NGH on FPSO - Slurry Process and Cost Estimate

Abstract

Abstract A hydrate slurry process is being developed for capturing associated gas on FPSO's. Natural gas hydrate contains 180 Sm of gas per m3 solid hydrate. It is this property that makes hydrates attractive for storage and transport of natural gas. Hydrate mixed with crude oil and refrigerated to -10 C remains stable at atmospheric pressure, for practical purposes. A capital cost estimate for a FPSO-based hydrate slurry process was carried out for 1,440,000 Sm3 associated gas and 16,000 Sm3 crude oil. The marginal capital cost was 160 million US dollars (the hydrate process only). The cost estimate was expanded to a hydrate slurry chain consisting of FPSO-based production, shuttle tanker transport and land-based receiving teminal. The hydrate chain consts were compared to transporting natural gas by a subsea pipeline. It was argued that hydrate slurry technology should be used for distances greater than 220 km.