Motion Analysis of PLET during the Setting-Down Process

Abstract
The design analysis of Subsea PLET should consider various cases, including in-place analysis, lifting analysis, setting down analysis and so on. The size and vessel space should be checked in the structural design, and the fishing protection function should also be covered. The accurate setting-down process is the prerequisite for the successful construction of the subsea project. Therefore, it is necessary to simulate the various conditions included in the setting down process. Based on practical YC13-1 project and subsea environment condition, a special type of subsea PLET is designed for the pipe rehabilitation. Theoretical study is performed to discuss the load and Fluent software is used to simulate the problems encountered in the setting-down process. Comparison on the calculation results with ROV condition and without ROV condition, it indicates the effective suppression of the movement of PLET with ROV tractive action. The study can be a good reference and guidance for the design and construction of South China Sea oil and gas field project.