Polyacrylamide microsphere profile control agent and preparation method thereof

Abstract

The present application relates to a kind of polyacrylamide microspheres profile control agent, at least contains three different structures of polymer microspheres, respectively is: the core is cationic, the shell is anionic core-shell structure polymer microspheres, anionic polymer microspheres, and the core is amphoteric, the shell is anionic core-shell structure polymer microspheres. By the effective compounding of three kinds of polymer microspheres, the dependence of microspheres on the matching relationship of microspheres particle size and pore throat in depth profile control can be broken through. At the same time, the profile control position of the profile control agent synthesized by the present application is jointly determined by the injection liquid propelling time and the degradation time of microspheres shell, and the profile control depth can be adjusted by adjusting the degradation rate of microspheres shell, to realize fixed-point profile control.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of polyacrylamide microspheres profile control agent and its preparation method. BACKGROUND

[0002] In global energy consumption, crude oil has been the most important source. With the continuous development of oil reservoir, long-term water injection in oilfield causes the dispersion of remaining oil, the enhancement of formation heterogeneity, and further causes the high water cut, the low efficiency of oilfield development, which becomes the main problem of restricting oil reservoir development in the era of low oil price. Therefore, profile control and channeling plugging have been an important means in oilfield development. Gel particles, polymer gel, polymer microspheres, etc. are widely used as important means.

[0003] Polymer microspheres are a kind of emulsion profile control agent synthesized on the ground. The microspheres are dispersed into water and migrate into the formation with the injected water, and plug the large pore in the formation. The traditional polymer microspheres will quickly swell to reach the absorption equilibrium after entering the formation, so the plugging ability in the near wellbore zone is the strongest, and the plugging ability gradually decreases with the aging and degradation of the microspheres in the high temperature and high salt environment, and the specific plugging depth of the microspheres cannot be controlled. At the same time, after the microspheres plug the large pore, they still undergo long-term aging in the high temperature and high salt environment. The microspheres are plugged by mechanical bridging and adsorption, etc. Long-term aging will reduce the interaction between the microspheres, and thus the effective period of plugging is short.

[0004] The plugging of traditional polymer microspheres mainly depends on the bridging of microspheres in pore throat. The interaction between the microspheres is weak, and it is difficult to form larger aggregates in the deep formation for plugging. In the document "Study on the matching relationship between polymer microsphere particle size and core pore throat", the author found through the plugging experiment of microspheres with different particle sizes and pore throat that Abrans theory is applicable to polymer microspheres, but the bridging plugging rate is not high, and it is greatly affected by the change of polymer microsphere particle size. The increase or decrease of polymer microsphere particle size will cause a significant decrease in plugging rate, which is difficult to match the application. When the ratio of microsphere particle size to pore throat diameter is 1.20-1.50, the microspheres have good migration ability and plugging effect, and the plugging rate is more than 40%. When the ratio of polymer microsphere particle size to core pore throat diameter is more than 1.50, the polymer microspheres have injection difficulty. The data confirms the contradiction of traditional microsphere profile control. If the ratio of microsphere particle size to core pore throat diameter is too small, the plugging rate is low, and if the ratio is too high, the injection is difficult. Under the premise of ensuring the injection, the main reason for the low plugging rate of microspheres is that the interaction between the microspheres is weak, which cannot effectively aggregate, and it is difficult to bridge and effectively plug when the microsphere particle size is too small.

[0005] In the literature of "Analysis of the hydration performance of cross-linked polymer microspheres system", "Blocking performance of cross-linked polymer microsphere dispersion system", the author studied the blocking performance of polymer microspheres with the extension of aging time. Because the specific surface area of microspheres is large, it can expand to the maximum value quickly, and then the performance gradually decreases with the extension of aging time, so the blocking ability of microspheres gradually deteriorates with the extension of aging time, and it cannot realize the fixed-point profile control of deep formation after long-time migration.

[0006] In summary, the conventional polymer microspheres used as profile control agents currently mainly have the shortcomings of gradually decreasing blocking ability during service period, insufficient controllable fixed-point profile control ability, and weak interaction force between microspheres, which limits the application of microspheres in oilfield development. SUMMARY

[0007] One of the technical problems to be solved by the present application is to solve the problem that the existing polyacrylamide microsphere profile control agent gradually decreases the blocking ability after entering the formation from the beginning of injection with migration in the formation, and to get rid of the dependence of the blocking of the conventional microspheres on the matching relationship of pore throat and particle size. In order to solve this problem, three-component polymer microspheres with different structures are introduced in the present application. The outer shell of the microspheres shows negative electric property at the initial stage of entering the formation, and the adsorption between the microspheres and the formation is weak, and the mechanical bridging between the microspheres cannot be effectively formed due to electrostatic repulsion, so the blocking ability is weak. With the degradation of the outer shell of the component one and component three microspheres in the three-component microspheres, the core of the microspheres is exposed, a large number of cationic groups endow the microspheres with strong electrostatic adsorption force with the formation, and also endow the core of the component one microspheres with strong electrostatic adsorption force with the component two microspheres, so that the blocking ability of the microspheres increases obviously after entering the deep part of the formation. At the same time, the cross-linked structure of the core of the component three microspheres is degraded, and the linear polymer is formed between the component one microspheres and the component two microspheres by electrostatic bridging and flocculation, and the aggregated structure with stronger blocking ability is formed.

[0008] The second technical problem to be solved by the present application is to solve the problem that the existing polyacrylamide microspheres cannot realize fixed-point controllable profile control when profile control and channeling blocking are performed. In order to solve this problem, a controllable degradable unstable cross-linked structure is introduced in the shell structure of the microspheres. The degradable structure can be degraded and failed at the reservoir temperature, and the degradation time is controlled by the cross-linking degree, which endows the microspheres with the function of fixed-time conversion of blocking ability, and assists the injection process with the pushing speed, so that the problem of uncontrollable profile control position can be effectively solved.

[0009] The third technical problem to be solved by the present application is to solve the problem of weak interaction force between polyacrylamide microspheres, which is easy to be washed away and causes plugging failure. In order to solve the problem, the present application introduces component three into the polyacrylamide microsphere profile control agent. The component three is in the form of microspheres at the initial stage of entering the aqueous solution, can pass through the large pore channel, and migrate to the deep formation. After the shell is degraded, the cross-linked structure in the core of component three is also degraded synchronously, and the linear polymer with amphoteric charge is released, which can bridge and flocculate the microspheres of component one and component two to form larger and more washable aggregate structures, and long-acting plugging of the pore channel is achieved.

