Abstract
Despite the existence of studies for separate evaluation of waterflooding, immiscible CO2 flooding, and CO2 water-alternating gas (WAG) for heavy oil recovery, there is a lack of an experimental, comparative evaluation of these three methods. The authors conducted tests for comparative evaluation of variable-injection rate waterflood (VIWF), immiscible CO2 flood, and CO2 WAG. The results illustrate the (a) effectiveness of VIWF, immiscible CO2 flood, and CO2 WAG; (b) effect of permeability and oil viscosity on VIWF, immiscible CO2 flood, and CO2 WAG; (c) effect of injection rate on VIWF; and (d) effect of slug ratio on CO2 WAG.