Studies on Temperature Drop of Buried Waxy Crude Pipelines in Shutdown: A General Review

The temperature drop characteristics of buried waxy crude pipelines in shutdown are summarized and compared with those in water pipelines, heavy crude pipelines and aerial waxy crude pipelines. Based on analysis on governing influencing factors, it is pointed out that two key problems have to be solved for better understanding and solving the temperature drop problem of huried waxy crude pipe¨nes in shutdown, which are the natural convection heat transfer in the initial period after shutdown, and the moving-boundary heat transfer associated with latent heat releasing due to wax precipitation. The commonly-used mathematical models for temperature drop of buried waxy crude pipelines in shutdown are discussed and compared.