qnli question: The final investment decision for what was finalized by Royal Dutch Shell in May 2011? sentence: On 20 May 2011, Royal Dutch Shell's final investment decision for the world's first floating liquefied natural gas (FLNG) facility was finalized following the discovery of the remote offshore Prelude field—located off Australia's northwestern coast and estimated to contain about 3 trillion cubic feet of natural gas equivalent reserves—in 2007.