An experimental study on the response of fsru in shallow water in comparison of mooring systems

Abstract

In this paper, the responses of a floating storage and regasification unit (FSRU) in shallow water are discussed. In this study, an FSRU is considered to have two different types of mooring system. The main concept of FSRU is supplying gas from the sea to the land with security and agility. To deliver gas from the regasification plant on the sea to the residence on the land, gas-supplying pipelines should be installed from the plant to the land. It is obvious that there will be distance limitations when installing pipelines in the technical and economic aspects. For these reasons, FSRU may be operated in the shallow water near the seashore rather than in the deep sea. A set of experiments was conducted to estimate the response of FSRU in shallow water. Two types of mooring system were adopted for comparison: the turretcatenary system and the tower yoke system. Three bilinear springs were designed and applied to simulate the characteristics of a catenary mooring system. A tower yoke system was developed in model scale for FSRU. A liquefied natural-gas carrier (LNGC) was attached to FSRU in side-by-side formation, and the heading-keeping system, which consists of three azimuth thrusters, was applied to regulate the fluctuation of the heading of FSRU. The experiment results will be used in the design of the mooring systems of FSRU. Copyright ？ 2012 by the International Society of Offshore and Polar Engineers (ISOPE).