ExxonMobil, BP and ConocoPhillips have unveiled new details of a massive project to export LNG from Alaska’s North Slope.The $45 billion to $65 billion concept, which the supermajors said still requires significant work, involves building three trains of 5 million to 6 million tonnes per annum apiece.The companies, along with Canadian pipeline player TransCanada, were thought to have been focusing on building a 1300-kilometre gas pipeline from Prudhoe Bay in the Arctic to the oil export centre of Valdez or Nikiski, home of the soon-to-be shuttered Kenai LNG plant.However,