Flow of foam through porous media

The pore level behavior of foam in porous media is investigated. Air is injected into porous micromodels filled with an aqueous solution of surfactant. Three homogenous models of different pore dimensions and one heterogeneous model are used. Visual observations are made to determine the flow characteristics of foam under varying air injection rates, pore dimensions and surfactant concentration. Foam flow mechanisms, as observed in the micromodels, are recorded on video tapes. The mechanisms are classified into membrane and foam bubble propagation. Propagation of membranes, air liquid interfaces, occurs in the homogeneous porous media at both low and high surfactant concentrations, and in the heterogeneous model at low surfactant concentration. Foam bubble propagation occurs only in the heterogeneous model at high surfactant concentrations. A considerable reduction of effective mobility is observed in the presence of foam, compared to air water systems without surfactant.