CN113122217B - A kind of carbon-based amphiphilic nanoflow for oil displacement and preparation method - Google Patents

Abstract

The invention discloses a carbon-based amphiphilic nanofluid for oil displacement. Using carbon-based nanopowder as a raw material, it is modified with a silane coupling agent and polyoxyethylene ether successively to obtain a carbon-based amphiphilic nanofluid. ; Carbon-based nano-powder is selected from graphite powder, carbon powder, graphene or graphene oxide. The preparation method of the amphiphilic nanofluid is as follows: disperse the carbon-based nanopowder in a mixed solvent with an equal mass ratio of toluene and dimethylformamide, then add a silane coupling agent, seal and stir, react in an oil bath at 96 °C for 6 h, and pump Filter, purify and dry to obtain the carbon-based nanopowder modified by the silane coupling agent; disperse the carbon-based nanopowder modified by the silane coupling agent in another mixed solvent of toluene and dimethylformamide in the same mass ratio; Polyoxyethylene ether was added, sealed and stirred, and the reaction was carried out in an oil bath at 90° C. for 6 hours. The carbon-based amphiphilic nanoflow was obtained by suction filtration, purification and drying. The carbon-based amphiphilic nanofluid of the present invention can be directly prepared with oil field injection water to obtain a carbon-based amphiphilic nanofluid dispersion.

Description

A kind of carbon-based amphiphilic nanoflow for oil displacement and preparation method

technical field

The invention relates to the technical field of oilfield chemistry, in particular to a carbon-based amphiphilic nanoflow for oil displacement and a preparation method.

Background technique

Since Degennes first proposed the concept of Janus in his Nobel Prize speech in 1991, amphiphilic particles with asymmetric properties in chemical composition have attracted extensive attention from scholars at home and abroad. In recent years, there are various types of nanomaterials based on Janus particles, with outstanding performance in many aspects such as mechanics, magnetism, optics, and energy industry. Because carbon has a large number of allotropes, especially the preparation and research of carbon-based composite nanomaterials has become a research hotspot in academia. Significant, but often requires the help of external instruments and equipment, or artificially given synthetic induction conditions other than the properties of the material itself.

For example, Xiao Peng et al. used the method of interfacial self-assembly to prepare ultrathin films of carbon nanotubes (CNTs). Furthermore, through self-initiated photografting photopolymerization (S) sub-functional modification, its application in the field of sensors and transistors is studied. The experimental results strongly demonstrate that the use of supramolecular self-assembly can easily and efficiently prepare large-area conductive carbon-based ultra-thin films, and the two-dimensional Janus hybrid ultra-thin films obtained by selective single-sided grafting of stimulus-responsive polymers can make the stimulation Responsive polymers and carbon-based films play a synergistic role, greatly expanding their applications in sensing, transistors, and other fields.

Yuan Kang of Jianghan University designed a route to synthesize graphene-based amphiphilic nanomaterials based _on SiO template, and synthesized amphiphilic graphene with modified EDTA on one side and C18 chain on the other. Through experimental analysis, he found that the enrichment ability of amphiphilic graphene for heavy metal ions is 2.4 times that of graphene oxide (GO), indicating that Janus graphene is an efficient heavy metal ion adsorbent and has certain application prospects in environmental purification. . It is worth noting that the amphiphilic graphene synthesized by him is hydrophilic on one side (EDTA side) and hydrophobic on the other side (C18 side), which has amphiphilic properties similar to surfactants. The performance of graphene applied to oil-water separation has been preliminarily studied, and the results show that amphiphilic graphene has a good effect on the removal of trace oil droplets in water.

Over the past 70 years, my country has become the world's largest energy producer. In terms of oil, although the overall reserve base is large, the demand for energy consumption is increasing day by day, and the degree of external dependence has already risen by more than half. Improving my country's oil recovery is the original intention and mission of scholars in the oil field. Traditional tertiary oil recovery, following water or gas injection flooding, thermal flooding, microbial flooding, and polymer flooding, has become the main theme of oilfield workers' research at this stage.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a carbon-based amphiphilic nanoflow for oil displacement and a preparation method.

