An amphiphilic nano titanium dioxide based nanofluid: Preparation, dispersion, emulsion, interface properties, wettability and application in enhanced oil recovery

Abstract

The emulsification flooding is an effective method for enhance oil recovery. In this work, an amphiphilic nano titanium dioxide (ANTD) was prepared by the chemical reaction of nano titanium dioxide (NTD) with the titanate coupling agent. The contact angle experiments shown that the contact angle of NTD changed from 11.6° to 110.6°after modification, which became more lipophilic. The dispersion testing shown that Span85 was the best dispersant for ANTD. The nanofluid was configured by using 0.05 g of ANTD and 100 ml of 0.05 % Span85, which was tested by the emulsification experiment, the interface tension experiment and the dilatation rheological experiment. The result shown that the nanofluid can be emulsified to form the W/O emulsion with the crude oil, the average emulsion particle size was 1.96 µm, and the nanofluid could reduce the oil-water interface tension and improve the strength of the interface film. The wettability alteration experiment shown that the nanofluid can change the core from oil-wet to water-wet. The flow displacement experiment demonstrated that the oil recovery rate increased by 26.4 % after the nanofluid flooding. Finally, the Nuclear Magnetic Resonance experiment shown that the nanofluid could reduce the oil-water mobility rate, and expand the swept volume, thus enhancing oil recovery.