Enhancing heavy-oil recovery by using middle carbon alcohol-enhanced hot polymer flooding

Abstract In this paper, the effects of middle carbon alcohol-enhanced hot polymer flooding for improving heavy-oil recovery were investigated by using several sandpack flooding tests. Before that, the effect of different middle carbon alcohols on viscosity reduction of heavy oil were examined. Then, a new method was developed to examine the diffusion of middle carbon alcohols from water to heavy oil and its effect on viscosity reduction of heavy oil. The results show that the effect of middle carbon alcohols on reducing heavy-oil viscosity increases with their carbon number; Besides, the middle carbon alcohols can diffuse from water to heavy oil to significantly reduce its viscosity, and the viscosity reduction effect increases with temperature, strring time in a certain range. Sandpack flooding tests show that injection of hot polymer and addition of middle carbon alcohols can both effectively enhance heavy-oil recovery; The effect of middle carbon alcohol-polymer flooding increases with the temperature of polymer solution and the injection rate of polymer solution.