[0010] To solve the above problems, the technical scheme adopted by the present application is as follows: a polyacrylamide microsphere profile control agent, by weight percentage, at least including the following three components:

[0011] (1) Component one: core-shell structure polymer microspheres with cationic core and anionic shell, content 4%-48%, preferably 20%-40%;

[0012] (2) Component two: anionic polymer microspheres, content 4%-48%, preferably 20%-40%;

[0013] (3) Component three: core-shell structure polymer microspheres with amphoteric core and anionic shell, content 4%-48%, preferably 20%-40%.

[0014] In the above technical scheme, the core of the component one has stable cross-linked structure units, and the shell has degradable cross-linked structure units;

[0015] The component two has both stable cross-linked structure units and degradable cross-linked structure units;

[0016] The core of the component three has degradable cross-linked structure units, and the shell has degradable cross-linked structure units;

[0017] The stable cross-linked structure units are selected from at least one of methylene bisacrylamide, divinylbenzene, N, N'-methylene bisacrylamide, and N, N'-m-phenylene bismaleimide; and the degradable cross-linked structure units are selected from at least one of dipropenyl phthalate, dipropenyl cyano acetic acid ethyl ester, polyethylene glycol diacrylate, ethylene glycol diacrylate, and pentaerythritol triacrylate.

[0018] The stable cross-linked structure units in the core of the component one and the component two can be the same or different; and the degradable cross-linked structure units in the shell of the component one, the component two, and the core and shell of the component three can be the same or different.

[0019] In the technical solution, the core of the component one is obtained by reaction of a reaction system I containing the following components:

[0020] (1) 1-30 parts of acrylamide;

[0021] (2) 0.1-10 parts of cationic monomer;

[0022] (3) 0.1-10 parts of nonionic monomer;

[0023] (4) 0.0001-0.5 parts of stable crosslinking structure unit;

[0024] The shell of the component one is obtained by reaction of a reaction system II containing the following components:

[0025] (1) 1-30 parts of acrylamide;

[0026] (2) 0.1-10 parts of nonionic monomer;

[0027] (3) 0.1-10 parts of anionic monomer;

[0028] (4) 0.0001-1 parts of degradable crosslinking structure unit;

[0029] The nonionic monomer in the core of the component one and the nonionic monomer in the shell can be the same or different.

[0030] In the technical solution, the component two is obtained by reaction of a reaction system III containing the following components:

[0031] (1) 1-30 parts of acrylamide;

[0032] (2) 0.1-10 parts of anionic monomer;

[0033] (3) 0.1-10 parts of nonionic monomer;

[0034] (4) 0.0001-0.5 parts of stable crosslinking structure unit;

[0035] (5) 0.0001-1 parts of degradable crosslinking structure unit.

[0036] In the technical solution, the core of the component three is obtained by reaction of a reaction system IV containing the following components:

[0037] (1) 1-30 parts of acrylamide;

[0038] (2) 0.1-10 parts of anionic monomer;

[0039] (3) 0.1-10 parts of cationic monomer;

[0040] (4) 0.1-10 parts of nonionic monomer;

[0041] (5) 0.0001-0.5 parts of degradable crosslinking structure unit;

[0042] The shell of the component three is obtained by reacting a reaction system V comprising the following components, by weight fraction:

[0043] (1) 1-30 parts of acrylamide;

[0044] (2) 0.1-10 parts of nonionic monomer;

[0045] (3) 0.1-10 parts of anionic monomer;

[0046] (4) 0.0001-1 parts of degradable crosslinking structure unit;

[0047] The anionic monomer in the core of the component three and the anionic monomer in the shell can be the same or different; the nonionic monomer in the core of the component three and the nonionic monomer in the shell can be the same or different.

[0048] In addition, the anionic monomer in the component one, the component two and the component three can be the same or different; the nonionic monomer in the component one, the component two and the component three can be the same or different.

[0049] In the above technical solution, the reaction system I-V further comprises:

[0050] (1) 0.0001-0.05 parts of initiator;

[0051] (2) 5-70 parts of water;

[0052] (3) 0.0001-1 parts of disodium ethylenediaminetetraacetate;

[0053] The reaction system I, III and IV further comprises:

[0054] (4) 10-90 parts of oil solvent;

[0055] (5) 0.5-30 parts of emulsifier, preferably 2.5-20 parts.

[0056] The anionic monomer is selected from at least one of acrylic acid, methacrylic acid, sodium vinyl sulfonate, p-vinylbenzenesulfonic acid, maleic acid, fumaric acid, vinylbenzenesulfonic acid, allyl sulfonic acid, allylbenzenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid and / or alkali metal salt and ammonium salt thereof; the non-ionic monomer is selected from at least one of methacrylamide, dimethylacrylamide, diethylacrylamide, hydroxymethylacrylamide, hydroxyethylacrylamide, dimethylamino propyl methacrylamide, hydroxymethyl methacrylate, hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, vinylpyrrolidone; the cationic monomer is selected from at least one of methacryloyloxyethyl trimethylammonium chloride, 2-acrylamido-2-methylpropyl trimethylammonium chloride, dimethylethylallyl ammonium chloride, dimethyldiallyl ammonium chloride, acryloyloxyethyl trimethylammonium chloride, acryloyloxyethyl dimethylbenzyl ammonium chloride, methacryloyloxyethyl dimethylbenzyl ammonium chloride.

[0057] The initiator is selected from at least one of ammonium persulfate, potassium persulfate, sodium persulfate, potassium bromate, sodium bromate, hydrogen peroxide, tert-butyl hydroperoxide, benzoyl peroxide, azobisisobutyronitrile, azobisisopentyl nitrile, azobisisoheptyl nitrile, dimethyl azobisbutyrate, azobisbutyramidine hydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride, azobis(2,5-dimethyl-6-carboxy)hexyl nitrile, 4,4'-azobis(4-cyanopentanoic acid), sodium bisulfite, sodium hydrosulfite, sodium metabisulfite, ammonium ferrous sulfate; the oil solvent is selected from at least one of aliphatic hydrocarbon, aromatic hydrocarbon, mineral oil or vegetable oil; the aliphatic hydrocarbon is selected from at least one of cyclohexane, hexane, heptane, octane and isooctane; the aromatic hydrocarbon is selected from at least one of benzene, toluene, ethylbenzene, xylene and cumene; the mineral oil is selected from at least one of liquid paraffin, white oil, gasoline, diesel and kerosene; the vegetable oil is selected from at least one of peanut oil, soybean oil, sunflower seed oil and castor oil; the emulsifier is selected from at least one of sorbitan oleate, sorbitan stearate, sorbitan palmitate, sorbitan laurate, fatty alcohol polyoxypropylene polyoxyethylene ether as shown in formula (i), aromatic alcohol polyoxypropylene polyoxyethylene ether as shown in formula (ii), fatty acid polyoxypropylene polyoxyethylene ester as shown in formula (iii), fatty amine polyoxypropylene polyoxyethylene ether as shown in formula (iv):

[0058]

[0059] wherein R1, R2 and R3 are each independently selected from C1-C6 hydrocarbon group; R4 and R5 are selected from hydrogen atom or C1-C6 hydrocarbon group. 28 28 ​R4 and R5 are independently selected from the group consisting of hydrogen atom, a hydrocarbon group, and a heteroatom-containing hydrocarbon group, and R4 and R5 cannot be hydrogen atom at the same time; m is selected from 0 to 30; and n is selected from 1 to 40.

