| 摘要 |
A deepwater pipeline is towed to a predetermined position by a bottom towing method with a leading end of the pipeline attached to a towing vessel and the trailing end of the pipeline attached to a trailing vessel. The trailing end is supported near the seabed using the trailing vessel, while the pipeline is dragged along the seabed. A towing speed is established, and a hang off angle for the leading end is maintained by raising and lowering the trailing end to control the length of the pipeline dragged along the seabed, and thus the amount of drag applied by the seabed to the pipeline. In a method for bottom towing and submerged flying of a riser having a leading end and a trailing end, the riser is towed by the bottom towing method at a first speed until the trailing end of the riser lifts off the seabed, whereupon the towing speed is increased. |
