Super-temperature-resistant and salt-resistant gel particle for deep flow regulation of oil reservoir and preparation method of super-temperature-resistant and salt-resistant gel particle

Abstract

The invention discloses a super-temperature-resistant and salt-resistant gel particle for deep flow regulation of an oil reservoir and a preparation method, and belongs to the technical field of oilfield chemistry, the super-temperature-resistant and salt-resistant gel particle is formed by polymerizing a monomer, a stabilizer, a buffer agent, a cross-linking agent and an initiator, the total addition amount of the stabilizer and the buffer agent is 10% of the amount of substance of the monomer, and the addition amount of the cross-linking agent is 10% of the amount of substance of the monomer. The addition amount of the cross-linking agent is 5.5% of the amount of substance of the monomer, and the addition amount of the initiator is 1% of the amount of substance of the monomer. The super-temperature-resistant and salt-resistant gel particles for deep flow regulation of the oil reservoir are synthesized by utilizing an emulsion polymerization method. The main process comprises the following steps: preparing a water phase solution, preparing an oil phase solution, preparing an initiator solution, preparing an emulsion, carrying out polymerization reaction, and freeze-drying. The gel particles provided by the invention have higher stability and mechanical strength in high-temperature and saline water environments, and also have excellent deep migration and plugging strength, and an effective solution is provided for deep flow regulation.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield chemistry, and in particular relates to ultra-temperature-resistant and salt-resistant gel particles used for deep flow regulation in oil reservoirs and a preparation method thereof. Background Art

[0002] Excessive water production is the biggest problem facing mature oil fields, which can lead to uneconomical oil production and even oil well shutdown. In conventional water injection development, water flows preferentially to high permeability areas after entering the formation, resulting in severe fingering or tongue-in during water flooding. Specifically, the flow rate of injected water exceeds the flow rate of crude oil, causing water channeling to form in areas where the injected water has already reached after water is seen in the production well. Subsequent injected water migrates along these water channeling channels, resulting in some areas not being affected by the water injection, forming dead oil zones, which contain a large amount of remaining oil or residual oil. The high water yield of oil wells has become an important obstacle to improving the recovery rate of low permeability reservoirs.

[0003] In view of the current situation of high water content in oil fields, the commonly used solution is plugging and flow adjustment, that is, injecting plugging agents into the formation to block deep priority channels, realize deep liquid flow diversion, increase the swept volume of injected water, and exploit the remaining oil in secondary channels. Polymer gel is the most synthesized and widely used plugging and adjustment chemical agent at present. It has the characteristics of controllable particle size, good plugging effect, and simple process. It can effectively control high-permeability priority channels, improve the heterogeneity between reservoir layers, and increase crude oil recovery. However, traditional polymer gel particles absorb water and swell quickly, accumulate in the near-well area, hinder the deep migration of particles, and cannot effectively plug deep reservoirs. In addition, it is very easy to hydrolyze under the action of high temperature, high salt and acidic environment, and has poor long-term aging stability, and cannot be effectively plugged for a long time.

[0004] Under the above background, there is an urgent need to develop a plugging and flow regulation material with good injectability and long-term stability in high-temperature and high-salinity oil reservoir environments. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a super-heat-resistant and salt-resistant gel particle for deep flow regulation in oil reservoirs and a preparation method. The gel particle contains components such as styrene, vinylacetic acid, ammonium bicarbonate, divinylbenzene and ammonium persulfate, and is synthesized by emulsion polymerization, and has excellent injectability and heat-resistant and salt-resistant properties. During the preparation process, the microstructure and performance of the gel particles are optimized by optimizing the synthesis conditions. The present invention introduces divinylbenzene containing benzene rings and double bonds as a cross-linking agent, which significantly enhances the cross-linking density of the gel particles, making them have higher stability and mechanical strength in high temperature and saline environments. Experimental verification shows that the gel particles can be stable for at least 90 days under the conditions of a temperature of 150°C and a mineralization of 200,000 mg / L, and their heat-resistant and salt-resistant performance far exceeds that of traditional gel materials. In addition, the gel particles of the present invention also perform well in deep migration and plugging strength, providing an effective solution for deep flow regulation.