The carbon-based amphiphilic nanofluid for oil displacement provided by the invention takes carbon-based nanopowder as a raw material, and successively uses a silane coupling agent and polyoxyethylene ether to modify it to obtain a carbon-based amphiphilic nanofluid.

The carbon-based nano-powder is selected from one of graphite powder, carbon powder, graphene or graphene oxide, and the smallest dimension of any one of the three dimensions is 1 nm-100 nm.

The silane coupling agent is γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-2-(aminoethyl) - One or a combination of two of 3-aminopropyltrimethoxysilane.

The weight average molecular weight of the polyoxyethylene ether is 260-6000 g/mol.

The carbon-based amphiphilic nanoflow for oil displacement is mainly suitable for water flooding to develop oil reservoirs. The carbon-based amphiphilic nanofluidic dispersion was prepared directly with oil field injection water. Moreover, the carbon-based amphiphilic nanofluid is used in combination with a surfactant.

The preparation method of the above-mentioned carbon-based amphiphilic nanofluid, the steps are as follows:

S1. Add 10-16g carbon-based nanopowder into 60-100g mixed solvent, heat in an oil bath at 80°C, and stir for 60min to obtain a uniformly dispersed dispersion; the mixed solvent is a mixture of toluene and dimethylformamide in an equal mass ratio.

S2. Add 5-10 g of silane coupling agent to the dispersion obtained in step S1 under the condition of oil bath at 80°C, seal and stir, react in oil bath at 96°C for 6 hours, filter, purify and dry to obtain modified silane coupling agent. Carbon-based nanopowder.

S3, adding 3-5 g of the carbon-based nanopowder modified by the silane coupling agent obtained in step S2 into another 15-30 g mixed solvent, heating in an oil bath at 80° C., stirring for 60 min, to obtain a uniformly dispersed dispersion; mixing; The solvent is a mixture of toluene and dimethylformamide in equal mass ratio.

S4. Add 1.5-3.6g of polyoxyethylene ether to the dispersion obtained in step S3 under the condition of oil bath at 90°C, seal and stir, carry out reaction in oil bath at 90°C for 6h, suction filter, purify and dry to obtain carbon-based Amphiphilic nanoflows.

The proportion of the silane coupling agent and the molecular weight of the polyoxyethylene ether can be selected according to the geological conditions of the reservoir and the viscosity of the crude oil, so as to realize the adjustment of the lipophilicity and the hydrophilicity of the carbon-based amphiphilic nanofluid. Permeability magnitude, heterogeneity, and reservoir wettability.

Compared with the prior art, the advantages of the present invention are:

(1) The present invention synthesizes the carbon-based amphiphilic nanofluid by an efficient and simple method, and uses the carbon-based amphiphilic nanofluid prepared by injecting water to be pumped into the formation, so that the interfacial tension between the carbon-based amphiphilic nanofluid and crude oil reaches a low level. order of magnitude, carbon-based amphiphilic nanoflows spontaneously enrich at the oil-water interface under shear flow conditions, forming an emulsion film, reducing the water mobility ratio at the water-oil interface, stabilizing the water displacement front, and expanding the water Drive wave and volume. The carbon-based amphiphilic nanoflow is directly dispensed with a water injection system, without the need for an additional dispensing system, saving energy and reducing emissions.

(2) At the same time, the carbon-based amphiphilic nanoflow improves the wettability of the rock, changes the oil-wet rock surface to a neutrally wet or even water-wet surface, improves the capillary power of the displacement, and improves the oil displacement efficiency.

(3) The carbon-based amphiphilic nanofluids cooperate to improve the swept volume and microscopic oil displacement efficiency, thereby effectively improving oil recovery.

(4) Carbon-based amphiphilic nanofluids, as high-efficiency oil-displacing agents, can spontaneously enrich at the oil-water interface, and emulsify and wash oil at low energy, which is efficient, economical, and environmentally friendly. The invention not only provides a new idea for improving crude oil recovery and ensuring the supply of crude oil production in my country, but also provides important theoretical support for the large-scale R&D and production of oil-displacing agents with huge economic benefits and significant effects.

