The rheological properties of waxy crude oil in sol-gel transition at constant temperature have been studied with rheometer RS75 in the modes of small amplitude oscillatory shearing and steady shearing. The recovered structures of the crude oil gel including equilibrium structures in rest are dependent on the pre-shear rates to a great extent. In the transition of gel to sol, the crude oil gel first shows linear visco-elastic behavior, then nonlinear visco-elastic behavior, and finally yielding property.

Key words: CRUDE OIL, SOL-GEL PROCESS, RHEOLOGICAL PROPERTY, SHEAR, VISCOELASTICITY