Oil leak: a handout photo from the Australian Maritime Safety Authority (AMSA) shows oil leaking from the West Atlas
Montara leak 'may take months to plug'
A leak from a well drilled at the Montara field, in the Timor Sea off Australia, may take up to two months to plug, operator PTTEP said today.
The announcement came as environmentalists voiced grave fears for wildlife in the region.
In a statement issued this morning, PTTEP Australasia said it planned to drill a relief well and pour mud to stop the leak, which began on Friday with a subsea blow-out at more than 3000 metres.
PTTEP said the the jack-up rig West Triton, a sister rig to the West Atlas, would drill the relief well.
The West Triton is likely to leave Singapore by barge on Tuesday. It will take 20 days to get the jack-up to the well's location.
Once it reaches the Montara development, the West Triton will be sited at least 2 kilometres from the West Atlas.
It will drill a relief well which, PTTEP said, will intersect the existing well and allow for the injection of heavy mud directly into the existing well bore. The heavy mud injection will, it is hoped, stop the well flowing.
PTTEP said the relief well will take about four weeks to drill.
Asked if this meant the well would flow for nearly two months, a company spokesman told Reuters: "That is pretty much the estimation."
Environmentalists have expressed concern about the giant slick, saying the entire area is ecologically significant and part of an "ocean super highway" for migrating animals between the Indian and Pacific Oceans.
Many breathe air and could surface in the oil, an official from WWF Australia told the news agency.
Earlier today the Australian Maritime Safety Authority (AMSA) used C-130 Hercules aircraft to spray dispersant chemicals on the slick, which at present is more than 8 nautical miles (15 kilometres) long.
Spokeswoman Tracey Jiggins said the results were encouraging but the agency was prepared for a long operation.
Thai operator PTTEP said a team of international experts recommended drilling a relief well, to intersect the existing well and stop its flow.
PTTEP has previously confirmed it will cover the costs for the AMSA oil dispersal operations, such as the aerial spraying at the scene.
Company spokesman Ian Williams gave no estimate of the amount of oil that would be released, but said the company believed it would be possible to prevent the slick spreading.
"There is a blow-out of some kind. It is very deep," Williams told Reuters, putting the depth at around 3500 metres.
An air exclusion zone had been set up and ships advised to stay more than 20 nautical miles away from the West Atlas which is considered too dangerous to board. On Friday all 69 crew on board the rig were evacuated to Darwin. No one was injured in the incident.
WWF Australia called for changes to ensure better preparations for such disasters, adding it took three days for the first dispersant to be sprayed.
"From a global scale this is one of the most important places on the planet for ocean wildlife," Gilly Llewelyn, WWF Australia's director of conservation, told Reuters.
Among the animals affected were three endangered species of turtles, plus sea snakes, she said. She added that a pygmy blue whale has been monitored in the region as well.
"It seems to be one of these critical migration routes - an oceanic super highway," she said.
Montara is due on stream later this year. The West Atlas is owned by Norwegian rig outfit Seadrill, but operated by PTTEP Australasia.
The well site has been given as about 250 kilometres off the coast of the Kimberley region in Western Australia.
Australia's official overseer for the petroleum industry, the National Offshore Petroleum Safety Authority, was investigating the incident.
- PTTEP has released a schema illustrating its plan to plug the well. The schema can be downloaded from the related files section to the right of this story.