Preparation method of production increasing agent for crude oil exploitation

Abstract

The preparation method comprises the following steps: (1) fully mixing 0.8-1.2 parts by mass of porous nanoparticles and 3-5 parts by mass of silicone oil, putting the mixture into a vacuum pump for vacuumizing to enable the silicone oil to enter the porous nanoparticles, and after the vacuum state is removed, standing and separating redundant silicone oil to obtain the porous nanoparticles containing the silicone oil; (2) carrying out hole sealing treatment on the porous nanoparticles containing the silicone oil to obtain hole-sealed porous nanoparticles; (3) adding 0.5-1 part by mass of hole-sealed porous nanoparticles and 4-6 parts by mass of ammonia water into 80-120 parts by mass of diesel oil, and stirring under a heating condition to obtain a mixed solution A; (4) keeping the heating condition in the step (3), adding 0.2-0.3 part by mass of a surfactant into the mixed solution A, and continuously stirring to obtain a mixed solution B; and (5) under the heating condition of the step (4), adding 2-3 parts by mass of a low surface energy substance and 0.1-0.3 part by mass of a silane coupling agent into the mixed solution B, and continuously stirring to obtain the production increasing agent.

Description

Technical Field

[0001] The invention relates to a method for preparing a recovery enhancing agent for crude oil exploitation. Background Art

[0002] Since the crude oil in the rock formation has more polar structures, it is easily adsorbed on the surface of the oil-wet core pore wall and is difficult to "separate" from the rock formation, resulting in low rock formation permeability and poor fluidity of crude oil in the rock formation. The flow resistance of crude oil increases during the mining process, and the overall recovery efficiency of the industry is only 12-14%. A large amount of resources still exist in the rock formation and are difficult to extract.

[0003] In order to solve the problems of large flow resistance and difficulty in exploitation caused by the strong adsorption of crude oil, current research mainly adopts the method of increasing micropores and displacement fluid oil displacement. Among them, the method of increasing micropores includes physical fracturing, acidification and plugging removal, dehydration and shrinkage, etc., which use physical and chemical means to increase the pores of the core and increase the effective flow pore size, thereby reducing the flow resistance of oil and water. However, these methods will increase the gaps in the rock formation and loosen the geological structure, which will cause serious damage to the formation and is not conducive to further exploitation. The displacement fluid oil displacement method includes polymer oil displacement method, surfactant oil displacement method, etc. The specific method is to drive the displacement fluid into the core, use its own viscoelasticity, adsorption, solubility and other properties to peel the crude oil from the core surface, and extract the crude oil from the mixture by separation means to increase the oil well production. However, due to the large capillary force of the core, the displacement fluid can only sweep the crude oil in the large pores, and the crude oil in the small pores cannot be affected, resulting in limited application of this method. In summary, the existing methods have the problem of being unable to completely remove the sediments in the rock gaps in the formation at the bottom of the oil well. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a method for preparing a recovery agent based on a bionic surface method. The recovery agent prepared by this method can, on the one hand, remove sediments in the cracks of the formation rocks at the bottom of the oil well, and on the other hand, can effectively inhibit the deposition of subsequent sediments in the crude oil in the cracks of the formation rocks, thereby increasing the flow rate of crude oil in the low permeability pores in the rock, thereby increasing the oil well production.

[0005] Technical solution: The method for preparing the recovery enhancing agent for crude oil production of the present invention comprises the following steps:

[0006] (1) 0.8-1.2 parts by weight of porous nanoparticles and 3-5 parts by weight of silicone oil are fully mixed, and the mixture is placed in a vacuum pump to evacuate the porous nanoparticles so that the silicone oil enters the porous nanoparticles. After the vacuum state is removed, the mixture is allowed to stand to separate the excess silicone oil (after the silicone oil and the porous nanoparticles are completely separated, the upper silicone oil is sucked away using a rubber-tipped dropper), thereby obtaining porous nanoparticles containing silicone oil;

[0007] (2) performing pore sealing treatment on the porous nanoparticles containing silicone oil to obtain sealed porous nanoparticles;

[0008] (3) adding 0.5 to 1 parts by weight of sealed porous nanoparticles and 4 to 6 parts by weight of aqueous ammonia to 80 to 120 parts by weight of diesel, and stirring under heating conditions to obtain a mixed solution A;

[0009] (4) while maintaining the heating condition in step (3), adding 0.2 to 0.3 parts by weight of a surfactant to the mixed solution A, and continuously stirring to obtain a mixed solution B;

[0010] (5) While maintaining the heating conditions of step (4), add 2 to 3 parts by weight of a low surface energy substance and 0.1 to 0.3 parts by weight of a silane coupling agent to the mixed solution B, and continue stirring to obtain a recovery enhancing agent.

