Sweet light crude gas and condensate are spilling into the Timor Sea from the West Atlas rig 690 kilometers (428 miles) west of Darwin in the Northern Territory and 250 km (155 miles) northwest of Truscott in Western Australia.
The leak started Friday from the mobile offshore drilling unit operated by Seadrill in the Montara oil field. It is under contract to PTTEP Australasia (Ashmore Cartier) Pty Ltd., a Thai publicly traded company.
The West Atlas drilling rig is leaking oil into the Timor Sea. (Photo courtesy AMSA)
The 69 personnel onboard the West Atlas were evacuated without incident.
The Australian Maritime Safety Authority, which has been coordinating the oil spill response effort, said Sunday, "This leak has occurred in one of the remotest locations possible, making any operation difficult. It is too early to determine the full impact of this incident."
The oil slick now covers an area 14 kilometers (eight nautical miles) long and 30 meters wide.
PTTEP chief executive Anon Sirisaengtaksin said that the company is focusing its efforts on eliminating the oil slick and controlling the well in order to stop the leak.
The company has been spraying chemical dispersant on the oil slick from a C-130 Hercules aircraft. "After two flights, the company found that the result was quite satisfactory as the size of the oil slick had been visibly reduced. This was also helped by the fact that Montara crude is light oil which evaporates relatively easily," said Sirisaengtaksin.
To control the well, PTTEP is planning to drill a relief well that would intersect the existing well and stop its oil and gas flow. The company has submitted this plan to the Government of Australia. At the same time, he said, the company is studying other methods to solve the problem based on its concern on safety and the effect on the environment.
The company is consulting with international experts in both fields. It is also working closely with the Australian Maritime Safely Authority and local authorities concerned to ensure that the work is done safely and with minimal environmental impact.
Hercules 130 aircraft spreads chemical dispersant over the West Atlas oil spill. (Photo courtesy AMSA)
Transport Minister Anthony Albanese, today called seven weeks "a conservative estimate," for the oil spill cleanup.
"All indications are that the spill is not growing and that, indeed, the dispersant is helping to assist the natural evaporation which is occurring," he told ABC Radio.
But the conservation group WWF-Australia warned today that the oil spill may take a heavy toll on the region's globally significant wildlife.
The spill occurred at the edge of Australia's continental shelf, an ocean highway used by loggerhead turtles, dolphins and endangered species such as the pygmy blue whale.
"This is a potential disaster for turtles, whales, dolphins, sea birds and sea snakes," said Dr. Gilly Llewellyn, WWF-Australia's conservation manager.
"The oil and gas spill is still not under control and is expected to continue leaking for two months. Depending on winds, the slick could be pushed to atolls like Scott and Ashmore Reef – areas that are globally significant for their unique wildlife."
Marine species such as green and loggerhead turtles are at serious risk from the pollution.
"Turtle hatchlings spend a huge amount of time on the surface of the water. Unfortunately, this means that recent hatchlings from the beaches and islands of North West Australia could be swimming into the slick," said Dr. Llewellyn.
WWF warned that increasing the number of offshore oil and gas ventures in the region is increasing the risk to marine life.
"The more industrial activity, the higher the risk – it is a simple equation," said Dr. Llewellyn. "We urgently need to consider both short and long term ways of preventing and containing spills like this one, as well as reducing the footprint of industrial development on creatures like marine turtles."
On Sunday, the Hercules aircraft flew two sorties that applied dispersant from the Darwin stockpile to the oil slick from the West Atlas and another sortie this morning.
An Australian Maritime Safety Authority aircraft provided top cover for the Hercules and reported that "the applications had appeared successful and the oil could be seen to disperse in the water."
Under National Plan arrangements, AMSA says it is "well prepared for a protracted clean-up operation and has mobilised personnel and resources including aircraft and stocks of dispersant to cope with the lengthy response."
Environment Minister Peter Garrett said on Sunday that response to the spill was "immediate."
"The Marine Safety Authority has taken charge of this issue, working very closely with both the West Australian authorities, the company and in communication with my department, to make absolutely sure that everything that has to be done can be done," the minister said.
"We have been a little bit lucky to have calm weather off the coast of Western Australia," he said. "That has meant that there has been access to and monitoring by officials and also that the aircraft that are spraying the dispersements down have been able to get access to the slick."
Garrett said, "My very strong hope is that we don't see the slick reach the environments of our coast but that is something which we will see rollout of the next coming days."
Copyright Environment News Service, ENS, 2009. All rights reserved.