f Ask ff inch theory|Analysis of accidents caused by floods in pipelines Zhang Junyi Du Jingshui (Safety and Environmental Protection Department of China Petroleum Pipeline Company) (China Petroleum and Natural Gas Pipeline Bureau Qingqing Oil Transportation Company) Zhang Junyi Du Jingshui: Analysis of accidents caused by floods, oil and gas storage and transportation, 2000, 19 (1) 1619. Improper case and low construction quality are the main reasons for pipeline breakage. In view of the problems existing in the current oil pipeline protection engineering, it is proposed that under different conditions, different geological and geomorphological conditions, hydraulic protection measures suitable for local conditions should be adopted according to local conditions, which can effectively avoid the occurrence of pipeline fracture accidents. The analysis of the fracture accidents adjusted the accident of the oil and gas pipelines of the China National Petroleum and Natural Gas Pipeline Bureau in the flood season. The results indicated that the main cause of the pipeline fracture was due to improper pipeline hydraulic protection scheme, followed by poor construction quality. Therefore, the correct design of the oil and gas pipeline hydraulic protection design and the quality of the construction determine the ability of the pipeline to withstand floods. Only by seriously demonstrating the plan and strictly controlling the construction quality can we effectively avoid such accidents. I. Causes of Pipeline Fracture Accidents Caused by Floods According to statistics, from 1971 to the present, China's oil and gas pipelines. V. Conclusions For the buried heat oil pipelines with large transmission and small changes in oil temperature along the line, the average wax thickness and average integrated heat transfer are used. The coefficient is used to calculate the hydrothermal force, and satisfactory results can be obtained. However, for low-volume hot oil pipelines with large changes in oil temperature along the line, the error of averaging treatment is large. Therefore, it is recommended to use the simulation method of the wax distribution function to calculate the wax layer of the tube wall. In the hydraulic thermodynamic calculation of the buried crude oil heat transfer pipeline, since the online viscosity is an undeterminable parameter, the calculation error of the wax thickness is sometimes increased. Therefore, the thermal conditions after the pigging operation should be fully utilized to determine the initial viscosity-temperature relationship to improve the calculation *065000, No. 81, Heping Road, Weifang City, Hebei Province; Tel: (0316) 2177502. The oil and gas pipeline to which the bureau belongs There were four accidents caused by floods in the flood season (see Table 1), accounting for 20% of the total faults in the pipeline. Through the analysis of the accident site, the main reasons for the pipeline fracture were as follows. The concentration of accidents occurred from late July to mid-August. Because of the large amount of precipitation during this period, the land of the river has been in a state of water saturation. If heavy rain falls again, it can hardly be absorbed. The river flows into the river and forms more floods. It is soaked in soft and easy to be destroyed. In some areas, mudslides are formed, which is more destructive to the pipeline. In the formulation of the hydraulic protection plan, the estimated flood disasters may be insufficient, resulting in deviations in the design (see the accident at No. 257 of the Shaanxi-Beijing line in Table 1). In general, the accuracy of the design is limited. The underground crude oil heat transfer pipeline that is regularly subjected to hot washing and pigging operations should be regarded as a stable oil transfer process. By using the method of this paper, the law of distribution variation of pipe wax distribution can be more fully grasped, so that a safe and reasonable operation cycle can be determined for such pipelines, so as to improve the management level of oil production.
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