A Hybrid-Dimensional Superhydrophobic Nano Drag Reducer and Its Preparation Method and Application

Abstract

The present invention discloses a hybrid-dimension superhydrophobic nano drag reducer and its preparation method and application. The hybrid-dimension superhydrophobic nano drag reducer includes hybrid-dimension superhydrophobic nano materials and a sacrificial layer wrapping the hybrid-dimension superhydrophobic nano materials, wherein the hybrid-dimension superhydrophobic nano materials at least include zero-dimensional nano materials, one-dimensional nano materials and two-dimensional nano materials. The hybrid-dimension superhydrophobic nano drag reducer provided by the present invention has a small single size and is not easily aggregated during the injection process. Moreover, due to the size difference, the hybrid-dimension superhydrophobic nano drag reducer is liable to form a "mechanical interlock" structure on the pore walls of the target formation, improving the adhesion fastness and density, so as to achieve the purpose of efficient pressure reduction and injection increase.

Description

Technical Field

[0001] The present invention belongs to the technical field of drag reducers, and relates to a drag reducer for low permeability oil reservoirs, and specifically relates to a mixed-dimensional super-hydrophobic nano drag reducer, and a preparation method and application thereof. Background Art

[0002] With the continuous development of oil and gas resources in my country, medium and high permeability reservoirs are gradually entering the medium and high water content period, and low permeability reservoirs will become the main resource for increasing reserves and production. -3 μm 2 The characteristics of low porosity, severe intra- and inter-layer heterogeneity, poor injection-production connectivity, and high residual oil saturation in water flooding lead to "high-pressure underinjection," whereby the injection wells have high injection pressures but severely insufficient water, leading to increased production costs and reduced economic benefits. Therefore, "high-pressure underinjection" is an urgent problem that needs to be solved in oilfield production and is the basis for ensuring the effectiveness of water-based development of low-permeability reservoirs.

[0003] Hydrophobic nanomaterial augmentation technology can improve the effectiveness of waterflooding in low-permeability reservoirs. The main process involves injecting a dispersion of (super)hydrophobic nano-drag reducers into the reservoir, closing the injection and production wells, and then reopening them after a certain period to begin waterflooding. Hydrophobic nano-drag reducer particles can firmly adsorb onto the pore walls of the target formation, forming a new adsorption surface, effectively preventing hydration and swelling of minerals adhering to the formation. They replace the hydration layer on the micropore walls, transforming the formation rock from hydrophilic to (super)hydrophobic. During water injection, nano-slippage occurs as the water flows through the hydrophobic adsorption layer, reducing flow resistance and achieving the goals of pressure reduction and augmentation. Currently, research has found that hydrophobic nano-SiO2 augmentation has significant effects, but the nano-SiO2 particles are large in size and easily aggregate and clog in areas such as the wellbore. They also have a small specific surface area, insufficient adhesion, and poor resistance to water erosion. Summary of the invention

[0004] The main purpose of the present invention is to provide a mixed-dimensional super-hydrophobic nano-drag reducer and its preparation method and application, so as to overcome the shortcomings of the prior art.

[0005] To achieve the aforementioned object of the invention, the technical solutions adopted in the embodiments of the present invention include:

[0006] An embodiment of the present invention provides a mixed-dimensional superhydrophobic nano drag reducer, comprising a mixed-dimensional superhydrophobic nanomaterial and a sacrificial layer wrapping the mixed-dimensional superhydrophobic nanomaterial, wherein the mixed-dimensional superhydrophobic nanomaterial comprises at least a zero-dimensional nanomaterial, a one-dimensional nanomaterial and a two-dimensional nanomaterial, and the thickness of the sacrificial layer is 0.5 to 10 μm.

[0007] Further, the mass ratio of the superhydrophobic zero-dimensional nanomaterials, superhydrophobic one-dimensional nanomaterials, and superhydrophobic two-dimensional nanomaterials in the mixed-dimensional superhydrophobic nano drag reducer is 1∶(1 - 2)∶(1 - 2).

[0008] Further, the mass ratio of the sacrificial layer to the mixed-dimensional superhydrophobic nanomaterials in the mixed-dimensional superhydrophobic nano drag reducer is 1∶(20 - 50).

[0009] The embodiment of the present invention also provides a preparation method of the aforementioned mixed-dimensional superhydrophobic nano drag reducer, including:

[0010] Uniformly mixing zero-dimensional nanomaterials, one-dimensional nanomaterials, and two-dimensional nanomaterials with a solvent to form a mixed solution;

[0011] Adding polyphenol compounds and aminopropyltriethoxysilane to the mixed solution, and reacting to obtain mixed-dimensional nanomaterials modified with polar groups;

[0012] Mixing fluorosiloxane and long-chain alkane with the mixed-dimensional nanomaterials modified with polar groups, and heating and reacting to obtain mixed-dimensional superhydrophobic nanomaterials;

[0013] Mixing the sacrificial layer material and surfactant with the mixed-dimensional superhydrophobic nanomaterials and reacting, and separating to obtain the mixed-dimensional superhydrophobic nanomaterials wrapped with the sacrificial layer, that is, the mixed-dimensional superhydrophobic nano drag reducer.

