Based on the assumption that waxy crude oil is deemed as the porous medium system under the temperature of losing flow point

the additional specific heat capacity method is used to describe the wax crystallization heat

and the momentum source term method is adopted to represent the flow resistance on the liquid oil due to the formation of network structure made by waxy crystal. The finite volume method is used to simulate the gelatinization process of waxy crude oil. The result shows that the gelatinization evolution is mainly conducted by the heat transfer mechanism and boundary condition. Affected by natural convection

the gelled crude oil first generates in the region surrounded by the sidewall and base wall

which is always the most serious gelled region in the tank. The integrated gelled oil layer first appears on the top wall

then it experiences two steps which include the slow growth and fast growth. Moreover

the gelled oil layer is gradually tends to be even when the cooling advances. Later after it appears on the top wall

the gelled oil layer covers the base wall which has the opposite development process from that on the top wall. The gelled oil layer covers the sidewall at the last step. On the sidewall the evolution of gelled oil layer has the trait of advancing from the base wall to the top wall along the sidewall. When natural convection gets stronger

the increasing rate of gelled oil layer turns to be smaller on the top wall

but it has the opposite behavior on the base wall. Based on the temperature profile and evolution of gelled structure

the cooling process can be divided into three states. Natural convection dominates the heat transfer behavior in the first stage. In the second stage

heat conduction gradually replaced the dominant role of natural convection. Finally the heat transfer behavior is conducted by heat conduction and boundary condition in the third stage. In the meantime

the rule of temperature profile and heat loss is also provided.