Modeling and Simulation of Deepwater Pipeline S-Lay With Coupled Dynamic Positioning

Abstract

Dynamic position (DP) control and pipeline dynamics are the two main parts of the deepwater S-lay simulation model. In this study, a fully coupled analysis tool for deepwater S-lay deployment by dynamically positioned vessels is developed. The method integrates the major aspects related to numerical simulation, including coupled pipeline motion and roller contact forces. The roller–pipe interaction is incorporated in the S-lay pipeline model using a contact search method based on a lumped-mass (LM) formulation in global coordinates. A proportional-integration-differentiation (PID) controller and a Kalman filter are applied in the vessel motion equation to calculate the thrust allocation of the DP system in time domain. Numerical simulation results showed that the dynamic effects add a significant contribution to the tension, but have little influence on the maximum pipe stress and strain. The dynamic response of the coupled S-lay and DP pipeline deployment system increases the demand on the tensioner load carrying capability as well as the maximum DP thruster power.

A Systematic Pipelaying Control Method Based on the Sliding Matrix for Dynamically Positioned Surface Vessels

“…The maximum value of the cross-track error of the pipeline is approximately 9.5 m, which may be caused by a sudden change of the desired heading when the vessel is traveling between a straight-line path to its adjacent circular arc path. Besides, it may also be caused by the assumption that the pipe is rigid, and the cross-track error of the pipeline should be less than this value if the pipeline dynamic model [3,6,36] is considered. However, the cross-track error is gradually converged to zero when the vessel travels past the transition points.…”

“…Over the last two decades, deep-water pipelaying has gone through a spectacular development and the present methods and trends in deep-water pipelay systems are described in [1] by Fossen. Three basic pipelay methods are commonly in use: S-lay, J-lay, and reeling which are described in [2,3] by Heerema and Ai et al, respectively. Xu et al [4] proposed a simple and feasible VFIFE model for the static and dynamic analysis of deepwater S-lay and J-lay pipelines.…”

“…It can provide the desired position, heading angle, speed, and other information for ship control and guide the ship to complete the relevant tracking tasks [7,8]. Therefore, dynamic positioning (DP) control and pipeline dynamics are the two main parts of the deepwater pipelaying simulation model [3].…”

“…The pipeline dynamic model is the other key and important problem in pipelaying operation. Ai et al [3] proposed a pipelaying nonlinear dynamic model, which integrates the major aspects related to numerical simulation, including coupled pipeline motion and roller contact forces. Jensen [34,35] proposed a nonlinear dynamic model which was capable of undergoing shearing, twist, and bending for the pipe string, and the model is suitable for pipelaying operations by a dynamically positioned surface vessel.…”

Numerical Investigation into Freak Wave Effects on Deepwater Pipeline Installation

“…Almost all six DoFs of the vessel motion responses were greatly noticeable for the quartering seas, in which the heave motion was comparatively remarkable for all seas. It is noted that the slow drift motion of the vessel was restrained to be very small by the advanced dynamic positioning system [31], so it was not taken into consideration in the following analyses due to its small effect on the pipeline dynamic behaviors.…”