[0006] The technical solution of the present invention is as follows:

[0007] The invention discloses a super-temperature-resistant and salt-resistant gel particle for deep flow regulation in oil reservoirs, which is polymerized by monomers, stabilizers, buffers, crosslinking agents and initiators. The total amount of stabilizers and buffers added is 10% of the amount of monomers, the amount of crosslinkers added is 5.5% of the amount of monomers, and the amount of initiators added is 1% of the amount of monomers.

[0008] Furthermore, the monomer is styrene.

[0009] Furthermore, the stabilizer is vinyl acetic acid and the buffer is ammonium bicarbonate.

[0010] Furthermore, the cross-linking agent is divinylbenzene.

[0011] Furthermore, the initiator is ammonium persulfate.

[0012] A method for preparing the ultra-temperature-resistant and salt-resistant gel particles for deep flow regulation in oil reservoirs as described above, characterized in that it comprises the following steps:

[0013] Step 1, prepare an aqueous solution; weigh a stabilizer, a buffer, and deionized water and add them to a beaker, and place the beaker on a magnetic stirrer and stir thoroughly;

[0014] Step 2, prepare an oil phase solution; weigh the monomer and the cross-linking agent, add them into a three-necked flask, and stir thoroughly;

[0015] Step 3, prepare an initiator solution; weigh the initiator and deionized water and add them into a beaker, and place the beaker on a magnetic stirrer to stir thoroughly;

[0016] Step 4, preparing an emulsion; fully mixing the aqueous phase solution and the oil phase solution in a three-necked flask, and mixing and dispersing them under the action of a homogenizer to obtain a uniform homogeneous emulsion;

[0017] Step 5, performing a polymerization reaction; placing the homogeneous emulsion in a constant temperature oil bath, stirring at a temperature of 70°C and a speed of 450rpm / min; installing a condensation reflux device, and passing N2 for deoxygenation at the same time, adding the prepared initiator after reacting for 5min, and reacting for 10h to obtain an emulsion product;

[0018] Step 6, freeze drying; cool the emulsion product after the reaction to room temperature and then put it into the freezer of a freeze dryer, freeze it at -40°C for 24 hours, and then put it into the vacuum chamber of the freeze dryer for vacuum drying for 12 hours to obtain a white powdery gel particle product. The white powdery gel particle product is the ultra-temperature-resistant and salt-resistant gel particle used for deep flow regulation in oil reservoirs.

[0019] Beneficial technical effects brought by the present invention: The super-heat-resistant and salt-resistant polymer gel particles of the present invention are different from conventional polymer gel particles. A divinylbenzene (DVB) cross-linking agent containing a benzene ring and a double bond is introduced. The cross-linking density formed with styrene is high, the three-dimensional network structure is stable, and the temperature resistance is strong. In addition, the three-dimensional network structure after cross-linking is very dense. In a salt water environment, dissolved salt ions and water molecules cannot easily enter the high-density cross-linked network, further improving the salt resistance. The present invention verifies that the provided heat-resistant and salt-resistant gel particles have good heat resistance and salt resistance by studying the changes in the particle morphology of the super-heat-resistant and salt-resistant gel particles under different mineralization and aging temperature conditions. The super-heat-resistant and salt-resistant polymer gel particles of the present invention are different from conventional polymer gel particles. They have a small initial particle size and good injectability. The particles reduce accumulation in the near-wellbore area and can enter the deep matrix pores of the formation to adjust the flow, thereby improving the deep migration ability of the particles. At the same time, the core displacement experiment verifies that the provided heat-resistant and salt-resistant gel particles have good deep migration and flow adjustment performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a flow chart of the preparation method of the ultra-temperature-resistant and salt-resistant gel particles used for deep flow regulation in oil reservoirs.

[0021] Figure 2 These are particle morphology diagrams at different stirring speeds in Example 1 of the present invention.

[0022] Figure 3 This is a curve diagram of particle size change at different stirring speeds in Example 1 of the present invention.

[0023] Figure 4 This is a graph showing the effect of mineralization on particle size in Example 2 of the present invention.

[0024] Figure 5This is a comparison chart of particles aged for 0 days and 90 days under the conditions of 150°C and 200,000 mg / L in Example 3 of the present invention; wherein (a) is the result chart of aging for 0 days; and (b) is the result chart of aging for 90 days.

