浅海埋地双层管道过渡段长度的计算

Computation of Transition Length of Offshore Buried Double-layer Pipeline

过渡段是浅海采油平台立管系统的一个部分,由于管道温差和内压引起的膨胀会使立管过渡段的端部产生位移,对整个立管系统产生影响。如果过渡段端部位移过大,过渡段将与平台接触,对整个立管系统和采油平台造成危害。因此,对立管系统进行分析必须考虑过渡段对立管系统的影响,而考虑过渡段的影响,必须首先确定过渡段的长度。考虑到目前浅海海底管道大多采用双层管结构,提出用整体等效法计算双层管结构过渡段的长度,并根据这种方法推导了过渡段长度的计算公式。提供的算例表明,该计算公式是可靠的,可为工程中埋地双层管结构过渡段长度的设计提供理论依据。

The transition is a section of riser system of offshore platform. Because of the expansion caused by pipeline temperature difference and internal pressure,there exists displacement in riser's transition termination , which will affect the total riser system. If the displacement of riser's transition termination is too large,the transition will contact with platform and damage to riser system and platform will take place. As a result,the effect of transition on riser system must be considered while analyzing riser,and the length of transition must be determined in the first place while considering the effect of transition. Considering double-layer structure adopted commonly in marine pipeline at present, the transition length of double-layer pipeline is calculated by integral equivalent method in this paper, and calculating equation of transition length is deduced according to the above method. Through a computational example,it shows that the computational equation of transition length of double-layer pipeline is reliable,and can provide theoretical dependence for engineering design in calculating transition length of buried double-layer pipeline.