Experimental Study on Enhanced Oil Recovery Method in Tahe High-Temperature and High-Salinity Channel Sand Reservoir: Combination of Profile Control and Chemical Flooding.

On account of the intralayer and interlayer heterogeneity, high temperature (110 °C), and high salinity (224,919 mg/L) of Tahe channel sand reservoir, single profile control or chemical flooding cannot greatly enhanced oil recovery. The goal of the current research was to optimize a polymer gel formula that was suitable for high-temperature and high-salinity reservoirs, screen an appropriate chemical flooding method, and determine the efficiency of the combination of profile control and chemical flooding. Experimental results indicated that the formed polymer gel could maintain relatively high strength after aging for 30 days. Moreover, the combination of profile control and surfactant flooding could result in an enhanced oil recovery of 17.9%, and the combination of profile control and foam flooding could result in an enhanced oil recovery of 23.0%, which was ascribed to the improvement of sweeping efficiency and displacement efficiency. All the results indicated that the formed polymer gel and the combination of profile control and chemical flooding have great application potential in Tahe high-temperature and high-salinity channel sand reservoir.