[0060] In the technical scheme, the component one and the component three are prepared by inverse emulsion polymerization or inverse suspension polymerization, including the following steps:

[0061] 1. The monomers, the crosslinking agent, the disodium ethylenediaminetetraacetate and water required for the inner core are configured into an aqueous solution with a pH value between 5 and 10;

[0062] 2. The required amount of emulsifier is dissolved in an oil solvent to prepare a solution;

[0063] 3. The solution obtained in step 2 is mixed with the solution obtained in step 1 to obtain a mixture A;

[0064] 4. The mixture A is purged with nitrogen for 30-60 minutes, and the initiator configured into an aqueous solution is added to perform the inner core polymerization. After the polymerization is completed, the temperature is kept at 50-85°C for 30-60 minutes, and then the temperature is reduced to room temperature;

[0065] 5. The monomers, the crosslinking agent, the disodium ethylenediaminetetraacetate and water required for the outer shell are configured into an aqueous solution with a pH value between 5 and 10, and then the reaction system obtained in step 4 is added;

[0066] 6. The mixture is purged with nitrogen for 30-60 minutes, and the initiator configured into an aqueous solution is added to perform the outer shell polymerization. After the polymerization is completed, the temperature is kept at 50-85°C for 30-60 minutes, and then the temperature is reduced to room temperature, and the product is discharged;

[0067] The concentration of the initiator aqueous solution is 0.005wt%-2.5wt%, and preferably 0.1wt%-2wt%.

[0068] In the technical scheme, the component two is prepared by inverse emulsion polymerization or inverse suspension polymerization, including the following steps:

[0069] 1. The monomers, the crosslinking agent, the disodium ethylenediaminetetraacetate and water required for the inner core are configured into an aqueous solution with a pH value between 5 and 10;

[0070] 2. The required amount of emulsifier is dissolved in an oil solvent to prepare a solution;

[0071] 3. The solution obtained in step 2 is mixed with the solution obtained in step 1 to obtain a mixture B;

[0072] 4. The mixture B is purged with nitrogen for 30-60 minutes, and the initiator configured into an aqueous solution is added to perform the polymerization. After the polymerization is completed, the temperature is kept at 50-85°C for 30-60 minutes, and then the temperature is reduced to room temperature, and the product is discharged.

[0073] In the present application, the performance of the profile control agent is mainly evaluated by core injection experiment, and the resistance factor, residual resistance factor and plugging retention rate are calculated, and the specific evaluation method is as follows:

[0074] I. Disperse the profile control agent sample in 10000mg / L salinity brine under stirring, wherein the calcium and magnesium ion content is 500ppm respectively;

[0075] II. After aging the above prepared solution at 85℃ for different time, carry out injection experiment in the water-saturated 1000mD permeability artificial core, the injection speed is 0.5mL / min, and the injection experiment flow chart is shown in the attached Figure 1 ;

[0076] III. Record the water injection pressure P1, the profile control agent injection equilibrium pressure P2, the subsequent water drive equilibrium pressure P3, the resistance factor, the residual resistance factor, and the plugging rate retention rate are calculated according to the following respectively:

[0077]

[0078]

[0079]

[0080] Technical effects

[0081] The traditional polymer microspheres have small particle size, fast water absorption and expansion, and reach water absorption equilibrium in water quickly, and at this time, the plugging capacity is the strongest, and with migration in the formation, the molecular chain is degraded and broken under the action of heat and oxygen shear, and the plugging capacity gradually decreases. The three-component polymer microspheres of the present application have no obvious interaction between the three components at the initial stage of entering the formation, with the degradation of the shell of component one and component three microspheres, the inner core of the microspheres is exposed, a large number of cationic groups endow the microspheres with strong electrostatic adsorption force with the formation, and also endow the inner core of component one microspheres with strong electrostatic adsorption force with component two microspheres, so that the plugging capacity of the microspheres is obviously increased after entering the deep formation. At the same time, the crosslinked structure of the inner core of component three microspheres is degraded, and the linear polymer is formed by bridging flocculation between component one microspheres and component two microspheres through electrostatic action, forming an aggregated structure with stronger plugging capacity. Through the improvement of the present application, the plugging capacity curve of the microspheres after entering the formation is changed from gradual weakening to spontaneous strengthening plugging, and the effect of plugging in the deep formation is truly realized. Therefore, the product obtained by the present application has weak plugging capacity before the degradation of the shell of component one and component three microspheres, and the plugging capacity is obviously improved after that.

[0082] The transformation time of the plugging capacity is the key point of the application, the transformation time of the plugging capacity is controlled by the cross-linking density control, the shell degradation time is controlled, and the controllable profile control is realized. For the plugging effect of the microsphere plugging capacity transformation, the traditional microsphere plugging agent is easy to fail due to long-term flushing, and the component three is introduced in the application, which becomes a linear polymer after degradation, forms a flocculation bridge between the microspheres, strengthens the plugging effect, and prolongs the effective period of plugging. Therefore, the residual resistance factor of the product of the application is much higher than that of the comparative example. BRIEF DESCRIPTION OF DRAWINGS

[0083] Figure 1 The flow chart for evaluating the plugging performance of the profile control agent. DETAILED DESCRIPTION

[0084] The following specific embodiments are described in conjunction with the application, and it is necessary to point out that the following embodiments are only used to further illustrate the application, and cannot be understood as limiting the protection scope of the application. Some non-essential improvements and adjustments of the application made by those skilled in the art according to the content of the application still belong to the protection scope of the application.

[0085] The raw materials used in the specific embodiments of the application are obtained from the market.

