Nanofluids because of their surface characteristics improve the oil production from reservoirs by enabling different enhanced recovery mechanisms such as wettability alteration,interfacial tension(IFT)reduction,oil vi...Nanofluids because of their surface characteristics improve the oil production from reservoirs by enabling different enhanced recovery mechanisms such as wettability alteration,interfacial tension(IFT)reduction,oil viscosity reduction,formation and stabilization of colloidal systems and the decrease in the asphaltene precipitation.To the best of the authors’ knowledge,the synthesis of a new nanocomposite has been studied in this paper for the first time.It consists of nanoparticles of both SiO2 and Fe3O4.Each nanoparticle has its individual surface property and has its distinct effect on the oil production of reservoirs.According to the previous studies,Fe3O4 has been used in the prevention or reduction of asphaltene precipitation and SiO2 has been considered for wettability alteration and/or reducing IFTs in enhanced oil recovery.According to the experimental results,the novel synthesized nanoparticles have increased the oil recovery by the synergistic effects of the formed particles markedly by activating the various mechanisms relative to the use of each of the nanoparticles in the micromodel individually.According to the results obtained for the use of this nanocomposite,understanding reservoir conditions plays an important role in the ultimate goal of enhancing oil recovery and the formation of stable emulsions plays an important role in oil recovery using this method.展开更多
Metallic nanoparticles and carbon nanomaterials have been extensively studied in enhanced oil recovery.Carbon nanotube(CNT)/TiO_(2) nanocomposite is synthesized and investigated in terms of contact angle,interfacial t...Metallic nanoparticles and carbon nanomaterials have been extensively studied in enhanced oil recovery.Carbon nanotube(CNT)/TiO_(2) nanocomposite is synthesized and investigated in terms of contact angle,interfacial tension(IFT),emulsion stability,etc.Its performance in oil displacement in porous media is evaluated through glass micromodel experiment.The synthesized CNT/TiO_(2) is composed of TiO_(2)-based nanocomposites and CNTs as reinforcement phase.TiO_(2) is the dominant crystalline phase,and TiO_(2) nanoparticles cover on the CNTs.CNT/TiO_(2) nanocomposite is able to alter the wetting conditions of the rock from strong oil-wet to hydrophilic conditions and effectively reduce the interfacial tension.CNT/TiO_(2) nanocomposite plays an effective role in stabilizing the Pickering emulsions,and even forms stable emulsions at high temperature as 90℃.For NaCl concentration of up to 2%,a stable emulsion can be formed even after 7 days.It is observed from glass micromodel experiments that the CNT/TiO_(2) nanofluid provides a higher recovery factor denoting its promising performance in enhanced oil recovery.展开更多
The nanofluid and porous medium together are able to fulfill the requirement of high cooling rate in many engineering problems.So,here the impact of various shapes of nanoparticles on unsteady stagnation-point flow of...The nanofluid and porous medium together are able to fulfill the requirement of high cooling rate in many engineering problems.So,here the impact of various shapes of nanoparticles on unsteady stagnation-point flow of Cu-H_(2)O nanofluid on a flat surface in a porous medium is examined.Moreover,the thermal radiation and viscous dissipation effects are considered.The problem governing partial differential equations are converted into self-similar coupled ordinary differential equations and those are numerically solved by the shooting method.The computed results can reveal many vital findings of practical importance.Firstly,dual solutions exist for decelerating unsteady flow and for accelerating unsteady and steady flows,the solution is unique.The presence of nanoparticles affects the existence of dual solution in decelerating unsteady flow only when the medium of the flow is a porous medium.But different shapes of nanoparticles are not disturbing the dual solution existence range,though it has a considerable impact on thermal conductivity of the mixture.Different shapes of nanoparticles act differently