Laboratory formula research of nitrogen foam flooding in Liuzhong area of Karamay oilfield

Liuzhong area of Karamay oilfield belongs to a conglomerate common heavy oil reservoir. The viscosity of initial formation in the east is 80 mPa·s and has the tendency of gradually increased viscosity and of poor waterflood recovery from east to west. Aiming at the fluid properties of the area, the laboratory formula research of foam flooding has been carried out and the formula has the characteristics of strong foamability, long half-time period, high foam viscosity and good stability. One-dimensional physical simulation experiment results show the injection volume is high up to 0.6 VP and the recovery can be enhanced by 40%.