(5) The method is reliable in principle, cheap and easily available raw materials, large-scale production of carbon-based amphiphilic nanofluids, convenient storage and transportation, outstanding economic benefits, and broad industrial application prospects. The range of applications is very broad, covering all waterflooding development reservoirs.

(6) Carbon-based amphiphilic nanofluids can also be used in combination with surfactants, which can greatly improve oil recovery by exerting the synergistic effect of interfacial mobility control and oil-water (ultra) low interfacial tension.

Other advantages, objects, and features of the present invention will appear in part from the description that follows, and in part will be appreciated by those skilled in the art from the study and practice of the invention.

Description of drawings

Figure 1. Microscopic view of carbon-based amphiphilic nanofluids.

Figure 2. The carbon-based amphiphilic nanofluids are enriched at the water-crude oil interface to form an emulsion film.

Figure 3. Oil displacement effect diagram of petroleum sulfonate.

Figure 4. The oil displacement effect of carbon-based amphiphilic nanofluids.

Detailed ways

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention.

Example 1

Add 10g graphite powder to a 500mL three-neck flask, then add 80g toluene and dimethylformamide solvent (mass ratio 1:1), stir for 60min in an oil bath at 80°C; couple 5g in an oil bath at 80°C The agent N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane was added to the graphite powder solution, sealed and stirred, and the combined reaction was carried out in an oil bath at 96 °C for 6 hours, and the obtained solution was suction filtered, purified and dried. Coupling agent modified graphite powder. Add 3g of graphite powder modified by coupling agent to a 500mL three-neck flask, then add 15g of toluene and dimethylformamide solvent (mass ratio 1:1), stir for 60min in an oil bath at 80°C; in an oil bath at 90°C 1.5 g of polyoxyethylene ether was added to the graphite powder solution modified by the coupling agent under the conditions, sealed and stirred, reacted in an oil bath at 90 °C for 6 h, filtered, purified and dried to obtain the carbon-based amphiphilic nanoflow 1.

Example 2

Add 13g of carbon powder to a 500mL three-neck flask, then add 90g of toluene and dimethylformamide solvent (mass ratio 1:1), stir for 60min in an oil bath at 80°C; couple 8g in an oil bath at 80°C The agent γ-aminopropyltriethoxysilane was added to the carbon powder solution, sealed and stirred, and the combined reaction was carried out in an oil bath at 96°C for 6 hours, and the carbon powder modified by the coupling agent was obtained by suction filtration, purification and drying. In a 500mL three-neck flask, add 6g of carbon powder modified by coupling agent, then add 20g of toluene and dimethylformamide solvent (mass ratio 1:1), stir for 60min in an oil bath at 80°C; in an oil bath at 90°C 2.0 g of polyoxyethylene ether was added to the coupling agent-modified carbon powder solution under the conditions; sealed and stirred, reacted in an oil bath at 90 °C for 6 h, suction filtered, purified and dried to obtain carbon-based amphiphilic nanoflow 2.

Example 3

Add 12g graphene to a 500mL three-neck flask, then add 100g toluene and dimethylformamide solvent (mass ratio 1:1), stir for 60min in an oil bath at 80°C; couple 5g in an oil bath at 80°C Agent N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and 5g coupling agent γ-aminopropyltriethoxysilane were added to the dispersed graphene, sealed and stirred, and placed in an oil bath for 96 ℃ to carry out the synthesis reaction for 6h, suction filtration, purification and drying to obtain the graphene modified by the coupling agent; add 3.2g of the graphene modified by the coupling agent into a 500mL three-neck flask, and then add 30g of toluene and dimethylformamide Solvent (mass ratio 1:1), stir for 60 min in an oil bath at 80°C; add 3.3 g of polyoxyethylene ether to the coupling agent-modified graphene solution at 90°C in an oil bath, seal and stir in oil The reaction was carried out in a bath at 90 °C for 6 h, and the carbon-based amphiphilic nanoflow 3 was obtained by suction filtration, purification and drying.