[0014] Further, the preparation method of the mixed-dimensional superhydrophobic nano drag reducer includes: uniformly dispersing zero-dimensional nanomaterials, one-dimensional nanomaterials, and two-dimensional nanomaterials in a solvent to form a mixed solution; preferably, the solvent includes a mixed solvent composed of water, ethanol, and ethyl acetate;

[0015] The volume ratio of the water, ethanol, and ethyl acetate is 1∶(1 - 4)∶(1 - 2);

[0016] The content of zero-dimensional nanomaterials in the mixed solution is 0.01 - 1 wt%, the content of one-dimensional nanomaterials is 0.01 - 1 wt%, and the content of two-dimensional nanomaterials is 0.01 - 1 wt%.

[0017] Further, the preparation method of the mixed-dimensional superhydrophobic nano drag reducer includes: adding polyphenol compounds and aminopropyltriethoxysilane to the mixed solution, and fully stirring and reacting at 10 - 50 °C for 0.5 - 7 days to obtain a mixed solution containing mixed-dimensional nanomaterials modified with polar groups;

[0018] Preferably, the addition ratio of the polyphenol compounds is 0.5 - 5 wt% of the mixed solution,

[0019] The addition ratio of the aminopropyltriethoxysilane is 0.5 to 5 wt% of the mixed solution.

[0020] Furthermore, the preparation method of the mixed-dimensional superhydrophobic nano drag reducer includes: adding fluorosiloxane and long-chain alkane to the mixed solution containing the mixed-dimensional nanomaterials modified with polar groups, and heating and reacting to obtain a mixed solution containing mixed-dimensional superhydrophobic nanomaterials; wherein, the temperature of the heating reaction is 30 to 80 °C, and the reaction time is 0.5 to 7 days.

[0021] Preferably, the addition ratio of the fluorosiloxane is 0.1 to 10 wt% of the mixed solution containing the mixed-dimensional superhydrophobic nanomaterials.

[0022] The addition ratio of the long-chain alkane is 0.1 to 10 wt% of the mixed solution containing the mixed-dimensional superhydrophobic nanomaterials.

[0023] Furthermore, the preparation method of the mixed-dimensional superhydrophobic nano drag reducer includes: adding a sacrificial layer material and a surfactant to the mixed solution containing the mixed-dimensional superhydrophobic nanomaterials, fully stirring and reacting for 0.5 to 2 days, and filtering to obtain the mixed-dimensional superhydrophobic nanomaterials wrapped by the sacrificial layer.

[0024] Preferably, the addition ratio of the sacrificial layer material is 0.1 to 5 wt% of the mixed solution containing the mixed-dimensional superhydrophobic nanomaterials.

[0025] Preferably, the addition ratio of the surfactant is 0.01 to 10 wt% of the mixed solution containing the mixed-dimensional superhydrophobic nanomaterials.

[0026] The material of the sacrificial layer includes any one or two of liquid paraffin or methyl silicone oil.

[0027] Furthermore, the surfactant includes any one or a combination of more than one of sodium dodecylbenzenesulfonate, polysorbate 80, and sorbitan stearate.

[0028] The embodiment of the present invention also provides the application of the aforementioned mixed-dimensional superhydrophobic nano drag reducer in the field of low-permeability oil reservoirs.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The hybrid - dimensional super - hydrophobic nano - drag reducer of the present invention includes zero - dimensional nano - materials, one - dimensional nano - materials, two - dimensional nano - materials and a sacrificial layer. The sacrificial layer can prevent damage during the injection process of the super - hydrophobic nano - drag reducer and the loss of super - hydrophobic properties. The hybrid - dimensional super - hydrophobic nano - drag reducer has a small individual size and is not easily aggregated during the injection process. And due to the size difference, the hybrid - dimensional super - hydrophobic nano - drag reducer is likely to form a "mechanical interlock" structure on the pore wall of the target formation (the "mechanical interlock" structure means that the specific surface area of one - dimensional and two - dimensional nano - materials is large, and they preferentially adhere to the pore wall of the target formation, and the small - sized zero - dimensional nano - materials fill the gaps, finally completely covering the pore wall of the target formation), improving the adhesion fastness and density, so as to achieve the purpose of efficient pressure reduction and injection increase.

[0031] (2) In the present invention, zero - dimensional nano - materials, one - dimensional nano - materials and two - dimensional nano - materials are uniformly dispersed in a mixed solvent, and their surfaces are modified by polyphenol compounds and aminopropyltriethoxysilane to introduce strongly polar active groups. Then, they are modified by low - surface - energy fluorosiloxane and long - chain alkanes to obtain the hybrid - dimensional super - hydrophobic nano - drag reducer. Liquid paraffin is wrapped on the outer surface of the drag reducer to form a sacrificial layer, which can prevent damage during the injection process of the super - hydrophobic nano - drag reducer and the loss of super - hydrophobic properties. Detailed implementation manners

[0032] The present invention will be more fully understood through the following specific implementation manners. Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the present invention, and the present invention can be embodied in various forms. Therefore, the specific functional details disclosed herein should not be construed as restrictive, but only as the basis of the claims and as a representative basis for teaching those skilled in the art to adopt the present invention in any appropriate detailed embodiment in different ways.

