Abstract
By means of DSC, test of flow parameters, and microscopic observation, this paper studied the relation between the influence on the low temperature flow properties and that on the waxy crystal of the PPD-treated crude oil due to different final temperature of dynamic cooling. It has been experimental confirmed that the influence caused by the final temperature of dynamic cooling on low temperature flow properties and waxy crystal vary from the different final temperature of dynamic cooling. With this temperature increases, the depressive effects first get worse, then improved and finally kept nearly unchanged at higher temperature.