A role of ultrasonic waves on oil viscosity changes in porous media

Theoretically, ultrasound method is an economical and environmentally friendly or “green” technology, which has been of interest for the purpose of enhancement of oil/heavy-oil production. However, in spite of many studies, questions about the effective mechanisms causing increase in oil recovery still existed. One of the changes that could be recognized in the fluid properties is viscosity reduction due to radiation of ultrasound waves. In this study, a technique was developed to directly investigate the effect of ultrasonic waves (frequencies of 25, and 68 kHz and powers of 100, 250, 500 W) on viscosity changes of Paraffin, Synthetic oil, and Kerosene. The experiments were carried out for uncontrolled and controlled temperature conditions in a smooth capillary tube. The viscosity of all the liquids was decreased under ultrasound in all the experiments. Cavitation and heat generation are identified as influencing mechanisms on oil viscosity reduction under ultrasound. The effect of ultrasound frequency, power and temperature on viscosity reduction is also discussed in this article.