CN104861946B - A kind of flexible control-release microsphere dispersion formed by natural water-soluble copolymer and its preparation and the application in intensified oil reduction - Google Patents

Abstract

The present invention relates to a kind of flexible control-release microsphere dispersion formed by natural water-soluble copolymer and its preparation and the application in intensified oil reduction, the dispersion includes the octane emulsion of the natural water-soluble copolymer aqueous solution, inorganic salt solution and surfactant-dispersed containing carboxyl and hydroxyl；The octane emulsion of described surfactant-dispersed is to adding octane and being uniformly dispersed to obtain in aqueous surfactant solution.The natural water-soluble copolymer source that the present invention is used is wide, it is renewable, it is environment-friendly, there is great amount of hydroxy group and appropriate carboxyl in strand, the appropriate flexible control-release microsphere with flexible core shell structure of chain density can be formed in the presence of polyvalent mineral salt ion.Flexible control-release microsphere is migrated in formation pore, can be blocked macropore and be shouted, and improves injection pressure, adjusts injection profile.

Description

A flexible controlled-release microsphere dispersion system formed by natural water-soluble polymers and its Preparation and application in enhanced oil recovery

technical field

The invention relates to a microsphere dispersion system formed by a natural water-soluble polymer, which can be used for plugging and profile control in oil field water injection production, and can carry high-efficiency oil displacement agent deep into the reservoir for controlled release, reducing the interfacial tension of crude oil, and once It can significantly increase the recovery rate and belongs to the field of oil field chemistry.

Background technique

As a strategic resource, oil plays an important role in its effective exploitation and utilization. Since oil is a non-renewable resource, with the continuous improvement of productivity, the society's demand for oil has risen sharply, and the chance of rediscovering large reserves of oil reservoirs has decreased, so that the improvement of the recovery rate of developed oil fields has attracted much attention, and technical means have been adopted Enhanced oil recovery has become a necessary production measure with great potential.

The channeling problem of the oil displacement system caused by the heterogeneity of the reservoir is the main contradiction restricting the improvement of oil recovery. With the expansion of the development scale, this contradiction becomes more and more serious, and the impact on the production becomes more and more serious. At present, oilfield water injection development mainly adopts profile control technology to improve the water absorption profile, such as injecting high-concentration small slug high-viscosity polymer solution into the oil layer to redirect the reservoir fluid and improve the sweep efficiency of injected water. However, existing plugging and profile control systems, such as polyacrylamide (HPAM) polymer solution or colloidal dispersion gel profile control and plugging system (CDG), are not resistant to dilution, chemical or biological degradation, and mechanical shear viscosity reduction. Fast, poor plugging control effect or large reservoir damage and other problems.

Polymer microspheres are a new type of deep profile control and plugging material developed in recent years. The results of laboratory experiments and mine field tests show that the injection of polymer microspheres can well raise the injection pressure and improve the oil production capacity of the well group. Its mechanism is mainly to block the high-permeability water channel by entering the deep part of the formation, causing the liquid flow to change direction, and achieving the purpose of expanding the swept volume of water flooding. Studies have shown that microspheres with good elasticity can meet the requirements of injection, plugging and migration of profile control agents, and can effectively plug high-permeability zones and improve oil production capacity.

The reported polymer microspheres are synthesized by chemical methods, and their biodegradability is poor, so there are certain hidden dangers in their application. In addition, polymer microspheres are injected into deep formations, only for plugging and profile control, and the effect is relatively simple. If the oil displacement agent can be carried into the formation and released under control, the recovery effect can be further improved, and the recovery rate can be greatly increased at one time.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a flexible controlled-release microsphere dispersion system formed by natural water-soluble polymers and its preparation and application in enhanced oil recovery. The flexible controlled-release microsphere dispersion system not only has the plugging Profile control performance, and can carry the oil displacement agent deep into the reservoir to control the release, further improving the recovery effect.

Terminology Explanation:

PV: Injected pore volume multiple, that is, the ratio of the fluid volume injected into the core sample to the pore volume of the core sample. For example: 1PV means that the ratio of the fluid volume injected into the core sample by the injected rock to the pore volume of the core sample is 1.