[0033] In view of the deficiencies of the prior art, the inventors of this case have, through long - term research and a large number of practices, been able to propose the technical solution of the present invention, which mainly forms a hybrid - dimensional super - hydrophobic nano - drag reducer through the synergistic effect of zero - dimensional nano - materials, one - dimensional nano - materials, two - dimensional nano - materials and a sacrificial layer. The technical solution, its implementation process and principle will be further explained below.

[0034] One aspect of the embodiment of the present invention provides a hybrid - dimensional super - hydrophobic nano - drag reducer, including hybrid - dimensional super - hydrophobic nano - materials and a sacrificial layer wrapping the hybrid - dimensional super - hydrophobic nano - materials. Among them, the hybrid - dimensional super - hydrophobic nano - materials at least include zero - dimensional nano - materials, one - dimensional nano - materials and two - dimensional nano - materials, and the thickness of the sacrificial layer is 0.5 - 10 μm.

[0035] In some preferred embodiments, the mass ratio of the superhydrophobic zero-dimensional nanomaterials, superhydrophobic one-dimensional nanomaterials, and superhydrophobic two-dimensional nanomaterials in the mixed-dimensional superhydrophobic nano drag reducer is 1∶(1 - 2)∶(1 - 2).

[0036] In some preferred embodiments, the mass ratio of the sacrificial layer to the mixed-dimensional superhydrophobic nanomaterials in the mixed-dimensional superhydrophobic nano drag reducer is 1∶(20 - 50).

[0037] In some preferred embodiments, the superhydrophobic zero-dimensional nanomaterials are obtained by modifying zero-dimensional nanomaterials with polar groups and superhydrophobic groups; the zero-dimensional nanomaterials may include any one or a combination of two or more of carbon quantum dots, SiO2 nanoparticles, TiO2 nanoparticles, etc., but are not limited thereto; among them, the average particle size of the carbon quantum dots is 2 - 10 nm, and the average particle sizes of the SiO2 nanoparticles and TiO2 nanoparticles are 10 - 100 nm. In some preferred embodiments, the superhydrophobic one-dimensional nanomaterials are obtained by modifying one-dimensional nanomaterials with polar groups and superhydrophobic groups; the diameter of the one-dimensional nanomaterials is 2 - 20 nm, and the aspect ratio is 100 / 1 - 2000 / 1, and the one-dimensional nanomaterials may include any one or a combination of two or more of carbon nanotubes, halloysite tubes, CuO nanowires, etc., but are not limited thereto.

[0038] In some preferred embodiments, the superhydrophobic two-dimensional nanomaterials are obtained by modifying two-dimensional nanomaterials with polar groups and superhydrophobic groups; the sheet thickness of the two-dimensional nanomaterials is 0.3 - 5 nm, and the sheet diameter is 0.5 - 5 μm, and the two-dimensional nanomaterials may include any one or a combination of two or more of graphene oxide, boron nitride nanosheets, C3N4 nanosheets, etc., but are not limited thereto.

[0039] In some preferred embodiments, the material of the sacrificial layer may include any one or two of liquid paraffin, methyl silicone oil, etc., but is not limited thereto.

[0040] Another aspect of the embodiments of the present invention provides a preparation method of the aforementioned mixed-dimensional superhydrophobic nano drag reducer, including:

[0041] Uniformly mixing zero-dimensional nanomaterials, one-dimensional nanomaterials, two-dimensional nanomaterials with a solvent to form a mixed solution;

[0042] Adding polyphenol compounds and aminopropyltriethoxysilane to the mixed solution, and reacting to obtain mixed-dimensional nanomaterials modified with polar groups;

[0043] Mixing fluorosiloxane and long-chain alkanes with the mixed-dimensional nanomaterials modified with polar groups, and heating and reacting to obtain mixed-dimensional superhydrophobic nanomaterials;

[0044] Mix the sacrificial layer material and the surfactant with the mixed - dimensional super - hydrophobic nanomaterial and react, then separate to obtain the mixed - dimensional super - hydrophobic nanomaterial wrapped by the sacrificial layer, namely the mixed - dimensional super - hydrophobic drag - reducing agent.

[0045] In some preferred embodiments, the preparation method of the mixed - dimensional super - hydrophobic drag - reducing agent includes: uniformly dispersing zero - dimensional nanomaterials, one - dimensional nanomaterials and two - dimensional nanomaterials in a solvent to form a mixed solution; preferably, the solvent includes a mixed solvent composed of water, ethanol and ethyl acetate;

[0046] The volume ratio of water, ethanol to ethyl acetate is 1∶(1 - 4)∶(1 - 2);

[0047] The content of zero - dimensional nanomaterials in the mixed solution is 0.01 - 1 wt%, the content of one - dimensional nanomaterials is 0.01 - 1 wt%, and the content of two - dimensional nanomaterials is 0.01 - 1 wt%.

