Comparative Study on Heat Transfer Models for Oilfield Gathering and Transportation Pipelines

This study compares four radial heat transfer models for buried oilfield gathering and transportation pipelines: DirectK, analytical thermal resistance, 1D FVM and 2D FVM, coupled with the same axial energy equation. Prescribed fluid properties and an internal heat transfer coefficient isolate the effects of radial model assumptions. After mesh, domain, boundary and transient checks, the 2D FVM is used as a numerical reference. Across 24 geometries, DirectK had a mean absolute relative heat-loss deviation of 32.5224%, whereas the maximum deviations of the analytical model and 1D FVM were 0.9344% and 0.9343%. Similar total heat losses did not imply identical local temperatures: the outer-surface top-to-bottom difference reached 6.8252 °C in the large-diameter, shallow-burial case. In case D, the 1D transient heat loss was 9.6510% lower than the 2D result at 168 h. The maximum startup temperature difference at 24 h was 0.2148 °C. Model selection therefore depends on the required temperature information, transient response and computational cost. These results are numerical comparisons under the stated assumptions, not field validation.