▎ 摘　　要

NOVELTY - Preparing an amphiphilic Janus graphene oxide oil-displacing nanofluid comprises e.g. (i) adding graphene oxide into deionized water, and ultrasonicating for 5-35 minutes to obtain graphene oxide dispersion; (ii) adding graphene oxide dispersion and kerosene into a round-bottomed flask equipped with a stirrer, stirring for 10 minutes to form an emulsion, adding a hydrophilic modifier, adjusting the pH to 2-3, stirring and reacting to obtain graphene oxide hydrophilic modified substance; (iii) adding sodium hydroxide into hydrophilic modified graphene oxide reaction system, adjusting the pH to 6-7, adding inorganic salt and hydrophobic modifier, stirring and reacting for 6-18 hours to obtain graphene oxide amphiphilic modified product; and (iv) centrifuging the graphene oxide hydrophilic modified substance, washing the precipitate, adding the washed product, polyvinylpyrrolidone, and anionic surfactant into deionized water, and dispersing ultrasonically. USE - The method is useful for preparing an amphiphilic Janus graphene oxide oil-displacing nanofluid is useful for enhancing oil recovery in high temperature and high salinity reservoirs. ADVANTAGE - The method prepares an amphiphilic Janus graphene oxide oil-displacing nanofluid with good temperature resistance and salt resistance, excellent interface performance, good oil displacement effect, and small oil displacement amount. DETAILED DESCRIPTION - Preparing an amphiphilic Janus graphene oxide oil-displacing nanofluid comprises (i) adding graphene oxide into deionized water, and ultrasonicating for 5-35 minutes to obtain graphene oxide dispersion, where the particle size of graphene oxide is 100-1000 nm, compared to the ultrasonic power of 1 liter dispersion liquid is controlled at 200-600 W, and the mass ratio of graphene oxide and deionized water is 1:(100-2000); (ii) adding graphene oxide dispersion and kerosene into a round-bottomed flask equipped with a stirrer, stirring for 10 minutes to form an emulsion, adding a hydrophilic modifier, adjusting the pH to 2-3, stirring at 600-2400 revolutions/minute and reacting at 10-40℃ for 6-18 hours to obtain graphene oxide hydrophilic modified substance, where the mass ratio of graphene oxide dispersion liquid, kerosene and hydrophilic modifier is 1:(0.1-1):(0.001-0.04); (iii) adding sodium hydroxide into the hydrophilic modified graphene oxide reaction system, adjusting the pH to 6-7, adding inorganic salt, adjusting at 40-80℃, adding a hydrophobic modifier, stirring at 600-2400 revolutions/minute, and reacting for 6-18 hours to obtain graphene oxide amphiphilic modified product, the mass ratio of the hydrophilic modified graphene oxide reaction system, inorganic salt and hydrophobic modifier is 1:(0.005-0.04):(0.001-0.05); and (iv) centrifuging the graphene oxide hydrophilic modified substance, washing the precipitate once with ethanol and deionized water respectively, adding the washed product, polyvinylpyrrolidone, and anionic surfactant into deionized water, and dispersing ultrasonically for 3-5 minutes, the molecular weight of polyvinylpyrrolidone is 20000-70000 g/mol, the mass ratio of the washed product, polyvinylpyrrolidone, anionic surfactant and deionized water is 1:(0.01-0.4):(0.01-0.4):(20-1000), the hydrophilic modifier comprises aminosulfonic acid, taurine or aminopropanesulfonic acid, the hydrophobic modifier comprises octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, dioctylamine or didecylamine, the inorganic salt comprises sodium chloride, potassium chloride or ammonium chloride and the anionic surfactant comprises sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, sodium α-olefin sulfonate, petroleum sulfonate or heavy alkyl benzene sulfonate.