Review on Enhancing Rheological Characteristics of Viscoelastic Surfactant Fracturing Fluids by Nanoparticles: Advances, Challenges, and Perspectives

In the past decade, there has been significant attention given to the use of viscoelastic surfactants (VESs) as fracturing fluids in the stimulation of oil and gas reservoirs. One key challenge in VES utilization is improving the rheological performance of the fracturing fluid, ensuring stability and high performance under reservoir conditions characterized by high temperature and pressure. This enhancement aims to increase the wormhole propagation in underground reservoir porous media. To address this, different categories of additives have been employed to improve the performance of the fracturing fluid due to the formation of a filter cake and residual sediment particles after VES application. Nanoparticles have emerged as a particularly interesting additive with unique mechanical and chemical properties and characteristics. Studies have shown that the addition of nanoparticles improves the rheological properties of VES fluids, enhancing their stability and viscosity. Furthermore, nanoparticles have been found to increase the carrying capacity of the VES fluids for particles, making them more effective in different medium. This review provides a comprehensive investigation into the various factors influencing the performance improvement and rheological behavior of VESs by nanoparticles. These factors include surfactants, particle shape and size, temperature, salt concentration, pH, and effects of internal and external breakers. The study also includes a thorough review of the previous research on the use of nanoparticles to enhance the behavioral performance of the VESs. Finally, some fundamental recommendations have been proposed to fill the gap in the related research subject. This work is helpful to the oil and gas industries in applications of VES fluids to different fields, especially in the field of fluid dynamics in reservoir engineering.