Abstract:

Aiming at the serious viscosity loss occurring during Alkali/Polymer (AP) flooding of Dagang Yangsanmu Oilfield,GH viscosity stabilizer is formulated and developed.In order to research whether this viscosity stabilizer is useful to ultimate displacement characteristics of AP flooding,its effectiveness on displacement properties of AP system is analyzed one by one.Thermaloxygen aging experiment,interfacial tensiometer and rheometer measurement,as well as SEM observation are applied to study longterm thermaloxygen stability,IFT,rheological properties,viscoelastic properties and microscopic shape of AP system when GH viscosity stabilizer is added and not.The result shows that GH can keep the pseudoplasticity rheologic property and ultralow interfacial tension of AP system and improve its longterm thermaloxygen stability and viscoelastic properties through strengthening its micromechanism.GH viscosity stabilizer contributes to improve the stability of AP system,and possesses favorable field practice prospect in EOR.

Key words: Dagang Oilfield, Alkali/Polymer compound flooding, viscosity, stability, displacement characteristics 