Floating production, storage and off-loading of liquefied natural gas for marginal gas field development

At present, the annual output of the offshore natural gas in the world is 4500×108 m3, accounting 21% of the total annual output of the natural gas in the world. For the exploitation of offshore natural gas, not only the stern environment, complex technique and tremendous investment will be confronted with but also the cycle is long, the cash recovery slow and the risk relatively great. Up to now, the developed gas fields are all large-sized commercial ones, while a large number of marginal offshore gas fields are generally medium- and small-sized ones. If these gas fields are developed by use of the common fixed platform, the profits will be relatively low and risk great, having no sufficient appeal to the investors. The floating production, storage and off-loading is a new technique for marginal gas field development, having the advantages of few investment, short construction cycle and repeatable utilization. In this paper, the concept of FPSO is presented and the technological process of the liquefaction, storage and off-load systems of LNG and the overall arrangement of FPSO are explained.