50 years of oil at Barrow Island

The Barrow Island oil field, located 56 km off the north-west coast of Western Australia, has yielded more than 320 million barrels of oil (MMbbl) and delivered more than $1 billion in revenue to the Western Australian community since oil was first discovered, making it the largest onshore oil field in Australia.

Oil production on the island peaked at 50,000 barrels per day (bbl/d) in 1971, however, over time, oil production has become more difficult, and the average current production of oil from Barrow Island is now 5,000 bbl/d. To help arrest declining production, water is now injected into the
underground oil reservoir to sweep it toward production wells.

A Gorgon future for Barrow

Barrow Island is now also home to Chevron’s Gorgon Project, Australia’s largest ever single resource investment which is currently under construction and includes a 15.6 million tonne per annum (MMt/a) LNG plant and a domestic gas plant with the capacity to supply 300 TJ/d of gas to Western Australia.

The Gorgon Project is using gas sourced from the Gorgon and Jansz-Io gas fields, located within the Greater Gorgon area, between 130 and 220 km off the northwest coast of Western Australia. Gorgon contains a vast resource of 40 Tcf of natural gas, the equivalent of 6.7 billion bbl of oil – enough to power a city of one million people for 140 years.

Gorgon LNG will be offloaded via a 2.1 km long loading jetty for transport to international markets.

Three 5 MMt/a LNG trains to be located on the central-east coast of Barrow Island will process the gas. Reservoir CO2 will be removed and re-injected into deep saline reservoirs beneath the island. LNG will then be shipped to international markets, while compressed domestic gas will be delivered via a 90 km, 508 mm diameter subsea pipeline to the Western Australian mainland, interconnecting with the Dampier to Bunbury Natural Gas Pipeline.

Construction on the project began in December 2009. Major construction activity commenced in the second half of 2010, with major works on the project expected to take a total of five years. As of June 2014, the project was 80 per cent complete, and plant start-up and first gas is planned for mid-2015.

The project is operated by Chevron, and is a joint venture of the Australian subsidiaries of Chevron (approximately 47.3 per cent), ExxonMobil (25 per cent), Shell (25 per cent), Osaka Gas (1.25 per cent), Tokyo Gas (1 per cent) and Chubu Electric Power (0.417 per cent).

Quarantined wildlife refuge

The 45-year old quarantine management system on Barrow Island has ensured that the island remains free from introduced species such as cats, rabbits, rats and mice, protecting the island’s 400 species of plants, 13 terrestrial native mammal species, more than 110 bird species, 44 terrestrial reptile species, at least 1,261 species of terrestrial invertebrates, and at least 59 species of subterranean fauna.

Despite drilling more than 900 wells and lifting over 10,000 cargoes since 1967, the island’s ecosystem has remained essentially intact. Barrow Island has maintained its Class A Nature Reserve status, and has received international recognition as an outstanding example of the co-existence of industry on a nature reserve while contributing to the economic wellbeing of the WA community.

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