UGS in giant offshore salt caverns to substitute the actual Brazilian NG storage in LNG vessels

This paper evaluates the importance of underground natural gas storage in Brazil and the selection of an area for such, considering logistical and geomechanical aspects. Currently, the power plants are fueled by natural gas. This gas consumption is seasonal, volatile and associated with the level of rainfall in the hydroelectric power plants' basins. Therefore, Brazil has been using floating stocks of Liquefied Natural Gas (LNG) in LNG carriers. This contingency storage is inefficient and costly. This article demonstrates the technical feasibility of replacing LNG floating stocks by underground caverns created by dissolving rock salt domes offshore. Rock salt has a negligible permeability to most fluids and gasses even under high pressure. The rock salt skeleton also develops the phenomenon of creep, through which can absorb high levels of strain and can self-heal cracks and faults over time. This article also presents the design of the caverns by computer simulation. The computer codes were developed by (Costa, 1978) and (Costa, 1984), since than theses codes have been used in several different types of geomechanical engineering projects.