An experimental investigation of the viscosity behavior of solutions of nanoparticles, surfactants, and electrolytes

Abstract

Several studies have reported that the viscosity profile of nanofluids has a similar trend to electrolytes. This behavior is attributed to the complex interactions of the ions of nanoparticles (NPs) with the ions of aqueous solutions. Recently, laboratory experiments have shown that nanofluids are suitable candidates for enhanced oil recovery in different reservoirs. The improvement in oil recovery during nanofluid injection is attributed to the wettability alteration, interfacial tension reduction, and viscosity modification. Low salinity water and surfactants are used to stabilize and prevent the aggregation of NPs, which are injected into the reservoir. However, the interactions between the reservoir/injected fluids with NPs alter the properties of the fluid. The complex interactions among the ions present in the solutions of NPs, surfactants, and electrolytes (NSE) that result in the viscosity modification are not completely understood. Therefore, this work presents a detailed study on the complex interactions existing between the ions of NPs and other ions of aqueous solution present in the reservoir fluid using the dynamic light scattering, transmission electron microscopy, and Fourier transform infrared spectroscopy techniques to understand the viscosity behavior of NSE solutions. The viscosity profile of NSE solutions with increasing concentration of NPs has the same trend as aqueous solutions, while that with increasing concentration of the sodium dodecyl sulfate surfactant behaves like spherical particles. The explained mechanisms behind the viscosity behavior of NSE solutions in this study can improve the optimization design for nanofluid injection into the reservoir.

Experimental Study on Alternating Injection of Silica and Zirconia Nanoparticles with Low Salinity Water and Surfactant into Fractured Carbonate Reservoirs for Enhanced Oil Recovery

“…The injection of LSW stabilizes the subsequent injection of NPs and prevents the deposition of NPs, which could cause formation damage . Again, the challenge of surfactant adsorption onto the pore walls of the carbonate cores is mitigated by the previously injected NPs since the surfactants are adsorbed onto the NPs. , It implies that the injection of surfactants before NPs in a reverse sequence would result in surfactant adsorption onto the surface of the carbonate core, leading to a relatively low recovery as also observed in the static imbibition experiment. Therefore, the best injection sequence, in this case, is the LNS alternating injection sequence.…”

“…Consequently, an increase of approximately 0.4 and 1.7% of the OOIP is recorded for CS and CZ core plugs, respectively, during the SDS injection. Additionally, the prior injection of NPs reduces the adsorption of SDS surfactants onto the surface of the carbonate core and, as a result, enhances the IFT reduction tendency of SDS. , …”

“…It should be noted that the solution of silica NPs is sonicated for approximately 1 h using the Qsonica sonicator (500 W, 20 kHz, and 40% amplitude) to enhance its stability. The SDS surfactant solution utilized in this study is prepared by dissolving 1000 ppm (0.1 wt %) of SDS in DI water, which is selected based on the estimated critical micelle concentration (CMC) value of 450 ppm to 600 ppm for SDS in brine and nanofluids via viscosity, zeta potential, and conductivity measurement techniques ,, and has been employed in the previous studies. ,, The solutions of zirconia NPs are prepared by dissolving approximately 100 ppm (0.01 wt %) of the powdered NPs in DI water and sonicating the entire solution for approximately 1 h. The concentration of zirconia NPs utilized is based on the optimum concentration for wettability alteration and IFT reduction reported in the literature, which was also evaluated in this study via static imbibition experiments. The properties of these fluids are presented in Table .…”

“…Accordingly, NPs are injected with LSW because they possess the tendency to reduce fines migration. Furthermore, various studies have shown that NPs are suitable candidates for EOR in carbonate reservoirs due to their effectiveness in the alteration of wettability, modification of viscosity, and reduction of interfacial tension (IFT). − It is worth mentioning that NPs have a high surface area to volume ratio, which enables them to behave as surface-active agents . Also, surfactant flooding has been applied in carbonate reservoirs by various studies as an EOR technique for decades.…”

Flow towards a Stagnation Region of a Curved Surface in a Hybrid Nanofluid with Buoyancy Effects

“…For additional references, the experimental study on the nanoparticle's viscosity behavior can be found in refs. [22,23].…”