Example 4

Add 16g graphene oxide to a 500mL three-necked flask, then add 100g toluene and dimethylformamide solvent (mass ratio 1:1), stir for 60min in an oil bath at 80°C; Linking agent N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 7g coupling agent N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane were added to In the graphene oxide solution, seal and stir, carry out the combined reaction in an oil bath at 96° C. for 6 hours, and filter, purify and dry to obtain the graphene oxide modified by the coupling agent. Add 3.6g of coupling agent-modified graphene oxide to a 500mL three-necked flask, then add 30g of toluene and dimethylformamide solvent (mass ratio 1:1), stir in an oil bath at 80°C for 60min; in an oil bath 3.6g of polyoxyethylene ether was added to the graphene oxide solution modified by the coupling agent at 90°C, sealed and stirred, reacted in an oil bath at 90°C for 6 hours, filtered, purified and dried to obtain carbon-based amphiphilic nanofluids. 4.

The performance test is as follows:

(1) Scale of carbon-based amphiphilic nanofluids

Disperse 15 mg of the carbon-based amphiphilic nanofluid synthesized in Example 2 in 10 mL of distilled water, seal and ultrasonicate for 10 min to obtain a carbon-based amphiphilic nanofluid dispersion. The microscopic morphology of the solution carbon-based amphiphilic nanofluids was observed by environmental scanning microscopy (SEM), as shown in Figure 1. The SEM microscopic topography shows that the carbon-based amphiphilic nanofluids have a two-dimensional nanostructure, and the thickness of the nanosheets is about 3 nm.

(2) Oil-water interfacial tension of carbon-based amphiphilic nanofluids

The salinity is 3.0×10 ⁴ mg/L (Ca ²⁺ , Mg ²⁺ concentration is 0.06×10 ⁴ mg/L) No. 1#, 5.0×10 ⁴ mg/L (Ca ²⁺ , Mg ²⁺ The concentration is 0.15×10 ⁴ mg/L) No. 2#, 7.5×10 ⁴ mg/L (Ca ²⁺ , Mg ²⁺ concentration is 0.2×10 ⁴ mg/L) No. 3#, 10×10 ⁴ mg/L (Ca ²⁺ , Mg ²⁺ concentrations are 0.5×10 ⁴ mg/L) No. 4# and 15×10 ⁴ mg/L (Ca ²⁺ , Mg ²⁺ concentrations are 0.75×10 ⁴ mg/L) No. 5# The mineralized water was stirred for 30 min.

The carbon-based amphiphilic nanoflow synthesized in Example 1 was added to 1#, the carbon-based amphiphilic nanoflow synthesized in Example 2 was added to 2#, and the carbon-based amphiphilic nanoflow synthesized in Example 3 was added to 3#, and 4 Add Example 2 carbon-based amphiphilic nanofluid to #, add Example 4 carbon-based amphiphilic nanofluid to 5#, and prepare a carbon-based amphiphilic nanofluidic dispersion with a mass concentration of 0.2% in 1#-5# mineralized water , stir and dissolve for 30min.

The interfacial tension between carbon-based amphiphilic nanoflows and degassed crude oil (viscosity of 35.8 mPa·s at 50 °C and shear rate of 10 s ^-1 , respectively) was measured with a TX500C rotating drop interfacial tensiometer at 50 °C. The measurement time was 2 h. A stable interfacial tension value was obtained, and the experimental results are shown in Table 1. It can be seen that under the condition of mineralized water of 3.0～15×10 ⁴ mg/L, the interfacial tension of oil and water is maintained at the order of 10 ^-1 mN/m, which indicates that the carbon-based amphiphilic nanoflow has good performance. interface activity.