[0086]

Example 1

[0087] Synthesis of polyacrylamide microsphere profile control agent component one:

[0088] 25 parts of acrylamide, 5 parts of dimethyl diallyl ammonium chloride, 3 parts of tert-butyl acrylamide, 0.025 parts of methylene bisacrylamide, and 0.005 parts of ethylenediaminetetraacetic acid disodium are dissolved in 30 parts of water to prepare a solution, and the pH value is adjusted to 7. 3 parts of sorbitan oleate and 0.5 parts of fatty alcohol polyoxyethylene ether are dissolved in 70 parts of 3# white oil. The oil solution and the aqueous solution are sequentially added to the reaction kettle, the stirring speed is 500 rpm, stirring is performed for 30 min, and nitrogen is introduced to remove oxygen. The temperature in the kettle is controlled to be 10-15℃. 0.00125 parts of potassium bromate is dissolved in 1 part of water to prepare an aqueous solution, which is added dropwise into the reaction kettle and stirred uniformly. 0.05 parts of sodium pyrosulfite is dissolved in 5 parts of water, and is slowly added into the reaction kettle. The reaction temperature is controlled to be not more than 2℃ / min by controlling the dropping speed of sodium pyrosulfite until the temperature rising is finished. 50℃ is maintained for 60 min, and the temperature is lowered to 25℃.

[0089] A solution was prepared by dissolving 25 parts of acrylamide, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 1 part of tert-butyl acrylamide, 0.025 part of polyethylene glycol diacrylate, and 0.005 part of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. The above aqueous solution was added to the reaction kettle in which the first step was completed, and stirred at a rate of 500 rpm for 30 min while removing oxygen by nitrogen bubbling. The temperature in the kettle was controlled at 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle and stirred uniformly. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle. The temperature rising rate was controlled to be not more than 2°C / min by controlling the dropwise adding rate of sodium pyrosulfite until the temperature rising was completed. The temperature was maintained at 50°C for 60 min, and then the temperature was lowered to 25°C to discharge the product.

[0090] [Example 2]

[0091] Synthesis of component two of polyacrylamide microsphere profile control agent:

[0092] A solution was prepared by dissolving 25 parts of acrylamide, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 1 part of tert-butyl acrylamide, 0.025 part of polyethylene glycol diacrylate, and 0.005 part of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. The above aqueous solution was added to the reaction kettle in which the first step was completed, and stirred at a rate of 500 rpm for 30 min while removing oxygen by nitrogen bubbling. The temperature in the kettle was controlled at 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle and stirred uniformly. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle. The temperature rising rate was controlled to be not more than 2°C / min by controlling the dropwise adding rate of sodium pyrosulfite until the temperature rising was completed. The temperature was maintained at 50°C for 60 min, and then the temperature was lowered to 25°C to discharge the product.

[0093] [Example 3]

[0094] Synthesis of component three of polyacrylamide microsphere profile control agent:

[0095] A solution was prepared by dissolving 25 parts of acrylamide, 5 parts of dimethyldiallylammonium chloride, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 3 parts of t-butyl acrylamide, 0.025 parts of polyethylene glycol diacrylate, and 0.005 parts of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. A solution was prepared by dissolving 3 parts of sorbitan oleate and 0.5 parts of fatty alcohol polyoxyethylene ether in 70 parts of 3# white oil. The oil solution and the aqueous solution were sequentially added to a reaction kettle, stirring was carried out at a stirring rate of 500 rpm for 30 min, and oxygen was removed by nitrogen bubbling. The temperature in the kettle was controlled at 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle, and stirring was carried out until uniformity was achieved. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle. The temperature increase rate was controlled at not more than 2°C / min by controlling the dropwise addition rate of sodium pyrosulfite until the temperature increase was completed. The temperature was maintained at 50°C for 60 min, and the temperature was decreased to 25°C.

[0096] A solution was prepared by dissolving 25 parts of acrylamide, 2 parts of 2-acrylamido-2-methylpropanesulfonic acid, 1 part of t-butyl acrylamide, 0.025 parts of polyethylene glycol diacrylate, and 0.005 parts of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. The aqueous solution was added to the reaction system of the first step, stirring was carried out at a stirring rate of 500 rpm for 30 min, and oxygen was removed by nitrogen bubbling. The temperature in the kettle was controlled at 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle, and stirring was carried out until uniformity was achieved. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle. The temperature increase rate was controlled at not more than 2°C / min by controlling the dropwise addition rate of sodium pyrosulfite until the temperature increase was completed. The temperature was maintained at 50°C for 60 min, and the temperature was decreased to 25°C.

[0097]

Example 4

[0098] Synthesis of the component one of the polyacrylamide microsphere profile control agent:

[0099] A solution was prepared by dissolving 25 parts of acrylamide, 5 parts of dimethyldiallylammonium chloride, 3 parts of t-butyl acrylamide, 0.025 parts of methylene bisacrylamide, and 0.005 parts of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. A solution was prepared by dissolving 3 parts of sorbitan oleate and 0.5 parts of fatty alcohol polyoxyethylene ether in 70 parts of 3# white oil. The oil solution and the aqueous solution were sequentially added to a reaction kettle, stirring was carried out at a stirring rate of 500 rpm for 30 min, and oxygen was removed by nitrogen bubbling. The temperature in the kettle was controlled at 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle, and stirring was carried out until uniformity was achieved. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle. The temperature increase rate was controlled to be not more than 2°C / min by controlling the dropwise addition rate of sodium pyrosulfite until the temperature increase was completed. The temperature was maintained at 50°C for 60 min, and the temperature was then decreased to 25°C.

[0100] A solution was prepared by dissolving 25 parts of acrylamide, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 1 part of t-butyl acrylamide, 0.05 parts of polyethylene glycol diacrylate, and 0.005 parts of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. The aqueous solution was added to the reaction system of the first step, stirring was carried out at a stirring rate of 500 rpm for 30 min, and oxygen was removed by nitrogen bubbling. The temperature in the kettle was controlled at 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle, and stirring was carried out until uniformity was achieved. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle. The temperature increase rate was controlled to be not more than 2°C / min by controlling the dropwise addition rate of sodium pyrosulfite until the temperature increase was completed. The temperature was maintained at 50°C for 60 min, and the temperature was then decreased to 25°C.

[0101]

Example 5

[0102] Synthesis of the third component of the polyacrylamide microsphere profile control agent:

[0103] A solution was prepared by dissolving 25 parts of acrylamide, 5 parts of dimethyldiallylammonium chloride, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 3 parts of t-butyl acrylamide, 0.025 parts of polyethylene glycol diacrylate, and 0.005 parts of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. A solution was prepared by dissolving 3 parts of sorbitan oleate and 0.5 parts of fatty alcohol polyoxyethylene ether in 70 parts of 3# white oil. The oil solution and the aqueous solution were sequentially added to a reaction kettle, stirring was carried out at a stirring rate of 500 rpm for 30 min, and oxygen was removed by nitrogen bubbling. The temperature in the kettle was controlled to be 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle, and stirring was carried out until uniformity was achieved. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle. The temperature of the reaction was controlled to be not more than 2°C / min until the end of the temperature increase. The temperature was maintained at 50°C for 60 min, and the temperature was decreased to 25°C.

