Calculation of allowable suspension span length for direct laying pipeline in shallow water area based on bending moment correction method
Suspended submarine pipelines are a common type of configuration in pipeline engineering construction.When the suspended span length of such a pipeline reaches a certain value,the pipeline is more prone to instability,and the consequences of the instability such as damage of suspended oil and gas pipelines are often very serious.Therefore,it is necessary to carry out regular maintenance and treatment of suspended submarine pipelines.However,due to the high cost and difficulty of offshore construction operations,it is necessary to temporarily not reinforce the suspended pipelines within the scope of safe suspension,which can greatly save construction costs.Therefore,it is necessary to calculate the allowable span length of the pipeline to provide a basis for the management of the pipeline.Since most of China's oilfields are located in offshore areas,the characteristics of waves in shallow water areas should be considered when considering the problem of pipeline suspension.In this paper,considering the nonlinear effect of waves in shallow water,the calculation formulas of horizontal and vertical flow velocity at any water point in the wave field in shallow water are derived,and according to these formulas and Morison equation,the expression of the hydrodynamic load of the overhang of the pipeline is further established.Finally,based on the bending moment correction method,the calculation formula of the allowable span length of the submarine pipeline in shallow water area is proposed.According to the research results of this paper and the subsea pipeline engineering of an oilfield in Bohai Bay,the allowable span length of the pipeline is calculated.
shallow-water wave theorybending moment correction methodunburied pipelinesuspended length
万方数据
维普
