Conventional and electrical EOR review: the development trend of ultrasonic application in EOR

A small portion of oil can be extracted during primary and secondary stages of oil production, and significant quantities of oil remain in reservoirs. Enhanced oil recovery methods are used to extract the trapped oil with high viscosity in reservoirs and improve the efficiency of the production wells. Ultrasonic-based enhanced oil recovery method has become of considerable interest to researchers in recent years. This paper mainly presents the in-depth literature review of ultrasonic wave to investigate its application development trend in enhanced oil recovery. Besides, it also presents an overview of conventional enhanced oil recovery techniques such as chemical, gas, and thermal methods and nonconventional techniques such as electromagnetic and microwave heating. The results exhibit an increasing implementation of the ultrasonic waves for oil recovery since it is an inexpensive and ecologically sound method, can be applied in any type of reservoir, protects the well against damage, prevents heat loss, and enables stimulation freely.