Oil Spill Center official Ivan Skibinski said 13,200 gallons of special chemicals were sent to Darwin, Northern Territory, to be used to disperse the oil slick, which was growing as oil continued to come from a West Atlas Offshore drilling rig, the Australian Broadcasting Corp. reported.
PTTEP Australasia, the company responsible for the off-shore drilling site, had not yet determined how to stem the leak of oil and gas at the rig.
The Oil Spill Center said while oil was still flowing, the expanding slick was not expected to reach shore.
The Sydney Morning Herald reported following the leak, which began early Friday, 69 workers were evacuated from the rig. The oil spill began when a plug at a drilling hole released for unspecified reasons following a hydrogen sulfide leak.
Australian Maritime Safety Authority chief executive Graham Peachey said the environmental impact of the slick, which has expanded to eight nautical miles in length and 98 feet in width, was unknown.
''It hasn't been contained but the slick hasn't grown overnight and indications are it is either breaking down or evaporating as quickly as it is leaking out of the ocean floor, but all of that has to be confirmed by science,'' Peach said.