The purpose of this study is improve the cage net volume deformation during typhoon attacking. A special bottom collar system is to substitute the sinkers system. The Research contents include the numerical development and the hydrodynamic physical model test in a wave tank. The numerical model is based on the lumped mass method to set up the equation of motion of the whole cage net system; meanwhile the solutions of equation have been solved through the Runge-Kutta fifth order method. The hydrodynamic physical model tests have been carried out to verify the goodness of the numerical model. The research results are as follows. The sinker system¡¦s numerical model simulation indicates that the error of the maximum tension at anchor is about 4.54% higher than the physical model results, and the error of net deformation rate is about 8.04% higher. While the bottom collar system¡¦s numerical model simulation indicates that the error of the maximum tension at anchor is 6.34% lower than physical model results, and the error of net deformation rate is 3.82% lower. The physical model show that the minimum side projection area deformation rates of net in the bottom collar system is about 4~6% higher than the sinker system¡¦s. According to the conclusions of this study, the presented numerical model is capable to predict the whole cage net system performance and indicates that the bottom collar system is practically feasible in improving the cage net volume deformation.

The most important resources to fulfill today’s energy demands are fossil fuels, such as oil and natural gas. When exploiting hydrocarbon reservoirs, a detailed and credible model of the subsurface structures to plan the path of the borehole, is crucial in order to minimize economic and ecological risks. Before that, the placement, as well as the operations of oil rigs need to be planned carefully, as off-shore oil exploration is vulnerable to hazards caused by strong currents. The oil and gas industry therefore relies on accurate ocean forecasting systems for planning their operations. This thesis presents visual workflows for creating subsurface models as well as planning the placement and operations of off-shore structures. Creating a credible subsurface model poses two major challenges: First, the structures in highly ambiguous seismic data are interpreted in the time domain. Second, a velocity model has to be built from this interpretation to match the model to depth measurements from wells. If it is not possible to obtain a match at all positions, the interpretation has to be updated, going back to the first step. This results in a lengthy back and forth between the different steps, or in an unphysical velocity model in many cases. We present a novel, integrated approach to interactively creating subsurface models from reflection seismics, by integrating the interpretation of the seismic data using an interactive horizon extraction technique based on piecewise global optimization with velocity modeling. Computing and visualizing the effects of changes to the interpretation and velocity model on the depth-converted model, on the fly enables an integrated feedback loop that enables a completely new connection of the seismic data in time domain, and well data in depth domain. For planning the operations of off-shore structures we present a novel integrated visualization system that enables interactive visual analysis of ensemble simulations used in ocean forecasting, i.e, simulations of sea surface elevation. Changes in sea surface elevation are a good indicator for the movement of loop current eddies. Our visualization approach enables their interactive exploration and analysis. We enable analysis of the spatial domain, for planning the placement of structures, as well as detailed exploration of the temporal evolution at any chosen position, for the prediction of critical ocean states that require the shutdown of rig operations. We illustrate this using a real-world simulation of the Gulf of Mexico.