Effect of Textural Properties and Surface Chemical Nature of Silica Nanoparticles from Different Silicon Sources on the Viscosity Reduction of Heavy Crude Oil

Abstract

The main objective of this study is to evaluate the effect of the textural properties and surface chemical nature of silica nanoparticles obtained from different synthesis routes and silicon precursors, on their interactions with asphaltenes and further viscosity reduction of heavy crude oil (HO). Four different SiO 2 nanoparticles were used, namely, commercial fumed silica nanoparticles (CSNs) and three in-house-synthesized nanoparticles (named based on the silicon source) modifying the silicon precursor: sodium silicate (SNSS), tetraethylorthosilicate (TEOS) (SNT), and rice husk (SNRH). The nanomaterials were characterized through dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, N 2 physisorption (S BET ), atomic force microscopy (AFM), and X-ray photoelectron (XP) spectroscopy (XPS). The adsorption of asphaltenes over the different nanoparticles was evaluated at a concentration of 1000 mg•L −1 in toluene. The asphaltene−nanoparticle interactions are closely related to several textural properties, such as roughness, surface area, and hydrodynamic diameter, as well as the surface chemical nature of the materials. The results in the textural characterization exhibited that the sizes of the nanoparticles from TEM ranged between 6.9 and 11.5 nm. Nevertheless, the standard deviation of the measurements showed that the sizes are statistically similar. Inversely, the hydrodynamic diameter changed, affecting the surface silanol group's availability due to a hindering effect on functional groups as the hydrodynamic size of the material increased. The rheological measurements were performed at a fixed nanoparticle dosage of 1000 mg•L −1 and showed that the trend of the degree of viscosity reduction (DVR) was CSN > SNT > SNSS > SNRH with the highest value yielding at 30%. The results of DVR are in accordance with the nanoparticles' adsorptive capacity as higher values were obtained with the material that leads to a higher amount of adsorbed asphaltenes. Also, the oxygen amount related to silanol groups, estimated by the XPS analysis, showed a direct relation regarding adsorption capacity and further HO viscosity reduction.

Design and Tuning of Nanofluids Applied to Chemical Enhanced Oil Recovery Based on the Surfactant–Nanoparticle–Brine Interaction: From Laboratory Experiments to Oil Field Application

“…The FTIR spectra of the nanoparticles are presented in Figure 5. As mentioned above, the wide band between 3650 and 3100 cm −1 correlated with O-H bonding, which in this case represented the Silanol Si-OH groups [61,76]. Moreover, the peak centered at 1600 cm −1 corresponded to the O-H scissoring [77], while the pronounced peak between 1000 and 1300 cm −1 denoted the asymmetric stretching of the O-Si-O bonds [49,78].…”

“…On the other hand, the inclusion of nanoparticles in the medium had a positive effect in reverting the rock preference from an oil-wet to a water-wet state as reported in other studies [ 9 ]. The main mechanisms governing this behavior is linked with a sort of decoration of the nanoparticles in the porous medium, and as the nanoparticles have high polarity due to the hydroxyl groups (O-H) on their surface [ 61 ], their interaction with water is also enhanced.…”

“…A concentric cylinders geometry (double GAP) was employed for carrying out the tests, ideal for these types of materials due to their low viscosity. An increasing shear rate ramp between 3 and 100 s −1 was used to perform the analysis at a temperature of 50 °C, as described in previous studies [ 12 , 61 , 62 ].…”

“…The flow curves were obtained using a Kinexus Pro (Malvern Instruments, Worcestershire, UK) rheometer equipped with a solvent trap and a Peltier cell for controlling the temperature with a precision of 1 × 10 −2 • C. A concentric cylinders geometry (double GAP) was employed for carrying out the tests, ideal for these types of materials due to their low viscosity. An increasing shear rate ramp between 3 and 100 s −1 was used to perform the analysis at a temperature of 50 • C, as described in previous studies [12,61,62].…”

SiO2 Biogenic Nanoparticles and Asphaltenes: Interactions and Their Consequences Investigated by QCR and GPC-ICP-HR-MS

“…), high specific surface (area-to-volume ratio), and in some cases, catalytic and magnetic properties 25,26 . Silica-based nanoparticles are among those commonly used primarily due to their wide availability, wellcharacterized surfaces that are easily modified and used as catalyst supports, but above all, because they have a high affinity for asphaltene adsorption 3,27 .…”