[0011] Wherein, in step (1), the porous nanoparticles are one of hollow mesoporous silica, nanocarbon spheres, graphite aggregates or fullerenes.

[0012] Wherein, in step (1), the reaction is carried out under vacuum for not less than 12 hours.

[0013] Among them, in step (2), the sealing process referred to in the present invention is specifically as follows: a cationic polymer (at least one of chitosan, polyethyleneimine, polystyrene or polyacrylamine) solution is mixed with porous nanoparticles containing silicone oil in a mass ratio of 1:2, and the cationic polymer is covered on the surface of the porous nanoparticles by electrostatic action under mechanical stirring conditions of 300r / 30min, and after centrifugation at 8000r / 3min, the excess cationic polymer is washed with ethanol or water to remove; after being covered with the cationic polymer, the surface of the porous powder is positively charged; then an anionic polymer (polystyrene) is added to the porous nanoparticles to form a pore-sealing agent; A solution of at least one of sodium olefin sulfonate, polyacrylic acid or polyacrylonitrile is mixed with the porous powder in a volume ratio of 1:2, and anionic polymers are covered on the surface of the porous nanoparticles by electrostatic action under mechanical stirring conditions of 300r / 30min. After centrifugation at 8000r / 3min, excess anionic polymers are washed with ethanol or water to remove them. A composite film layer constructed of cationic polymers and anionic polymers is obtained on the surface of the porous nanoparticles to complete the sealing treatment of the porous nanoparticles. The composite film layer has a loose network structure, which can both release the silicone oil and slow down the release rate of the silicone oil.

[0014] Wherein, in step (3), the diesel is 0# diesel among light diesel.

[0015] Wherein, in step (4), the surfactant is one of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyoxyethylene alkylamine or polyoxyethylene alkanolamide.

[0016] Wherein, in step (5), the low surface energy substance is one of isobutyltrimethoxysilane, chlorine-terminated polydimethylsiloxane, perfluorosiloxane, perfluoropolyether or perfluorosiloxane oligomer; preferably BHN, F 8815 (perfluoropolyether) or SC Concentrate (perfluorosilicone oligomer), most preferred SC Concentrate.

[0017] Wherein, in step (5), the silane coupling agent is one of silane coupling agents KH550, KH560 or KH570.

[0018] Among them, in steps (3) to (5), the heating temperature is 50 to 60° C., and the heating method is water bath heating or oil bath heating.

[0019] When used, the recovery agent is injected into the oil well formation by fracturing. After the recovery agent flows into the formation, on the one hand, the sediments tightly adhering to the rock surface and pores of the formation are washed away by a specific surfactant, and the flow channel in the rock is dredged. Since the oil well is deep, usually ranging from 2500 to 4000 meters, the formation temperature at the bottom of the oil well is relatively high (ranging from 80 to 160°C), so it can best stimulate the cleaning effect of the surfactant; on the other hand, after cleaning the sediment, the recovery agent can clean the small pores with low permeability in the rock ( The oil recovery agent is used to hydrophobically modify the oil recovery channel. After the oil recovery agent removes the blockage of the rock by washing oil, the oil recovery agent in contact with the rock can quickly condense into a film on the rock and in its cracks due to the high temperature, thereby forming a hydrophobic and oleophobic lubricating film on the inner surface of the rock channel. The lubricating film is composed of porous nanoparticles and low surface energy substances, so that the crude oil can quickly pass through the low permeability channel to avoid adhering to the inner wall of the channel due to small flow rate and high viscosity. The lubricating film can effectively prevent the substances that are easy to precipitate and deposit in the crude oil from being deposited in the channel, thereby increasing the production of the oil well. The present invention improves the wettability of the core and constructs a bionic coating on the micropore wall, so that the crude oil can be completely desorbed from the core, reducing the flow resistance of oil and water, thereby improving the recovery efficiency. By constructing a micro-nano composite structure on the core pores, the capillary force of the core is improved, and the active substance is grafted on the surface through chemical bonds, which changes the surface energy of the core and makes it have excellent oil desorption performance.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: after the recovery enhancing agent of the present invention is injected into the bottom of the well, it can clean the crude oil and the deposited substances on the surface of the core, and at the same time, it uses hydrophobic and oleophobic measures (after the nano-scale porous nanoparticles are loaded with silicone oil, they are grafted with low surface energy substances to make the formed film have hydrophobic and oleophobic properties) to modify the rock flow surface, on the one hand, it can achieve the effect of removing sediments, and on the other hand, after the recovery enhancing agent is injected, it can greatly delay the formation of asphalt deposition and allow crude oil to quickly pass through the low permeability pores; the recovery enhancing agent of the present invention can solve the blockage problem of crude oil channels in existing rock formations, thereby improving the oil field production capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a comparison chart of the effects of imbibition oil recovery; Figure 1 (a) is the core morphology after surface scaling; Figure 1 (b) is a diagram showing the cleaning effect of the recovery enhancing agent of Example 1; Figure 1 (c) is a diagram showing the cleaning effect of water;

