▎ 摘　　要

NOVELTY - Enhanced (M1) oil recovery (EOR), comprises: combining a lamellar phase comprising Janus nanoparticles, a petroleum surfactant, crude oil, and water with additional water to give a flooding fluid; pumping the flooding fluid through a wellbore into a subterranean formation via a centrifugal pump; and affecting a property of hydrocarbon in the subterranean formation via contact of the flooding fluid with the hydrocarbon. USE - The method is useful for enhanced oil recovery. ADVANTAGE - The methods: provide Janus nanoparticles (e.g. Janus metal-oxide nanoparticles, or Janus graphene oxide nanosheet) at larger scale and with crude oil as the organic solvent, and promote application of the Janus nanoparticles in the oil-and-gas industry and other industries and the techniques may advance economical mass production of Janus nanomaterial; and utilizes Janus nanoparticles for oil displacement and/or injectivity improvement in oil reservoirs and can further improve EOR efficiency. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) synthesizing (M2) Janus nanoparticles for EOR, comprising forming in a vessel a lamellar phase comprising water layers, crude oil layers, and a zwitterionic petroleum surfactant, reacting chemical reagents in the lamellar phase in the vessel to form Janus nanoparticles at interfaces of the water layers with the crude oil layers and collecting the lamellar phase from the vessel for distribution to an EOR application comprising nanofluid flooding via the nanoparticles and surfactant flooding via the zwitterionic petroleum surfactant; and (2) enhanced (M3) oil recovery, comprising forming in the reactor vessel the lamellar phase comprising water layers, crude oil layers, and a petroleum surfactant, reacting chemical reagents in the lamellar phase in the reactor vessel to form the nanoparticles at interfaces of the water layers with the crude oil layers, mixing water with the lamellar phase to give a flooding fluid comprising nanofluid, providing the flooding fluid via a pump through a wellbore into a subterranean formation and flooding the subterranean formation as EOR, where the flooding comprises nanofluid flooding via the Janus nanoparticles.