Nanoparticle Stabilized Foam in Carbonate and Sandstone Reservoirs

Foam flooding as a mechanism to enhance oil recovery has been intensively studied and is the subject of multiple research groups. However, limited stability of surfactant-generated foam in presence of oil and low chemical stability of surfactants in the high temperature and high salinity of an oil reservoir are among the reasons for foam EOR not being widely applied in the field. Unlike surfactants, nanoparticles, which are shown to be effective in stabilizing bulk foam, are chemically stable in a wide range of physicochemical conditions. Recent studies suggest that synthesized nanoparticles with altered surface properties can aid foam generation and increase foam stability in porous media. In this paper, the focus lies on a silica-based nanoparticle that is available in large quantities and can be processed economically without separate surface treatment, which gives it the potential to become a practical solution in the field. The research is primarily conducted by performing core-flooding experiments under varying conditions to quantitatively assess and compare the potential of the nanoparticle-enhanced foam. Two types of reservoir rocks have been investigated: sandstone and carbonate rocks. It is observed that by adding even low concentrations of nanoparticles to a near-CMC surfactant solution, the foam viscosity considerably increases.