Synthesizing CNT-TiO2 nanocomposite and experimental pore-scale displacement of crude oil during nanofluid flooding

Abstract

Metallic nanoparticles and carbon nanomaterials have been extensively studied in enhanced oil recovery. Carbon nanotube (CNT)/TiO2 nanocomposite is synthesized and investigated in terms of contact angle, interfacial tension (IFT), emulsion stability, etc. Its performance in oil displacement in porous media is evaluated through glass micromodel experiment. The synthesized CNT/TiO2 is composed of TiO2-based nanocomposites and CNTs as reinforcement phase. TiO2 is the dominant crystalline phase, and TiO2 nanoparticles cover on the CNTs. CNT/TiO2 nanocomposite is able to alter the wetting conditions of the rock from strong oil-wet to hydrophilic conditions and effectively reduce the interfacial tension. CNT/TiO2 nanocomposite plays an effective role in stabilizing the Pickering emulsions, and even forms stable emulsions at high temperature as 90 °C. For NaCl concentration of up to 2%, a stable emulsion can be formed even after 7 days. It is observed from glass micromodel experiments that the CNT/TiO2 nanofluid provides a higher recovery factor denoting its promising performance in enhanced oil recovery.

Keywords

• carbon nanotubes
• TiO2
• nanocomposite
• nanofluid
• Pickering emulsion
• enhanced oil recovery