Nano-colloid based suspensions and emulsions used as means for enhanced oil recovery

Abstract

Aqueous solutions of polyphenols extracted from parsley leaves are mixed with solution of ferric chloride hexahydrate to synthesize suspensions of polyphenol-coated iron oxide nanoparticles, which are then used to prepare Pickering oil (n-decane)-in water emulsions. The performance of the nano-colloid suspensions and emulsions as agents of enhanced oil recovery (EOR) is assessed with secondary imbibition tests performed under constant flow rate on a glass-etched pore network, after a drainage / primary imbibition cycle for paraffin oil / brine (0.25M NaCl solution) system. The transient changes of the fluid saturation profile along with the pressure drop across the porous medium are recorded. Comparative analysis of the oil recovery efficiency attained with nano-colloid suspensions of varying iron concentration, and Pickering emulsion, enables us to classify them, and select the most efficient ones for further studies.