Abstract: The scaling locations in the heat exchanger processing SZ36-1 crude oil in a refinery were analyzed. XRD, IR, and hydrocarbon element analysis techniques were used to characterize the main components of the scale. The XRD results showed that the inorganic components in the scale except sand mainly came from the water corrosion in crude oil on pipelines and equipment. The hydrogen-carbon ratios of the scale and the crude oil indicated that the organic components in the scale mainly came from crude oil.The infrared spectroscopy results indicated that the scale contained acrylamide polymers, and its characteristic peak was consistent with the hydrophobically associated polyacrylamide injected in upstream process. It was believed that the generation of scale was related to the hydrophobic associated polyacrylamide added during the oil recovery process. The dynamic simulation showed that when water content was more than 5% and at 85℃，scaling occurred in the position of heat exchanger where flow rate was low. At the same time, the physical properties of the simulated scale were consistent with the scale samples collected from the oil refining device, which further proved that polyacrylamide mainly acts as agglomeration and crosslinking, binding the crude oil material to form scale.

Key words: hydrophobic associated polyacrylamide, crude oil heat exchanger, scaling, dynamic simulation