法兰连接式柔性软管膨胀弯在工程中的应用

海洋石油工程股份有限公司

柔性软管;膨胀弯;悬空处理;弯曲限位;法兰对接

Engineering application of flanged flexible expansion bend
LIU Peng, FENG Hu, YU Yinhai, XIA Changbin

Offshore Oil Engineering Co. Ltd.

flexible hose, expansion bend, suspension treatment, bending limit, flange connection

备注

在海流作用下,海底管道因海床冲刷而产生悬空的现象时有发生,尤其位于沉箱式平台附近时更为明显,极大地影响了在役海底管道的安全运营。在复杂特殊的海洋环境下,选择合适的膨胀弯材料,是确保整条海底管道长期安全运行的关键。以辽东某油田柔性膨胀弯安装工程为例,介绍了所选取的柔性软管膨胀弯的结构形式和基本参数,分析了柔性软管膨胀弯相比钢制膨胀弯的优势,并对安装方法进行了研究。针对柔性软管膨胀弯安装存在的3 个技术难点提出了解决措施:使用水泥沙袋对冲刷部位及立管悬空进行处理,为柔性软管膨胀弯提供支撑;合理设置弯曲限位,实现软管膨胀弯安装路由与设计相符;采用水平撑杆将柔性软管膨胀弯吊装下水,在平台基础结构上安装2 个临时吊点,通过倒链调整膨胀弯法兰位置,完成立管法兰对接。以上措施在工程实践中取得了良好的效果,可为今后类似安装工程提供一定参考。(图7表2,参[20]

Under the action of ocean current, some submarine pipeline is suspended as the result of seabed scouring, especially in the place near the caisson platform, and it seriously affects the safe operation of in-service submarine pipelines. In similar special environment, it is crucial to select appropriate expansion bend materials for the long-term safe operation of the entire submarine pipeline. Taking the flexible expansion bend installation works in one oilfield in Liaodong as the example, the structural form and basic parameters of the selected flexible expansion bend were introduced, the advantages of the flexible expansion bend over s teel expansion bend were analyzed, and the installation method was studied. The following measures were proposed to solve the three technical difficulties in installing the flexible expansion bend, including using cement sandbags for the scour position and riser suspension treatment to facilitate the support of the flexible expansion bend, setting reasonable bending limit to ensure the consistency of installation route and flexible expansion bend design, and hoisting the flexible expansion bend into the water with horizontal stays, with two temporary lifting points installed on the platform foundation structure so that the expansion bend flange position can be adjusted by chain block to complete the riser flange connection. The above measures have been verified to be effective in engineering practice and are expected to provide references for similar installation projects in the future. (7 Figures, 2 Tables, 20 References)