浮吊船搭载骑跨式挖沟机进行海底管道挖沟作业的优化方案

Optimization method of pipeline post-trenching operation with floating crane and jetting sled trencher

当南海近岸极浅水海域登陆管道存在挖沟需求时,配备折臂吊及DP系统的深水工程船因吃水过深无法驶入作业;而浮吊船搭载骑跨式挖沟机的作业方案虽然成熟地应用于渤海浅水地区,但对于南海复杂海况适应性差,存在长期待机甚至无法作业的风险.根据南海某实际工程项目施工条件,对浮吊船搭载骑跨式挖沟机的作业方案进行了优化.通过改变浮吊船甲板布置、布锚及移船方式,解决了抛锚浮吊船因横对涌浪无法作业的问题;同时使船舶艏向一定程度可调,改善了此类挖沟方式对于海况的适应能力;此外,也增加了单个锚位的移船距离并减少挖沟机下放回收的作业时间,提高了挖沟作业效率.

When there is trenching requirement for landing subsea pipelines in extra-shallow waters of the South China Sea,due to the limitation of the water depth,the deep-water engineering vessels adapted to high sea conditions cannot enter.While the mature method of floating crane and jetting sled trencher in the Bohai Sea has poor adaptability to the complex sea conditions of the South China Sea,which will causes a long weather stand-by time.Based on the construction conditions of an actual project in the South China Sea,this paper provide optimization for the original trenching method of floating crane and jetting sled trencher.By changing the arrangement of the deck layout,the anchor position and the direction of vessel moving,the problem that the anchored floating crane cannot work due to the transverse surge is solved.At the same time,the vessel heading can be adjusted,which improves the adaptability of the trenching method to the sea conditions.In addition,this method increases the distance of the vessel moving in a single anchor arrangement and reduces the time of launching and recovering trencher to increase the efficiency of trenching operation.