Reducing surfactant adsorption on rock by silica nanoparticles for enhanced oil recovery

This paper aims at making a thorough investigation on surfactant adsorption on rock under the influence of silica nanoparticles (SNP). The results showed that SNP can reduce surfactant adsorption effectively. With SNP concentration of 0.1, 0.2 and 0.3 wt%, static adsorption experiments showed that sodium dodecyl sulfate (SDS) adsorption can be significantly reduced to 2.57, 2.12, and 1.73 from 2.84 mg/g, and the dynamic adsorption of SDS decreased to 0.92, 0.77, and 0.66 from 1.16 mg/g, respectively. Our subsequent tests conformed a 4.68% growth of oil recovery by the injection of SNP - surfactant solution compared to the normal surfactant solution. The mechanism of the enhanced oil recovery is assumed to be the inhibition of surfactant adsorption and the profile control capability of silica nanoparticles. This study proves the SNP - surfactant flooding is a cost-effective way for enhanced oil recovery.