[0104] A solution was prepared by dissolving 25 parts of acrylamide, 2 parts of 2-acrylamido-2-methylpropanesulfonic acid, 1 part of t-butyl acrylamide, 0.05 parts of polyethylene glycol diacrylate, and 0.005 parts of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. The aqueous solution was added to the reaction system of the first step, stirring was carried out at a stirring rate of 500 rpm for 30 min, and oxygen was removed by nitrogen bubbling. The temperature in the kettle was controlled to be 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle, and stirring was carried out until uniformity was achieved. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle. The temperature of the reaction was controlled to be not more than 2°C / min until the end of the temperature increase. The temperature was maintained at 50°C for 60 min, and the temperature was decreased to 25°C.

[0105]

Example 6

[0106] Synthesis of the component one of the polyacrylamide microsphere profile control agent:

[0107] A solution was prepared by dissolving 5 parts of acrylamide, 10 parts of dimethyldiallylammonium chloride, 10 parts of t-butyl acrylamide, 0.001 part of methylene bisacrylamide, and 0.5 part of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. A solution was prepared by dissolving 3 parts of sorbitan oleate and 0.5 part of fatty alcohol polyoxyethylene ether in 70 parts of 3# white oil. The oil solution and the aqueous solution were sequentially added to a reaction kettle, stirring was carried out at a stirring rate of 500 rpm for 30 min, and oxygen was removed by nitrogen bubbling. The temperature in the kettle was controlled to be 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle, and stirring was carried out until uniformity was achieved. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle, the temperature increase was controlled to be no more than 2°C / min until the end of the temperature increase, and the reaction was carried out at 50°C for 60 min, and then the temperature was decreased to 25°C.

[0108] A solution was prepared by dissolving 5 parts of acrylamide, 10 parts of 2-acrylamido-2-methylpropane sulfonic acid, 7.5 parts of t-butyl acrylamide, 0.25 part of polyethylene glycol diacrylate, and 0.05 part of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. The aqueous solution was added to the reaction system of the first step, stirring was carried out at a stirring rate of 500 rpm for 30 min, and oxygen was removed by nitrogen bubbling. The temperature in the kettle was controlled to be 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle, and stirring was carried out until uniformity was achieved. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle, the temperature increase was controlled to be no more than 2°C / min until the end of the temperature increase, and the reaction was carried out at 50°C for 60 min, and then the temperature was decreased to 25°C, and the product was discharged.

[0109]

Example 7

[0110] Synthesis of component one of the polyacrylamide microsphere profile control agent:

[0111] A solution was prepared by dissolving 15 parts of acrylamide, 0.5 part of dimethyldiallylammonium chloride, 2.5 parts of t-butyl acrylamide, 0.4 part of methylene bisacrylamide, and 0.5 part of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. A solution was prepared by dissolving 3 parts of sorbitan oleate and 0.5 part of fatty alcohol polyoxyethylene ether in 70 parts of 3# white oil. The oil solution and the aqueous solution were sequentially added to a reaction kettle, stirring was carried out at a stirring rate of 500 rpm for 30 min, and oxygen was removed by nitrogen bubbling. The temperature in the kettle was controlled to be 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle, and stirring was carried out until uniformity was achieved. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle, the temperature increase was controlled to be no more than 2°C / min until the end of the temperature increase, and the temperature was maintained at 50°C for 60 min, and then the temperature was decreased to 25°C.

[0112] A solution was prepared by dissolving 15 parts of acrylamide, 2 parts of 2-acrylamido-2-methylpropane sulfonic acid, 0.5 part of t-butyl acrylamide, 0.75 part of polyethylene glycol diacrylate, and 0.075 part of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. The aqueous solution was added to the reaction system of the first step, stirring was carried out at a stirring rate of 500 rpm for 30 min, and oxygen was removed by nitrogen bubbling. The temperature in the kettle was controlled to be 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle, and stirring was carried out until uniformity was achieved. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle, the temperature increase was controlled to be no more than 2°C / min until the end of the temperature increase, and the temperature was maintained at 50°C for 60 min, and then the temperature was decreased to 25°C, and the product was discharged.

[0113]

Example 8

[0114] Synthesis of component two of the polyacrylamide microsphere profile control agent:

[0115] A solution was prepared by dissolving 10 parts of acrylamide, 7.5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 7.5 parts of t-butyl acrylamide, 0.25 part of methylene bisacrylamide, 0.25 part of polyethylene glycol diacrylate, and 0.005 part of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. A solution was prepared by dissolving 3 parts of sorbitan oleate and 0.5 part of a fatty alcohol polyoxyethylene ether in 55 parts of 3# white oil. The oil solution and the aqueous solution were sequentially added to a reaction kettle, stirring was carried out at a rate of 500 rpm for 30 min, and oxygen was removed by passing nitrogen gas. The temperature in the kettle was controlled to be 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle while stirring. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle, and the temperature of the reaction was controlled to be not more than 2°C / min until the end of the temperature increase. The temperature was maintained at 50°C for 60 min, and the temperature was decreased to 25°C to discharge the product.

[0116]

Example 9

[0117] Synthesis of the third component of the polyacrylamide microsphere profile control agent:

[0118] A solution was prepared by dissolving 5 parts of acrylamide, 9.5 parts of dimethyldiallylammonium chloride, 9.5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 9.5 parts of t-butyl acrylamide, 0.0025 parts of polyethylene glycol diacrylate, and 0.025 parts of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. A solution was prepared by dissolving 3 parts of sorbitan oleate and 0.5 part of a fatty alcohol polyoxyethylene ether in 70 parts of 3# white oil. The oil solution and the aqueous solution were sequentially added to a reaction kettle, stirring was carried out at a rate of 500 rpm for 30 min, and oxygen was removed by passing nitrogen gas. The temperature in the kettle was controlled to be 10-15°C. A solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction kettle while stirring. A solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction kettle, and the temperature of the reaction was controlled to be not more than 2°C / min until the end of the temperature increase. The temperature was maintained at 50°C for 60 min, and the temperature was decreased to 25°C.

[0119] A solution was prepared by dissolving 5 parts of acrylamide, 9.5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 9.5 parts of t-butyl acrylamide, 0.35 parts of polyethylene glycol diacrylate, and 0.0005 parts of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. The above aqueous solution was added to the reaction vessel in which the first step was completed, and stirred at a rate of 500 rpm for 30 min while removing oxygen by passing nitrogen gas. The temperature in the reaction vessel was controlled to be 10-15°C. An aqueous solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction vessel while stirring. An aqueous solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction vessel. The temperature of the reaction was controlled to be not more than 2°C / min until the end of the temperature increase by controlling the rate of dropwise addition of sodium pyrosulfite. The temperature was maintained at 50°C for 60 min, and then the temperature was decreased to 25°C to discharge the product.

