Umbilical Cable Recovery Load Analysis

Umbilical cable is a kind of integrated subsea cable widely used in the exploration and exploitation of oil and gas field. The severe ocean environment makes great challenges to umbilical maintenance and repair work. Damaged umbilical is usually recovered for the regular operation of the offshore production system. Analysis on cables in essence is a two-point boundary problem. The tension load at the mudline must be known first, and then the recovery load and recovery angle on the vessel can be solved by use of catenary equation. The recovery analysis also involves umbilical- soil interaction and becomes more complicated. Calculation methods for recovery load of the exposed and buried umbilical are established and the relationship between the position of touch down point and the recovery load as well as the recovery angle and recovery load are analyzed. The analysis results provide a theoretical reference for offshore on-deck operation.

Analysis of Optimization for Preliminary Design of Multi-Component Mooring Systems

Multi-component mooring systems become widely used in deep water position-keeping of drilling and production platforms. However, versatile materials make it difficult to design appropriate mooring lines made of several segments. Based on catenary equations of a multi-component mooring line at a specific water depth, this paper establishes a minimum model for designing this kind of lines. The model is solved by Genetic Algorithm and Multi-Objective Planning respectively. The model is verified by its application to a practical mooring design assignment—a quasi-static analysis for a large semi-submersible. The optimal result is finally obtained with the aid of design graphs.

Simulation Research on Operation of Union Purchase System in Navigation Simulator

Navigation is the only way to develop and utilize marine resources,while the promotion of seafarers1 quality is the basic force of navigation,so navigation simulator plays an important role in modern navigation education.The simulation research on the operation of the union purchase is important to improve the special operation training of the actual cargo handling of the union purchase.On the basis of the Cartesian coordinate system transformation algorithm,the algorithm model of the union purchase operation is constructed.On the basis of three-dimensional(3D)rendering engine technology of open scene graph(OSG),the algorithm model of finding the space coordinates of the cargo point is established.The model of catenary equation is used to optimize the scene appearance of the cargo wire.By combination of QT channel signal mechanism and OSG,the simulation interaction of the union purchase operating system is realized.By acquiring the 3D coordinate values of each point,we fit the trajectories of each point in the operation and compare the trajectories.The results show that the model has high interactivity and small error.The comparison of the states of the cargo wire before and after optimization shows that the optimized wire is more realistic and the high fidelity meets the needs of operational training and simulation systems.