Visual Filling Model Experiment Study on the Enhanced Oil Recovery Mechanism of Novel Polymer Viscosity Reducer Flooding in Heavy Oil Reservoirs.

Chemical flooding is an effective method to enhance heavy oil recovery, and the viscosity reducer is often injected into the formation as the main reagent of chemical flooding. In the paper, a novel polymer viscosity reducer (FMP) was used to inject into a visual filling model, which can simulate the reservoir. The mechanism of enhancing heavy oil recovery by FMP is studied by macroscopic and microscopic analysis methods. The model can obtain macroscopic images and production data, including pressure, water cut, and oil recovery. The model can observe some microscopic processes, which can analyze the mechanism of enhanced oil recovery. Five processes of emulsifying viscosity reduction are summarized by using microscopic images: membrane oil removal, gradual emulsification, flocculation into droplet groups, active dispersion, and agglomeration into droplets. The FMP molecules can affect the interfacial properties of oil, water, and rock to enhance the wishing oil efficiency. Moreover, the decrease in the stability of the oil-water interface leads to flocculation into droplet groups and agglomeration into droplets occurring at the throat of the strong seepage zone, which increases the sweep coefficient from 0.56 to 0.90. The oil recovery has increased from 18 to 34%, which indicates that the FMP flooding obviously enhances the effect of heavy oil reservoir development.