Technical scheme of the present invention is as follows:

A flexible controlled-release microsphere dispersion system formed by a natural water-soluble polymer, including an aqueous solution of a natural water-soluble polymer containing carboxyl and hydroxyl groups, an aqueous solution of an inorganic salt, and an octane emulsion dispersed by a surfactant;

The surfactant-dispersed octane emulsion is obtained by adding octane to an aqueous surfactant solution and dispersing it uniformly;

The mass ratio of the natural water-soluble polymer aqueous solution containing carboxyl and hydroxyl groups, inorganic salt solution and surfactant-dispersed octane emulsion is (12-35): (50-100): (1-3);

The mass concentration of the natural water-soluble polymer aqueous solution is 0.05%-1.0%, the concentration of the inorganic salt solution is 50ppm-10000ppm, and the mass concentration of the surfactant aqueous solution is 0.05%-0.6%. The mass ratio of the surfactant aqueous solution to octane is (2-10): (1-2).

According to the present invention, preferably, the flexible controlled-release microspheres have a diameter of 0.01-5.0 microns.

According to the present invention, preferably, said natural water-soluble polymer containing carboxyl and hydroxyl is modified cellulose, modified starch, gelatin, chitosan and/or alginate; further preferably, said containing The molecular weight range of natural water-soluble polymers of carboxyl and hydroxyl groups is 20,000 to 1,500,000.

According to the present invention, preferably, the inorganic salt includes barium chloride, aluminum chloride, ferric chloride, ferric sulfate, copper chloride, zinc chloride, zinc sulfate and/or calcium chloride.

According to the present invention, preferably, the surfactant is one or both of alkanolamide, petroleum sulfonate, fatty acid ethyl ester sulfonate, alkyl carboxylate, sulfobetaine and carboxybetaine Mix the above kinds; the size distribution of latex particles in the octane emulsion dispersed by the surfactant is 0.1-0.5 microns.

According to the present invention, preferably, the tolerable salinity range of the flexible controlled-release microspheres is: the total salinity is 50 ppm-100000 ppm, and the total concentration of calcium and magnesium ions is 50 ppm-10000 ppm.

According to the present invention, the preparation method of the above-mentioned flexible controlled-release microsphere dispersion system comprises the following steps:

(1) dissolving the natural water-soluble polymer containing carboxyl and hydroxyl groups in water, continuously stirring until completely dissolved, and preparing an aqueous solution of natural water-soluble polymer with a mass concentration of 0.05%-1.0%;

(2) surfactant is dissolved in water and is mixed with the solution that mass concentration is 0.05%-0.6%, is (2-10) by the mass ratio of surfactant aqueous solution and octane: (1-2) adds octane, Stir evenly and ultrasonically disperse to obtain surfactant-dispersed octane emulsion;

(3) The octane emulsion dispersed in the surfactant obtained in step (2) is added to the natural water-soluble polymer aqueous solution obtained in step (1), and stirred evenly to obtain a mixed solution;

(4) Prepare the inorganic salt into an inorganic salt solution with a concentration of 50ppm-10000ppm, and drop the mixed solution obtained in step (3) into the inorganic salt solution at a rate of 20ml/h-100ml/h to obtain a flexible controlled-release microparticle ball dispersion system.

According to the method of the present invention, preferably, the time for ultrasonic dispersion in step (2) is 1-3 hours.

According to the present invention, the above-mentioned flexible controlled release microsphere dispersion system has plugging profile control and controlled release performance, and can be used as a plugging agent or profile control agent in the oil production process;

Preferably, the specific application method includes steps as follows:

Dilute the flexible controlled-release microsphere dispersion system with water to a mass concentration of 0.05%-0.3%, inject 0.3-0.6PV into the oil reservoir to be recovered, and then switch to water injection.

According to the application of the flexible controlled-release microsphere dispersion system of the present invention, preferably, after the flexible controlled-release microsphere dispersion system is diluted with water, the surfactant is gradually released as an oil displacement agent, and the flexible controlled-release microsphere dispersion system is diluted to the mass concentration 0.1-0.3%. The water used for dilution can be formation water or underground produced water reused after treatment.

The flexible controlled-release microsphere dispersion system of the present invention can be applied to fractured carbonate reservoirs and conventional sandstone reservoirs, and can increase the recovery rate.