[0048] In some more preferred embodiments, the zero - dimensional nanomaterials can include any one or a combination of two or more of carbon quantum dots, SiO₂ nanoparticles, TiO₂ nanoparticles, etc., but not limited thereto; wherein, the average particle size of the carbon quantum dots is 2 - 10 nm, and the average particle size of the SiO₂ nanoparticles and TiO₂ nanoparticles is 10 - 100 nm.

[0049] In some more preferred embodiments, the super - hydrophobic one - dimensional nanomaterials are obtained by modifying the one - dimensional nanomaterials with polar groups and super - hydrophobic groups; the diameter of the one - dimensional nanomaterials is 2 - 20 nm, and the aspect ratio is 100 / 1 - 2000 / 1, and the one - dimensional nanomaterials can include any one or a combination of two or more of carbon nanotubes, halloysite tubes, CuO nanowires, etc., but not limited thereto.

[0050] In some more preferred embodiments, the super - hydrophobic two - dimensional nanomaterials are obtained by modifying the two - dimensional nanomaterials with polar groups and super - hydrophobic groups; the sheet thickness of the two - dimensional nanomaterials is 0.3 - 5 nm, and the sheet diameter is 0.5 - 5 μm, and the two - dimensional nanomaterials can include any one or a combination of two or more of graphene oxide, boron nitride nanosheets, C₃N₄ nanosheets, etc., but not limited thereto.

[0051] In some preferred embodiments, the preparation method of the mixed - dimensional super - hydrophobic drag - reducing agent includes: adding polyphenol compounds and aminopropyltriethoxysilane to the mixed solution, and fully stirring and reacting at 10 - 50 °C for 0.5 - 7 days to obtain a mixed solution containing mixed - dimensional nanomaterials modified with polar groups.

[0052] In some more preferred embodiments, the addition ratio of the polyphenol compound is 0.5 to 5 wt% of the mixed solution.

[0053] The addition ratio of the aminopropyltriethoxysilane is 0.5 to 5 wt% of the mixed solution.

[0054] In some more preferred embodiments, the polyphenol compound may include any one or a combination of dopamine, catechol, tannic acid, etc., but is not limited thereto.

[0055] In some preferred embodiments, the method for preparing the mixed-dimensional superhydrophobic nano drag reducer includes: adding fluorosiloxane and long-chain alkane to the mixed solution containing the mixed-dimensional nanomaterial modified with polar groups, and heating and reacting to obtain a mixed solution containing the mixed-dimensional superhydrophobic nanomaterial; wherein, the temperature of the heating reaction is 30 to 80 °C, and the reaction time is 0.5 to 7 days.

[0056] In some more preferred embodiments, the addition ratio of the fluorosiloxane is 0.1 to 10 wt% of the mixed solution containing the mixed-dimensional superhydrophobic nanomaterial.

[0057] The addition ratio of the long-chain alkane is 0.1 to 10 wt% of the mixed solution containing the mixed-dimensional superhydrophobic nanomaterial.

[0058] In some more preferred embodiments, the fluorosiloxane may include any one or a combination of 1H, 1H, 2H, 2H-heptadecafluorodecyltrimethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorohexyltriethoxysilane, 1H, 1H, 2H, 2H-nonafluorohexyltrimethoxysilane, etc., but is not limited thereto.

[0059] In some more preferred embodiments, the long-chain alkane may include any one or a combination of hexadecylamine, octadecylamine, hexadecanethiol, etc., but is not limited thereto.

[0060] In some preferred embodiments, the method for preparing the mixed-dimensional superhydrophobic nano drag reducer includes: adding a sacrificial layer material and a surfactant to the mixed solution containing the mixed-dimensional superhydrophobic nanomaterial, fully stirring and reacting for 0.5 to 2 days, and filtering to obtain the mixed-dimensional superhydrophobic nanomaterial wrapped with the sacrificial layer.

[0061] In some more preferred embodiments, the addition ratio of the sacrificial layer material is 0.1 to 5 wt% of the mixed solution containing the mixed-dimensional superhydrophobic nanomaterial.

[0062] In some more preferred embodiments, the addition ratio of the surfactant is 0.01 to 10 wt % of the mixed solution containing the mixed-dimensional super-hydrophobic nanomaterial.

[0063] In some more preferred embodiments, the material of the sacrificial layer may include any one or two of liquid paraffin, methyl silicone oil, etc., but is not limited thereto. In some more preferred embodiments, the surfactant may include any one or more combinations of, but is not limited to, sodium dodecylbenzene sulfonate, polysorbate 80, sorbitan stearate, etc.

