granulating, drying, crushing and screening the polymer gel blocks in sequence to obtain the filtrate reducer.

Comparative example 9

Comparative example 9 is substantially the same as example 1 except that:

in step (1), the preparation of the adopted structure regulator is as follows: 500 parts of 2-hydroxy propionic acid is added into a three-neck flask with a stirrer, a condenser pipe and a thermometer, the temperature of a water bath is started to be 60 ℃, 25 parts of 98% by mass of concentrated sulfuric acid is dropwise added in 1h, the reaction is continued for 3h (including 1h of dropwise adding of the concentrated sulfuric acid and 2h of continuous reaction after the dropwise adding is completed), the reaction is cooled to room temperature after the completion of the reaction, rotary evaporation is performed by a rotary evaporator, and the solvent is distilled off, so that an intermediate A is obtained, namely the structural regulator.

Comparative example 10

Comparative example 10 is substantially the same as example 1 except that:

in step (1), the preparation of the adopted structure regulator is as follows:

(2) 240 parts of intermediate A, 150 parts of butanol amine and 39 parts of N, N-dimethylformamide are added into a three-neck flask with a stirrer, a condenser pipe and a thermometer, and are uniformly mixed, a water bath is started to control the temperature to 45 ℃ and the constant temperature reaction is carried out for 3 hours; after the reaction is finished, rotary evaporation is carried out by a rotary evaporator, and the solvent is distilled off to obtain an intermediate B, namely the intermediate B is used as a structure regulator.

Comparative example 11

Comparative example 11 is substantially the same as example 1 except that:

in the step (1), the structure regulator is not added, and the structure regulator is replaced by acrylamide, namely 13 parts of acrylamide is added.

Evaluation of performance:

The fluid loss performance (including fluid loss) of each of the fluid loss additives prepared in each of examples and comparative examples was evaluated with reference to the method in Q/SH 0047-2007 general technical requirement for high temperature and salt resistant fluid loss additives for drilling fluids, in which brine was used in a 30wt% aqueous calcium chloride solution (the mass fraction of calcium chloride contained in the aqueous calcium chloride solution is 30%). The fluid loss additives prepared in each example and each comparative example were evaluated for rheological properties (including indexes AV, PV, YP, phi 6/phi 3) by referring to the methods in SY/T5660-95, coating agent for drilling fluid PAC141, fluid loss additive PAC142, fluid loss additive PAC143, wherein brine was 30wt% calcium chloride aqueous solution, and the results are shown in Table 1.

Table 1: results of evaluation of the performances of the fluid loss additives of examples 1 to 5 and comparative examples 1 to 11.

In table 1, AV represents apparent viscosity; PV represents plastic viscosity; YP represents the dynamic shear force; phi 6/phi 3 represents six-speed viscometer readings under the test condition of 6-rotation and 3-rotation respectively; in Table 1, symbol "-" indicates that the filtration loss before aging was not measured.

As can be seen from the data in Table 1, the molecular chain of the fluid loss additive prepared by the invention has extremely high temperature resistance and salt resistance, can maintain the viscosity and the fluid loss performance in ultra-mineralized water, has stable rheological property, and has the dynamic shear force of more than 20Pa in brine-based drilling fluid, the dynamic shear force of 21 Pa-30 Pa, the phi 6/phi 3 of more than 12/9 and the fluid loss of less than 5mL.

The invention is not described in detail in a manner known to those skilled in the art.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. The preparation method of the filtrate reducer is characterized by comprising the following steps of:

(1) Uniformly mixing acrylamide, acryloylmorpholine, an enhanced monomer, a hydrolysis-resistant monomer, a cutting-lifting monomer, a structure regulator and water to obtain a mixed solution, introducing nitrogen into the mixed solution to remove oxygen, and then adding an initiator to initiate polymerization reaction to obtain a polymer gel block; the reinforcing monomer is 3- (3-methoxy-4-methylphenyl) acrylic acid and/or 3- (4-methoxybenzoyl) acrylic acid; the hydrolysis-resistant monomer is vinyl trimethylsilane and/or 4-acetoxyl styrene; the stripping and cutting monomer is one or more of 2-phenoxyethyl acrylate, furfuryl alcohol methacrylate and 2-phenyl ethyl acrylate; in the step (1), each raw material for preparing the polymer gel block comprises, by weight, 10-30 parts of acrylamide, 35-60 parts of acryloylmorpholine, 55-85 parts of a reinforcing monomer, 40-80 parts of a hydrolysis-resistant monomer, 25-45 parts of a cutting-up monomer, 1-5 parts of a structure regulator, 650-800 parts of water and 1.5-6 parts of an initiator;

(2) Granulating the polymer gel block to obtain polymer gel particles; the particle size of the polymerized colloidal particles obtained in the step (2) is smaller than 0.5mm;

(3) Uniformly mixing a modifier, potassium hydroxide, an activator and water to obtain a modified liquid, and then spraying the polymerized colloidal particles with the modified liquid to perform a modification reaction to obtain a filtrate reducer;

the modifier is hydroxylamine sulfate; the activator is fatty alcohol polyoxyethylene ether; in the step (3), the mass ratio of the polymeric colloidal particles, the modifier, the potassium hydroxide, the activator and the water is 1000: (20-25): (5-10): (10-20): (40-60);

the structure regulator is prepared by the following steps:

2. The method of claim 1, further comprising the steps of pulverizing, drying, grinding and sieving the fluid loss additive in that order.

