Aim ed at how to develop high temperature reservoir after water flooding

we proposed the in-situ emulsion flooding by injecting surfactant solutions to evaluate the emulsifying property and study on the oil displacement by the emulsion of the OB-2 system for the W/O（water in oil）emulsifier. The results showed that the emulsion viscosity firstly increased and then decreased along with emulsifier concentration. For oil in reservoir-X

the optimal emulsifier concentration was 0.3 wt% at which could make the interfacial tension reduce to 10

-2

mN/m order of magnitude. When the water-oil ratio was lower than 7∶3

the complete emulsification of oil-water happened and th

e W/O emulsion with high viscosity would form. The maximum emulsion viscosity appearde when the oil-water ratio was 7∶3

with the viscosity increasing rate of as high as 370 %. The results of emulsion flooding indicated that the recovery factor of the homogeneous core could increase another 26.15 % after water flooding by injecting 0.3PV OB-2 system. On the other hand

when the permeability ratio of parallel cores was lower than 7.6

applying the OB-2 system could achieve good mobility control and heterogeneity regulation.