Fig. 9

Effect of salinity on foam and emulsion performance in conformance control at two salinity levels (35,000 ppm and 5,000 ppm) at a specific time, and in the presence and absence of waterflooded residual oil. The red arrow indicates the vertical distance between the foam fronts in the high-permeability (top) and low-permeability (bottom) layers, serving as a quantitative measure of interlayer conformance control. Shorter arrows reflect better conformance due to synchronized front advancement.