Drainage type oil and heavy-oil displacement in circular capillary tubes: Two- and three-phase flow characteristics and residual oil saturation development in the form of film at different temperatures

The experimental observations suggest that for heavy oil there is a threshold capillary number around 1.0E−2 over which the oil recovery (and therefore the residual oil saturation) is very sensitive to the capillary number, i.e., the injection rate, interfacial tension, wettability and temperature. At lower capillary numbers (typical range for oil reservoirs) temperature and hence viscosity do not have a significant influence in the residual oil saturation of the processed and crude oils; for horizontal displacement the residual oil saturation is a function of the capillary forces and for gravity drainage experiments it depends of the competition between capillary and gravity forces (Bond number).