Table 1. Stable interfacial tension between carbon-based amphiphilic nanofluids and crude oil

(3) Synergistic effect of carbon-based amphiphilic nanofluids and surfactants

The salinity is 3.0×10 ⁴ mg/L (Ca ²⁺ , Mg ²⁺ concentration is 0.06×10 ⁴ mg/L) No. 1#, 5.0×10 ⁴ mg/L (Ca ²⁺ , Mg ²⁺ The concentration is 0.15×10 ⁴ mg/L) No. 2#, 7.5×10 ⁴ mg/L (Ca ²⁺ , Mg ²⁺ concentration is 0.2×10 ⁴ mg/L) No. 3#, 10×10 ⁴ mg/L (Ca ²⁺ , Mg ²⁺ concentrations are 0.5×10 ⁴ mg/L) No. 4# and 15×10 ⁴ mg/L (Ca ²⁺ , Mg ²⁺ concentrations are 0.75×10 ⁴ mg/L) No. 5# The mineralized water was stirred for 30 min.

The mineralization level of 1#-5# is divided into two parts. In 1#-1, commercial sodium dodecyl sulfonate with a mass concentration of 0.2% is added, and 2#-1 is added with a commercial concentration of 0.2%. For sale sodium alpha-alkenyl sulfonate, add commercially available dodecyl betaine with a mass concentration of 0.2% in 3#-1, add commercially available coconut oil monoethanolamide with a mass concentration of 0.2% in 4#-1, Commercially available dodecyl/tetradecyl glycosides with a mass concentration of 0.2% were added to 5#-1, and the mixture was stirred and dissolved for 30 minutes. In 1#-2, add 0.15% commercially available sodium dodecyl sulfonate and 0.05% carbon-based amphiphilic nanofluids synthesized in Example 1; in 2#-2, add 0.15% commercially available sodium dodecyl sulfonate. Sodium α-alkenyl sulfonate, 0.05% carbon-based amphiphilic nanoflow synthesized in Example 2; 3#-2 was added with commercially available dodecyl betaine with a mass concentration of 0.15%, 0.05% synthesized in Example 3 Carbon-based amphiphilic nanoflow; 4#-2 was added with a mass concentration of 0.15% of commercially available coconut oil monoethanolamide and 0.05% of the carbon-based amphiphilic nanoflow synthesized in Example 2; 5#-2 was added with a mass concentration of 0.15% of commercially available dodecyl/tetradecyl glycosides, 0.05% of carbon-based amphiphilic nanofluids of Example 4; both were dissolved by stirring for 30 min. The interfacial tension between carbon-based amphiphilic nanoflows and degassed crude oil (viscosities of 21.3 mPa·s at 50 °C and shear rate of 10 s ^-1 , respectively) was measured by a TX500C rotating drop interfacial tensiometer at 50 °C. The measurement time was 2 h. A stable interfacial tension value was obtained, and the experimental results are shown in Table 2. It can be seen that under the condition of mineralized water of 3.0～15×10 ⁴ mg/L, the interfacial tension of oil and water remains at the order of 10 ^-2 mN/m, and the compound system of carbon-based amphiphilic nanofluid and surfactant The interfacial tension is lower, some of which reach the order of 10 ^-3 mN/m, indicating that the compound use of carbon-based amphiphilic nanofluids with various types of surfactants has good synergistic properties and improves the oil displacement efficiency of carbon-based amphiphilic nanofluids. .

Table 2. Stable interfacial tension between carbon-based amphiphilic nanofluids and crude oil

Mineralized water preparation system Stable oil-water interfacial tension (mN/m) 1#-1 0.062 1#-2 0.021 2#-1 0.043 2#-2 0.0087 3#-1 0.049 3#-2 0.031 4#-1 0.055 4#-2 0.0097 5#-1 0.076 5#-2 0.047

(4) Distribution of carbon-based amphiphilic nanofluids at the oil-water interface

