REBASDO


sábado, 3 de maio de 2025

Overview

The challenges for the offshore oil and gas industry moving into deep water fields is to design, build, install and operate oil and gas production systems profitably, with at least the same safety and reliability as in shallow water. An important change when working in water depth of 2000 m and beyond is to extend and further develop the technology for floater, riser and mooring systems in terms of architecture, functional loads and exposure to environmental actions.
The major challenge in the cost effective and efficient use of floating offshore vessels for the production of hydrocarbons, in particular in European waters of the North Sea, is the harsh environmental loads. The availability of advanced models of the environment and their induced loads and responses are essential for the design and for the planning of the operation of these systems. This project will provide an improved description of both loads and responses. This will have an impact both on the design of these vessels but also on their operation, with clear economic benefits.

The project will address a modern design approach that should allow the improved design of FPSO structures, and their mooring and riser systems, which are the main platform concept currently being considered for the exploitation of deep water and of marginal fields.

Fixed and floating offshore production units are very much prone to the effects of the weather, in particular as a result of their requirement to remain in the same position. Ships, which are comparable types of floating structures, have the ability to choose their routes and to decide whether to avoid a storm and thus the models that were developed for those applications need further improvements.

Some platforms are more sensitive to the direction of the environmental loads than others. The TLPs, that represent one concept against which FPSO are competing, have often-similar longitudinal and transverse dimensions as well as four legs, and thus a 90º repeatability of geometry. FPSOs have a ship like form with a 180º symmetry and with the longitudinal dimension much larger than the transverse one, which make them much more sensitive to the direction of the loading. Furthermore, FPSOs are very much susceptible to combined loading from more than one direction. Due to weather vaning characteristics, the attitude of the vessel will result from the combined effect of waves, current and wind. Often these effects do not have the same direction and it occurs that the predominant effects may force the vessel to assume one attitude while other effects will load it from a direction 90º away, which may lead to significant responses and even to damage of process equipment.

Therefore, advanced methods for design and planning of operation of these vessels require more advanced models of the directionality of the environmental loads as well as models of hydrodynamic loads and structural response that are able to cope with the additional directional information.

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