[0064] In some more specific implementation cases, the preparation method of the mixed-dimensional super-hydrophobic nano drag reducer comprises the following steps:

[0065] (1) uniformly dispersing 0.01-1 wt% of zero-dimensional nanomaterial, 0.01-1 wt% of one-dimensional nanomaterial, and 0.01-1 wt% of two-dimensional nanomaterial in a mixed solvent consisting of water, ethanol, and ethyl acetate;

[0066] (2) adding 0.5-5 wt% of a polyphenol compound and 0.5-5 wt% of aminopropyltriethoxysilane to the mixed solution prepared in the first step, stirring and reacting for 0.5-7 days to obtain a mixed solution containing a polar group-modified mixed-dimensional nanomaterial;

[0067] (3) adding 0.1 to 10 wt % of fluorosilicone and 0.1 to 10 wt % of long-chain alkane to the mixed solution prepared in the second step, heating to 30 to 80° C., and reacting for 0.5 to 7 days to obtain a mixed solution containing mixed-dimensional superhydrophobic nanomaterials;

[0068] (4) adding 0.1-5 wt% of liquid paraffin and 0.01-10 wt% of a surfactant to the mixed solution prepared in the third step, stirring and reacting for 0.5-2 days, filtering, and obtaining a mixed-dimensional superhydrophobic nano drag reducer wrapped with a sacrificial layer.

[0069] During the preparation process, the role of adding a surfactant is to improve the dispersibility and compatibility of the sacrificial layer material in the mixed solution of the mixed-dimensional super-hydrophobic nanomaterial prepared in step (3), which ultimately facilitates the loading of the sacrificial layer material on the surface of the mixed-dimensional super-hydrophobic nanomaterial.

[0070] Another aspect of the embodiments of the present invention further provides the application of the aforementioned mixed-dimensional superhydrophobic nano drag reducer in the field of low permeability oil reservoirs.

[0071] The present invention will be described in more detail below with reference to the embodiments, but the embodiments do not limit the present invention. All variations that can be associated with or derived from the contents disclosed in the present invention are considered to be within the scope of protection of the present invention.

[0072] Example 1

[0073] (1) 0.01 wt% carbon quantum dots, 1 wt% carbon nanotubes and 1 wt% graphene oxide were uniformly dispersed in a mixed solvent composed of water, ethanol and ethyl acetate (volume ratio 1:1:1) to form a mixed solution;

[0074] (2) 0.5 wt% dopamine and 5 wt% aminopropyltriethoxysilane were added to the mixed solution, and the mixture was stirred vigorously for 0.5 days to obtain a mixed solution containing mixed-dimensional nanomaterials modified with polar groups;

[0075] (3) 0.1 wt% 1H,1H,2H,2H-heptadecafluorodecyltrimethoxysilane and 10 wt% hexadecylamine were added to the mixed solution containing mixed-dimensional nanomaterials modified with polar groups, and the mixture was heated to 30 °C and reacted for 7 days to obtain a mixed solution containing mixed-dimensional superhydrophobic nanomaterials;

[0076] (4) 0.1 wt% liquid paraffin and 1 wt% sodium dodecylbenzenesulfonate were added to the mixed solution containing mixed-dimensional superhydrophobic nanomaterials, and the mixture was stirred vigorously for 0.5 - 2 days, followed by filtration to obtain a sacrificial layer-coated mixed-dimensional superhydrophobic nanofriction reducer.

[0077] Example 2

[0078] (1) 1 wt% SiO2 nanoparticles with an average particle size of 10 - 100 nm, 0.01 wt% halloysite nanotubes and 0.01 wt% boron nitride nanosheets were uniformly dispersed in a mixed solvent composed of water, ethanol and ethyl acetate (volume ratio 1:4:2) to form a mixed solution;

[0079] (2) 5 wt% catechol and 0.5 wt% aminopropyltriethoxysilane were added to the mixed solution, and the mixture was stirred vigorously for 7 days to obtain a mixed solution containing mixed-dimensional nanomaterials modified with polar groups;

[0080] (3) 10 wt% 1H,1H,2H,2H-perfluorodecyltriethoxysilane and 0.1 wt% octadecylamine were added to the mixed solution containing mixed-dimensional nanomaterials modified with polar groups, and the mixture was heated to 80 °C and reacted for 0.5 days to obtain a mixed solution containing mixed-dimensional superhydrophobic nanomaterials;

[0081] (4) 5 wt% liquid paraffin and 0.01 wt% polysorbate 80 were added to the mixed solution containing mixed-dimensional superhydrophobic nanomaterials, and the mixture was stirred vigorously for 0.5 - 2 days, followed by filtration to obtain a sacrificial layer-coated mixed-dimensional superhydrophobic nanofriction reducer.

