Evaluation of Heavy Oil Recovery Factor by Water Flooding and Polymer Flooding at Different Temperatures

Abstract

Abstract This paper compares the effiency of heavy oil recovery factor by water and polymer flooding under different level of temperature (26°, 50° and 75°C). The performances of both methods were assessed by analyzing the fractional flow curves and the oil recovery factor (%OOIP) for the same temperature. Rheological measurements were carried out to characterize and to select the fluids. Buckley-Leverett model was applied to evalute the effectiveness of the recovery method after the injected fluid breakthrough. Due to the high oil viscosity, the displacement for water flooding is unfavarable. However, the polymer addition improves the viscosity ratio injected/displaced fluids, making the displacement front more sharp. The fractional flow curves showed that the polymer flooding reduces the amount of the remaining oil more than water flooding and the oil recovery are greatly influenced by the test temperature. As the temperature increases, the oil recovery increases, for both methods. At the same temperature, the final oil recovery is equal for water and polymer flooding, showing that the used polymer has not affected the residual oil saturation. However, the polymer flooding was able to anticipate the oil production and the anticipation was more pronounced for higher temperatures. The mobility ratio reduction with temperature rising turned the displacement more piston-like, highlighting the anticipation of the produced oil by polymer flooding.