ESTIMATION OF GAS AND OIL PIPELINES CONDITION BASED ON THE METHOD OF METAL MAGNETIC MEMORY

摘要

Ageing of oil- and gas-trunk pipelines places the task of their functioning safety and reliability assurance in the list of the most important state problems. At present the general length of trunk pipelines in Russia is over 300 thousand kilometers. And about 40 % of gas pipelines and 60% of oil pipelines have been in operation for more than 20 years. The accident rate analysis shows that already after 15 years of operation the intensity of pipelines failures starts growing abruptly. Thus, practically all trunk pipeline systems nowadays require performing of diagnostic investigations and recovery repairs. It should be noted that the conditions of the pipeline metal operation are particularly specific and differ from operation in other steel structures by the whole number of factors. The article considers the abilities of the method of metal magnetic memory (MMM method) to estimate stress-strained state (SSS) of gas and oil pipelines directly on equipment and to trace the development of metal fatigue failure process in these zones. Based on 100% equipment inspection using the MMM method it is suggested to detect all potentially dangerous zones with developing defects and to timely remove them during the repairs. Thus, an opportunity is offered to assess the real equipment life.