Now showing 1 - 3 of 3
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    Publication
    Evaluation of ionanofluid for chemical-enhanced oil recovery for matured crude oil reservoirs
    (01-01-2022)
    Sharma, Ankit
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    Kakati, Abhijit
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    Sakthivel, Sivabalan
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    Jadhawar, Prashant
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    The purpose of the present work is to evaluate applicability of ionanofluids for enhanced oil recovery (EOR) applications. Two different ionanofluids have been prepared for this study by adding silica nanoparticles into two different ionic liquids (tripropyl ammonium sulphate and triethyl ammonium sulphate) solutions. The effects of nanoparticle and ionic liquid on the interfacial tension of crude oil-nanofluid and their enhanced oil recovery performances have been evaluated. Ionanofluids are found to have the ability to reduce the interfacial tension to a significantly low value. The results of this study also indicate that ionanofluids has much higher enhanced oil recovery efficiencies in comparison to nanofluid and ionic liquid alone. Therefore, ionanofluids have the potential to be used as an excellent future EOR agent.
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    Publication
    Effect of monovalent and divalent salts on the interfacial tension of pure hydrocarbon-brine systems relevant for low salinity water flooding
    (01-01-2017)
    Kakati, Abhijit
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    Interfacial tension between hydrocarbon liquids and salt water is a very important property for many industrial applications, especially in petroleum industry. Interfacial tension, in addition to other factors, has direct impact on displacement process in porous media so thus on oil recovery. Very recently, the salinity of injection brine has been regarded as a key factor in oil recovery using low salinity water flooding process. Decrease in the interfacial tension between crude oil and injection brine at low salinity condition might be a reason behind recovery improvement as suspected by some researchers; but there are also other effects associated with low salinity water flooding like wettability alteration, fine migration, mineral dissolution etc. It is suspected that the interaction of polar components at oil-water interface lead to the reduction of interfacial tension. However, the actual mechanism is not known and still under research. The main objective of this work is to determine the effect of salt concentration and type of ions present in an aqueous phase on the interfacial tension between pure hydrocarbon liquids and water. Different hydrocarbon liquids, such as aliphatic and aromatics, have been tested to understand the interaction of monovalent and divalent salts on the interfacial tension. The study reports the interfacial tension of five pure hydrocarbon liquids against solutions of three different salts (NaCl, MgCl2 and CaCl2) over a wide range of salinities. The interfacial tension measurements were done using Wilhelmy plate method by a dynamic contact angle tensiometer. All the experiments were conducted at room temperature and atmospheric pressure. The results lead us to the view that there is low a salinity concentration where the hydrocarbon/brine interfacial tension shows a minimum value. The type of salt also has a significant effect on interfacial tension of aliphatic and aromatic hydrocarbons. Monovalent salt found to be effective in reducing interfacial tension of aliphatic hydrocarbons while divalent salts were found to be effective for aromatic hydrocarbons. The possible mechanism for the reduction in IFT at low salt concentration has also been explained using Gibb's adsorption isotherm. In addition, the trend in IFT has been explained in the light of well-known Jones-Ray effect.
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    Publication
    Controlled salinity water flooding and zeta potential: Insight into a novel enhanced oil recovery mechanism
    (01-12-2023)
    Rahevar, Satyajeet
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    Kakati, Abhijit
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    Kumar, Ganesh
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    Myers, Matthew
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    Al-Yaseri, Ahmed
    Controlled salinity water flooding also known as engineered water flood has been tested as a potential enhanced oil recovery (EOR) method in laboratory as well as at pilot/field scale. However, there are cases seen where the method has failed to show its potential for EOR. Scientists believe that the lack of understanding of case specific underlying mechanism is the primary reason. Many of the literatures claims reduction of interfacial tension as the primary oil recovery mechanism; but recent findings highlighted that modification of electrical charges on rock surface with response to injection brine salinity has greater effect. In order to investigate the same and in search of more insightful mechanism, in this study we have designed and performed experiments with selected chemicals which can modify surface properties of sandstone and also the oil water interfacial tension. The electrical charge of the rock surface and oil–brine​ interfacial tension were modified by tuning salinity of injection water and adding surfactants (sodium dodecyl benzene sulfonate, SDBS and cetyltrimethylammonium bromide, CTAB). The electrical charge of the sandstone surfaces was quantified with zeta potential measurement. The oil recovery potential of the injection fluids was tested through laboratory core flooding experiments at controlled near reservoir conditions. Superposition of all the obtained results revealed that low salinity injection brine modifies the sandstone surface to higher negatively charged state than high salinity water. Therefore, with a negatively charged oil–brine interface it causes strong repulsive forces promoting detachment of residual oil and subsequent mobilization. The hypothesis is also proved by the fact that SDBS in spite of resulting in a lower interfacial tension reduction than CTAB yielded higher oil recovery. This is because of the negative zeta potential caused by SDBS to sandstone surface in comparison to the positive zeta potential observed in the case of CTAB.