[0082] Example 3

[0083] (1) 0.5 wt% of TiO₂ nanoparticles with an average particle size of 10 - 100 nm, 0.5 wt% of CuO nanowires, and 0.5 wt% of C₃N₄ nanosheets were uniformly dispersed in a mixed solvent composed of water, ethanol, and ethyl acetate (volume ratio 1:1:1) to form a mixed solution;

[0084] (2) 1 wt% of tannic acid and 2 wt% of aminopropyltriethoxysilane were added to the mixed solution, and the mixture was stirred vigorously for 2 days to obtain a mixed solution containing mixed - dimensional nanomaterials modified with polar groups;

[0085] (3) 1 wt% of 1H,1H,2H,2H - perfluorohexyltriethoxysilane and 5 wt% of hexadecanethiol were added to the mixed solution containing mixed - dimensional nanomaterials modified with polar groups, and the mixture was heated to 60 °C and reacted for 2 days to obtain a mixed solution containing mixed - dimensional superhydrophobic nanomaterials;

[0086] (4) 3 wt% of methyl silicone oil and 10 wt% of sorbitan stearate were added to the mixed solution containing mixed - dimensional superhydrophobic nanomaterials, and the mixture was stirred vigorously for 1 day and then filtered to obtain a mixed - dimensional superhydrophobic nano - drag reducer wrapped with a sacrificial layer.

[0087] Example 4

[0088] (1) 0.5 wt% of carbon quantum dots, 0.5 wt% of carbon nanotubes, and 0.5 wt% of graphene oxide were uniformly dispersed in a mixed solvent composed of water, ethanol, and ethyl acetate (volume ratio 1:1:1) to form a mixed solution;

[0089] (2) 2 wt% of dopamine and 2 wt% of aminopropyltriethoxysilane were added to the mixed solution, and the mixture was stirred vigorously for 2 days to obtain a mixed solution containing mixed - dimensional nanomaterials modified with polar groups;

[0090] (3) 1 wt% of 1H,1H,2H,2H - nonafluorhexyltrimethoxysilane fluorosiloxane and 1 wt% of hexadecylamine were added to the mixed solution containing mixed - dimensional nanomaterials modified with polar groups, and the mixture was heated to 60 °C and reacted for 5 days to obtain a mixed solution containing mixed - dimensional superhydrophobic nanomaterials;

[0091] [[ID=2,4]](4) 2 wt% of liquid paraffin and 5 wt% of sodium dodecylbenzenesulfonate were added to the mixed solution containing mixed - dimensional superhydrophobic nanomaterials, and the mixture was stirred vigorously for 1 day and then filtered to obtain a mixed - dimensional superhydrophobic nano - drag reducer wrapped with a sacrificial layer.

[0092] Comparative Example 1: This comparative example is basically the same as Example 4, except that: one - dimensional nanomaterials were not added.

[0093] Comparative Example 2: This comparative example is basically the same as Example 4, except that no two-dimensional nanomaterial is added.

[0094] Comparative Example 3: This comparative example is basically the same as Example 4, except that no three-dimensional nanomaterial is added.

[0095] Comparative Example 4: This comparative example is basically the same as Example 4, except that no liquid paraffin is added.

[0096] Performance Characterization: The water contact angle test and the drag reduction rate test were carried out on the samples in Examples 1-4 and Comparative Examples 1-4.

[0097] 1. Water Contact Angle Test

[0098] The water contact angle of the dry drag reducer was measured using a contact angle measuring instrument (Dataphysics, OCA20). The volume of the water droplet was 2 μL, the test temperature was 25 °C, and each sample was tested at least five times. The average value was taken, and the results are shown in Table 1.

[0099] 2. Drag Reduction Rate Test

[0100] Before and after the drag reducer was adsorbed on the wall of the Ubbelohde viscometer, the change in the time for deionized water to flow through the Ubbelohde viscometer (scale line m1 to scale line m2) was measured, and the drag reduction rate (RE, %) was calculated to simply and quickly evaluate the drag reduction effect of the drag reducer. The dispersion medium of the drag reducer was tetrahydrofuran, the concentration was 50 ppm, the adsorption time was 48 hours, and the test temperature was 25 ± 1 °C. The results are shown in Table 1.

[0101] The calculation formula for the drag reduction rate (RE, %) is as follows:

[0102] RE = (t0 - t) / t0 × 100%

[0103] t0: The time for deionized water to flow through the Ubbelohde viscometer (scale line m1 to scale line m2) before the drag reducer was adsorbed

[0104] t: The time for deionized water to flow through the Ubbelohde viscometer (scale line m1 to scale line m2) after the drag reducer was adsorbed

[0105] Table 1 Comparison of water contact angle and drag reduction effect between Examples 1-4 and Comparative Examples 1-4

[0106] Water contact angle (°) Drag reduction rate (%) Example 1 152±1 45±2 Example 2 153±3 50±1 Example 3 157±4 47±4 Example 4 164±5 41±1 Comparative Example 1 144±3 5±1 Comparative Example 2 130±3 3±2 Comparative Example 3 128±4 4±1 Comparative Example 4 154±3 2±1

[0107] As can be seen from Table 1, the sacrificial-layer-wrapped hybrid-dimensional superhydrophobic nano drag reducer, which is composed of sacrificial-layer-wrapped superhydrophobic zero-dimensional nanomaterials, sacrificial-layer-wrapped superhydrophobic one-dimensional nanomaterials, and sacrificial-layer-wrapped superhydrophobic two-dimensional nanomaterials, has a high drag reduction rate and exhibits excellent drag reduction effect; excellent drag reduction rate cannot be obtained for the sacrificial-layer-wrapped superhydrophobic nanomaterials lacking any dimension or the nanomaterials lacking sacrificial-layer protection.

