Polymer-Nanosilica-assisted to evaluate oil recovery performances in sandstone reservoirs

Abstract Implementation of Nanosilica particles in chemical flooding processes would be of interest for petroleum industries as nanoparticles can improve the polymer performances during oil recovery processes. In this paper, three different injectivity scenario of polymer–Nanosilica, Polymer solution, and water flooding were experimentally investigated to measure oil recovery factor, contact angle, and interfacial tension. Oil recovery factor for polymer–Nanosilica, polymer, and water flooding is 65%, 55%, and 50% respectively. Water flooding was performed until 2 PV and it did not continue as there is no progress in recovery factor in this scenario. After that, polymer solution was injected until 5 PV to reach a plateau. K rw has witnessed its minimum value of 0.3 and 0.15 for water–polymer–Nanosilica and polymer–Nanosilica respectively. This issue has a capillary forces decrease, which would be a proper reason for oil recovery enhancement. Secondary water drive mechanism would be an increasing point on the K rw for both scenarios. Regarding the increase of surface hydrophilicity in the presence of Nanosilica–polymer, contact angle has been decreased dramatically in the low concentration of Nanosilica. Nanosilica addition into water and polymer has caused to reduce the IFT by the increase of Nanosilica concentration. This reduction corresponds to the decrease of Gibbs energy in the presence of Nanosilica particles.