The temperature drop is one of the parameters that is taken into account when calculating the strength and stability of the main oil pipeline in accordance with the requirements of the industry regulatory standard (SNiP). The acceptable values of the temperature drop are determined as the result of calculation for the accepted pipeline design based on the limit state of the pipeline, which is determined in accordance with industry standards. However, at the operation stage, the absolute values of this parameter may not correspond to the design values, since seasonal and daily temperature fluctuations, thermal interaction of the underground oil trunk pipeline and the ground lead to changes in the temperature field around the pipe along the pipeline route. As a result, there are differences between the standard values of the temperature drop and the actual values at which the pipeline was filled with soil during construction and its subsequent operation. For this reason, longitudinal and transverse displacements and stress increase, which causes the spatial positions of the sections of the linear part to deviate from the design and may lead to loss of bearing capacity and reliability of the pipeline, as well as the risk of accidents. The paper presents the results of a study of changes in the reliability of sections of the linear part and the level of risk that occurs during the operation of the main oil pipeline, depending on different values of the temperature difference in the pipe wall.
main oil pipeline, linear part, temperature drop, reliability, probability of failure, risk