Enhancing the Performance of Viscoelastic Surfactant Fluids Using Nanoparticles

Abstract

Viscoelastic surfactant (VES) based fluids are used in many applications in the oil industry. Their viscoelastic behavior is due to the overlap and entanglement of long wormlike micelles. The growth of these wormlike micelles depends on the charge of the head group, salt concentration, temperature, and the presence of other interacting components. The problem with these surfactants is that they are expensive and used at temperatures less than 200°F.The viscoelasticity of nanoparticle-networked VES fluid systems were analyzed by rotational and oscillatory viscometers. Apparent fluid viscosities were measured by using 2-4 vol% amidoamine oxide surfactant in 13 to 14.2 ppg CaBr 2 brines and 10.8 to 11.6 ppg CaCl 2 brines at different temperatures up to 275°F and a shear rate of 10 s -1 . The nanoparticles evaluated were MgO and ZnO at 6 pptg concentration. In addition, the effect of different nanoparticle concentrations (0.5 to 8 pptg) and particle size on the viscosity of VES fluid was investigated. The oscillatory shear rate sweep (100 to 1 s -1 ) was performed for the 4 vol% VES in 14.2 ppg CaBr 2 from 100 to 250°F.This study showed that the addition of nanoparticles improved the thermal stability of VES micellar structures in CaBr 2 and CaCl 2 brines up to 275°F and showed an improved viscosity yield at different shear rates. Micron and nano-size particles have potential to improve the viscosity of VES fluids. Lab tests show for VES micellar systems without nanoparticles, the dominant factor is the viscous modulus but when nanoparticles are added to the system at 275°F the elastic modulus becomes the dominant factor. These positive effects of nanoparticles on VES fluid characteristics suggest that these particles can reduce treatment cost and will extend the temperature range of the surfactants to 275°F.

Laboratory Study Displacement Efficiency of Viscoelastic Surfactant Solution in Enhanced Oil Recovery

“…15 Their viscoelastic behavior is due to the overlap and entanglement of long wormlike micelles. 16 In straight tubing experiments, fluid concentration and pipe shear are both having notable effects on fluid elasticity. 17 VES has been developed to take place of polymer solution in a board range of reservoir conditions with good injectivity even when using very viscous VES solutions (i.e., up to 1000 mPa s) and low permeability reservoir.…”

“…20 Studies illustrated that the addition of nanoparticles-MgO or ZnO improved the thermal stability of VES micellar structures in CaBr 2 and CaCl 2 brines up to 275 °F (135 °C) and showed an improved viscosity yield at different shear rates. 16 Series of VES fluids have been developed that the temperature range has been extended to 300 °F21 and have good stability in 18.6% highly saline brine. 22 Additionally, fluid-loss controlling technology improves the performance of VES.…”

Recent Advances in Viscoelastic Surfactants for Improved Production from Hydrocarbon Reservoirs

“…Further improvement of VES-based fluids was accomplished with the development of a system that is thermally stable up to 275°F (Gurluk et al 2013). Base fluids were prepared with either 2 or 4 vol% amidoamine oxide surfactant in 14.2 ppg CaBr 2 brine.…”

Study of Rheological Property and Flow Behavior for Nanoparticles Enhanced VES System in Porous Media

“…The oscillatory rheological measurements for nanoparticles in viscoelastic surfactant fluids noted that the nanoparticles apparently strengthened the micelle-micelle interactions. Lab proppant settling tests demonstrated that the nanoparticle induced VES micelle network structures that dramatically increased the capacity of the surfactant fluid to suspend and transport proppant in well treatments Huang and Crews, 2007;Crews and Huang, 2008;Crews and Ahmed, 2012;Gurluk, et al, 2013). M.F.…”