FPSO Systems - A Classification Society's Perspective
Authors: Alford G. , Potthurst R. 
Published: March 2009

The paper deals with technical and regulatory issues regarded as important todesigners and operators aiming for successful classification andlong-termservice for the facility.

Observations are made based on the experience LR have acquired through theircontinuous involvement in many FPSO projects worldwide.

FPSO's comprise of a combination of marine and offshore technology and mustcomply with therequirements and regulations of the classification society, flagadministration, IMO and national authorities, The paper addresses many of theimportant issues involved and assists operators and designers to comply withthe relevant regulations.

INTRODUCTION

In the past, application of classification requirements involved a traditionalapproach where a completed project design was submitted by the client to theclassification society for approval. However, the modern world demands a moreforward looking approach which encourages interaction and dialogue at an earlystage in the project, possibly before alternative project options have beenfully developed or the preferred option identified, This early dialogue enablesthe classification society to adopt a positive role and make a meaningfulcontribution to the development of the design and to lower project costs. Onekey example of this support is the "Concept safetyevaluation programme"outlined in Section 4.

LR has been involved with many different installations over the years the mostnotable are outlined in Table 1. LR's newly published "ShipRight"procedures are offered in the paper as an effective way to satisfyrequirements for strength and fatigue of an FPSO and would also go a long wayto provide cost effective reliability and minimal downtime in service.

Classification and certification are discussed and some coverage is given tointernational regulations and certificates. Position keeping, a key issue forthe safe operation of floating installations, is included together with processplant and riser systems. On site inspection during service life is also vitalto the economic and safe operation of the FPSO and LR's approach to this isgiven in the paper, LR has recently published new classification rules forfloating production and storage installations. The new rules form an additionalpart of the existing rules for fixed offshore installations.

REGULATIONS

General

Classification, which is concerned with the integrity and safety of marinestructures, is a form of regulation based on compliance with a classificationsociety's own ules. These rules and regulations are regularly updated to takeaccount of developments arising from service experience, new design techniquesand materials and construction methods.

Classification of a new structure will normally involve supervision duringconstruction to ensure compliance of the design with the approved plans andother relevant documents. In order to maintainclassification regularinspections must be carried out throughout the life of the facility.

The procedure whereby offshore installations have to satisfy the regulationsimposed by the national administration in whose territorial waters they willoperate, is generally known as certification, Although each country'sregulations tend to have varying approaches they all require some form ofindependent technical assessment free of direct commercial interest.