Experimental study on ultrasonic viscosity-reduction method of crude oil

A series of experiments on the ultrasonic treatment of viscosity-reduction for crude oil were carried out using the whole-wave length power-collecting piezoelectric ultrasonic transducer developed by the authors and the horn-dipping reactor. The effects of the ultrasonic treatment parameters, such as treatment time, current of the transducer in operation and water cut, on the viscosity-reduction efficiency of crude oil were analyzed. A set of viscosity-temperature curves were obtained. The transportation of crude oil can be maintained continuously when the treatment time is three minutes, the transducer current is 0.36 A and the oil viscosity is 200 mPa · s at 25°C. However, the viscosity of crude oil will be high when the ultrasonic treatment takes longer time than the proposed time. The experiments showed that the viscosity-reduction rate was over 60% after ultrasonic treatment for crude oil with water cut 60% and 75%, respectively. The paraffin crystals morphology under the different parameters was observed using the scanning electron microscopy. It is demonstrated that the ultrasonic treatment method can get good effectiveness, and the reduced viscosity of crude oil is non-recoverable.