The maiden cargo from Origin Energy's $24.7 billion Australia Pacific Liquefied Natural Gas plant has left Gladstone but the depressed oil price have muted celebrations given the project does not cover its operational and financing costs at current prices. The Methane Spirit tanker carrying the first cargo left Curtis Island in Gladstone harbour on Saturday, just over 12 months since the first LNG shipment left Gladstone, from BG Group's Queensland Curtis project which lies at an adjacent site on the island.