Synthesis and application of magnetic chitosan nanoparticles in oilfield

Abstract

The novel magnetic Co_0.5Mn_0.5Fe₂O₄-chitosan nanoparticles has the advantage of excellent biodegradation and a high level of controllability. The Co_0.5Mn_0.5Fe₂O₄-chitosan nanoparticles was prepared successfully. The size of the Co_0.5Mn_0.5Fe₂O₄-chitosan nanoparticles were all below 100 nm. The saturated magnetization of the Co_0.5Mn_0.5Fe₂O₄-chitosan nanoparticles could reach 80 emu/g and showed the characteristics of superparamagnetism at the same time. The image of TEM and SEM electron microscopy showed that the cubic-shape magnetic Co_0.5Mn_0.5Fe₂O₄ particles were encapsulated by the spherical chitosan nanoparticles. The evaluation on the interfacial properties of the product showed that the interfacial tension between crude oil and water could be reduce to ultra-low values as low as 10^–3 mN/m when the magnetic Co_0.5Mn_0.5Fe₂O₄-chitosan nanoparticle was used in several blocks in Shengli Oilfield without other additives. Meanwhile, the magnetic Co_0.5Mn_0.5Fe₂O₄-chitosan nanoparticles possessed good salt-resisting capacity.