[0025] Figure 6 These are electron micrographs of particles aged for 0 and 90 days at 150°C and 200,000 mg / L in Example 3 of the present invention; wherein (c) is an electron micrograph of particles aged for 0 days; and (d) is an electron micrograph of particles aged for 90 days.

[0026] Figure 7 This is a curve diagram showing the change of displacement pressure with particle injection volume in Example 4 of the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0028] In the first aspect, the present invention provides a super-temperature-resistant and salt-resistant gel particle for deep flow regulation in oil reservoirs, which is polymerized by monomers, stabilizers, buffers, cross-linking agents, and initiators, wherein the total amount of stabilizers and buffers added is 10% of the amount of monomers, the amount of cross-linking agents added is 5.5% of the amount of monomers, and the amount of initiators added is 1% of the amount of monomers; specifically, it comprises the following components: styrene, vinyl acetic acid, ammonium bicarbonate (NH4HCO3), divinylbenzene (DVB), and ammonium persulfate (APS). Among them, the stabilizer vinyl acetic acid and the buffer ammonium bicarbonate (NH4HCO3) together account for 10% of the amount of monomers (vinyl acetic acid: ammonium bicarbonate = 2:1) (amount of substance), the cross-linker divinylbenzene (DVB) accounts for 5.5% of the amount of monomers, the initiator ammonium persulfate (APS) accounts for 1% of the amount of monomers, and the remainder is water.

[0029] In the second aspect, the present invention provides a method for preparing ultra-heat-resistant and salt-resistant gel particles for deep flow regulation in oil reservoirs. Among the components, the monomer can be dispersed in water to form an emulsion with the help of mechanical stirring, and a polymerization reaction occurs to generate gel particles. In a specific embodiment of the present invention, the monomer used is styrene. The cross-linking agent can help the system form a network three-dimensional structure and control the cross-linking density of the particles. In a specific embodiment of the present invention, the cross-linking agent used is divinylbenzene (DVB). The buffer can maintain the stability of the pH of the emulsion system. In a specific embodiment of the present invention, the buffer used is ammonium bicarbonate (NH4HCO3). The initiator can promote the polymerization reaction of the monomer and control the polymerization rate. In a specific embodiment of the present invention, the initiator used is ammonium persulfate (APS).

[0030] like Figure 1As shown, the polymer gel particles with good injectability, controllable particle size, acid and salt resistance, etc. are synthesized by emulsion polymerization. The steps are as follows:

[0031] Step 1: Prepare an aqueous solution. Weigh a certain amount of vinyl acetic acid, ammonium bicarbonate (NH4HCO3), and deionized water, add them into a beaker, fully dissolve the vinyl acetic acid and ammonium bicarbonate (NH4HCO3) in the deionized water, and place the beaker on a magnetic stirrer to stir fully.

[0032] Step 2: Prepare the oil phase solution: Weigh a certain amount of styrene and divinylbenzene (DVB), add them into a three-necked flask, and stir them thoroughly.

[0033] Step 3, prepare an initiator solution: Weigh ammonium persulfate (APS) and deionized water and add them into a beaker, and place the beaker on a magnetic stirrer for thorough stirring.

[0034] Among them, the stabilizer vinyl acetic acid and the buffer ammonium bicarbonate (NH4HCO3) together account for 10% of the amount of monomer substance (vinyl acetic acid: ammonium bicarbonate = 2:1) (amount of substance), the cross-linking agent divinylbenzene (DVB) accounts for 5.5% of the amount of monomer substance, and the initiator ammonium persulfate (APS) accounts for 1% of the amount of monomer substance.

[0035] Step 4: Prepare an emulsion: Fully mix the aqueous phase solution and the oil phase solution in a three-necked flask, and mix and disperse them under the action of a homogenizer to obtain a uniform homogeneous emulsion.

[0036] Step 5, conduct polymerization reaction. Place the homogeneous emulsion in a constant temperature oil bath, stir at 70°C and 450rpm / min, install a condensation reflux device, and pass N2 for deoxygenation. After reacting for 5 minutes, add the prepared initiator ammonium persulfate (APS), and react for 10 hours to obtain an emulsion product.

