Nano-stabilized foam for enhanced oil recovery using green nanocomposites and anionic surfactants: An experimental study

With the decline in hydrocarbon resources around the world, the use of different enhanced oil recovery (EOR) methods became more attractive. Recently, gas foams have been considered by researchers as one of the most effective ways to increase oil recovery. Despite its functions, the conventional foams have low stability. Recently, nanomaterials, as appropriate agents, are used to increase the stability of foams in enhances oil recovery. In this study, the synthesized nanocomposites (NCs), SiO2/KCl/Xanthan NCs was used to stabilize the foams obtained from sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) surfactants. Thus, the synergic effect of the surfactant and NCs was investigated along with the salinity, foam quality, alkalinity and oil properties. The experimental measurements of conductivity, pH, surface tension (ST), interfacial tension (IFT), contact angle (CA) and oil displacement were performed. The obtaining results showed that the SDS and CTAB surfactants have the critical micelle concentration (CMC) of 2000 and 300 ppm, respectively. In terms of the foam stability, both surfactants demonstrated the same behavior of equal stability, while it is improved under the influence of NaCl and NaOH at different concentrations with reducing the ST, IFT and foam generation time (tg). In addition, the optimal NCs concentrations for SDS and CTAB surfactants which improved the foam stability significantly, reduced the CA by 73.27 and improved the oil recovery by 20 % original oil in place (OOIP) were 1000 ppm and 500 ppm, respectively. This was also confirmed by macroscopic analysis of the formulated nanosurfactant systems. On the other hand, the viscosity, density and the gas rate had the inverse influence on the foam stability.