Synthesize of Carbon Nanotube/ Silica Nanohybrids as a Pickering Emulsion Stabilizer Agent and a Study on Formation Water/Oil Systems

Functionalized multi-walled carbon nanotube (MWCNT)/silica nanohybrid was synthesized and proposed as a stabilizing agent for water-in-oil pickering emulsion. The high cation content of the formation water balanced the hydrophilicity/ hydrophobicity of the structure and therefore stabilized an emulsion phase without any chemical or mechanical treatment. Bivalent cations, such as magnesium and calcium, changed the hydrophilic-lipophilic balance (HLB) more intensely than the sodium univalent cation. The experiments conducted on the formation water samples from two oil reservoirs, located in the southwest of Iran, revealed that other anions/cations did not impact the performance of the nanohybrid as the pickering emulsion stabilizer. The proposed nanohybrid may hold a great promise to be adopted in enhanced oil recovery (EOR) processes as it does not require any emulsifier and it is free of any mechanical treatments. The key factor, which affected the performance of the proposed nanohybrid, pertained to the type of the cation contained in water. Bivalent cations, such as magnesium and calcium, changed the hydrophilic-lipophilic balance (HLB) more intensely than the sodium univalent cation.