[0037] Step 6, freeze drying: The emulsion after the reaction is cooled to room temperature and then placed in the freezer chamber of a freeze dryer, frozen at -40°C for 24 hours, and then placed in the vacuum chamber of the freeze dryer for vacuum drying for 12 hours to obtain a white powdery gel particle product.

[0038] In the third aspect, the present invention provides a new solution for improving the heat resistance and salt resistance of gel particles. At present, common gel materials mostly use ester compounds as cross-linking agents, and ester bonds are prone to breakage at high temperatures. The bond energy of ester bonds is relatively low, and it is easy to hydrolyze or other chemical reactions at high temperatures, resulting in molecular decomposition, so the thermal stability is poor. In view of the complex reservoir conditions of the reservoir, the present invention introduces divinylbenzene (DVB) containing benzene rings and double bonds as a cross-linking agent, and the conjugated π electron cloud of the benzene ring makes it have high thermal stability. The aromaticity of the benzene ring structure provides additional stability, making the molecule difficult to decompose at high temperatures. And there are two double bonds in the divinylbenzene (DVB) molecule, and the cross-linking density formed with styrene is high, the three-dimensional network structure is stable, and the temperature resistance is strong. In addition, the three-dimensional network structure after cross-linking is very dense, which not only provides mechanical strength, but also reduces the penetration of external chemicals (such as salt ions). In a salt water environment, dissolved salt ions and water molecules cannot easily enter the high-density cross-linked network, further improving salt resistance.

[0039] Fourthly, the present invention optimizes the conditions that affect the stability of the emulsion and the microscopic state of the gel particles during the synthesis process, such as the emulsion homogenization power, the synthesis stirring speed, the synthesis reaction temperature, and the initiation conditions of the reaction system. By optimizing the preparation conditions of the temperature-resistant and salt-resistant gel particles, a uniform and stable emulsion and polymer gel particles with good uniformity, good roundness, and an initial particle size that meets the deep migration conditions are finally obtained.

[0040] In a fifth aspect, the present invention provides ultra-temperature-resistant and salt-resistant gel particles for deep flow regulation in oil reservoirs, which have superior temperature resistance, salt resistance, deep migration performance and deep plugging performance.

[0041] In order to demonstrate the feasibility and superiority of the present invention, the following examples are given.

[0042] Embodiment 1:

[0043] Weigh a certain amount of vinyl acetic acid, ammonium bicarbonate (NH4HCO3), and deionized water, add them to a beaker, fully dissolve the vinyl acetic acid and ammonium bicarbonate (NH4HCO3) in the deionized water, and stir them on a magnetic stirrer. Weigh a certain amount of styrene and divinylbenzene (DVB), add them to a three-necked flask, and stir them. Weigh a certain amount of ammonium persulfate (APS) and deionized water, add them to a beaker, fully dissolve the ammonium persulfate (APS) in the deionized water, and stir them on a magnetic stirrer.

[0044] The molar ratio of the substances is: styrene:vinyl acetic acid:ammonium bicarbonate=30:2:1, the crosslinking agent divinylbenzene (DVB) accounts for 5% of the molar ratio of the monomer substances, and the initiator ammonium persulfate (APS) accounts for 1% of the molar ratio of the monomer substances.

[0045] The aqueous phase solution and the oil phase solution are fully mixed in a three-necked flask, and mixed and dispersed under the action of a homogenizer to obtain a uniform emulsion. The homogenized emulsion is placed in a constant temperature oil bath, and stirred at a temperature of 70°C, with the speeds set to 300rpm / min, 350rpm / min, 400rpm / min, 450rpm / min, 500rpm / min, and 550rpm / min. A condensation reflux device is installed, and N2 is passed for deoxygenation. After reacting for 5 minutes, the prepared initiator ammonium persulfate (APS) is added, and the reaction is carried out for 10 hours to obtain an emulsion product. The obtained emulsion is diluted 20 times in deoxygenated water, and the particle morphology is observed using a transmission electron microscope and the particle size is measured. The particle morphology at each stirring speed is shown in FIG. Figure 2 The particle size changes at different stirring speeds are shown in Figure 3 .Depend on Figure 2 It can be seen that when the stirring speed is 450 rpm / min, the particle roundness is the best and the reaction is sufficient. Figure 3 It can be seen that the particle size increases first and then decreases with the increase of stirring speed. This is because a faster stirring speed will provide higher shear force, causing the droplets of the dispersed phase to break into smaller particles, resulting in a smaller particle size of the formed gel particles. At the same time, a higher stirring speed helps to disperse the monomer and initiator more evenly, promote the uniform progress of the reaction, reduce the large particles and agglomeration produced during the reaction, and thus generate more uniform and smaller gel particles. When the stirring speed is too high, although the droplets continue to break, the excessive shear force may cause the droplets to coalesce, that is, the small droplets re-aggregate into larger droplets, resulting in an increase in the particle size of the formed gel particles. When the stirring speed is 500rpm / min, the particle size is the smallest, at 200nm.