[0022] Figure 2 Schematic diagram of the water contact angle (a) and oil contact angle (b) after the core is cleaned with the recovery enhancement agent in Example 1;

[0023] Figure 3 The microscopic appearance of the core before and after the recovery enhancement agent is modified in Example 1. Figure 3 (a), (b), and (c) are the microscopic appearances of the core before modification at 200 nm, 1 μm, and 5 μm, respectively. Figure 3 (d)(e)(f) are the microscopic appearances of the modified core at 200nm, 1μm, and 5μm, respectively;

[0024] Figure 4 Comparison diagrams of crude oil contaminated cores (a), (b) and after imbibition of the recovery enhancement agent in Example 1 (c), (d);

[0025] Figure 5 The anti-scour performance diagram of the core surface modified by the production enhancement agent under different pressures;

[0026] Figure 6 This is the daily production curve of Cangxi 3-1 well in a certain oil field;

[0027] Figure 7 This is the daily production curve of Well Cai 4-6 in a certain oil field. DETAILED DESCRIPTION

[0028] Example 1

[0029] The preparation method of the production enhancing agent of the present invention comprises the following steps:

[0030] (1) 0.8 parts by weight of hollow mesoporous silica and 3 parts by weight of silicone oil are fully mixed, placed in a vacuum pump and evacuated, and maintained in a vacuum state for 12 hours to allow the silicone oil to enter the hollow mesoporous silica. After the vacuum state is removed, the mixture is allowed to stand, and after the silicone oil and the hollow mesoporous silica are completely separated, the upper silicone oil is sucked away using a rubber-tipped dropper, and the excess silicone oil is separated to obtain hollow mesoporous silica containing silicone oil;

[0031] (2) sealing the hollow mesoporous silica containing silicone oil to obtain sealed hollow mesoporous silica; the particle size of the hollow mesoporous silica is 1 to 15 nm;

[0032] (3) adding 0.5 parts by weight of the sealed hollow mesoporous silica and 4-6 parts by weight of aqueous ammonia to 80 parts by weight of diesel, and stirring for 10 minutes under the condition of heating in a water bath at 50° C. to obtain a mixed liquid A; the diesel is 0# diesel among light diesel;

[0033] (4) adding 0.2 parts by weight of fatty alcohol polyoxyethylene ether to the mixed solution A while maintaining heating at 50° C. in a water bath, and stirring for 30 minutes to obtain a mixed solution B;

[0034] (5) While maintaining the temperature at 50° C. in a water bath, add 2 parts by mass of perfluorosilicone and 0.1 parts by mass of KH550 to the mixed solution B, and continue stirring for 0.5 hours to obtain a recovery enhancing agent.

[0035] like Figure 1 As shown, Figure 1 To compare the effects of imbibition oil recovery, two blank cores (cores are selected as test objects here to accurately express the essential characteristics of geological samples) are placed in crude oil for aging to form scale on their surfaces. The morphology after scaling is as follows: Figure 1 As shown in (a), two cores (the scaling degree of the two core surfaces is basically the same) are placed in the recovery enhancement agent of Example 1 and water respectively, heated to 50°C, and taken out after 2 hours. The core cleaning effect is shown in FIG. Figure 1 (b) and Figure 1 As shown in (c), the final cleaning effect shows that the oil-absorbing and washing effect of the recovery agent in Example 1 is more obvious, and its smaller average particle size can effectively penetrate into a large number of small pores in the core, and the recovery agent is bonded with the core base under the action of capillary force, so that the core surface structure is flattened, and the crude oil can easily slide off the core surface, thereby increasing the oil yield of the core.

