Regulation status and safety assessment for LNG floating production storage and offloading units

摘要

The content of the paper takes its origin from the European Project AZURE -Full floating LNG chain, coordinated by Bouygues Offshore and involving eight European Organisations, among which Bureau Veritas and RINA Spa. The aim of the project was to verify for the first time the industrial feasibility of a full floating LNG chain, based on a floating LNG production/storage tenaaaal (FPSO for LNG) and a floating LNG storage and regassification terminal (FSRU) linked by a shuttle LNG tanker fleet. When dealing with a new technology, the regulation status is not always up to date and able to satisfy the designers' as well as the operators' needs. An adaptation and proactive process is therefore necessary to build a reference applicable to the new system. One of the purposes of the Project was therefore the revision of the current rules, standards and codes applicable to offshore as well as onshore LNG facilities, in order to define a reference framework fitted to the LNG floating chain, which designers and operators could refer to when undertaking a new project. The limitation of the current regulation when addressing features concerning the system as a whole, and its reactive nature, was then overcome by the introduction of a global goal setting verification approach for safety assessment. The method guides the investigation of the risks related to the total system and the identification of interface problems with a view on operational issues. However as the design remains at a conceptual phase it was not possible to develop the human and organizational aspects which will need further investigation at a more advanced stage of the project. The first aim of the paper is to discuss the regulation framework for the LNG floating chain. A classification of codes, rules and standards according to their importance and applicability are provided in order to give the potential users an understanding of its applicability and limitations. The global safety assessment approach is then presented, showing the way it can supplement the rules, standards and codes when they are too specific and equipment/subsystem oriented. Reference to a case study, with special focus on the liquefaction process, the regassification and the offloading activities will support understanding the process and its value.