[0046] Embodiment 2:

[0047] Take the emulsion synthesized by the reaction at 70°C and 450rpm / min in Example 1, cool it to room temperature, put it into the freezer of a freeze dryer, freeze it at -40°C for 24 hours, and then put it into the vacuum chamber of the freeze dryer for vacuum drying for 12 hours to obtain a white powdery gel particle product. Prepare formation simulated water with mineralization levels of 50000mg / L, 100000mg / L, 150000mg / L, and 200000mg / L, respectively. Prepare a suspension of the provided heat-resistant and salt-resistant gel particles at a concentration of 2wt% in the above formation simulated water and deoxygenated ion water. After fully dispersing for 6 hours, observe the particle morphology and measure the particle size using a transmission electron microscope, study the change in the gel particle size with mineralization, and verify the salt resistance of the provided heat-resistant and salt-resistant gel particles. The results are as follows Figure 4 As shown. Figure 4The results show that with the increase of mineralization, the particle size of gel particles does not change significantly, and the mineralization has little effect on the particle size. This shows that the cross-linking density of gel particles is high and the three-dimensional network structure is stable, which reduces the penetration of salt ions and water molecules and weakens the influence of mineral ions in the formation on the particle size of gel particles, thereby achieving the salt resistance of gel particles.

[0048] Embodiment 3:

[0049] Take the emulsion synthesized by reaction at 70°C and 450rpm / min in Example 1, cool it to room temperature, put it into the freezer of a freeze dryer, freeze it at -40°C for 24 hours, and then put it into the vacuum chamber of the freeze dryer to evacuate and dry it for 12 hours to obtain a white powdery gel particle product. After the obtained gel particles are fully dispersed under the condition of 200000mg / L mineralization for 6 hours, they are aged at 150°C. By observing the changes in particle morphology with aging time, the heat resistance of the heat-resistant and salt-resistant gel particles provided is studied. The results are as follows Figure 5 , Figure 6 As shown. Figure 5 , Figure 6 Analysis shows that with the increase of aging time, the morphology of the heat-resistant and salt-resistant gel particles does not change much, there is normal agglomeration phenomenon, and they can be dispersed after homogenization, indicating that they have strong stability under high temperature conditions and good heat resistance.

[0050] Embodiment 4:

[0051] Through core displacement experiments, the variation of displacement pressure of the provided temperature-resistant and salt-resistant gel particles with the injection volume during the injection process was analyzed. The specific steps are as follows:

[0052] (1) Place the outcrop core in a wide-mouth bottle, add deionized water to submerge the core, ultrasonicate it in an ultrasonicator for 90 min, wash it, and dry it in a 90°C constant temperature vacuum drying oven for 24 h. Weigh the dried core to obtain its dry weight, and use a vernier caliper to measure the length and diameter of the core. Use an automatic permeability meter to measure the permeability of the core to 200 mD.

[0053] (2) Place the dried core in a suction filtration bottle, add mineralized water to submerge the core, and evacuate and saturate for 24 hours. Weigh the core saturated with mineralized water to obtain its wet weight, and calculate the core water pore volume and porosity using the following formula;

[0054]

[0055] Where V p is the water-measured pore volume of the core, cm 3 ;w s is the wet weight of the core, g; w d is the dry weight of the core, g; ρw is the density of simulated formation water, g·mL -1 ; φ is the porosity of the core, %; V f is the volume of the core, cm 3 ; l is the length of the core, cm; D is the diameter of the core, cm.

