BHP, Exxon set to approve $9.5b floating LNG venture off WA coast

BHP Billiton and ExxonMobil could approve a new $US10 billion ($9.56 billion) gas project in Australian waters as early as next year, documents published on Tuesday show.

The companies released planning documents for their proposed Scarborough joint venture, off Western Australia's coast, and declared that a floating LNG system was their preferred option for developing the resource.

Such technology is not operating in Australian waters at present.

By processing the gas on-board, the floating LNG concept removes the need to build an onshore processing hub and thereby avoids many of the environmental and landowner issues that have plagued rival projects, including Woodside's Browse LNG venture.

Essentially a large ship, the floating LNG can be located directly above offshore gas fields, and makes it viable to work in fields that would be uneconomic to exploit from land.

It can also be disconnected and shifted to other parts of the world.

In documents submitted to the federal Environment Department, Exxon and BHP said the floating platform would be 495-metres long and 75-metres wide, and would house the equipment needed for gas treatment, liquefaction and transfer into vessels that will ship the product to market.

Up to 600 people would work during the commissioning period and once operating, the workforce could reach 200.

The companies said the first wells were likely to be drilled in 2018 and 2019, and production would begin in 2020 at the earliest.