An Economic Study of CNG Floating Processing and Storage Platform and the Supporting CNG Carriers

Abstract An Economic Study of CNG Floating Processing and Storage Platform and the CNG Carriers to support it are presentenced. There are many small (Stranded) gas fields that are not economical to exploit with LNG. It has been shown by a number of researchers that Compressed Natural Gas can be an economical alternative for the stranded gas fields and even the associated gas from oil fields especially as the gas demand and price increases. Even though the carriage of CNG has been proposed over the past 10 years nothing has happened due to the economics of the carrier designs and currently abundance of gas in certain countries. However, many other countries do not have natural gas sources and as their energy demand increases natural gas is a clean and efficient fuel. There are thousands of offshore oil production platforms that currently flare off the gas. This will not be allowed in the future and they must find a way to dispose of the gas. CNG Carriers may be the answer to this problem in that they could transport the associated gas provided that gas compression capabilities were added to the oil production platforms. The basis of this paper is a new containment tank which offers significantly improved volumetric efficiency and deadweight coefficients for the carriers and the FCNGPSO. It is believed that this new tank offers a breakthrough that provides a design and economical acceptable solution for the collection, storage and transportation of CNG. 1.0 INTRODUCTION While there are no CNG carriers currently in operation, several design solutions have been proposed:SEA NG Coselle CNG Carrier,EnerSea -Volume Optimized Transport and Storage (VOTRANS),Gas Transportation Module (GTM),Knutsen PNG,TransOcean Gas- Cassettes,Statoil/Tee Kay/Høegh- Consortium Compressed Gas Shuttle, andIFP - GAS CONTAINERS.Cubic Doughnut Tank System (CDTS) A number of alternative technologies exist that have the potential to make the development of small fields - of under five tcf in size - economically viable. None of these however, has yet been developed and proven on a commercial scale, though they have each proven themselves viable on technical parameters. The most advanced among these alternative technologies include:floating LNG processing and storage offshore,GTL(gas-to-liquid) floating production storage and offloading(GTL-FPSO),natural gas hydrates, (NGH) These technologies have been developed to a point where commercial scale deployment is not too far away, in the case of GTL and NGH, and demonstration plants have been in operation for several years. What remains to be seen is whether these technologies can run on a commercial scale and still be economically viable.