[0036] like Figure 2 As shown, Figure 2 (a) and Figure 2(b) are schematic diagrams of the water contact angle and oil contact angle of the core after cleaning with the recovery enhancing agent of Example 1, wherein the water contact angle is 141° and the oil contact angle is 132.5°, which indicates that the recovery enhancing agent has excellent hydrophobic and oleophobic properties after forming a coating on the core surface.

[0037] Figure 3 The microscopic appearance of the core before and after the recovery enhancement agent is modified in Example 1. Figure 3 (a), (b), and (c) are the microscopic appearances of the core before modification at 200 nm, 1 μm, and 5 μm, respectively. Figure 3 (d)(e)(f) are the microscopic appearances of the modified cores at 200nm, 1μm, and 5μm, respectively. Compared with the cores before modification, the modified cores are overall smooth, and there are a large number of agglomerated nanoparticles on the surface, forming a uniform micro-nano composite structure on the cores.

[0038] Figure 4 This is a comparison chart of the crude oil contaminated core and the core after the recovery enhancement agent in Example 1 is imbibed, where Figure 4 (a) shows the microscopic morphology of the core contaminated by crude oil; Figure 4 (b) is the wettability diagram of the core surface contaminated by crude oil; Figure 4 (c) shows the microscopic morphology of the core after the production enhancement agent is imbibed; Figure 4 (d) is the wettability diagram of the core surface after the production enhancement agent is imbibed.

[0039] Depend on Figure 4 (a) and (b) show that a large amount of crude oil is adsorbed on the surface of the core, showing an oil-wetting property, and the oil contact angle is 35°; after the recovery enhancing agent of Example 1 is imbibed and modified in the core, a large amount of agglomerated crude oil stains on the surface of the core are eliminated, and the surface of the core forms a relatively flat structure under the action of the recovery enhancing agent, so the flow resistance of oil droplets on the surface of the core is small, such as Figure 4 As shown in (c) and (d), it is shown that the recovery enhancement agent can enter the small pores of the core through the nano-size effect and capillary action in the pores, forming a coating to replace the crude oil originally adsorbed on the surface. At the same time, after filling the small pores, the surface structure of the core is smoother, preventing oil droplets from sinking into and adhering to the inner wall of the structure, thereby reducing the flow resistance of crude oil in the pores.

[0040] Figure 5The figure shows the anti-scouring performance of the core surface after modification with the recovery enhancing agent of Example 1 under different pressures. After the core was scoured with 100PV at three pressures, the oil sliding angle on the surface of the lubricating film formed by the recovery enhancing agent on the core increased. This is because the continuous scouring of the water flow causes the loss of some low surface energy substances in the lubricating film. However, compared with the friction between the water flow and the lubricating film, the lubricating film and the core base have a stronger bonding ability. Therefore, under a pressure of 10 kPa, the oil sliding angle of the lubricating film does not change by more than 5° before and after 100PV scouring. This shows that the recovery enhancing agent can form a lubricating film with strong adhesion on the core base, and the structure of the film can remain stable after continuous water scouring.

[0041] Example 2

[0042] The preparation method of the production enhancing agent of the present invention comprises the following steps:

[0043] (1) 1.2 parts by weight of nano-carbon spheres and 5 parts by weight of silicone oil were fully mixed, placed in a vacuum pump for evacuation, and maintained in a vacuum state for 24 hours to allow the silicone oil to enter the nano-carbon spheres. After the vacuum state was removed, the mixture was allowed to stand, and after the silicone oil and the nano-carbon spheres were completely separated, the upper silicone oil was sucked away using a rubber-tipped dropper to separate the excess silicone oil, thereby obtaining nano-carbon spheres containing silicone oil;

[0044] (2) performing pore sealing treatment on the nano-carbon spheres containing silicone oil to obtain pore-sealed nano-carbon spheres; the particle size of the nano-carbon spheres is 1 to 15 nm;

[0045] (3) adding 1 part by mass of the sealed nano-carbon spheres and 6 parts by mass of ammonia water to 120 parts by mass of diesel, and stirring for 20 minutes under the condition of heating in a water bath at 60° C. to obtain a mixed liquid A; the diesel is 0# diesel among light diesel;

[0046] (4) adding 0.3 parts by weight of fatty alcohol polyoxyethylene ether to the mixed solution A while maintaining heating at 60° C. in a water bath, and stirring for 50 minutes to obtain a mixed solution B;

[0047] (5) While maintaining the temperature at 60° C. in a water bath, 3 parts by mass of perfluorosilicone and 0.3 parts by mass of KH560 were added to the mixed solution B, and the mixture was stirred for 2 hours to obtain a recovery enhancing agent.

