The relationship between the sweep efficiency and displacement efficiency of function polymer in heterogeneous reservoir after polymer flood

A function polymer is considered to be a kind of potential Enhanced Oil Recovery (EOR) agent that can further enhance oil recovery after polymer flooding. Based on the typical geologic features and development history of the Daqing Oilfield, a function polymer displacement experiment was conducted using a 3D laboratory physical model with a high-permeability channel between the injection end and the production end to study the EOR mechanism of the function polymer solution. In this article, the displacement feature and oil/water distribution of function polymer flooding is presented, as well as the swept effect in pores of different sizes. The experimental results show that the function polymer flooding after regular polymer flooding further enhances oil recovery by 10.29%. Moreover, the increment of sweep efficiency and displacement efficiency reaches 3.02% and 11.78%, respectively, which clearly demonstrates that the function polymer system improves the displacement efficiency by the emulsificat...