This book is a guide to the application of ionic liquids (ILs) in the oil industry. It includes ten chapters that review basic and advanced topics. Starting with a general introduction to IL structure and properties, the book comprehensively explains the use of ILs in key petroleum extraction processes such as pollutant removal, demulsification, crude oil transport and oil recovery. Additional applications that are important for the sustainability management of petrochemical operations such as deepwell hydrate inhibition, CO2 capture, corrosion engineering, catalysis, hydrocarbon separation, bitumen extraction and stabilization are also included. Each chapter also provides bibliographic references for further reading.The wide range of topics makes this an informative reference to students and professionals in petroleum engineering, chemical engineering programs and any other training course that requires reading material for an understanding of the oil industry. General readers and researchers interested in the fascinating chemistry of ionic liquids will also enjoy this book.