Numerical study on viscosity reduction in mining heavy oil by circulating hot water

Abstract

Viscosity reduction is an important process in mining heavy oil. To predict the temperature variation and viscosity variation of heavy oil in flow direction, computational fluid dynamics(CFD) was adopted to simulate the process of heat transfer and flow in this paper. Moreover, an objective function, namely viscosity reduction efficiency, was established to analyze the effect of viscosity reduction. The results indicate that circulating hot water can reduce viscosity significantly, and that the effect of viscosity reduction depends on the inlet temperature and inlet volumetric flow rate of hot water. There is a maximum temperature of heavy oil in flow direction. With the inlet volumetric flow rate of 2.0 m3/h and the inlet temperatures of 60,°C, 70,°C and 80,°C, viscosity reduction efficiencies are 94.6%, 96.7% and 97.3%, respectively. With the inlet temperature of 70,°C and the volumetric flow rates of 1.5 m3/h, 2.0 m3/h and 2.5 m3/h, viscosity reduction efficiencies are 94.4%, 96.7% and 97.2%, respectively.