On the Research and Development of Floating Offshore Platform

Abstract

Japan, a land-resource-poor country, has an Exclusive Economic Zone with the area of the sixth place in the world, 4.47 million km2. In order to utilize the resources in EEZ, the Ministry of Land, Infrastructure, Transport and Tourism started a project of floating offshore platform in 2007 and National Maritime Research Institute is conducting the project. In this paper the outline of the project and some results are mentioned. One of the objectives of this project is to develop key technologies of floating platform necessary for various activities in EEZ. One technology is motion reduction for ensuring the safety and operation in severe seas. Other than hull shape such as semi-submergibles and strong mooring, the effect of fins on reducing not only motion but also drifting at the same time is focused. Another one is deep sea mooring. Composite mooring lines with synthetic fiber, new types of anchors and so on are studied. The third one is maintenance. In order to make the life-time cost minimum, developing a rational maintenance method based on reliability analysis, which should replace the current empirical one, is necessary. This project does not have any specific target platform at the beginning. Therefore, the rough design and evaluation of various types of platforms should be carried out. In order to make it efficiently, the harmonic design program, a software integrating the above-mentioned evaluation tools, ocean database and some other functions is being developed for evaluating the safety, economy and environmental effect of a platform. The other objective of the project is to propose some offshore platforms for promising utilization. For the proposal a database of ocean, including wind, waves, water depth, current and so on, is necessary. In this paper the ocean database is introduced and some utilizations are presented.