The challenging development of new platform concepts and their installation in deeper water in more remote areas and more severe weather conditions require a direct feedback from offshore experience to design and engineering. Moreover the platform operation itself can be enhanced by utilizing the actual behavior of the platform and its environmental conditions.
Present day sensor technology, data acquisition and transmission systems enable continuous monitoring of the dynamic response of structures in relation to the actual environmental conditions. Motions, loads, structural response as well as the detailed wind, wave and current conditions at the platform can be recorded to derive the environmental loading, the platform response characteristics and special phenomena such as VIV. Obviously adequate analysis and presentation of the measured results is crucial to meet the objectives of a monitoring campaign.
This has proven to be a powerful combination not only to provide feedback to design and engineering but also to give 'feed forward' to the operation itself as well as to inspection and maintenance procedures. Design and engineering are based on limited input such as metocean data which is used for computational methods and guidelines with obvious limitations. Full scale data provide the actual input data and results to validate and develop design and engineering methods. In other cases the actual operation benefits from monitoring as decision making can be based on solid data. Finally monitoring can contribute to record the history of loading and response of platforms which is important for long-term purposes such as structural health monitoring.
Experience has always been a driver for improvement. Some people have argued that experience is mainly based on mistakes. Others have stated that there is no such thing as a 'bad experience' as we always learn from them.
In offshore technology, experience has been built up from the early days when oil had to be produced inshore in shallow water by means of 'marinized' rigs located in sheltered areas, to the present deep water oil and gas production in deep, harsh and remote locations around the world.
Many innovations have been achieved by combining practical experience with a thorough understanding of physics. Experiments and laboratory tests have greatly contributed to this development and they still do. For each major offshore platform concept scale model wave basin tests are still being performed. Not only to check design values but also to observe whether certain phenomena have not been overlooked in the design process and numerical analysis. Sophisticated analytical and later numerical models have been developed (often with the aid of model basins) to analyze the dynamic behavior of platforms in further detail and they enabled the evaluation of various concepts in an early design stage.
Computational and physical scale models share the fact that they have been constructed by people with a specific purpose and therefore they do not necessarily resemble reality in all its aspects and detail. Relevance, applicability and accuracy of these models have to depend on each aspect under investigation.