The carbon-based amphiphilic nanofluids prepared in Example 2 were dispersed in 7.5×10 ⁴ mg/L (Ca ²⁺ , Mg ²⁺ concentration of 0.2×10 ⁴ mg/L) number 3# of mineralized water, and stirred for 1 hour , to prepare a carbon-based amphiphilic nanofluidic dispersion with a mass concentration of 0.10%. Then add kerosene to the carbon-based amphiphilic nanofluid dispersion according to the oil-water volume ratio of 5:5, seal it, shake it slightly by hand for 30-45 s, and let it stand for 2-4 hours to observe the distribution of the carbon-based amphiphilic nanofluid. The results are shown in the figure. 2 shown. The concentration of carbon-based amphiphilic nanofluids at the oil-water interface is significantly higher than other parts, and an obvious emulsion film is formed with crude oil, which proves that the amphiphilic nature of carbon-based amphiphilic nanofluids enables them to spontaneously move at the oil-water interface. Concentrate and form an emulsion film.

(5) Improvement of rock wettability by carbon-based amphiphilic nanofluids

The carbon-based amphiphilic nanofluids prepared in Example 3 were dispersed in mineralized water number 2# with a concentration of 5×10 ⁴ mg/L (Ca ²⁺ and Mg ²⁺ concentrations were 0.15×10 ⁴ mg/L), and stirred for 1 hour, prepare a carbon-based amphiphilic nanofluidic dispersion liquid with a mass concentration of 0.15%, and divide it into two equal parts. Then, the natural lipophilic and hydrophilic rock sheets (sandstone rocks) were immersed in the carbon-based amphiphilic nanofluid dispersion, sealed, and the carbon-based amphiphilic nanofluid was contacted with the core sheet at 100 °C; DSA100 pendant drop interfacial tension meter was used. The solid-water-crude oil contact angles of the core pieces were tested at different contact times, as shown in Table 3. Rocks with a contact angle greater than 90° are lipophilic, and those with a contact angle less than 90° are hydrophilic. It can be seen from Table 3 that the carbon-based amphiphilic nanoflow can change the surface of the lipophilic rock into a hydrophilic surface, and at the same time make the surface of the hydrophilic rock more hydrophilic.

Table 3. Modification of rock wettability by carbon-based amphiphilic nanofluids

rock number 0d (original contact angle) 1d 3d 5d 7d 14d 8-1 136.2° 118.4° 97.5° 83.4° 77.2° 76.1° 8-2 82.3° 79.2° 70.2° 65.7° 64.2° 63.8°

(6) Carbon-based amphiphilic nanofluids enhance oil recovery performance

Mineralized water with a salinity of 5.0×10 ⁴ mg/L (Ca ²⁺ and Mg ²⁺ concentrations of 0.15×10 ⁴ mg/L) was prepared and divided into two parts. One portion was added to the carbon-based amphiphilic nanofluid synthesized in Example 4 to prepare a carbon-based amphiphilic nanofluid with a mass concentration of 0.30%, and stirred and dissolved for 30 minutes to obtain a carbon-based amphiphilic nanofluid dispersion. As a comparative experiment, another portion was added sequentially with commercially available graphene oxide (GO) and petroleum sulfonate (KPS), slowly stirred and dissolved for 30 min, and left standing for 24 hours to prepare a GO/KPS dispersion with a mass concentration of 0.4%. solution (wherein the concentration of GO is 0.15%, and the concentration of KPS is 0.25%). Two artificial two-layer heterogeneous cores (45×45×300mm long cores, gas permeability 100/500mD, porosity 18-20% respectively), experimental temperature 90℃, crude oil viscosity 27.3mPa·s, original oil saturation Degree is about 60%.

