Effects of Silica Nanoparticle after Modification with (3-Aminopropyl) Triethoxysilane and Its Combination with Surfactant for Enhanced Oil Recovery

Abstract

Silica nanoparticle (SNP) shows exceptional characteristics and therefore attracts much attention in enhancing the oil recovery factor. However, it tends to agglomerate in the water phase due to the presence of tremendous surface free energy, which limits greatly application in oil fields. To this end, it is essential to perform the modification of the SNP surface to increase its dispersibility. In this work, (3-aminopropyl) triethoxysilane (KH550) was used to modify the SNP surface, and the structural characterization of the KH550-SNP was carried out using FT-IR and TGA. Then, a composite system (KH550-SNP/SDBS) was prepared by integrating negatively charged sodium dodecylbenzene sulfonate (SDBS) and positively charged KH550-SNP under the action of the electrostatic attraction force, and its interface properties and imbibition efficiency were further evaluated. The characterization results indicated that the modification process of the SNP surface by KH550 was successful. Besides, the interfacial tension (IFT) of the composite system (KH550-SNP: SDBS = 0.05%: 0.05%) was 0.6 mN/m and the water contact angle (CA) of the core slice treated with the composite system (KH550-SNP: SDBS = 0.05%: 0.01%) was 36.5° compared to the KH550-SNP of 15.1 mN/m and 42.6°, which stated that the composite system had better interface properties than the KH550-SNP. Finally, the imbibition recovery factors were 24.7% and 30.8% when the KH550-SNP and composite system (KH550-SNP: SDBS = 0.05%: 0.01%) was used.