Impact of Internal Structure on Foam Stability in Model Porous Media

Abstract

Application of foam in EOR, increases macroscopic sweep efficiency via awesome increscent of mobility control. Macroscopic manifestation of foam application performance in porous media is complex process that involves several interacting microscopic foam events. Stability as an important factor in foam injection within large reservoirs, depends on several variables including oil saturation, connate water salinity and the foam texture. In addition to mentioned parameters, internal structure is known to affect the foam's stability and performance via influencing foam formation and destruction mechanisms within the porous media. In this paper we mathematically expressed main mechanism of snap-off for foam generation, mechanisms of capillary suction and diffusion coarsening for foam coalescences in some simplified models. Then we extended the calculations to more realistic 2D spherical models of porous media which were manufactured applying some morphological parameters. Simulation results show that in topologies in which the structure represents high difference in pore and throat average diameters, foam formation mechanisms are dominant making foam flow more stable while conversely when the path tortuosity is high, foam destruction mechanisms overcome and the stability decreases.