Enhanced oil recovery by foam flooding using foam stabilized with modified Fe3O4 nanoparticles

Nanoparticles (NPs) could enhance the stability of foam to allow recovery of greater amounts of residual oil during foam flooding . However, conventional nanoparticles are non-recyclable and affect the quality of the produced oil. Magnetic nanoparticles could respond to magnetic field and be recycled for reuse, thus reducing the cost for enhanced oil recovery (EOR) process and improving the quality of the produced oil. In this study, Fe 3 O 4 nanoparticles were used as foam stabilizer. The Fe 3 O 4 nanoparticles were modified with tetraethyl orthosilicate (TEOS) and n -dodecyltrimethoxysilane (WD-10) to make them hydrophobic. The optimal nanoparticles were Fe 3 O 4 @SiO 2 -700 with a contact angle of 68.5°. Foam was generated by sodium dodecyl sulphate (SDS) surfactant and the longest drainage half-life time was 746 s in the 1 wt% NPs+0.23 wt% SDS+3 wt% NaCl foam system . After evaluating foam stability, the nanoparticles were recycled and reused to stabilize foam again, and the results indicated that recycling nanoparticles three times was optimal. Finally, the core flooding experiments showed that the nanoparticles stabilized foam EOR rate was 17.4% and the system obtained a greater pressure drop to improved sweep area. These results indicated that the magnetic nanoparticles could stabilize foam effectively and could be recycled by magnetic field to reuse in stabilizing foam. This study suggested directions for further studies concerned with the application of magnetic nanoparticles for enhanced oil recovery .