Study on Creep and Recovery of Water-in-Crude Oil Emulsion

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.

کلیدواژه ها:

Crude Oil ، W/O Emulsion ، Creep ، Recovery