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%. [ABSTRACT FROM AUTHOR]