Discussion on the Treatment Method of ASP Flooding Produced Sewage Back Injection and Oil Displacement

摘要

The produced sewage from ASP flooding and polymer flooding in Daqing area are both weakly alka-line water. The effects of interfacial tension and viscosity on oil displacement efficiency of ASP flooding produced sewage were tested by using the laboratory physical simulation experiment sys-tem. The results of the experiment show that the interfacial tension between ternary flooding pro-duced water and crude oil is 10−1 mN/m order of magnitude, the oil-water viscosity ratio is 4, and the oil displacement efficiency is only 2.3; According to the experimental results of the injection capacity of the ternary flooding produced sewage compound system and oil displacement, the en-hanced recovery rate of the ternary flooding produced sewage compound system is 17 as com-pared with the ordinary ternary system under the condition that the suspended matter and oil content of the produced sewage compound system meet the standard. Therefore, the produced sewage from ASP flooding can be directly injected back into the formation, and can be compounded with the ASP system.