توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Study on Creep and Recovery of Water–in–Crude Oil Emulsion
اطلاعات انتشار: کنفرانس بین المللی فرآورش پلیمرها، سال
تعداد صفحات: ۴
Emulsions are of great concern due to their widespread occurrence in everyday life and industry. The understanding of rheological properties of crude oils and their emulsions is of great significance in transportation and crude oil processing. Creep, as a time and temperature dependent phenomenon, is of importance for material applications requiring long–term durability and reliability. In this study,the creep and recovery of a heavy crude oil and its emulsion were investigated. Creep–recovery method is very useful to investigate the viscoelasticity. Creep and recovery tests have been performed to study the viscoelastic behavior of water–in–crude oil (W\O) emulsions. The viscoelastic behavior of W\O emulsion is strongly influenced by temperature and water cut. It was found that the creep strain reduces with decreasing temperature and enhancingwater content. The master curves show that the creep compliance of emulsions was obviously lower than that of the crude oil, which indicates the role of water cut and interaction between the water droplets. Newtonian behavior was observed for the dilute emulsion, but at higher water cuts, shear thinning properties wereobserved.The shear thinning effect increased with decreasing droplet size due to stronger interactions between droplets.In addition, shear stress variations and their effects on creep and recovery were investigated.<\div>

۲Rheological Study of Heavy Crude Oils and Their Emulsions
اطلاعات انتشار: کنفرانس بین المللی فرآورش پلیمرها، سال
تعداد صفحات: ۵
The increasing oil demand is leading to usage of the very large world resources of heavy crude oils that are of the same order of magnitude than conventional oils. However, the major difficulty for producing and transporting these crude oils comes from their very high viscosities. Emulsions either water–in–oil or oil–in–water emulsions can be important in almost all stages of upstream activities in petroleum industry such as transportation, production, completion,drilling, and separation of emulsified crude oils. Therefore, an understanding of the rheological behavior of these types of crude oils and their emulsions is important to choose the right approach in designing the required facilities. In this study, the emulsion rheological behavior was investigated as a function of shear rate, temperature, surfactant concentration, and dispersed phase concentration. A rheometer (PAAR Physica MCR 301) was used to measure the rheological behavior of the crude oil and its emulsions. Emulsion characterization was determined by measuring the droplet size distribution of the dispersed phase using optical microscopy. Rheological modeling of emulsion as a function of temperature, dispersed phase concentration, and shear rate, was also another aim of this work. Experimental data suggest that the rheological behavior of emulsions can be best approximated by a power–law relation. The results show that at low dispersed phase concentration, the emulsions behave as Newtonian fluids, however, at high dispersed phase concentration they behave as non–Newtonian fluids. It was also observed that the viscosity decreases with temperature, and the highest viscosity was observed at the point close to phase inversion<\div>
نمایش نتایج ۱ تا ۲ از میان ۲ نتیجه