Viscoelastic surfactants application in hydraulic fracturing, it's set back and mitigation - an overview

Abstract

Fracturing fluid is an essential component of hydraulic fracturing stimulation. The oil and gas industry has experienced transformation in fluid technology for hydraulic fracturing. Fracturing fluid should have the reasonable viscosity that can suspend and transport proppants into the fracture. It should also be able to keep the fracture open throughout the life of the well. Sometimes ago polymers were used for this purpose as it's able to withstand high temperature under well condition. However due to formation of filter cake caused by the polymer based fluids, there are formation and conductivity damages to the formation, therefore its application in fracking a bit limited. Viscoelastic surfactant (VES) were then applied in fracturing operation as they exhibit viscous and elastic behavior in brine (increased viscosity) by entanglement of the VES micelles, but its viscosity is drastically reduced at high temperature. Then additions of inorganic or organic nanoparticles have been found to help in stabilizing the viscosity of this VES fluid at very harsh condition of high temperature and pressure. Internal breakers are also added to the VES fluid to help break the fluid into low viscosity fluid after fracturing has been completed so as to enhance easy flow-back (cleanup) of VES to the surface. This paper however highlights the process of VES fluid application in hydraulic fracturing stimulation, its set back and mitigation approach adopted in the industry using nanoparticles to stabilize its viscosity at high temperature.