Subsea Equipment Decommissioning Using Fiber Rope

Abstract

A comparative study of lifting lines for subsea equipment decommissioning was conducted to evaluate the applicability of fiber ropes. Generally, conventional steel wire ropes are used for subsea equipment decommissioning operations, but there are some disadvantages in using steel wires as the lifting lines at deepwater depth. To overcome the disadvantages, fiber ropes are proposed for using as lifting lines. The comparative methods to evaluate the performance of both lifting lines include three sections of calculations, payload capacity, and horizontal offset due to current, critical length of lifting line. Moreover, dynamic analysis using Orcaflex was performed to compare the dynamic forces occurring in the lifting lines during subsea equipment decommissioning. The results showed that the fiber ropes had advantages in payload capacity, critical length of lifting line and lower dynamic forces occurred compared to the steel wire ropes at deepwater depth.