[0048] Example 3

[0049] The preparation method of the production enhancing agent of the present invention comprises the following steps:

[0050] (1) 0.9 parts by weight of graphite aggregates and 4 parts by weight of silicone oil were fully mixed, placed in an empty pump to evacuate, and maintained in a vacuum state for 16 hours to allow the silicone oil to enter the graphite aggregates. After the vacuum state was removed, the mixture was allowed to stand, and after the silicone oil and the graphite aggregates were completely separated, the upper silicone oil was sucked away using a rubber-tipped dropper, and the excess silicone oil was separated to obtain a graphite aggregate containing silicone oil;

[0051] (2) performing a pore sealing treatment on the graphite aggregate containing silicone oil to obtain a pore-sealed graphite aggregate; the particle size of the graphite aggregate is 1 to 15 nm;

[0052] (3) adding 0.7 parts by weight of the sealed graphite aggregate and 5 parts by weight of aqueous ammonia to 100 parts by weight of diesel, and stirring for 15 minutes under the condition of heating in an oil bath at 55° C. to obtain a mixed liquid A; the diesel is 0# diesel among light diesel;

[0053] (4) adding 0.25 parts by weight of polyoxyethylene alkylamine to the mixed solution A while maintaining the mixture in an oil bath at 55° C., and stirring for 40 minutes to obtain a mixed solution B;

[0054] (4) While maintaining the temperature at 55° C. in an oil bath, 2.5 parts by mass of perfluorosilicone and 0.2 parts by mass of KH570 were added to the mixed solution B, and the mixture was stirred for 1 hour to obtain a recovery enhancing agent.

[0055] Example 4

[0056] The preparation method of the production enhancing agent of the present invention comprises the following steps:

[0057] (1) 1.1 parts by weight of fullerene and 4.5 parts by weight of silicone oil are fully mixed, placed in an empty pump and evacuated, and maintained in a vacuum state for 14 hours to allow the silicone oil to enter the fullerene. After the vacuum state is removed, the mixture is allowed to stand, and after the silicone oil and fullerene are completely separated, the upper silicone oil is sucked away using a rubber-tipped dropper, and the excess silicone oil is separated to obtain fullerene containing silicone oil;

[0058] (2) performing a pore sealing treatment on the fullerene containing silicone oil to obtain a pore-sealed fullerene; the particle size of the fullerene is 1 to 15 nm;

[0059] (3) adding 0.9 parts by weight of the sealed fullerene and 5.5 parts by weight of aqueous ammonia to 110 parts by weight of diesel, and stirring for 12 minutes in an oil bath heated at 52° C. to obtain a mixed solution A; the diesel is 0# diesel among light diesel;

[0060] (4) adding 0.27 parts by weight of polyoxyethylene alkanolamide to the mixed solution while maintaining the mixture in an oil bath at 52° C., and stirring for 35 minutes to obtain a mixed solution B;

[0061] (5) While maintaining the temperature at 52°C in an oil bath, add 2.3 parts by weight of SC Concentrate and 0.15 parts by mass of KH570 were added and stirred for 1.5 hours to obtain a production enhancing agent.

[0062] The effect of the recovery enhancing agent of the present invention is explained below by taking its actual application in a certain oil field.

[0063] Cangxi 3-1 oil well in a certain oil field:

[0064] Measures: From March 1 to March 19, 2024, the Cangxi 3-1 oil well in a certain oil field was injected with an enhancement agent, and 84.5 cubic meters of the enhancement agent solution of Example 1 with a volume concentration of 1% (the enhancement agent solution is prepared by the enhancement agent and water at a volume ratio of 1:99) were squeezed in, and the well was stewed for 3.10 to 3.12 seconds;

[0065] like Figure 6 As shown, before the injection of the recovery enhancing agent of Example 1, the oil well produced 1.4 tons of oil per day, 1.9 tons of liquid per day, and a water content of 24.2%; when it was re-exploited on March 19, 2024; the daily oil production was maintained at about 5 tons, the daily liquid production was maintained at about 5.5 tons, the water content was 10%, and the daily increased oil production was maintained at 3.6 tons. As of August 6, 2024, the cumulative oil production was 493.2 tons, and the production was still increasing.

