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    Effects of low-salinity water coupled with silica nanoparticles on wettability alteration of dolomite at reservoir temperature

    , Article Petroleum Science and Technology ; Volume 34, Issue 15 , 2016 , Pages 1345-1351 ; 10916466 (ISSN) Sadatshojaei, E ; Jamialahmadi, M ; Esmaeilzadeh, F ; Ghazanfari, M. H ; Sharif University of Technology
    Taylor and Francis Inc 
    Wettability alteration in porous media is one of the mechanisms for enhancing oil recovery through injecting low-salinity water into carbonate reservoirs, in which active ions can remove the carboxylic oil component from the rock surface, altering the rock's wettability toward a water-wet condition. This study investigated the concomitant effects of low-salinity water and hydrophilic SiO2 nanoparticles on oil-wet dolomite rock. Results revealed that low-salinity water coupled with hydrophilic nano-SiO2 in oil-wet dolomite rock remarkably affected the wettability alteration of the rock, showing that the simultaneous presence of ions in water and hydrophilic nano-SiO2 led to considerable... 

    Characterisation of nanocrystalline sulfated titania modified with transition metals and aluminum as solid acids for esterification

    , Article Progress in Reaction Kinetics and Mechanism ; Volume 41, Issue 1 , 2016 , Pages 57-66 ; 14686783 (ISSN) Rahman Setayesh, S ; Abolhasani, E ; Ghasemi, S ; Sharif University of Technology
    Science Reviews 2000 Ltd  2016
    TiO2, transition metal (Cr, Mn, Fe, Co, Ni, Cu, and Zn)- and aluminum-doped TiO2 nanoparticles were prepared by the sol-gel technique. The sulfated catalysts were prepared by the impregnation method with H2SO4 solution. The catalysts were characterised by X-ray diffraction (XRD), BET surface area measurement, diffuse reflectance spectroscopy (DRS), and Fourier transform infrared (FTIR) techniques. The sulfate content of the metal-incorporated samples was considerably higher than for SO4 2-/TiO2. The metal doping brought about a considerable reduction in the extent of sulfate loss from the catalyst surface due to the wide dispersion on the surface. The SO4 2-/TiO2 and SO4 2-/M/TiO2... 

    Wettability alteration in carbonates during "Smart Waterflood": Underling mechanisms and the effect of individual ions

    , Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 487 , 2015 , Pages 142-153 ; 09277757 (ISSN) Rashid, S ; Mousapour, M. S ; Ayatollahi, S ; Vossoughi, M ; Beigy, A. H ; Sharif University of Technology
    Elsevier  2015
    There are increasing evidences that adjusting the chemistry of the injecting water improves the oil recovery efficiency. However, the underlying mechanisms for this technique which is referred to as "smart waterflood" have not yet been thoroughly understood. It is needed to explore the role of individual ions through set of different tests, to find the right mechanisms behind "smart waterflood". This study is focused on the fluid/solid (carbonate) interactions through systematic wettability measurement. Contact angle measurements accompanied by spontaneous imbibition tests were employed to determine the role of individual monovalent and divalent ions in wettability alteration process by...