Anomalous Viscosity of High-Molecular Petroleum Fractions in Process of Relaxation after High- Intensity Ultrasonic Treatment

Background/Objectives: Lower output of light oil and gradual depletion of its resources result in stronger interest in developing heavy oil deposits. However, its extraction is complicated because of its high viscosity. Methods: Principal methods of reducing oil viscosity imply preheating the oil-bearing bed and applying solvent agents. However, those methods are expensive and environmentally insecure. Another method is represented by high-intensity ultrasonic treatment. Its application helps reduce expenses and is environmentally safe. Therefore, there is an interest in the petroleum extraction practices that apply ultrasound. Such methods are developed in China, Iran, Russia, the USA, Western Europe and in other countries. Findings: The authors have investigated the effects produced by different kinds of ultrasonic treatment on kinematic viscosity of such oil products as black oil grade M-100, applying the ultrasound of different power and duration. The samples of black oil were subjected to direct effects of high-intensity treatment and the kinetic viscosity was measured before and after the treatment. Within 10 days, in the process of relaxation, the changes in viscosity of the treated samples were observed. The dependencies of viscosity on the duration of the fixed power ultrasound treatment have been discovered, the nonlinear and non-monotone nature of those dependencies have been established. Anomalous non-monotone nature of viscosity change in black oil grade M-100 has been observed. Under some modes of treatment, periods of viscosity lowering were observed. These anomalies are likely to be caused by the clots that were formed of the most viscous fractions of the product and that left the fractions with lower viscosity beyond, thus explaining the lower total viscosity in the process of relaxation. Applications/Improvements: The results can be used for selecting the regimes of ultrasonic treatment for the purposes of developing heavy oil production equipment and for improving petroleum and oil products handling operations.