Optimal Profile Control Agent After High-Speed Water Flooding of Low-Viscosity Sandstone Reservoirs

In the early stage of general water injection and high-speed development of overseas sandstone oil fields, when the water cut is 98.5% and the degree of geological reserve recovery reached 52%, the degree of vertical utilization of oil fields is only about 60%. Through the profile adjustment of water injection wells, it has become an inevitable choice to improve the degree of longitudinal utilization of oil fields. In order to select profile control agents suitable for oil fields, profile control experiments on polymers, emulsions, self-assembled microspheres and gels are carried out. During the injection of the polymer profile regulating agent, the recovery rate has hardly increased, indicating that the polymer solution is transported in the raw water flooding site (or channel) with low saturation of the residual oil, and rarely contacts and repels the residual oil; because the gel formation is very sensitive to temperature and is limited by the underground glue formation time, the gel profile control system is difficult to apply on site; the dispersion system (emulsion and microspheres) profile control agent can partially enter the micro- and macroscopic local crude oil enrichment areas, which play a role in repelling the residual oil and the remaining oil, and the profile control effect is good. This shows that compared with other profile control agents, dispersion systems such as microspheres and emulsions are more suitable for deep profile control of reservoirs where residual oil and residual oil are highly dispersed.