深水S型铺管管道形态及力学分析方法研究

On Configuration and Mechanical Analysis Method for Deepwater S-Lay Subsea Pipeline

S型铺管是一种效率很高的铺设海底管道的方法,研究深水S型铺设管道形态及力学分析方法对于开发我国南海油气田具有重大意义。本文建立了深水S型铺管中管道形态的大挠度梁微分方程,并且通过数值方法求解得到的结果论证了深水S型铺管中管道悬垂段形态可以用自然悬链线近似,并在接下来的对S型铺管中管道的整体力学特性的有限元分析中,对过弯段管道采取在托辊所处位置,约束法向自由度,切向和转动自由度释放,模拟铺管作业中过弯段管道的状态;对海底土壤地基对触底段管道的垂向,侧向,轴向的反力作用进行了模拟,并将计算结果与其他方式边界条件下的铺管有限元模拟计算结果进行了比较,以保证所采用的分析方法及有限元仿真模型的准确度。

S-lay is a very efficient pipe-laying method for subsea pipeline.It is significant to research on configuration and mechanical analysis method of S-lay for deepwater subsea pipeline for the development of oil and gas resources in the South China Sea.The large-angle deflection beam differential equations of deepwater subsea pipeline of S-lay were established.The feasibility demonstrate that the simple catenary could be approximated to the configuration of sagbend of deepwater subsea pipeline in pipe-playing.FEM analysis on global mechanical characteristics of the pipe in pipe-laying was performed by constraining the normal degree of freedem of verbend of the pipeline at the location of rollers and by releasing the tangential and rotational degree of freedoms of the overbend,in which way the real state of the pipline of that part was simulated in the pipe-playing process.The reaction forces of vertical,lateral and axial directions of soil foundation which were subject to the bottom part of pipeline were also simulated.The results were compared with those obtained by FEM using other kinds of boundary conditions,to ensure the accuracy of analysis method and FEM modelling.