to enhance the heat transfer characteristics of the base fluid,i.e.,the water here.On the other hand,the existence range of dual solutions becomes wider for a larger permeability parameter related to the porous medium.Regarding the cooling rate of the heated surface,it rises with the permeability parameter,shape factor(related to various shapes of Cu-nanoparticles),and radiation parameter.The surface drag force becomes stronger with the permeability parameter.Also,with growing values of nanoparticle volume fraction,the boundary layer thickness(BLT)increases and the thermal BLT becomes thicker with larger values of shape factor.For decelerating unsteady flow,the nanofluid velocity rises with permeability parameter in the case of upper branch solution and an opposite trend for the lower branch is witnessed.The thermal BLT is thicker with radiation parameter.Due to the existence of dual solutions,a linear stability analysis is made and it is concluded that the upper branch and unique solutions are stable solutions.展开更多
Hybrid nanofluids are remarkable functioning liquids that are intended to reduce the energy loss while maximizing the heat transmission.In the involvement of suction and nonlinear thermal radiation effects,this study ...Hybrid nanofluids are remarkable functioning liquids that are intended to reduce the energy loss while maximizing the heat transmission.In the involvement of suction and nonlinear thermal radiation effects,this study attempted to explore the energy transmission features of the inclined magnetohydrodynamic(MHD)stagnation flow of CNTs-hybrid nanofluid across the nonlinear permeable stretching or shrinking sheet.This work also included some noteworthy features like chemical reactions,variable molecular diffusivity,quadratic convection,viscous dissipation,velocity slip and heat omission assessment.Employing appropriate similarity components,the model equations were modified to ODEs and computed by using the HAM technique.The impact of various relevant flow characteristics on movement,heat and concentration profiles was investigated and plotted on a graph.Considering various model factors,the significance of drag friction,heat and mass transfer rate were also computed in tabular and graphical form.This leads to the conclusion that such factors have a considerable impact on the dynamics of fluid as well as other engineering measurements of interest.Furthermore,viscous forces are dominated by increasing the values ofλ_(p),δ_(m)andδ_(q),and as a result,F(ξ)accelerates while the opposite trend is observed for M andφ.The drag friction is boosted by the augmentation M,λ_(p)andφ,but the rate of heat transfer declined.According to our findings,hybrid nanoliquid effects dominate that of ordinary nanofluid in terms of F(ξ),Θ(ξ)andφ(ξ)profiles.The HAM and the numerical technique(shooting method)were found to be in good agreement.展开更多
文摘Nanofluids because of their surface characteristics improve the oil production from reservoirs by enabling different enhanced recovery mechanisms such as wettability alteration,interfacial tension(IFT)reduction,oil viscosity reduction,formation and stabilization of colloidal systems and the decrease in the asphaltene precipitation.To the best of the authors’ knowledge,the synthesis of a new nanocomposite has been studied in this paper for the first time.It consists of nanoparticles of both SiO2 and Fe3O4.Each nanoparticle has its individual surface property and has its distinct effect on the oil production of reservoirs.According to the previous studies,Fe3O4 has been used in the prevention or reduction of asphaltene precipitation and SiO2 has been considered for wettability alteration and/or reducing IFTs in enhanced oil recovery.According to the experimental results,the novel synthesized nanoparticles have increased the oil recovery by the synergistic effects of the formed particles markedly by activating the various mechanisms relative to the use of each of the nanoparticles in the micromodel individually.According to the results obtained for the use of this nanocomposite,understanding reservoir conditions plays an important role in the ultimate goal of enhancing oil recovery and the formation of stable emulsions plays an important role in oil recovery using this method.
