Research On Oil Displacement Technology Of Polymer/surfactant System In Xing 12 Block

Based on the reservoir characteristic of Xing 12 block, the polymer/surfactant (PS) displacement system was studied in order to overcome the scaling and the emulsify of production fluid in ASP flooding and study the application and development of combination flooding technology in Daqing Oilfield. The key to the success of polymer/surfactant flooding is the choice of chemicals, program optimization and the experimental study on physical analog oil displacement of PS system in laboratory. The resistance factor and residual resistance factor of different polymer solutions were tested in order to optimize the polymer and its concentration for different permeability cores, by making use of core flowing test. Then the interfocail tension, viscosity, emulsification and quiescent-adsorption of PS system that combinated by the preferred polymer and HLX surfactant or BS surfactant were evaluated by experiment, as well as the displacement effect was systematically studied by physical analog oil displacement. The experimental results show that the displacement effect of polymer/BS surfactant system is better than that of polymer/HLX surfactant system under the experimental condition in this paper. When the PS systems are alternately injected, the recovery of chemical flooding and total recovery can increase by increasing the main slug or polymer slug, or decreasing alternating slug. Under the condition of the same slug size, the displacement effect of polymer/BS surfactant system whose injecting method is optimized is better than that of polymer solution with high concentration (Cp=2000 mg/L). Under the condition of the same injecting method, the displacement effect of polymer/BS surfactant system is better than that of polymer solution with high concentration. Under the condition of the same chemical cost, the displacement effect of polymer solution with high concentration is better than that of polymer/BS surfactant system.