[0056] (3) A suspension of the provided heat-resistant and salt-resistant gel particles with a concentration of 2 wt% was prepared in 200,000 mg / L of simulated formation water and stirred for 6 hours. -1 At an injection rate of , 1PV (1PV is the pore volume of the core) of simulated formation water, 1PV of salt-resistant and slow-swelling gel particle suspension, and 3PV of simulated formation water were continuously injected, and the changes in injection pressure with injection volume were recorded.

[0057] (4) Draw Figure 7 The injection pressure and injection volume curve shown in Figure 2 are used to calculate the core plugging rate of the gel particles:

[0058]

[0059] Where, η is the core plugging rate, %; P w1 is the first water drive balance pressure, kPa; P w2 is the second water drive balance pressure, kPa.

[0060] Depend on Figure 7 It can be seen that during the initial water injection, the pressure will gradually increase with the increase of the injection volume. After reaching a stable state, the pressure difference is small. During the particle injection stage, the injection pressure increases rapidly. This is because the gel particles gradually gather in the core pores, forming a plugging effect and increasing the flow resistance. After the second water drive, the equilibrium pressure is significantly higher than the first water drive equilibrium pressure. The plugging rate of the provided temperature-resistant and salt-resistant gel particles is calculated to be 89%, indicating that the particles can effectively achieve plugging of deep reservoirs.

[0061] The above examples show that the ultra-temperature-resistant and salt-resistant polymer gel particles of the present invention have good injectability and controllable particle size, can maintain good stability under high temperature and high salt conditions, and can effectively achieve plugging and flow regulation in deep reservoirs.

[0062] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. An ultra-temperature-resistant and salt-resistant gel particle for deep flow regulation in oil reservoirs, characterized in that: It is polymerized by monomers, stabilizers, buffers, crosslinking agents and initiators. The total amount of stabilizers and buffers added is 10% of the amount of monomers, the amount of crosslinkers added is 5.5% of the amount of monomers, and the amount of initiators added is 1% of the amount of monomers.

2. The ultra-temperature-resistant and salt-resistant gel particles for deep flow regulation in oil reservoirs according to claim 1, characterized in that: The monomer is styrene.

3. The ultra-temperature-resistant and salt-resistant gel particles for deep flow regulation in oil reservoirs according to claim 1, characterized in that: The stabilizer is vinyl acetic acid and the buffer is ammonium bicarbonate.

4. The ultra-temperature-resistant and salt-resistant gel particles for deep flow regulation in oil reservoirs according to claim 1, characterized in that: The crosslinking agent is divinylbenzene.

5. The ultra-temperature-resistant and salt-resistant gel particles for deep flow regulation in oil reservoirs according to claim 1, characterized in that: The initiator is ammonium persulfate.

6. A method for preparing ultra-temperature-resistant and salt-resistant gel particles for deep reservoir flow regulation as claimed in any one of claims 1 to 5, characterized in that: The steps include: Step 1, prepare an aqueous solution; weigh a stabilizer, a buffer, and deionized water and add them to a beaker, and place the beaker on a magnetic stirrer and stir thoroughly; Step 2, prepare an oil phase solution; weigh the monomer and the cross-linking agent, add them into a three-necked flask, and stir thoroughly; Step 3, prepare an initiator solution; weigh the initiator and deionized water and add them into a beaker, and place the beaker on a magnetic stirrer to stir thoroughly; Step 4, preparing an emulsion; fully mixing the aqueous phase solution and the oil phase solution in a three-necked flask, and mixing and dispersing them under the action of a homogenizer to obtain a uniform homogeneous emulsion; Step 5, performing a polymerization reaction; placing the homogeneous emulsion in a constant temperature oil bath, stirring at a temperature of 70°C and a speed of 450rpm / min; installing a condensation reflux device, and passing N2 for deoxygenation at the same time, adding the prepared initiator after reacting for 5min, and reacting for 10h to obtain an emulsion product; Step 6, freeze drying; cool the emulsion product after the reaction to room temperature and then put it into the freezer of a freeze dryer, freeze it at -40°C for 24 hours, and then put it into the vacuum chamber of the freeze dryer for vacuum drying for 12 hours to obtain a white powdery gel particle product. The white powdery gel particle product is the ultra-temperature-resistant and salt-resistant gel particle used for deep flow regulation in oil reservoirs.

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