Principle of the present invention:

Natural water-soluble polymers contain a large number of hydroxyl groups and an appropriate amount of carboxyl groups. An appropriate concentration of multivalent cations can chelate with an appropriate amount of hydroxyl groups and carboxyl groups (polymers), so that the chains of the water-soluble polymers are intertwined. Flexible microspheres with a flexible core-shell structure with appropriate chain density are formed. When the mass ratio of surfactant aqueous solution and octane is (2-10): (1-2), a uniformly dispersed and stable emulsion system can be formed, but when the amount of octane added is too high (exceeding the above ratio), the prepared octane The alkane emulsion is extremely unstable and affects the preparation of the mixed solution in the next step. The surfactant-dispersed octane emulsion can be dispersed in the core and shell of flexible microspheres with a core-shell structure. During the dilution process of the flexible microspheres, hydration swelling will occur to gradually release the surface active substances in the flexible microspheres. The flexible microspheres will degrade completely after 300 days.

Technical characteristics of the present invention and good effect are as follows:

1. The natural water-soluble polymer used in the present invention has a wide source, is reproducible, and is environmentally friendly. There are a large number of hydroxyl groups and an appropriate amount of carboxyl groups in the molecular chain, and it can form a flexible polymer with appropriate chain density in the presence of multivalent inorganic salt ions. Flexible controlled-release microspheres with core-shell structure. The flexible controlled-release microspheres migrate in the pores of the formation, which can block the large pores, increase the injection pressure, and adjust the injection profile.

2. The flexible controlled-release microsphere dispersion system of the present invention has good stability, and it will degrade after a period of migration underground, and will not pollute the environment.

3. The present invention can wrap the oil-displacing agent inside the flexible controlled-release microspheres, and carry it to the deep part of the formation to release the oil-displacing agent slowly, so as to continuously reduce the oil-water interfacial tension and improve the oil-displacing efficiency.

4. The preparation and application method of the flexible controlled-release microsphere dispersion system of the present invention is simple, the material cost is low, and the flexible controlled-release microsphere dispersion system has strong adaptability to polyvalent inorganic cations and has no secondary pollution to the environment.

5. The flexible controlled-release microsphere dispersion system of the present invention is green and environmentally friendly. It can not only realize deep profile control, but also can control the release of surfactants to reduce the interfacial tension of oil and water. Therefore, it has an important application prospect in the field of enhanced oil recovery.

Description of drawings

Figure 1 is a curve showing the change in size of flexible controlled-release microspheres with time in Example 1 of the present invention.

Fig. 2 is a diagram of the rupture and degradation of the flexible controlled-release microspheres observed with a microscope in Example 1 of the present invention.

detailed description

The present invention will be further described below in conjunction with the examples, but not limited thereto.

The raw materials used in the examples are conventional raw materials, commercially available products.

Example 1:

A flexible controlled-release microsphere dispersion system formed by a natural water-soluble polymer, including an aqueous solution of a natural water-soluble polymer containing carboxyl and hydroxyl groups, an aqueous solution of an inorganic salt, and an octane emulsion dispersed by a surfactant;

The surfactant-dispersed octane emulsion is obtained by adding octane to an aqueous surfactant solution and dispersing it uniformly;

The mass ratio of the natural water-soluble polymer aqueous solution containing carboxyl and hydroxyl groups, inorganic salt solution and surfactant-dispersed octane emulsion is 12:50:2.4;

The mass concentration of the described natural water-soluble polymer aqueous solution is 0.6%, the concentration of the described inorganic salt solution is 8000ppm, the mass concentration of the described surfactant aqueous solution is 0.1%, and the described surfactant aqueous solution and octane The mass ratio of alkane is 2:1;

The natural water-soluble polymer is alginate, the inorganic salt is copper chloride and calcium chloride, and the surfactant is alkanolamide.

The preparation method comprises steps as follows:

(1) Mix 0.6 g of alginate with 100 g of water, and mechanically stir at 25° C. until the alginate is completely dissolved to obtain a natural water-soluble polymer aqueous solution with a mass concentration of 0.6%;

(2) Mix 0.1g alkanolamide with 100g water, stir mechanically at 25°C until it dissolves completely, forming a uniform and transparent solution, add octane according to the mass ratio of alkanolamide aqueous solution to octane 2:1, stir evenly, Ultrasound for 1 hour to obtain a stable surfactant-dispersed octane emulsion with a size distribution of 0.1-0.5 microns;

(3) mixing the step (1) natural water-soluble polymer aqueous solution with the octane emulsion dispersed in the step (2) surfactant and stirring evenly to obtain a mixed solution;

(4) Prepare copper chloride and calcium chloride into an inorganic salt solution with a total concentration of 8000ppm, place it in a constant temperature water tank, and keep the constant temperature at 40°C; Inject the mixed solution into the inorganic salt solution at a high speed to prepare a flexible controlled-release microsphere dispersion system with a diameter of 0.01-1.0 microns.