[0120] Example 10

[0121] Synthesis of component three of the polyacrylamide microsphere profile control agent

[0122] A solution was prepared by dissolving 15 parts of acrylamide, 7.5 parts of dimethyldiallylammonium chloride, 7.5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 7.5 parts of t-butyl acrylamide, 0.25 parts of polyethylene glycol diacrylate, and 0.05 parts of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. A solution was prepared by dissolving 3 parts of sorbitan oleate and 0.5 parts of fatty alcohol polyoxyethylene ether in 70 parts of 3# white oil. The above oil solution and the above aqueous solution were sequentially added to the reaction vessel, and stirred at a rate of 500 rpm for 30 min while removing oxygen by passing nitrogen gas. The temperature in the reaction vessel was controlled to be 10-15°C. An aqueous solution of 0.00125 parts of potassium bromate in 1 part of water was added dropwise to the reaction vessel while stirring. An aqueous solution of 0.05 parts of sodium pyrosulfite in 5 parts of water was slowly added dropwise to the reaction vessel. The temperature of the reaction was controlled to be not more than 2°C / min until the end of the temperature increase by controlling the rate of dropwise addition of sodium pyrosulfite. The temperature was maintained at 50°C for 60 min, and then the temperature was decreased to 25°C.

[0123] A solution was prepared by dissolving 15 parts of acrylamide, 7.5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 7.5 parts of tert-butyl acrylamide, 0.5 parts of polyethylene glycol diacrylate, and 0.05 parts of disodium ethylenediaminetetraacetate in 30 parts of water, and adjusting the pH to 7. The above aqueous solution was added to the reaction system after the first step was completed, the stirring rate was 500 rpm, and the stirring was performed for 30 min, and nitrogen was introduced to remove oxygen. The temperature in the kettle was controlled to be 10-15°C. After 0.00125 parts of potassium bromate was dissolved in 1 part of water to prepare an aqueous solution, the aqueous solution was added dropwise into the reaction kettle and stirred uniformly. 0.05 parts of sodium pyrosulfite was dissolved in 5 parts of water, and was slowly added into the reaction kettle. The dropping speed of sodium pyrosulfite was controlled, and the temperature of the reaction was controlled to be not more than 2°C / min until the end of the temperature rising. The temperature was maintained at 50°C for 60 min, and the temperature was decreased to 25°C to discharge the product.

[0124] [Example 11]

[0125] The product obtained in Example 1 (35 parts), the product obtained in Example 2 (35 parts), and the product obtained in Example 3 (30 parts) were sequentially added into a reaction kettle, the stirring rate was 200 rpm, and the stirring was performed for 30 min, and the product was discharged to obtain a polyacrylamide microsphere profile control agent 1#.

[0126] [Example 12]

[0127] The product obtained in Example 4 (35 parts), the product obtained in Example 2 (35 parts), and the product obtained in Example 5 (30 parts) were sequentially added into a reaction kettle, the stirring rate was 200 rpm, and the stirring was performed for 30 min, and the product was discharged to obtain a polyacrylamide microsphere profile control agent 2#.

[0128] [Example 13]

[0129] The product obtained in Example 4 (35 parts), the product obtained in Example 2 (25 parts), and the product obtained in Example 5 (40 parts) were sequentially added into a reaction kettle, the stirring rate was 200 rpm, and the stirring was performed for 30 min, and the product was discharged to obtain a polyacrylamide microsphere profile control agent 3#.

[0130] [Example 14]

[0131] The product obtained in Example 1 (40 parts), the product obtained in Example 2 (40 parts), and the product obtained in Example 3 (20 parts) were sequentially added into a reaction kettle, the stirring rate was 200 rpm, and the stirring was performed for 30 min, and the product was discharged to obtain a polyacrylamide microsphere profile control agent 4#.

[0132] [Example 15]

[0133] The product obtained in Example 6 (20 parts), the product obtained in Example 8 (45 parts), and the product obtained in Example 9 (35 parts) were sequentially added into a reaction kettle, the stirring rate was 200 rpm, and the stirring was performed for 30 min, and the product was discharged to obtain a polyacrylamide microsphere profile control agent 5#.

[0134] Example 16

[0135] The product obtained in Example 7 was taken 5 parts, the product obtained in Example 8 was taken 47 parts, and the product obtained in Example 10 was taken 48 parts, which were sequentially added into a reaction kettle, the stirring rate was 200 rpm, and stirring was performed for 30 min, and then the product was discharged to obtain a polyacrylamide microsphere profile control agent 6#.

[0136] Example 17

[0137] The product obtained in Example 6 was taken 48 parts, the product obtained in Example 8 was taken 8 parts, and the product obtained in Example 10 was taken 44 parts, which were sequentially added into a reaction kettle, the stirring rate was 200 rpm, and stirring was performed for 30 min, and then the product was discharged to obtain a polyacrylamide microsphere profile control agent 7#.

[0138] Example 18

[0139] The product obtained in Example 7 was taken 47 parts, the product obtained in Example 8 was taken 45 parts, and the product obtained in Example 9 was taken 8 parts, which were sequentially added into a reaction kettle, the stirring rate was 200 rpm, and stirring was performed for 30 min, and then the product was discharged to obtain a polyacrylamide microsphere profile control agent 8#.

[0140] Comparative Example 1

[0141] 25 parts of acrylamide, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 3 parts of tert-butyl acrylamide, 0.025 parts of methylene bisacrylamide, and 0.005 parts of ethylenediaminetetraacetic acid disodium were dissolved in 30 parts of water to prepare a solution, and the pH value was adjusted to 7. 3 parts of sorbitan oleate and 0.5 parts of fatty alcohol polyoxyethylene ether were dissolved in 55 parts of 3# white oil. The above oil solution and the aqueous solution were sequentially added into a reaction kettle, the stirring rate was 500 rpm, stirring was performed for 30 min, and nitrogen was introduced to remove oxygen. The temperature in the kettle was controlled to be 10-15 ℃. 0.00125 parts of potassium bromate was dissolved in 1 part of water to prepare an aqueous solution, which was added dropwise into the reaction kettle and stirred uniformly. 0.05 parts of sodium pyrosulfite was dissolved in 5 parts of water, which was slowly added into the reaction kettle. By controlling the dropping speed of sodium pyrosulfite, the temperature rise was controlled to be not more than 2 ℃ / min until the end of temperature rise. The temperature was maintained at 50 ℃ for 60 min, and then the temperature was decreased to 25 ℃, and the product was discharged. Comparative sample 1# was obtained.