[0108] In addition, the inventor of this case also conducted tests in the manner of Examples 1-4 with other raw materials and conditions listed in this specification, and also prepared a hybrid-dimensional superhydrophobic nano drag reducer with a high drag reduction rate.

[0109] Although the present invention has been described with reference to the illustrative embodiments, those skilled in the art will understand that various other changes, omissions and / or additions can be made without departing from the spirit and scope of the present invention and elements of the embodiments can be replaced with substantial equivalents. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the present invention without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the specific embodiments disclosed for carrying out the present invention, but is intended to cover all embodiments falling within the scope of the appended claims. In addition, unless specifically stated, any use of the terms first, second, etc. does not denote any order or importance, but the terms first, second, etc. are used to distinguish one element from another.

Claims

1. A hybrid-dimension superhydrophobic nano drag reducer, characterized in that, It includes mixed - dimensional super - hydrophobic nanomaterials and a sacrificial layer wrapping the mixed - dimensional super - hydrophobic nanomaterials. Among them, the mixed - dimensional super - hydrophobic nanomaterials at least include super - hydrophobic zero - dimensional nanomaterials, super - hydrophobic one - dimensional nanomaterials, and super - hydrophobic two - dimensional nanomaterials. The thickness of the sacrificial layer is 0.5 - 10 μm; the material of the sacrificial layer is selected from any one or two of liquid paraffin or methyl silicone oil; the super - hydrophobic zero - dimensional nanomaterials are obtained by modifying zero - dimensional nanomaterials with polar groups and super - hydrophobic modification; the super - hydrophobic one - dimensional nanomaterials are obtained by modifying one - dimensional nanomaterials with polar groups and super - hydrophobic modification; the super - hydrophobic two - dimensional nanomaterials are obtained by modifying two - dimensional nanomaterials with polar groups and super - hydrophobic modification; The mixed - dimensional super - hydrophobic nanomaterials are prepared by the following method: Uniformly mix zero - dimensional nanomaterials, one - dimensional nanomaterials, two - dimensional nanomaterials with a solvent to form a mixed solution; add polyphenol compounds and aminopropyltriethoxysilane to the mixed solution, and react to obtain mixed - dimensional nanomaterials with polar - group modification; Mix fluorosiloxane and long - chain alkane with the mixed - dimensional nanomaterials with polar - group modification, and heat - react to obtain mixed - dimensional super - hydrophobic nanomaterials; The zero - dimensional nanomaterials are selected from any one or a combination of two or more of carbon quantum dots, SiO2 nanoparticles, TiO2 nanoparticles. The diameter of the one - dimensional nanomaterials is 2 - 20 nm, and the aspect ratio is 100 / 1 - 2000 / 1. And the one - dimensional nanomaterials are selected from any one or a combination of two or more of carbon nanotubes, halloysite tubes, CuO nanowires; the sheet thickness of the two - dimensional nanomaterials is 0.3 - 5 nm, and the sheet diameter is 0.5 - 5 μm. And the two - dimensional nanomaterials are selected from any one or a combination of two or more of graphene oxide, boron nitride nanosheets, C3N4 nanosheets.

2. The hybrid-dimension superhydrophobic nano drag reducer according to claim 1, wherein: In the mixed - dimensional super - hydrophobic nano - drag - reducer, the mass ratio of the super - hydrophobic zero - dimensional nanomaterials, super - hydrophobic one - dimensional nanomaterials, and super - hydrophobic two - dimensional nanomaterials is 1:(1 - 2):(1 - 2).

3. The hybrid-dimensional superhydrophobic nano-drag reducer according to claim 1, characterized in that: In the mixed - dimensional super - hydrophobic nano - drag - reducer, the mass ratio of the sacrificial layer and the mixed - dimensional super - hydrophobic nanomaterials is 1:(20 - 50).

4. The preparation method of the hybrid-dimensional superhydrophobic nano drag reducer according to any one of claims 1-3, characterized in that It includes: Uniformly mix zero - dimensional nanomaterials, one - dimensional nanomaterials, two - dimensional nanomaterials with a solvent to form a mixed solution; add polyphenol compounds and aminopropyltriethoxysilane to the mixed solution, and react to obtain mixed - dimensional nanomaterials with polar - group modification; Mix fluorosiloxane and long - chain alkane with the mixed - dimensional nanomaterials with polar - group modification, and heat - react to obtain mixed - dimensional super - hydrophobic nanomaterials; Mix the sacrificial - layer material and surfactant with the mixed - dimensional super - hydrophobic nanomaterials and react, and separate to obtain the mixed - dimensional super - hydrophobic nanomaterials wrapped by the sacrificial layer, that is, the mixed - dimensional super - hydrophobic nano - drag - reducer. The material of the sacrificial layer is selected from any one or two of liquid paraffin or methyl silicone oil.

