Production from the John Brookes field, which is owned and operated by Apache on a 55% stake, has been shut in, a spokesman for Santos, which holds the remaining 45% interest, told UpstreamOnline.

He added that it is too early to say when the field will be back online. Santos' equity production from the field in the first quarter stood at 1.36 million barrels of oil equivalent.

Production at the Harriet joint venture, which comprises Apache on 68.5%, Kuwait Foreign Petroleum Exploration (Kufpec) on 19.2771% and Tap Oil with 12.2229%, has been halted, Perth-based Tap said in a statement today.

Tap said that the explosion and fire at the plant has affected export pipelines that deliver gas from Varanus Island to the domestic market. The outfit added that supply is likely to be affected for a number of days.

Varanus Island supplies 30% to 40% of Western Australia’s domestic gas supply.

"We are aware that this incident will result in downtime for our customers and will work with other energy suppliers and the gas transmission pipeline operator to help minimise the impact of this incident," Apache's managing director, Tim Wall, said in a statement released today.

About 330 million cubic feet of gas per day and 8000 barrels of oil per day are usually produced at the island. Apache’s share of the total is about 200 MMcfd of gas and 5000 bpd of oil, it said in a statement.

Apache evacuated 152 people from Varanus Island after the blast, but said an emergency response team of 14 people remained on the island, 60 kilometres west of Karratha, to monitor the situation.

The team will today be joined by Apache's managing director and engineers to inspect the damage to infrastructure and direct an investigation.

"We expect the initial assessment will take a number of days to complete with a full internal enquiry to follow," said Wall.

Published: 04 June 2008 02:55 GMT  | Last updated: 04 June 2008 06:33 GMT