The Australian Marine Oil Spill Centre says the extent of an oil slick off Australia's north-west coast is still not known and that more oil is continuing to flow out.
Federal authorities are preparing for a major clean-up after 69 workers were yesterday evacuated from the West Atlas Offshore drilling rig, 690 kilometres west of Darwin.
Ivan Skibinski, from the Australian Marine Oil Spill Centre, says 50,000 litres of chemicals have been sent to Darwin today to be used by Hercules aircraft on the spill this afternoon.
He says the Hercules will take about 20,000 litres at a time to spray the spill and that it is enough chemical to deal with the size the spill is expected to take, ABC News reports.
Chief Executive Anon Sirisaengtaksin told Reuters it would take time for the company to assess the situation and decide whether it would start commercial operations in November 2009 as planned.
"There is no environmental impact. We have measures to prevent that, and we will take specialists to look after it," he added.
Accorsing to AFP, aircraft carrying tonnes of chemicals were Saturday sent to spray a massive oil and gas leak which forced the evacuation of an oil rig off Australia's northwest coast, officials said.
The spill, about eight nautical miles (15 kilometres) long and 30 metres wide, began just before dawn Friday at the West Atlas drilling rig, 250 kilometres from the Australian mainland, the Australian Maritime Safety Authority (AMSA) said.