Method study for application of heterogeneous oil displacement agent

Now no effective technical means are qualified for the development of the reservoirs after polymer flooding and the third-level and fourth-level reservoirs in Shengli Oilfield. In view of the characteristics of the reservoirs, an idea is presented for the development of new chemical agents and the design of oil displacement system. PPG, a new type of heterogeneous oil displacement agent featuring in temperature and salt resistance, and high capacity of expansion, is developed. Through structural design and performance evaluation test, PPG with favorable performance is selected. On this basis, the design idea for multi-flooding system of “PPG-surfactant-polymer” is put forward. The interaction of PPG and surfactant and polymer and the rule of improving efficiency are reviewed. Through physical simulation experiment, the oil displacement results of different systems are compared. Results show that the heterogeneous oil displacement system owns strong capability of expansion and oil washing. It can be used for the development of low permeability areas with high efficiency. By using the system, remaining oil rich regions, which cannot be touched using polymers, can be developed. So the oil recovery is enhanced a lot.