文摘Metallic nanoparticles and carbon nanomaterials have been extensively studied in enhanced oil recovery.Carbon nanotube(CNT)/TiO_(2) nanocomposite is synthesized and investigated in terms of contact angle,interfacial tension(IFT),emulsion stability,etc.Its performance in oil displacement in porous media is evaluated through glass micromodel experiment.The synthesized CNT/TiO_(2) is composed of TiO_(2)-based nanocomposites and CNTs as reinforcement phase.TiO_(2) is the dominant crystalline phase,and TiO_(2) nanoparticles cover on the CNTs.CNT/TiO_(2) nanocomposite is able to alter the wetting conditions of the rock from strong oil-wet to hydrophilic conditions and effectively reduce the interfacial tension.CNT/TiO_(2) nanocomposite plays an effective role in stabilizing the Pickering emulsions,and even forms stable emulsions at high temperature as 90℃.For NaCl concentration of up to 2%,a stable emulsion can be formed even after 7 days.It is observed from glass micromodel experiments that the CNT/TiO_(2) nanofluid provides a higher recovery factor denoting its promising performance in enhanced oil recovery.
文摘The nanofluid and porous medium together are able to fulfill the requirement of high cooling rate in many engineering problems.So,here the impact of various shapes of nanoparticles on unsteady stagnation-point flow of Cu-H_(2)O nanofluid on a flat surface in a porous medium is examined.Moreover,the thermal radiation and viscous dissipation effects are considered.The problem governing partial differential equations are converted into self-similar coupled ordinary differential equations and those are numerically solved by the shooting method.The computed results can reveal many vital findings of practical importance.Firstly,dual solutions exist for decelerating unsteady flow and for accelerating unsteady and steady flows,the solution is unique.The presence of nanoparticles affects the existence of dual solution in decelerating unsteady flow only when the medium of the flow is a porous medium.But different shapes of nanoparticles are not disturbing the dual solution existence range,though it has a considerable impact on thermal conductivity of the mixture.Different shapes of nanoparticles act differently to enhance the heat transfer characteristics of the base fluid,i.e.,the water here.On the other hand,the existence range of dual solutions becomes wider for a larger permeability parameter related to the porous medium.Regarding the cooling rate of the heated surface,it rises with the permeability parameter,shape factor(related to various shapes of Cu-nanoparticles),and radiation parameter.The surface drag force becomes stronger with the permeability parameter.Also,with growing values of nanoparticle volume fraction,the boundary layer thickness(BLT)increases and the thermal BLT becomes thicker with larger values of shape factor.For decelerating unsteady flow,the nanofluid velocity rises with permeability parameter in the case of upper branch solution and an opposite trend for the lower branch is witnessed.The thermal BLT is thicker with radiation parameter.Due to the existence of dual solutions,a linear stability analysis is made and it is concluded that the upper branch and unique solutions are stable solutions.
基金funded by King Mongkut’s University of Technology North Bangkok with Contract no.KMUTNB-Post-65-07。
文摘Hybrid nanofluids are remarkable functioning liquids that are intended to reduce the energy loss while maximizing the heat transmission.In the involvement of suction and nonlinear thermal radiation effects,this study attempted to explore the energy transmission features of the inclined magnetohydrodynamic(MHD)stagnation flow of CNTs-hybrid nanofluid across the nonlinear permeable stretching or shrinking sheet.This work also included some noteworthy features like chemical reactions,variable molecular diffusivity,quadratic convection,viscous dissipation,velocity slip and heat omission assessment.Employing appropriate similarity components,the model equations were modified to ODEs and computed by using the HAM technique.The impact of various relevant flow characteristics on movement,heat and concentration profiles was investigated and plotted on a graph.Considering various model factors,the significance of drag friction,heat and mass transfer rate were also computed in tabular and graphical form.This leads to the conclusion that such factors have a considerable impact on the dynamics of fluid as well as other engineering measurements of interest.Furthermore,viscous forces are dominated by increasing the values ofλ_(p),δ_(m)andδ_(q),and as a result,F(ξ)accelerates while the opposite trend is observed for M andφ.The drag friction is boosted by the augmentation M,λ_(p)andφ,but the rate of heat transfer declined.According to our findings,hybrid nanoliquid effects dominate that of ordinary nanofluid in terms of F(ξ),Θ(ξ)andφ(ξ)profiles.The HAM and the numerical technique(shooting method)were found to be in good agreement.