5. The preparation method of the hybrid-dimension superhydrophobic nano drag reducer according to claim 4, characterized in that, It includes: Uniformly disperse zero - dimensional nanomaterials, one - dimensional nanomaterials, and two - dimensional nanomaterials in a solvent to form a mixed solution; The content of the zero-dimensional nanomaterials in the mixed solution is 0.01-1 wt%, the content of the one-dimensional nanomaterials is 0.01-1 wt%, and the content of the two-dimensional nanomaterials is 0.01-1 wt%.

6. The preparation method of the hybrid-dimension superhydrophobic nano drag reducer according to claim 5, wherein: The solvent includes a mixed solvent composed of water, ethanol and ethyl acetate; the volume ratio of water, ethanol to ethyl acetate is 1:(1-4):(1-2).

7. The preparation method of the hybrid-dimensional superhydrophobic nano drag reducer according to claim 4 or 5, characterized in that: The zero-dimensional nanomaterials are selected from any one or a combination of two or more of carbon quantum dots, SiO2 nanoparticles, and TiO2 nanoparticles; Among them, the average particle size of the carbon quantum dots is 2-10 nm, and the average particle size of the SiO2 nanoparticles and TiO2 nanoparticles is 10-100 nm.

8. The preparation method of the hybrid-dimension superhydrophobic nano drag reducer according to claim 4, characterized in that It includes: Adding polyphenol compounds and aminopropyltriethoxysilane to the mixed solution, and fully stirring and reacting at 10-50 °C for 0.5-7 days to obtain a mixed solution containing mixed-dimensional nanomaterials modified with polar groups.

9. The preparation method of the hybrid-dimensional superhydrophobic nano-drag reducer according to claim 8, characterized in that: The addition ratio of the polyphenol compounds is 0.5-5 wt% of the mixed solution; The addition ratio of the aminopropyltriethoxysilane is 0.5-5 wt% of the mixed solution.

10. The preparation method of the hybrid-dimension superhydrophobic nano drag reducer according to claim 8, characterized in that: The polyphenol compounds include any one or a combination of dopamine, catechol, tannic acid, etc.

11. The preparation method of the hybrid dimensional superhydrophobic nano drag reducer according to claim 4, characterized in that It includes: Adding fluorosiloxane and long-chain alkane to the mixed solution containing mixed-dimensional nanomaterials modified with polar groups, and heating and reacting to obtain a mixed solution containing mixed-dimensional superhydrophobic nanomaterials; wherein, the temperature of the heating reaction is 30-80 °C, and the reaction time is 0.5-7 days.

12. The preparation method of the hybrid-dimension superhydrophobic nano drag reducer according to claim 11, characterized in that: The addition ratio of the fluorosiloxane is 0.1-10 wt% of the mixed solution containing mixed-dimensional superhydrophobic nanomaterials; the addition ratio of the long-chain alkane is 0.1-10 wt% of the mixed solution containing mixed-dimensional superhydrophobic nanomaterials.

13. The preparation method of the hybrid-dimensional superhydrophobic nano drag reducer according to claim 11, characterized in that: The fluorosiloxane includes any one or a combination of 1H,1H,2H,2H-heptadecafluorodecyltrimethoxysilane, 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 1H,1H,2H,2H-perfluorohexyltriethoxysilane or 1H,1H,2H,2H-nonafluorohexyltrimethoxysilane.

14. The preparation method of the hybrid-dimension superhydrophobic nano drag reducer according to claim 11, characterized in that: The long-chain alkane includes any one or a combination of hexadecylamine, octadecylamine or hexadecanethiol.

15. The preparation method of the hybrid-dimension superhydrophobic nano-drag reducer according to claim 4, characterized in that It includes: Adding a sacrificial layer material and a surfactant to the mixed solution containing mixed-dimensional superhydrophobic nanomaterials, fully stirring and reacting for 0.5-2 days, and filtering to obtain mixed-dimensional superhydrophobic nanomaterials wrapped with a sacrificial layer.

16. The preparation method of the hybrid-dimension superhydrophobic nano-drag reducer according to claim 15, characterized in that: The addition ratio of the sacrificial layer material is 0.1-5 wt% of the mixed solution containing mixed-dimensional superhydrophobic nanomaterials.

17. The preparation method of the hybrid-dimensional superhydrophobic nano drag reducer according to claim 15, characterized in that: The addition ratio of the surfactant is 0.01-10 wt% of the mixed solution containing mixed-dimensional superhydrophobic nanomaterials.

18. The preparation method of the hybrid-dimensional superhydrophobic nano drag reducer according to claim 15, characterized in that: The surfactant includes any one or a combination of sodium dodecylbenzenesulfonate, polysorbate 80, sorbitan stearate, etc.

19. Application of the mixed-dimensional superhydrophobic nano drag reducer according to any one of claims 1-3 in the field of low-permeability oil reservoirs.