After 37 years of development, the recovery degree of C oilfield has reached 40% and the comprehensive water cut has reached 90%. It is very difficult to stabilize production. In order to formulate potential tapping measures to ensure efficient oilfield development, three-dimensional visual physical model experiment and reservoir numerical simulation based on geological reservoir characteristics of C Oilfield were carried out. The physical simulation and numerical simulation were verified against each other and the influencing factors of remaining oil were analyzed and studied. The results show that the edge water mainly invades along the bottom of the reservoir. After long-term displacement, the reservoir type gradually changes from edge water reservoir to secondary bottom water reservoir. The water cone at the well points of production wells is serious, and the remaining oil is enriched between wells and at the top of the reservoir. The greater the permeability level difference, the smaller the formation dip angle and the higher the crude oil viscosity, the more obvious the water cone phenomenon. According to the research results, the infill adjustment of horizontal wells between directional wells has been implemented in the C oilfield, and good potential tapping effect has been achieved. The research in this paper provides guidance for tapping the potential of remaining oil in similar oilfields at the double high stage.