Modified Fe3O4 nanoparticle used for stabilizing foam flooding for enhanced oil recovery

Abstract

Nanoparticle stabilized foam flooding is a new rising technology of enhanced oil recovery (EOR) which could be applied to produce more crude oil from low permeability reservoirs, but it is still in lab-scale studies. In this paper, Fe3O4 nanoparticles were selected and grafted 1,2-epoxy dodecane for increasing the hydrophobicity of particles’ surface and then characterized by FTIR, TGA and TEM. The samples with four different contact angles (12.7°, 20.6°, 57.5° and 94.3°) were chosen to prepare surface unmodified and modified Fe3O4/sodium dodecyl sulfate/polyacrylamide ((M)Fe3O4/SDS/HPAM) foam dispersion systems and compared their static foam stability. The results showed that the modification on the surface of nanoparticles method could prolong foam half-time of Fe3O4 stabilized foam system. The foam half-time of the system stabilized by the modified Fe3O4 nanoparticles with the contact angle of 94.3° was 2.36 times higher than that of unmodified ones. The core flooding experiments were conducted with the low permeability core samples (< 10 mD)saturated with Dagang crude oil at 80 ℃, 18 MPa, and the results indicated that CO2 foam stabilized by modified Fe3O4 with the contact angle of 94.3° could result in a higher oil recovery rate of 10.64 % OOIP after water flooding. It can be concluded that the modified Fe3O4 nanoparticle stabilizing CO2 foam system could be a promising tertiary oil recovery method for low permeability reservoirs.