LAUSR

Abstract For oil and gas gathering and transportation field, shutdown is inevitable. After the pipeline of buried geothermal oil is shutdown, the crude oil will dissipate quickly and solidify easily. The phase change process of crude oil in the pipeline is complicated, which is accompanied by latent heat release, liquid-solid interface location tracking, crude oil rheological characteristics, natural convection treatment and other key issues. An Enthalpy-Porous medium method was used to establish the thermal model of crude oil in shutdown. Fluent software was used for numerical simulation and analysis. The influence factors such as soil depth, atmospheric temperature, initial temperature of crude oil and thermal insulation materials on the total freezing time of crude oil in the pipeline were analyzed. The results of this study can provide theoretical basis for the determination of the allowable shutdown time of pipeline.