Keyword: «main gas pipeline»

A considerable length of main gas pipelines (MGP), a variety of natural-climatic, geocryological conditions and impacts determine the need to allocate sections, in which the development of dangerous natural processes and impacts on MGP is predicted. For such sections requirements on protection of MG from dangerous influences should be formulated, and also measures on monitoring of development of dangerous processes, changes of a spatial position of the pipeline and an estimation of its stress-strain state (STS) should be established. In the article methodological bases of calculated forecasting and classification of pipeline sections in the zones of development of geocryological engineering processes were developed: – integrated methodology for the analysis and prediction of the stress-strain state of MGP in the areas of development of dangerous geocryological processes; – the principles of classifying the sections according to the predicted hazard; – criteria for assessing the impact of natural processes on the pipeline and their ranking in terms of significance levels; – classification of MG sections according to the predicted hazard.

The article presents a methodology for assessing the residual resource of main gas pipelines and reservoirs operated in the Republic of Sakha (Yakutia) based on the developed methodology for assessing the limiting condition of structural materials. This method of estimating the remaining resource does not require the use of non-destructive testing methods and sophisticated equipment. The calculation of the remaining resource of the main gas pipeline is shown.

The article addresses the challenge of rapid on-site determination of natural gas leak locations from a transmission gas pipeline under field conditions. The difficulty lies in the frequent absence of visual indicators, while gas plumes disperse in the soil and the atmosphere. A practice-oriented approach is proposed, based on along-line surveying with a portable gas analyzer and local assessment of the gas release rate through a defect. The study comprises two stages. First, the pipeline axis is staked out, and methane anomalies are identified using thresholds in ppm and %LEL. An algorithm is presented for ranking leaks by flux density. Experimental data were obtained for eight defects on an in-service pipeline segment. It is shown that the method provides localization accuracy of 0.5–1.5 m and yields a quantitative estimate of the release rate. Ranking by efflux density enables prioritization of repair work and improves monitoring planning. The limitations of the approach and the requirements for measurement conditions are discussed.