The effects of water content, shear rate, temperature, and solid particle concentration on viscosity reduction （VR） caused by forming stable emulsions were investigated using Omani heavy crude oil. The viscosity of ...The effects of water content, shear rate, temperature, and solid particle concentration on viscosity reduction （VR） caused by forming stable emulsions were investigated using Omani heavy crude oil. The viscosity of the crude oil was initially measured with respect to shear rates at different temperatures from 20 to 70℃. The crude oil exhibited a shear thinning behavior at all the temperatures. The strongest shear thinning was observed at 20℃. A non-ionic water soluble surfactant （Triton X-100） was used to form and stabilize crude oil emulsions. The emulsification process has significantly reduced the crude oil viscosity. The degree of VR was found to increase with an increase in water content and reach its maximum value at 50 % water content. The phase inversion from oil- oil emulsion occurred at 30 in-water emulsion to water-in- % water content. The results indicated that the VR was inversely proportional to temperature and concentration of silica nanoparticles. For water-in-oil emulsions, VR increased with shear rate and eventually reached a plateau at a shear rate of around 350 s^-1. This was attributed to the thinning behavior of the continuous phase. The VR of oil-in-water emulsions remained almost constant as the shear rate increased due to the Newtonian behavior of water, the continuous phase.展开更多
The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this...The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this research,a novel surfactant,tri-triethanolamine monosunflower ester,was synthesized in the laboratory by extracting fatty acids present in sunflower（Helianthus annuus）oil.Synthesized surfactant was used to prepare oil-in-water emulsions of a heavy crude oil from the western oil field of India.After emulsification,a dramatic decrease in pour point as well as viscosity was observed.All the prepared emulsions were found to be flowing even at 1°C.The emulsion developed with 60%oil content and 2wt%surfactant showed a decrease in viscosity of 96%.The stability of the emulsion was investigated at different temperatures,and it was found to be highly stable.The effectiveness of surfactant in emulsifying the heavy oil in water was investigated by measuring the equilibrium interfacial tension（IFT）between the crude oil（diluted）and the aqueous phase along with zeta potential of emulsions.2wt%surfactant decreased IFT by almost nine times that of no surfactant.These results suggested that the synthesized surfactant may be used to prepare a stable oil-in-water emulsion for its transportation through offshore pipelines efficiently.展开更多
Efficient extraction of crude oil,the major energy resource of current concern and high demand worldwide,is of paramount importance in both energy and environmental fields.However,it remains a great challenge to separ...Efficient extraction of crude oil,the major energy resource of current concern and high demand worldwide,is of paramount importance in both energy and environmental fields.However,it remains a great challenge to separate the crude oil-in-water emulsions with an ultralow oil content of<200 ppm.Here,the three-dimensional and superwetting channels are developed by coating titanium foams with anodic TiO_(2) nanotube arrays.The channels render superhydrophilic and underwater superoleophobic feature,which enables rapid formation of water channels that expel the oil droplets.A high separation efficiency of ∼96.8% and low total organic carbon content of ∼6 ppm are thus achieved for the ultralow-concentration crude oil-in-water emulsions.The pressure and time dependence of the separation process is systematically studied with a critical pressure of 12.25 kPa.Such a high performance is close to the theoretical limit imposed by the ultralow concentration,and shows obvious advances over either organic membranes or inorganic frameworks.展开更多
The crude oil recovery process is frequently associated with the formation of stable emulsions due to factors such as turbulent flow in pipelines and the presence of surface-active substances that naturally occur in c...The crude oil recovery process is frequently associated with the formation of stable emulsions due to factors such as turbulent flow in pipelines and the presence of surface-active substances that naturally occur in crude oil.These emulsions are undesirable for the petroleum industry because their destruction/treatment adds to the overall production cost and causes the loss of valuable amounts of crude oil.Therefore,it is essential,for economic and environmental reasons,to optimize the crude oil demulsification process.The effective treatment of crude oil emulsions requires understanding of the process and factors leading to their formation and stabilization.In this sense,suitable treatment methods and possible preventive measures to avoid their formation can be employed.The present study reviews recent oilfield emulsion types and the factors responsible for their formation and stabilization.The different demulsification techniques employed were then extensively examined.Demulsification tech-niques include mechanical,thermal,electrical,and chemical methods with different demulsification mechanisms affected by many factors such as emulsions type and properties,demulsifiers characteris-tics,presence of solids stabilized emulsions,etc.The demulsification efficiency depends on the operating parameters of the process,the economics involved,and the environmental impact,which are the main factors considered in selecting a suitable demulsification technique.Future research on the demulsifi-cation of crude oil emulsions should focus on real crude oil emulsions studies at a pilot scale level,the effect of aging on crude oil emulsions,the combination of multiple demulsification techniques and their synergistic effects,and the use of natural,ecofriendly demulsifiers.展开更多
The stability of different crude oil emulsions from ASP flooding production well is studied by the method of a stirred tank. The demulsifying of crude-oil emulsion by different demulsifying agents is discussed. The br...The stability of different crude oil emulsions from ASP flooding production well is studied by the method of a stirred tank. The demulsifying of crude-oil emulsion by different demulsifying agents is discussed. The breakage of the crude oil emulsions from the well PO11 by the different types and concentrations of the emulsifying agents is also discussed. The breaking mechanism of the demulsifying agent is described microscopically.展开更多
文摘The effects of water content, shear rate, temperature, and solid particle concentration on viscosity reduction （VR） caused by forming stable emulsions were investigated using Omani heavy crude oil. The viscosity of the crude oil was initially measured with respect to shear rates at different temperatures from 20 to 70℃. The crude oil exhibited a shear thinning behavior at all the temperatures. The strongest shear thinning was observed at 20℃. A non-ionic water soluble surfactant （Triton X-100） was used to form and stabilize crude oil emulsions. The emulsification process has significantly reduced the crude oil viscosity. The degree of VR was found to increase with an increase in water content and reach its maximum value at 50 % water content. The phase inversion from oil- oil emulsion occurred at 30 in-water emulsion to water-in- % water content. The results indicated that the VR was inversely proportional to temperature and concentration of silica nanoparticles. For water-in-oil emulsions, VR increased with shear rate and eventually reached a plateau at a shear rate of around 350 s^-1. This was attributed to the thinning behavior of the continuous phase. The VR of oil-in-water emulsions remained almost constant as the shear rate increased due to the Newtonian behavior of water, the continuous phase.