[0142] Comparative Example 2

[0143] A solution was prepared by dissolving 25 parts of acrylamide, 5 parts of dimethyldiallylammonium chloride, 3 parts of t-butyl acrylamide, 0.025 parts of methylene bisacrylamide, and 0.005 parts of ethylenediaminetetraacetic acid disodium salt in 30 parts of water, and adjusting the pH to 7. 3 parts of sorbitan oleate and 0.5 parts of fatty alcohol polyoxyethylene ether were dissolved in 55 parts of 3# white oil. The oil solution and the aqueous solution were sequentially added to a reaction kettle, the stirring rate was 500 rpm, and the stirring was performed for 30 min, and nitrogen was introduced to remove oxygen. The temperature in the kettle was controlled to be 10-15°C. 0.00125 parts of potassium bromate was dissolved in 1 part of water to prepare an aqueous solution, which was added dropwise into the reaction kettle and stirred uniformly. 0.05 parts of sodium pyrosulfite was dissolved in 5 parts of water, which was slowly added into the reaction kettle. The dropping speed of sodium pyrosulfite was controlled, and the temperature rise was controlled to be no more than 2°C / min until the end of temperature rise. The temperature was maintained at 50°C for 60 min, and then the temperature was decreased to 25°C to discharge the product. Comparative sample 2# was obtained.

[0144]

Comparative Example 3

[0145] The sample obtained in Example 1 was evaluated for its plugging performance alone, as Comparative Example 3#.

[0146]

Comparative Example 4

[0147] The sample obtained in Example 2 was evaluated for its plugging performance alone, as Comparative Example 4#.

[0148] The injection experiment results of different samples are shown in Table 1. After the above samples are prepared, they are dispersed in 10000 mg / L salinity brine, and the calcium and magnesium ion content is 500 ppm. After the above prepared solution is aged at 85°C for different time, the injection experiment is carried out in a 1000 mD permeability artificial core, and the injection pressure is recorded to calculate the resistance factor and residual resistance factor, which are shown in the following table. It can be seen that the resistance factor and residual resistance factor of the sample obtained by the present application are smaller before aging. The shell degradation time of the sample of Example 1# is about 10 days, so after 10 days of aging, the plugging capacity is obviously enhanced, and the plugging capacity of the sample of Example 2# is obviously enhanced after 20 days of aging. The time of the change of the plugging capacity is different, and the injection advancing speed can be combined to effectively realize the site plugging. Compared with the sample of Example 2#, the content of component three of the sample of Example 3# is increased, so after the shell is degraded, the content of the microsphere itself is reduced, and the content of the linear molecule is increased. It can be seen that the resistance factor is decreased, but the resistance to flushing is improved, and the residual resistance factor and the plugging retention rate calculated by the ratio of the resistance factor are improved. The content of component three of the sample of Example 4# is the lowest, and the content of the microsphere after the shell is degraded is the highest, so the resistance factor of the plugging is the highest, but the plugging retention rate is the lowest. The resistance factor and residual resistance factor of the samples of Example 5# and Example 7# after aging are higher, mainly because the ion monomer content of component one contained therein is higher, so the adsorption with the formation is enhanced. The samples of Example 6# and Example 8# need a longer aging time to enhance the plugging capacity, because the shell crosslinking degree of component one is higher, and a longer time is needed to fully degrade the core to expose it.

[0149] In comparison, the plugging capacity of Comparative Example Samples 1# and 2# gradually decreases from before aging, and the plugging capacity is relatively lower than that of the samples obtained by the present application. The residual resistance factor of the samples obtained by the present application is higher than that of the samples obtained by the comparative example, mainly because the flushing resistance of the aggregate structure formed by the three components of the present application is obviously improved, and the plugging retention rate is high. Comparative Example Samples 3# and 4# are the plugging experiment effects of component one and component two in Examples 1 and 2 of the present application alone. It can be seen that because the adsorption capacity increases obviously after the shell of component one is degraded, and the swelling ratio increases after the degradable crosslinked structure of component two is degraded, both can cause the plugging capacity to increase after 10 days of aging, but the resistance factor and residual resistance factor are not as good as those of the samples of Examples 1-4#, and because there is no compounding of other components in the present application, the plugging capacity decreases obviously after further aging to 20 days.

[0150] Table 1 Injection experiment results of different samples

[0151]

Claims

1. A polyacrylamide microsphere profile control agent, comprising at least the following three components by weight percentage: (1) Component 1: Core-shell polymer microspheres with a cationic core and an anionic shell, with a content of 4%-48%; (2) Component 2: Anionic polymer microspheres, content 4%-48%; (3) Component 3: Core-shell polymer microspheres with a bipolar core and an anionic shell, with a content of 4%-48%; The core of component one has a stable cross-linked structural unit, and the outer shell has a degradable cross-linked structural unit; The second component contains both stable cross-linking structural units and degradable cross-linking structural units; The three-core component has degradable cross-linked structural units, and the outer shell has degradable cross-linked structural units; The core of component one and the stable cross-linked structural units in component two may be the same or different; the shell of component one, the core of component two, and the shell of component three may be the same or different. The core of component one, by weight, is obtained by reacting a reaction system I containing the following components: (1) 1-30 parts acrylamide; (2) 0.1-10 parts cationic monomer; (3) 0.1-10 parts of nonionic monomer; (4) 0.0001-0.5 parts of stable cross-linked structural units; The outer shell of component one, by weight, is obtained by reacting reaction system II, which contains the following components: (1) 1-30 parts acrylamide; (2) 0.1-10 parts of nonionic monomer; (3) 0.1-10 parts of anionic monomer; (4) 0.0001-1 part of degradable cross-linked structural units; The nonionic monomers in the core and the nonionic monomers in the shell of component one may be the same or different; Component two, by weight, is obtained from reaction system III, which contains the following components: (1) 1-30 parts acrylamide; (2) 0.1-10 parts of anionic monomer; (3) 0.1-10 parts of nonionic monomer; (4) 0.0001-0.5 parts of stable cross-linked structural units; (5) 0.0001-1 part of degradable cross-linked structural units; The core of component three, by weight, is obtained by reaction in reaction system IV, which contains the following components: (1) 1-30 parts acrylamide; (2) 0.1-10 parts of anionic monomer; (3) 0.1-10 parts cationic monomer; (4) 0.1-10 parts of nonionic monomer; (5) 0.0001-0.5 parts of biodegradable cross-linked structural units; The outer shell of component three is obtained by reacting, by weight, a reaction system V containing the following components: (1) 1-30 parts acrylamide; (2) 0.1-10 parts of nonionic monomer; (3) 0.1-10 parts of anionic monomer; (4) 0.0001-1 part of degradable cross-linked structural units; The anionic monomers in the three-core component and the anionic monomers in the shell are either the same or different; The nonionic monomers in the three-component core and the nonionic monomers in the shell may be the same or different.