3. The method of manufacturing according to claim 1, characterized in that:

in the step (a), the mass fraction of the concentrated sulfuric acid is not less than 98%, the use amount of the concentrated sulfuric acid is 4-6% of the mass of the 2-hydroxy propionic acid, and/or the reaction temperature is 55-65 ℃, and the reaction time is 2.5-4 hours; and/or

In step (b), the mass ratio of the intermediate A to the butanolamine is 8: (4-6), wherein the dosage of the N, N-dimethylformamide is 8-15% of the sum of the mass of the intermediate A and the mass of the butanol amine, and/or the reaction temperature is 40-50 ℃, and the reaction time is 2.5-4 h.

4. A method of preparation according to claim 3, characterized in that:

in step (a), the concentrated sulfuric acid is used in an amount of 5% by mass of the 2-hydroxypropionic acid.

5. A method of preparation according to claim 3, characterized in that:

in step (a), the reaction time is 3h.

6. A method of preparation according to claim 3, characterized in that:

in step (b), the mass ratio of the intermediate A to the butanolamine is 8:5.

7. A method of preparation according to claim 3, characterized in that:

in step (b), the amount of N, N-dimethylformamide is 10% of the sum of the mass of intermediate a and the mass of butolamine.

8. A method of preparation according to claim 3, characterized in that:

in step (b), the reaction time is 3h.

9. The method of claim 1, wherein in step (c):

the mass ratio of the intermediate B to the cinnamoyl chloride is 8: (4-6);

the dosage of the 1, 2-dichloroethane is 10-20% of the sum of the mass of the intermediate B and the mass of the cinnamoyl chloride;

the dosage of the diethylamine is 1-5% of the sum of the mass of the intermediate B and the mass of the cinnamoyl chloride;

dropwise adding cinnamoyl chloride at the temperature of-5 ℃; and/or

After the cinnamoyl chloride is added dropwise, controlling the reaction temperature to be 30-35 ℃ and reacting for 1.5-3 hours at the temperature of 30-35 ℃.

10. The method of manufacturing according to claim 9, wherein:

the mass ratio of the intermediate B to the cinnamoyl chloride is 8:5.

11. The method of manufacturing according to claim 9, wherein:

the amount of 1, 2-dichloroethane is 15% of the sum of the mass of intermediate B and cinnamoyl chloride.

12. The method of manufacturing according to claim 9, wherein:

the amount of diethylamine is 3% of the sum of the mass of intermediate B and cinnamoyl chloride.

13. The method of manufacturing according to claim 9, wherein:

After the cinnamoyl chloride is added dropwise, controlling the reaction temperature to be 30-35 ℃ and reacting for 2 hours at 30-35 ℃.

14. The preparation method according to claim 1 or 2, characterized in that:

the initiator comprises azo initiator and redox initiator, wherein the azo initiator is azodiisobutyronitrile and/or azodiisobutylamidine hydrochloride, the oxidant in the redox initiator is one or more of hydrogen peroxide, di-tert-butyl peroxide and tert-butyl hydroperoxide, and the reducing agent in the redox initiator is sodium bisulphite.

15. The method of manufacturing according to claim 14, wherein:

the mass ratio of the azo initiator to the redox initiator is (1-3): (0.5-3).

16. The preparation method according to claim 1 or 2, characterized in that:

in the step (3), the mass ratio of the polymeric colloidal particles, the modifier, the potassium hydroxide, the activator and the water is 1000:23:8:15:50.

17. The preparation method according to claim 1 or 2, characterized in that:

in the step (1), before introducing nitrogen to the mixed solution to remove oxygen, adjusting the pH of the mixed solution to 6.5-7.0;

In the step (1), the time for introducing nitrogen and removing oxygen is 40-80 min;

in the step (1), an initiator is added at the temperature of 5-7 ℃ to initiate a polymerization reaction, and the time of the polymerization reaction is 2-4 hours; and/or

In the step (3), the temperature of the modification reaction is 70-80 ℃, and the time of the modification reaction is 3-4 hours.

18. The method of manufacturing according to claim 17, wherein:

in the step (1), an initiator is added at 5-7 ℃ to initiate polymerization, and the polymerization time is 3h.

19. A fluid loss additive produced by the production process of any one of claims 1 to 18.

20. Use of a fluid loss additive made by the method of any one of claims 1 to 18 in brine-based drilling fluids.