This book focuses on the use of nanoemulsion in enhanced oil recovery, along with a brief information about the emulsion and its types and different physico-chemical properties used to analyse the efficiency of the emulsions and nanoemulsions. The author discussed about the nanoemulsion, classification of emulsions and nanoemulsion and use of nanoemulsions in petroleum industry. A special attention has been laid on nanoemulsion and its advantages over commercial product, physico-chemical properties like emulsification, interfacial tension and wettability alteration study as a screening criteria for application in EOR. Given this content, this book offers an assessment for the undergraduate and postgraduate students of petroleum and chemical engineering along with the researchers working in the field of EOR. It is a subject of interest for oil and gas industry professionals.