Experimental Analysis for EOR Effect by the Injection of Nanoscale Colloidal Dispersion Containing Zwitterion Surfactant

Abstract

The colloidal dispersions using nanoparticle have been recently studied for enhanced oil recovery (EOR) applications. Especially, a study for the modification of surface using modifier agent has been actively processed to improve both dispersibility and oil-water interfacial activation. This study developed the colloidal dispersion formed by combination of anionic polymer and zwitterion surfactant on nanoparticle of silica. With the use of this colloidal dispersion in core flooding experiments, this study evaluated emulsifying efficiency and enhanced oil recovery. From the experimental results using the developed colloidal dispersion, it was found to be a stable solution due to sufficient repulsion between nanoparticles by anionic polymer. Also, zwitterion surfactant as component of colloidal dispersion reduced interfacial tension of oil and water. Thus, it was found that this developed colloidal dispersion improved emulsifying efficiency in oil-water system. As the results of above, this colloidal dispersion prevented aggregation of nanoparticles, unlikely colloidal dispersion using cationic surfactant as previous studies. Therefore, the developed colloidal dispersion could readily move into pore throat, so that it could be adsorbed at the oil-water interface. In core flooding experiments using colloidal dispersion containing zwitterion surfactant, it was ascertained that the oil recovery was enhanced over 15% greater than conventional water flooding. This was mainly because of the lowered interfacial tension by zwitterion surfactant molecules and the improved dispersibility between nanoparticles. In the results for various injection rates and oil viscosities regarding viscous force, it was found that residual oil was reduced almost two times greater comparing to the case for absence of zwitterion surfactant in colloidal dispersion. Therefore, it was concluded that the nanoscale colloidal dispersion developed in this study has a potential as an agent material in the enhanced oil recovery technique.