2. The polyacrylamide microsphere profile control agent according to claim 1, characterized in that, In the polyacrylamide microsphere profile control agent (1) The content of component one is 20%-40%; (2) The content of component two is 20%-40%; (3) The content of component three is 20%-40%.

3. The polyacrylamide microsphere profile control agent according to claim 1, characterized in that, The stable crosslinking structural unit is selected from at least one of methylenebisacrylamide, divinylbenzene, N,N'-methylenebismethylacrylamide, and N,N'-m-phenylenebismaleimide; the degradable crosslinking structural unit is selected from at least one of diallyl phthalate, diallyl cyanoethyl acetate, polyethylene glycol diacrylate, ethylene glycol diacrylate, and pentaerythritol triacrylate.

4. The polyacrylamide microsphere profile control agent according to any one of claims 1 to 3, characterized in that, The reaction systems I to V further include: (1) 0.0001-0.05 parts initiator; (2) 5-70 parts water; (3) 0.0001-1 parts of disodium ethylenediaminetetraacetate; The reaction systems I, III, and IV further include: (4) 10-90 parts of oil solvent; (5) 0.5-30 parts emulsifier.

5. The polyacrylamide microsphere profile control agent according to claim 4, characterized in that, The reaction systems I, III, and IV further include: (5) 2.5-20 parts emulsifier.

6. The polyacrylamide microsphere profile control agent according to any one of claims 1 to 3, characterized in that, The anionic monomer is selected from at least one of acrylic acid, methacrylic acid, sodium vinyl sulfonate, p-vinylbenzenesulfonic acid, maleic acid, fumaric acid, vinylbenzenesulfonic acid, allyl sulfonic acid, allylbenzenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid and / or its alkali metal salt and ammonium salt; The nonionic monomer is selected from at least one of methacrylamide, dimethacrylamide, diethylacrylamide, hydroxymethylacrylamide, hydroxyethylacrylamide, dimethylaminopropylmethacrylamide, hydroxymethyl methacrylate, hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, and vinylpyrrolidone. The cationic monomer is selected from at least one of methacryloyloxyethyltrimethylammonium chloride, 2-acrylamido-2-methylpropyltrimethylammonium chloride, dimethylethylallylammonium chloride, dimethyldiallylammonium chloride, acryloyloxyethyltrimethylammonium chloride, acryloyloxyethyldimethylbenzylammonium chloride, and methacryloyloxyethyldimethylbenzylammonium chloride.

7. The polyacrylamide microsphere profile control agent according to claim 4, characterized in that... The initiator is selected from at least one of the following: ammonium persulfate, potassium persulfate, sodium persulfate, potassium bromate, sodium bromate, hydrogen peroxide, tert-butyl hydroperoxide, benzoyl peroxide, azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, dimethyl azobisisobutyrate, azobisisobutylamidine hydrochloride, 2,2'-azo[2-(2-imidazolin-2-yl)propane] dihydrochloride, azobis(2,5-dimethyl-6-carboxy)hexanonitrile, 4,4'-azobis(4-cyanopentanoic acid), sodium bisulfite, sodium dithionite, sodium metabisulfite, and ferrous ammonium sulfate. The oil solvent is selected from at least one of aliphatic hydrocarbons, aromatic hydrocarbons, mineral oils, or vegetable oils; the aliphatic hydrocarbon is selected from at least one of cyclohexane, hexane, heptane, octane, and isooctane; the aromatic hydrocarbon is selected from at least one of benzene, toluene, ethylbenzene, xylene, and cumene; the mineral oil is selected from at least one of liquid paraffin, white oil, gasoline, diesel, and kerosene; and the vegetable oil is selected from at least one of peanut oil, soybean oil, sunflower seed oil, and castor oil. The emulsifier is selected from at least one of the following: sorbitan oleate, sorbitan stearate, sorbitan palmitate, sorbitan laurate, fatty alcohol polyoxypropylene polyoxyethylene ether as shown in formula (i), aromatic alcohol polyoxypropylene polyoxyethylene ether as shown in formula (ii), fatty acid polyoxypropylene polyoxyethylene ester as shown in formula (iii), and fatty amine polyoxypropylene polyoxyethylene ether as shown in formula (iv). Among them, R1, R2 and R3 are each independently selected from hydrocarbon groups of C1 to C28; R4 and R5 are taken from hydrogen atoms or hydrocarbon groups of C1 to C28, and R4 and R5 cannot be hydrogen atoms at the same time; m is selected from 0 to 30; n is selected from 1 to 40.

8. The polyacrylamide microsphere profile control agent according to any one of claims 1 to 3, characterized in that, Components one and three are prepared by reverse emulsion or reverse suspension polymerization, including the following steps: ① Prepare an aqueous solution with a pH value between 5 and 10 by mixing the required monomers, cross-linking agent, disodium EDTA, and water. ② The required amount of emulsifier is dissolved in the oil solvent to prepare a solution; ③ Mix the solution obtained in step 2 with the solution obtained in step 1 to obtain mixture A; ④ Purge mixture A with nitrogen for 30-60 minutes, add an aqueous solution prepared with initiator, and carry out core polymerization. After polymerization is completed, keep it at 50-85℃ for 30-60 minutes, and then cool it to room temperature. ⑤ Prepare an aqueous solution with a pH value between 5 and 10 by mixing the required monomers for the shell, crosslinking agent, disodium ethylenediaminetetraacetate, and water, and add it to the reaction system obtained in step 4; ⑥ Purge with nitrogen for 30-60 minutes, add an aqueous solution prepared with initiator, and carry out shell polymerization. After polymerization, keep at 50-85℃ for 30-60 minutes, cool to room temperature, and discharge.

9. The polyacrylamide microsphere profile control agent according to any one of claims 1 to 3, characterized in that, Component two is prepared by reverse emulsion or reverse suspension polymerization, including the following steps: ① Prepare an aqueous solution with a pH value between 5 and 10 by mixing the required monomer, crosslinking agent, disodium ethylenediaminetetraacetate, and water; ② Dissolve the required amount of emulsifier in an oil solvent to prepare a solution; ③ Mix the solution obtained in step 2 with the solution obtained in step 1 to obtain mixture B; ④ Purge mixture B with nitrogen for 30-60 minutes, add an aqueous solution prepared with initiator, and polymerize. After polymerization, keep at 50-85℃ for 30-60 minutes, cool to room temperature, and discharge.

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