Surface modification of synthesized Fe3O4 super-paramagnetic nanoparticles and performance investigation in gelation parameters enhancement: application in enhanced oil recovery

Application of different surface modified Fe3O4 nanoparticles for enhancing the gel polymers properties and oil recovery increase using gel polymers has been investigated. Fe3O4 Super-paramagnetic nanoparticles were prepared using co-precipitation method, and the surface modified using citric acid, ascorbic acid and tetraethyl orthosilicate (TEOS, SiO2). All the surface modified nanoparticles were super-paramagnetic, considering the vibrating sample magnetometer test results. Adding Fe3O4 and Fe3O4@SiO2 to the gellant samples has resulted in shear viscosity increase of the gel (9.32-9.92 Pa.s and 10.28 Pa.s), but Fe3O4@ascorbic acid has resulted in shear viscosity decrease (8.79 Pa.s) and the gellant sample containing Fe3O4@citric acid did not convert to gel polymer. The samples containing Fe3O4@ascorbic acid synersised after 5-10 days. Nanoparticles has changed the order and constant of the gelation reaction, too. The injection of the gel sample containing 8000 ppm Fe3O4@SiO2 nanoparticles in a heterogeneous micromodel resulted in blocking the high permeability zone and subsequently led to a significant increase in the oil recovery factor from 27.3 to 54%.