In the water flooding stage (displacement rate of 1.0 mL/min), the water flooding degree was low due to the unfavorable water-oil mobility ratio, and the recovery rate with a water cut of 98% was 39-42%. The GO/KPS dispersion was injected, the injection pressure was increased, and oil was discharged from the outlet. The GO/KPS dispersion was regulated by GO and KPS oil was washed to expand the swept volume and improve the oil displacement efficiency. The GO/KPS dispersion with 0.4 times the pore volume and subsequent Water flooding increases the oil recovery factor by 18.5%, and the cumulative recovery factor is 60.5%. The displacement effect is shown in Figure 3. The other core was injected with a carbon-based amphiphilic nanodispersion of 0.4 times the pore volume after water flooding and subsequent water flooding, the injection pressure was increased, and oil was discharged from the outlet. It is proved that the in situ carbon-based amphiphilic nanofluids are spontaneously enriched at the oil-water interface, and adsorbed at the oil-water interface under the induction of formation shear to form an emulsion film, which can regulate the fluidity of the oil-water interface and stabilize the displacement front. In addition, the carbon-based amphiphilic nanodispersion reduces the oil-water interfacial tension and improves the wettability of the core, and improves the microscopic oil displacement efficiency. The recovery rate is 25.3%, and the cumulative recovery rate is 64.3%. The displacement effect is shown in Figure 4. By comparison, the enhanced recovery rate of the carbon-based amphiphilic nanoflow is 6.8% higher than that of the high-quality concentration GO/KPS dispersion, and the cumulative recovery rate is 6.8%. The yield is 3.8% higher, and the carbon-based amphiphilic nanoflow has the advantages of low concentration and high performance, and the effect of improving oil recovery is remarkable.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Technical personnel, within the scope of the technical solution of the present invention, can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical content disclosed above, but any content that does not depart from the technical solution of the present invention, according to the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solutions of the present invention.

Claims (7)

1. a carbon-based amphiphilic nano-flow for oil displacement, is characterized in that, with carbon-based nano-powder as raw material, successively adopt silane coupling agent and polyoxyethylene ether to modify it, obtain carbon-based amphiphilic Nanoflow; the carbon-based nanopowder is selected from one of graphite powder, carbon powder, graphene or graphene oxide, and any one-dimensional minimum dimension in the three-dimensional size is 1nm-100nm; The steps of the preparation method of carbon-based amphiphilic nanofluids are as follows: S1, disperse the carbon-based nanopowder in the mixed solvent of the mass ratio of toluene and dimethylformamide; S2. Add the silane coupling agent to the dispersion obtained in step S1 under the condition of oil bath at 80°C, seal and stir, react in the oil bath at 96°C for 6 hours, filter, purify and dry to obtain the carbon modified by the silane coupling agent. based nanopowder; S3, disperse the carbon-based nano-powder modified by the silane coupling agent obtained in step S2 in another mixed solvent of toluene and dimethylformamide and other mass ratios; S4. Add polyoxyethylene ether to the dispersion obtained in step S3 under the condition of oil bath at 90°C, seal and stir, carry out reaction in oil bath at 90°C for 6h, suction filter, purify and dry to obtain carbon-based amphiphilic nanoflow . 2. The carbon-based amphiphilic nanoflow for oil displacement as claimed in claim 1, wherein the silane coupling agent is γ-aminopropyl triethoxysilane, N-(β-aminoethyl group)-γ-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, or a combination of both. 3 . The carbon-based amphiphilic nanofluid for oil flooding according to claim 1 , wherein the polyoxyethylene ether has a weight-average molecular weight of 260-6000 g/mol. 4 . 4. the carbon-based amphiphilic nano-flow for oil flooding according to any one of claims 1-3, characterized in that, it is suitable for water injection to develop oil reservoirs, and directly prepares the carbon-based amphiphilic nano-flow with oil field injection water Dispersions. 5 . The carbon-based amphiphilic nanofluid for oil flooding according to claim 1 , wherein the carbon-based amphiphilic nanofluid is used in combination with a surfactant. 6 . 6. carbon-based amphiphilic nanoflow as claimed in claim 1, is characterized in that, step S1 is specifically, adding carbon-based nanopowder in the mixed solvent of toluene and dimethylformamide and other mass ratios, oil bath heating 80 ℃, stirring for 60min to obtain a uniform dispersion. 7. carbon-based amphiphilic nanofluid as claimed in claim 1, is characterized in that, step S3 is specifically, the carbon-based nanopowder modified by the silane coupling agent obtained in step S2 is added to another part of toluene and dimethyl In the mixed solvent of the same mass ratio of dimethylformamide, the oil bath was heated at 80 °C and stirred for 60 min to obtain a uniform dispersion.

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