Saeed Naseri; Jamshid Moghadasi; Mohammad Jamialahmadi
Abstract
Sulfate scale deposition (BaSO4, CaSO4, and SrSO4) is a common problem in oilfield operations around the world, which causes significant formation damage during production and injection activities. This paper presents the results of an experimental study on the permeability reduction of porous media ...
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Sulfate scale deposition (BaSO4, CaSO4, and SrSO4) is a common problem in oilfield operations around the world, which causes significant formation damage during production and injection activities. This paper presents the results of an experimental study on the permeability reduction of porous media due to sulfate scale deposition. A set of experiments were conducted to investigate the effects of cation (Ba2+, Ca2+, and Sr2+ ions) concentration and the number of cation species on the permeability reduction resulting from single sulfate scales (single BaSO4, CaSO4, and SrSO4 scales) and mixed BaSO4, CaSO4, and SrSO4 scale deposition in porous media during water injection. The experiments were performed at a constant temperature of 70 °C and a constant anion (SO42- ion) concentration of 3968 ppm in the pack of glass beads as the porous media. The results show that the intensity of permeability reduction increases with increasing cation concentration. These results also declare that the permeability reduction of porous media due to mixed BaSO4, CaSO4, and SrSO4 is clearly severer than single scales.
Mohsen Seid Mohammadi; Jamshid Moghadasi; Saeed Naseri
Abstract
Wettability alteration is one of the most important methods for oil recovery from sandstone and carbonate reservoirs. The effects of salinity, pH, temperature, and chemicals such as surfactants and fatty acids on the alteration of the wettability were described in previous studies. In recent years, attention ...
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Wettability alteration is one of the most important methods for oil recovery from sandstone and carbonate reservoirs. The effects of salinity, pH, temperature, and chemicals such as surfactants and fatty acids on the alteration of the wettability were described in previous studies. In recent years, attention has been directed to nanoparticles as a wettability alteration agent. The effect of some nanoparticles on the wettability alteration and oil recovery of sandstone and a few carbonate reservoir rocks have been investigated in several works. In this study, the effect of γ-Al2O3 on the wettability alteration of one of the Iran carbonate reservoirs is presented. The results show that the adsorption of γ-Al2O3 nanoparticles on the calcite surface changes the wettability from oil-wet to water-wet. At a γ- Al2O3 nanofluid concentration of 0.5 wt.%, the maximum change in contact angle was observed. It was observed that the oil recovery increased by 11.25% when 0.5 wt.% γ-Al2O3 nanofluid was injected into the core sample in a tertiary mode. This work illustrates the successful application of gamma alumina nanoparticle in enhancing oil recovery in carbonate rocks through the wettability alteration of rock surfaces.
