Zhovtulia L. Improvement of diagnostic method of underground oil and gas pipelines by means of evaluation of their stress-strain state

The dissertation is aimed at improving the method of technical diagnostics of underground oil and gas pipelines of considerable length by estimating the stress-deformed state of the underground part of main oil and gas pipelines by means of contactless measurement of the displacement of its axis, pipeline parameters and operating conditions. The methodology for estimating the stress-strain state of underground sections of main oil and gas pipelines, which involves mathematical modeling of the process of deformation of pipelines according to the data on the change of their spatial configuration, is developed, and differs in that the level of stress is determined by calculation on the basis of a mathematical model taking into account the parameters of the pipeline and operating conditions, and the main parameter, the movement of the axis of the underground pipeline relative to the planned position, determined by contactless. The methodology was successfully tested in industrial conditions on the existing main gas pipeline "Pasechna-Dolina" of UMG "Prykarpatransgas" PAT "Ukrtransgaz".