PTTEP, a Thailand-based company, is in charge of the damaged well.

Engineers are currently trying to plug a 25cm hole that lies more than 2.5km under the sea bed.

Failed attempts

Three attempts to plug the leak have failed, and a fourth attempt was aborted last weekend because of technical difficulties.

PTTEP has thus far failed to stop the flow of sweet light crude oil, gas and condensate from the Montara wellhead, 250km northwest of the Truscott air base in Western Australia's Kimberley region.

A 25cm hole located 2.5km under the seabed is trying to be plugged
The Australian government has released a report saying long-term monitoring will be needed to understand the full extent of the damage.

The report also said the presence of dying birds and sea snakes suggest animals have already been affected.

Gilly Llewellyn, director of conservation from the WWF, told Al Jazeera that if the spill happened closer to shore, there would be global outrage.

"If this spill was seen to affect Australian surfers or residents living near the beaches, more attention would be paid. But since it is so far out to sea, it seems to be a case of 'out of sight, out of mind'."

Clean-up operations

PTTEP is using electromagnetic ranging tools to home in on the damaged casing, and is calculating each failed drill attempt's distance from the pipe.

About 300 people are working on addressing the spill, PTTEP said.

Seventeen vessels and nine aircraft, including a Boeing 747, have been used in the operation.

The cost of the clean-up is said to have reached $4.9 million, an Australian senate hearing heard last week.

PTTEP has said it will pick up the bill for the operation.