Deposition of Dispersed Nanoparticles in Porous Media Similar to Oil Sands. Effect of Temperature and Residence Time

The use of nanoparticles for a wide variety of purposes is attracting much interest among large oil producers. Technologies that intend to adsorb noxious components or to modify flow patterns to enhance oil recovery or to upgrade the oil in place before pipelining are being subject to significant consideration with high potential to impact the environmental and economic performance of this industry. A key aspect for chemical processes targeting the construction of adsorbers or reaction zones in the reservoir strides in the particles retention in the porous medium zone of interest, especially when a temperature above the one in the reservoir is applied. This work addresses the effect of different operation variables in the nanoparticle deposition process. Of great importance is not only the amount of particles retained but also the profile, morphology, dispersion, and penetration in the porous medium. A Ni–Mo–W dispersed nanoparticulate was evaluated. The deposition process was conducted at moderate conditions of temperature and residence time. During this process, retention of naturally occurring metals, mainly vanadium, in the bitumen was found to be in the low range of 25–70 ppm wt. High particle retention, over 95%, was obtained in every case, with no observable effect on the sandpack’s oil permeability. The analysis of particle size distributions before and after passing through the sand pack was shown to have no significant variation. The concentration profiles along the porous media are similar for all experimental conditions investigated with around 30% of nanoparticles depositing at the entrance of the media. Correlations for the profile and cumulative concentration along the porous media core are proposed. Particles were identified and measured by Scanning Electron Microscopy-Energy Dispersion X-ray Analysis (SEM-EDX) along the full length of the porous media core in each case. Low temperature deposition test runs showed particles deposited as large agglomerates all along the porous medium, while for high temperature deposition test runs, individually deposited particles were observed