[0066] Cai 4-6 oil well in a certain oil field

[0067] Measures: On July 14, 2024, the production enhancement agent of Example 1 was injected, and 100m3 of the production enhancement agent solution with a concentration of 1% by volume was squeezed into the formation. 3 The injection pump pressure gradually increases from 2MPa to 10MPa, and the displacement is 6-10m 3 / h. After the construction was completed, the well was shut down for three days from July 16 to 18, and the shut-in pressure was 0MPa. Pumping started on July 19;

[0068] like Figure 7 As shown, before the injection of the recovery enhancing agent of Example 1 into the Cai 4-6 oil well in a certain oil field, the daily oil production was 1.2 tons, the daily liquid production was 20 tons, and the water content was 94%; when it was produced within 4 to 7 days after the injection, the daily oil production was about 1.8 tons, the daily liquid production was about 20 tons, and the water content was 91%; when it was produced seven days after the injection, the daily oil production was 3.6 tons, the daily liquid production was 20 tons, and the water content was 82%. As of October 24, 2024, based on the daily oil increase of 2.4 tons, the cumulative oil increase was 288 tons.

[0069] The recovery enhancing agent of the present invention can solve the problem of blockage of the bottom formation of the oil well caused by asphalt deposition during the oil field exploitation process, and can also delay the formation of the sedimentary layer while removing the blockage, thereby effectively increasing the output of the oil field.

Claims

1. A method for preparing a recovery enhancing agent for crude oil production, characterized in that: The steps include: (1) 0.8-1.2 parts by weight of porous nanoparticles and 3-5 parts by weight of silicone oil are fully mixed, and the mixture is placed in a vacuum pump to evacuate the mixture so that the silicone oil enters the porous nanoparticles. After the vacuum state is removed, the mixture is allowed to stand to separate excess silicone oil, thereby obtaining porous nanoparticles containing silicone oil; (2) performing pore sealing treatment on the porous nanoparticles containing silicone oil to obtain sealed porous nanoparticles; (3) adding 0.5 to 1 parts by weight of sealed porous nanoparticles and 4 to 6 parts by weight of aqueous ammonia to 80 to 120 parts by weight of diesel, and stirring under heating conditions to obtain a mixed solution A; (4) while maintaining the heating condition in step (3), adding 0.2 to 0.3 parts by weight of a surfactant to the mixed solution A, and continuously stirring to obtain a mixed solution B; (5) While maintaining the heating conditions of step (4), add 2 to 3 parts by weight of a low surface energy substance and 0.1 to 0.3 parts by weight of a silane coupling agent to the mixed solution B, and continue stirring to obtain a recovery enhancing agent.

2. The method for preparing a recovery enhancing agent for crude oil production according to claim 1, characterized in that: In step (1), the porous nanoparticles are one of hollow mesoporous silica, nanocarbon spheres, graphite aggregates or fullerenes.

3. The method for preparing a recovery enhancing agent for crude oil production according to claim 1, characterized in that: In step (1), the reaction is carried out under vacuum for not less than 12 hours.

4. The method for preparing a recovery enhancing agent for crude oil production according to claim 1, characterized in that: In step (1), the particle size of the porous nanoparticles is 1 to 15 nm.

5. The method for preparing a recovery enhancing agent for crude oil production according to claim 1, characterized in that: In step (3), the diesel is 0# diesel among light diesel.

6. The method for preparing a recovery enhancing agent for crude oil production according to claim 1, characterized in that: In step (4), the surfactant is one of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyoxyethylene alkylamine or polyoxyethylene alkanolamide.

7. The method for preparing a recovery enhancing agent for crude oil production according to claim 1, characterized in that: In step (5), the low surface energy substance is one of isobutyltrimethoxysilane, chlorine-terminated polydimethylsiloxane, perfluorosiloxane, perfluoropolyether or perfluorosiloxane oligomer.

8. The method for preparing a recovery enhancing agent for crude oil production according to claim 1, characterized in that: In step (5), the silane coupling agent is one of silane coupling agents KH550, KH560 or KH570.

9. The method for preparing a recovery enhancing agent for crude oil production according to claim 1, characterized in that: In steps (3) to (5), the heating temperature is 50 to 60°C.

10. The method for preparing a recovery enhancing agent for crude oil production according to claim 9, characterized in that: The heating method is water bath heating or oil bath heating.

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