(50a) Plant Operating Strategy in Dealing with Gas Supply Shortages to the Badak Lng Plant

The shortage in feed gas supply causes PT Badak to look into its running plant strategy in achieving the optimum operating mode. With the current gas supply, the company is running the plant at a border line between seven and eight LNG trains capacity. Running with eight trains will cause higher energy consumption because the refrigeration compressors are operating with recycle valves open to avoid surging due to low load. On the other hand, running with seven trains will result in approaching the maximum production of each train, and the Plant has very little cushion to absorb more gas if required.

Individually, an LNG train has optimum energy consumption at approximately 88% of its maximum production. Beyond this optimum point, the energy consumption is higher per cubic meter of LNG produced. From this point of view, it is best to operate the train at its optimum energy consumption. However, from plant-wide point of view, putting one train on idle and pushing the LNG production a little higher on the remaining running trains will give the best compromise in term of plant energy consumption, because there is a fixed energy requirement to run the LNG train, regardless of its production level. Therefore, there is a certain point where the whole plant production level will reach the best energy efficiency level, even though, individually, each train runs beyond its optimum level.

This paper describes the gas supply chain in the East Kalimantan region in relation to the function of the Badak LNG Plant as the swing plant to absorb gas supply fluctuation. The paper also discusses several parameters used to represent its efficiency. In addition, it discusses the potential risk that the gas producers may face due to higher back pressure to the upstream operations, if one of the LNG train trips. Shutting down old wells to avoid gas venting due to excessive gas supply will put the wells at risk.