Crude oil is one of the prominent resources to fulfill the need of day-to-day
life. With few reservoirs, the proper utilization and maximization of oil recovery from
existing oil wells are one of the foremost objectives in today’s scenario.
Conventionally, the inbuilt pressure and artificial pumping followed by water flooding
could result in 30-50% of oil recovery. Thus, to produce the remaining residual crude
oil, various enhanced oil recovery methods are adopted, including gas flooding, fire
flooding, chemical EOR, etc. Still, oil recovery in large quantities persists to be a
challenging task for engineers throughout the world. The major limitation for
improving the oil recovery is the water enrichment of the reservoirs, which governs the
oil displacement efficiency from the reservoir to the production platform.
The application of sound waves in reservoir engineering is an established technology.
In seismic surveys, sound waves of various frequencies have been used to predict oil
and gas reserves. The advancement of the application of ultrasound irradiation on
multiple sectors, including the enhancement of oil recovery from wells, has also been
analyzed and tested. The idea behind applying cavitation technology is that the passage
of ultrasound waves releases the energy in terms of transient cavitation and allows the
formation of the fine emulsion of two immiscible phases. The emulsion enables the
improvement of oil movability toward the production well without changing the
porosity and permeability of rocks. Thus, the cavitation technique can be applied to
estimate oil-water saturation in reservoirs and can further improve the oil recovery
factor. This chapter emphasizes the fundamentals of enhanced oil recovery schemes,
their mechanisms, and the application of ultrasound irradiation toward improved oil
recovery.
Keywords: Cavitation, Crude oil production, Enhanced oil recovery, Emulsion, Permeability, Surface tension.