In this process, the pore diameter of the capillary is used to simulate the pores of the formation, and the pressure of the injected water is simulated by adjusting the injection speed of the micro injector.

Experimental example 1:

The flexible controlled-release microspheres prepared in Example 1 were placed in a flowing mineralized aqueous solution with a salinity of 2000ppm, the temperature of the constant mineralized water was 40°C, and the formation environment was simulated to observe the size change of the flexible controlled-release microspheres and degradation.

A microscope was used to monitor the hydration expansion of the flexible controlled-release microspheres in the process of free migration in the formation. The change in size of the flexible controlled-release microspheres with time is shown in Figure 1. It can be seen from Figure 1 that the flexible controlled-release microspheres gradually swelled with time. Therefore, during the formation migration process, the flexible controlled-release microspheres will hydrate and expand until the plugging effect occurs.

After 300 days, the flexible controlled-release microspheres ruptured and degraded completely. It can be seen that the flexible controlled-release microspheres will degrade during formation migration and will not pollute the environment.

Experimental example 2:

In Experimental Example 1, the surfactant will be released gradually during the expansion process of the flexible controlled-release microspheres. The external solution of the flexible controlled-release microspheres was collected by filtration, and the ability of the released surfactant to reduce the interfacial tension was measured by a spinning drop interfacial tensiometer. The model of the interfacial tensiometer used is TEXAS-500, the experimental temperature is adjusted to 50°C, the oil phase used is Shengtuokou Outer Oil, and the rotational speed is adjusted to 6000r/min. It was found that the surfactant released by the flexible controlled release microspheres It can reduce the oil-water interfacial tension to 10 ^-2 mN.m ^-1 within 15 minutes.

Example 2:

A flexible controlled-release microsphere dispersion system formed by a natural water-soluble polymer, including an aqueous solution of a natural water-soluble polymer containing carboxyl and hydroxyl groups, an aqueous solution of an inorganic salt, and an octane emulsion dispersed by a surfactant;

The surfactant-dispersed octane emulsion is obtained by adding octane to an aqueous surfactant solution and dispersing it uniformly;

The mass ratio of the natural water-soluble polymer aqueous solution containing carboxyl and hydroxyl groups, inorganic salt solution and surfactant-dispersed octane emulsion is 35:100:3;

The mass concentration of the described natural water-soluble polymer aqueous solution is 0.8%, the concentration of the described inorganic salt solution is 100ppm, the mass concentration of the described surfactant aqueous solution is 0.1%, and the described surfactant aqueous solution and octane The mass ratio of alkane is 1:1;

The natural water-soluble polymer is chitosan, the inorganic salt is calcium chloride, and the surfactant is carboxybetaine.

The preparation method comprises steps as follows:

(1) 0.8g chitosan is mixed with 100g water, mechanically stirred at 25 DEG C, until chitosan dissolves completely, the obtained mass concentration is 0.8% natural water-soluble polymer aqueous solution;

(2) Mix 0.1g carboxybetaine with 100g water, stir mechanically at 25°C until it dissolves completely, forming a uniform and transparent solution, add octane according to the mass ratio of carboxybetaine aqueous solution to octane 1:1, stir evenly, Ultrasound for 1 hour to obtain a stable surfactant-dispersed octane emulsion with a size distribution of 0.1-0.5 microns;

(3) mixing the step (1) natural water-soluble polymer aqueous solution with the octane emulsion dispersed in the step (2) surfactant and stirring until uniform to obtain a mixed solution;

(4) Calcium chloride is prepared into an inorganic salt solution with a total concentration of 100ppm, and the configured inorganic salt solution is placed in a constant temperature water tank at a constant temperature of 40°C; a micro-syringe is used to pass through a capillary tube with a diameter of 10 μm, and the concentration is 80ml/ Inject the mixed solution into the inorganic salt solution at an injection speed of h to prepare a flexible controlled-release microsphere dispersion system with a diameter of 0.1-5.0 microns.

