The forces that hold back the oil in the porous body of the reservoir are the interfacial tension between the different phases of oil, water and gas flowing in the porous medium and the viscosity of the crude oil. The interfacial tension may be overcome by injection of surface active agents (surfactants) or by the injection of a gas that is miscible with the crude oil (miscible flooding) using CO2 at high presssures). The viscosity of the oil may be reduced by applying heat to the reservoir, or the viscosity of the displacing phase may be adapted to the viscosity of the crude oil, which is accomplished by adding a water soluble polymer to the flood water (viscosifier).
Enhanced Oil Recovery
The forces that hold back the oil in the porous body of the reservoir are the interfacial tension between the different phases of oil, water and gas flowing in the porous medium and the viscosity of the crude oil. The interfacial tension may be overcome by injection of surface active agents (surfactants) or by the injection of a gas that is miscible with the crude oil (miscible flooding) using CO2 at high presssures). The viscosity of the oil may be reduced by applying heat to the reservoir, or the viscosity of the displacing phase may be adapted to the viscosity of the crude oil, which is accomplished by adding a water soluble polymer to the flood water (viscosifier).