Nano- stabilized Foam Flooding: Stability Analysis and Pore Scale Displacement Mechanisms

Gas flooding is one of the widely used method for enhanced oil recovery but the unfavorable mobility ratio in this process can lead to a poor volumetric sweep efficiency. Foaming of injection gas can obviate mentioned problem in gas flooding but foam stability is one of major challenges. An experimental study focused on effect of nanoparticles on static foam stability and a pore level visual study of foam propagation in porous media is presented here.In this article, silica nanoparticles with an cationic surfactant, CTAB (Cetyl trimethylammonium bromide), and nitrogen gas were used together to assess foam stability . The results showed that with an increase in nano silica concentration, the foam stability increased too. By monitoring the turbidity of drained liquid from the column of foam, it has been demonstrated that nanoparticles attached to air-water interface. According to micromodel observations, flow resistance of small bubble can divert flow of other larger bubble to low permeable layer. This flow resistance of small bubbles seems to be the main mechanism that made foam flooding as a promising technique for EOR. As it has been observed, snap-off and lamella division are two major processes that generate small bubbles in porous media.

Keywords:

foam stability , nano stabilized , foam flooding , displacement mechansims , micromodel