When the flexible controlled-release microspheres prepared in this example are injected into the formation, the surfactant will be released, and the remaining natural water-soluble polymers can continue to react with the multivalent metal ions contained in the formation to further form a flexible controlled-release microsphere. Microspheres block the pores and throats, and the specific rules are similar to those of Experimental Examples 1 and 2. It has been determined that the released surfactant can reduce the interfacial tension of crude oil and water to 10 ^-2 mN.m ^-1 .

Example 3:

A flexible controlled-release microsphere dispersion system formed by a natural water-soluble polymer, including an aqueous solution of a natural water-soluble polymer containing carboxyl and hydroxyl groups, an aqueous solution of an inorganic salt, and an octane emulsion dispersed by a surfactant;

The surfactant-dispersed octane emulsion is obtained by adding octane to an aqueous surfactant solution and dispersing it uniformly;

The mass ratio of the natural water-soluble polymer aqueous solution containing carboxyl and hydroxyl groups, inorganic salt solution and surfactant-dispersed octane emulsion is 20:80:3;

The mass concentration of the described natural water-soluble polymer aqueous solution is 1.0%, the concentration of the described inorganic salt solution is 2000ppm, the mass concentration of the described surfactant aqueous solution is 0.2%, and the described surfactant aqueous solution and octane The mass ratio of alkane is 3:1;

The natural water-soluble polymer is modified starch, the inorganic salt is ferric chloride, calcium chloride, zinc sulfate and barium chloride, and the surfactant is petroleum sulfonate.

The preparation method comprises steps as follows:

(1) Mix 1 g of modified starch with 100 g of water, and mechanically stir at 25° C. until the modified starch is completely dissolved to obtain a natural water-soluble polymer aqueous solution with a mass concentration of 1%;

(2) Mix 0.2g of petroleum sulfonate with 100g of water, stir mechanically at 25°C until completely dissolved to form a uniform and transparent solution, add octane according to the mass ratio of petroleum sulfonate aqueous solution to octane 3:1, and stir Uniform, ultrasonic for 1 hour to obtain a stable surfactant-dispersed octane emulsion with a size distribution of 0.1-0.5 microns;

(3) mixing the step (1) natural water-soluble polymer aqueous solution with the octane emulsion dispersed in the step (2) surfactant and stirring until uniform to obtain a mixed solution;

(4) Ferric chloride, calcium chloride, zinc sulfate and barium chloride are formulated into mineralized water with a total salinity of 2000ppm, and the configured mineralized water is placed in a constant temperature water tank with a constant temperature of 40°C; Use a micro-syringe to inject the mixed solution into the inorganic salt solution at an injection speed of 20ml/h through a capillary tube with a diameter of 10 μm to prepare a flexible controlled-release microsphere dispersion system with a diameter of 0.1-5.0 μm.

When the flexible controlled-release microspheres prepared in this example are injected into the formation, they will hydrate and expand to block the pores and throats, and gradually release the surfactant. The specific rules are similar to those of Experimental Examples 1 and 2. It has been determined that the released surfactant can reduce the interfacial tension of crude oil and water to 10 ^-2 mN.m ^-1 .

Example 4:

A flexible controlled-release microsphere dispersion system formed by a natural water-soluble polymer, including an aqueous solution of a natural water-soluble polymer containing carboxyl and hydroxyl groups, an aqueous solution of an inorganic salt, and an octane emulsion dispersed by a surfactant;

The surfactant-dispersed octane emulsion is obtained by adding octane to an aqueous surfactant solution and dispersing it uniformly;

The mass ratio of the natural water-soluble polymer aqueous solution containing carboxyl and hydroxyl groups, inorganic salt solution and surfactant-dispersed octane emulsion is 15:75:3;

The mass concentration of the described natural water-soluble polymer aqueous solution is 0.1%, the concentration of the described inorganic salt solution is 10000ppm, the mass concentration of the described surfactant aqueous solution is 0.1%, and the described surfactant aqueous solution and octane The mass ratio of alkane is 1:1;

The natural water-soluble polymer is modified cellulose, the inorganic salt is aluminum chloride, calcium chloride, zinc chloride and barium chloride, and the surfactant is fatty acid ethyl ester sulfonate.

