Reuters/Sydney

Thailand’s PTT Exploration and Production (PTTEP) has plugged an oil well in the Timor Sea that had leaked for over 2 months, creating what environmentalists said was one of Australia’s worst ever spills.

PTTEP, part of the Thai state-controlled energy group PTT, said in a statement yesterday it had “killed the leaking well and stopped the main fire at the Montara well head platform and surrounding the West Atlas drilling rig”.

“Some material on the topside of the West Atlas rig might still be on fire but it is expected to be extinguished as the fuel source burns out,” PTTEP’s Australasia unit said.

A picture issued by PTTEP of the rig, owned by Norwegian driller Seadrill, showed light black smoke rising from a charred and badly damaged structure. The rig, worth around $200mn according to analysts at Citigroup, caught fire on Sunday during operations to stop the leak.

Between 300 and 400 barrels a day were estimated to have been leaking from the well, the Department of Resources and Energy and Tourism said on its website, and environmentalists had warned that birds and endangered sea life were at risk.

PTTEP said it plugged the leak by pumping 3,400 barrels of heavy mud down a relief well.

The West Atlas rig was due to start commercial operations this month. The Montara field could be one of the main sources of profit for PTTEP in the second half of this year as analysts expect higher output from new oil and gas fields to boost its sales.