Study On The Factors Of Oil Displacement Effect Of Weak Base ASP System After Polymer Flooding

At present, ASP system flooding in Daqing oil field has entered the stage of industrialization. A large number of experiments show that, strong base ASP system flooding is destructive of formation and oil displacement device, this displacement method is not advocated, but ASP system is no doubt to improve oil recovery after polymer flooding, so this paper chooses weak base ASP system to do the micro visual displacement experiment,and to study on the factors of oil displacement effect after polymer flooding. This can further explain the reason that many problems in this imperfect EOR technology, we can have a more comprehensive and in-depth understanding of weak base ASP system after polymer flooding to improve oil recovery.In this paper, we use the micro visual oil displacement experiment device to study the mechanism of weak base ASP system how to start and migration the residual oil.We carried out the contrast experiment that the weak base ASP system has different quantity degree of interfacial tension, the weak base ASP system has the same quantity degree of interfacial tension and the different emulsification condition, and the different viscoelasticity. We analyzed the types and the production process of residual oil after polymer flooding of the oil wetting model and water wetting model.And we analyzed the start and migration process of the columnar residual oil, membranous residual oil, droplets residual oil, corners residual oil,complex residual oil, respectively from the interfacial tension and the viscoelasticity to research the mechanism of start and migration residual oil of weak base ASP flooding.The experimental results show that: with the decrease of the oil-water interfacial tension’s quantity degree of the weak base ASP system, the better start and migration of the residual oil after polymer flooding,the more increased the recovery; the same interfacial tension’s quantity degree of the weak base ASP system, the residual oil in the experimental process from the emulsified oil droplets to stretch the oil silk and become the oil wall, the better the effect of this condition,the more increased the recovery after the compound flooding;the big of the weak base ASP system viscoelasticity, the better to improve the recovery. The results analysis the reason that the effect of oil displacement effect of weak base ASP system after polymer flooding,this provides an experimental basis for weak base ASP system flooding’s scheme selection.