The preparation method comprises steps as follows:

(1) Mix 0.1 g of modified cellulose with 100 g of water, and mechanically stir at 25° C. until the modified cellulose is completely dissolved to obtain a natural water-soluble polymer aqueous solution with a mass concentration of 0.1%;

(2) Mix 0.1g of fatty acid ethyl ester sulfonate with 100g of water, stir mechanically at 25°C until it dissolves completely, forming a uniform and transparent solution, and add it according to the mass ratio of fatty acid ethyl ester sulfonate aqueous solution to octane 1:1 Octane, stirred evenly, and ultrasonicated for 1 hour to obtain a stable surfactant-dispersed octane emulsion with a size distribution of 0.1-0.5 microns;

(3) mixing the step (1) natural water-soluble polymer solution with the octane emulsion dispersed in the step (2) surfactant and stirring until uniform to obtain a mixed solution;

(4) Aluminum chloride, calcium chloride, zinc chloride and barium chloride are prepared into an inorganic salt solution with a concentration of 10000ppm, and the configured inorganic salt solution is placed in a constant temperature water tank with a constant temperature of 40°C; The syringe injects the mixed solution into the inorganic salt solution at an injection speed of 100ml/h through a capillary tube with a diameter of 20 μm to prepare a flexible controlled-release microsphere dispersion system with a diameter of 0.1-5.0 μm.

Claims (6)

1. A flexible controlled-release microsphere dispersion system formed by a natural water-soluble polymer, characterized in that the flexible controlled-release microsphere dispersion system comprises a natural water-soluble polymer aqueous solution containing carboxyl and hydroxyl, an inorganic salt solution and a surface Active agent dispersed octane emulsion; The surfactant-dispersed octane emulsion is obtained by adding octane to an aqueous surfactant solution and dispersing it uniformly; The mass ratio of the natural water-soluble polymer aqueous solution containing carboxyl and hydroxyl groups, inorganic salt solution and surfactant-dispersed octane emulsion is (12-35): (50-100): (1-3); The mass concentration of the natural water-soluble polymer aqueous solution is 0.05%-1.0%, the concentration of the inorganic salt solution is 50 ppm-10000 ppm, and the mass concentration of the surfactant aqueous solution is 0.05%-0.6% , the mass ratio of the surfactant aqueous solution to octane is (2-10): (1-2); Described natural water-soluble polymer containing carboxyl and hydroxyl is modified cellulose, modified starch, gelatin, chitosan and/or alginate, and the molecular weight of described natural water-soluble polymer containing carboxyl and hydroxyl The range is 20000~1500000; Described inorganic salt comprises barium chloride, aluminum chloride, ferric chloride, ferric sulfate, cupric chloride, zinc chloride, zinc sulfate and/or calcium chloride; The surfactant is one or a mixture of two or more of alkanolamides, petroleum sulfonates, fatty acid ethyl ester sulfonates, alkyl carboxylates, sulfobetaines and carboxybetaines. 2. The flexible controlled-release microsphere dispersion system according to claim 1, characterized in that, the diameter of the flexible controlled-release microsphere is 0.01-5.0 microns. 3. a preparation method of the flexible controlled-release microsphere dispersion system described in any one of claims 1-2, comprising steps as follows: (1) Dissolving natural water-soluble polymers containing carboxyl and hydroxyl groups in water, stirring continuously until completely dissolved, to prepare an aqueous solution of natural water-soluble polymers with a mass concentration of 0.05% - 1.0%; (2) Dissolve the surfactant in water to prepare a solution with a mass concentration of 0.05% - 0.6%. According to the mass ratio of the surfactant aqueous solution to octane (2-10): (1-2) add octane, Stir evenly and ultrasonically disperse to obtain surfactant-dispersed octane emulsion; (3) adding the surfactant-dispersed octane emulsion obtained in step (2) to the natural water-soluble polymer aqueous solution obtained in step (1), stirring evenly to obtain a mixed solution; (4) Prepare the inorganic salt into an inorganic salt solution with a concentration of 50 ppm-10000 ppm, and drop the mixed solution obtained in step (3) into the inorganic salt solution at a rate of 20 ml/h-100 ml/h to obtain Flexible controlled release microsphere dispersion system. 4. The preparation method of the flexible controlled-release microsphere dispersion system according to claim 3, characterized in that the ultrasonic dispersion time in step (2) is 1-3 h. 5. The application of the flexible controlled-release microsphere dispersion system according to any one of claims 1-2 as a plugging agent or a profile control agent in an oil production process. 6. The application according to claim 5, wherein the specific application method comprises the following steps: Dilute the flexible controlled-release microsphere dispersion system with water to a mass concentration of 0.05%-0.3%, inject 0.3-0.6 PV into the oil reservoir to be recovered, and then switch to water injection.