High performance emulsifier magnetic Janus nanoparticle for stabilizing the water-in-crude oil Pickering emulsion—application to a new oil recovery method: Viscosity increased-emulsion flooding

Abstract

When crude oil is in-situ emulsified in reservoir by the injected fluid to form water-in-crude oil emulsion the fluid with higher viscosity than that of the continuous phase is obtained in the displacing front, which results in the decrease of mobility ratio and the increase of sweep volume. This is a new method for enhancing oil recovery via increasing viscosity of crude oil in emulsion flooding. To achieve this result, the high-performance Janus nano-emulsifier (HMJP) has been obtained in this paper, which employs the low-cost, environmental-friendly, and recyclable magnetic nano-Fe3O4 to be the core. Then, the relationship between the emulsifying crude oil performance and the wettability of this Janus nanoparticle has been discovered and the related interfacial stabilization mechanism is discussed by interfacial dilatation rheology. Results show that the synthesized HMJPs have strong magnetic property and can be recyclable. For the given crude oil in this paper, when 0.04% of Q-16 (the carbon number used is equal to 16) is dispersing in 0.08% of LAD-30 surfactant fluid the water content of emulsion has been 90% and the emulsion viscosity is 10732.3mPa•s, which also reached excellent oil recovery. The emulsifying crude oil performance of HMJP is strongly associated with its wettability. The inborn interface-property of HMJP, surfactant, and the active components in crude oil all play a key role to decide the wettability of HMJP in preparing water in crude Pickering emulsion. The wettability of the modified HMJP is more neutral the emulsifying performance is stronger.