(31f) LNG Expert : the Latest Evolution in LNG Storage Tank Management

With an increasing diversification of LNG supply sources caused by a growing number of liquefaction plants around the world, an increase in short-term trade and a general trend toward a worldwide liberalization of gas markets, reception terminals need to deal with a greater variety of incoming LNG qualities.

With the need to minimize operating costs in order to enhance competitiveness, existing storage capacity must be used to its maximum extent. This often pushes operators to handle different LNGs in the same tank. This can lead to the creation of LNG stratifications, which result from the incomplete mixing of cargo and heel LNGs. Therefore, it is vital that operators have at their disposal monitoring and predictive tools in order to optimally manage such situations.

It is within this context, and as a response to the above mentioned trends, that Whessoe, in collaboration with Gaz de France, has developed a software model called LNG EXPERT, which represents the latest evolution in LNG storage tank management. LNG EXPERT is an on-line and fully automatic rollover predictive and alarming software. Based on Gaz de France's LNG behavior predictive software named LNG MASTER, it provides the user with a watchdog that monitors all site components that impact and influence the formation and evolution of LNG stratifications. It continuously monitors all data and calculates the expected evolution of any detected stratification. In case it foresees any stratification to evolve into a rollover situation, it automatically generates an alarm, thus leaving sufficient time to the operators to take remedial actions. As such, LNG EXPERT meets all requirements put forward in the European Directive named SEVESO II.

This paper will present the LNG EXPERT software, show some utilization examples and highlight some of the operational validation data which was used to develop the software.