Experimental Investigation of Hot Water Injection into Low-permeability Carbonates Heavy Oil Reservoirs

The major mechanisms on hot water injection are: thermal expansion, viscosity reduction, wettability<br>alteration and oil / water IFT reduction. In this study, hot water injection experiments were carried out<br>using unpreserved carbonate core samples obtained from the oil zones of heavy oil low- permeability<br>reservoirs. These experiments were conducted at reservoir condition and in various temperature ranges up<br>to 500°F using wide variety of oils. The final oil recovery, residual oil saturation, irreducible water<br>saturation and pressure drop were compared in each experiment. Results show that it is possible to recover<br>high percent of oil using high pressure/temperature injection even from heavy oils in low-permeability<br>carbonate reservoirs. In the heavy oil system, the oil production to hot water injection ratio is higher than<br>the medium and the extra heavy oil, but the values are less than the reported values for conventional heavy<br>oil reservoirs. Also it was found that the residual oil saturation decreases and irreducible water saturation<br>increases when the temperature increases.