基金the Indian Institute of Technology (Indian School of Mines), Dhanbad for providing necessary laboratory facilities and financial support
文摘The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this research,a novel surfactant,tri-triethanolamine monosunflower ester,was synthesized in the laboratory by extracting fatty acids present in sunflower（Helianthus annuus）oil.Synthesized surfactant was used to prepare oil-in-water emulsions of a heavy crude oil from the western oil field of India.After emulsification,a dramatic decrease in pour point as well as viscosity was observed.All the prepared emulsions were found to be flowing even at 1°C.The emulsion developed with 60%oil content and 2wt%surfactant showed a decrease in viscosity of 96%.The stability of the emulsion was investigated at different temperatures,and it was found to be highly stable.The effectiveness of surfactant in emulsifying the heavy oil in water was investigated by measuring the equilibrium interfacial tension（IFT）between the crude oil（diluted）and the aqueous phase along with zeta potential of emulsions.2wt%surfactant decreased IFT by almost nine times that of no surfactant.These results suggested that the synthesized surfactant may be used to prepare a stable oil-in-water emulsion for its transportation through offshore pipelines efficiently.
基金supported by the National Natural Science Foundation of China(51871037)Chongqing Youth Talents Program(CQYC201905023)the National Key Research and Development Program of China(2020YFF0421893).
文摘Efficient extraction of crude oil,the major energy resource of current concern and high demand worldwide,is of paramount importance in both energy and environmental fields.However,it remains a great challenge to separate the crude oil-in-water emulsions with an ultralow oil content of<200 ppm.Here,the three-dimensional and superwetting channels are developed by coating titanium foams with anodic TiO_(2) nanotube arrays.The channels render superhydrophilic and underwater superoleophobic feature,which enables rapid formation of water channels that expel the oil droplets.A high separation efficiency of ∼96.8% and low total organic carbon content of ∼6 ppm are thus achieved for the ultralow-concentration crude oil-in-water emulsions.The pressure and time dependence of the separation process is systematically studied with a critical pressure of 12.25 kPa.Such a high performance is close to the theoretical limit imposed by the ultralow concentration,and shows obvious advances over either organic membranes or inorganic frameworks.
文摘The crude oil recovery process is frequently associated with the formation of stable emulsions due to factors such as turbulent flow in pipelines and the presence of surface-active substances that naturally occur in crude oil.These emulsions are undesirable for the petroleum industry because their destruction/treatment adds to the overall production cost and causes the loss of valuable amounts of crude oil.Therefore,it is essential,for economic and environmental reasons,to optimize the crude oil demulsification process.The effective treatment of crude oil emulsions requires understanding of the process and factors leading to their formation and stabilization.In this sense,suitable treatment methods and possible preventive measures to avoid their formation can be employed.The present study reviews recent oilfield emulsion types and the factors responsible for their formation and stabilization.The different demulsification techniques employed were then extensively examined.Demulsification tech-niques include mechanical,thermal,electrical,and chemical methods with different demulsification mechanisms affected by many factors such as emulsions type and properties,demulsifiers characteris-tics,presence of solids stabilized emulsions,etc.The demulsification efficiency depends on the operating parameters of the process,the economics involved,and the environmental impact,which are the main factors considered in selecting a suitable demulsification technique.Future research on the demulsifi-cation of crude oil emulsions should focus on real crude oil emulsions studies at a pilot scale level,the effect of aging on crude oil emulsions,the combination of multiple demulsification techniques and their synergistic effects,and the use of natural,ecofriendly demulsifiers.
文摘The stability of different crude oil emulsions from ASP flooding production well is studied by the method of a stirred tank. The demulsifying of crude-oil emulsion by different demulsifying agents is discussed. The breakage of the crude oil emulsions from the well PO11 by the different types and concentrations of the emulsifying agents is also discussed. The breaking mechanism of the demulsifying agent is described microscopically.
