In 1965 an Esso/BHP Billiton joint venture drilled Australia's first offshore well and discovered the Barracouta gas field in Bass Strait.

Two years later the joint venture discovered Kingfish, the first offshore oil field, which to this day remains the nation's largest oil field.

These, and other subsequent world-class discoveries in Bass Strait, off Victoria's Gippsland coast, have led to significant changes to Australia's industry and economy.

Since the first Bass Strait platform, Barracouta, started operations in October 1969, more than 3.5 billion barrels (556 billion litres) of crude oil and ~6 trillion cubic feet of gas have been produced.

Massive infrastructure costing billions of dollars has been built to develop, produce and process the crude oil and gas, which is used to power industry, fuel vehicles, heat homes and manufacture products in Australia and overseas.

New platforms and other production facilities have been regularly added, the most recent being the Blackback sub-sea facility, which at a depth of nearly 400 metres is one of Australia's deepest water oil developments.

There are now 21 offshore platforms and installations in Bass Strait which feed a network of 600km of underwater pipelines and keep the oil and gas flowing, 24 hours a day.

Living and Working Offshore

Up to 300 ExxonMobil personnel and contractors are living and working offshore at any one time. Platforms operate 24 hours a day and crews typically work 12 hour shifts on a seven-days-on and seven-days-off roster.

The biggest platforms are capable of sleeping up to 80 people at any one time although the actual number of personnel on a platform varies considerably depending on the platform's current work program.

An effort is made to provide as many home comforts as possible. The platforms have gymnasiums and recreational rooms where off-duty personnel can workout, watch television, play pool or computer games. There are also fully equipped kitchens which provide thousands of meals each year.

Reflecting the international nature of the oil and gas industry the platforms usually comprise a mix of personnel from all over the world. At any one time it would not be unusual for more than a dozen nationalities to be represented in Bass Strait.

Platform crews are typically made up of a supervisor, who oversees all work undertaken on the platform; operators, who control the crude oil and gas flow to the surface and monitor the processing facilities on each platform; maintenance personnel, who look after electrical, mechanical and instrumentation equipment; crane drivers; trades assistants; and platform services operators who also carry out first aid duties as required. Contractors do most of the other specialised jobs like drilling, construction, diving, painting and catering.

The Bass Strait Air and Sea Lifelines

Helicopters are one of the crucial lifelines that support the oil and gas operations in Bass Strait. ExxonMobil operates Australia's largest privately owned helicopter fleet from its heliport at Longford near Sale, 220 kilometres east of Melbourne.

Sikorsky S-76C helicopters operate regular morning and afternoon flights to ferry personnel to and from the platforms which are between 25 and 80 kilometres offshore.

The helicopters are capable of seating up to 12 people. They also carry more than 20 tonnes of urgent freight and critical spares per month.

In addition, two supply ships operate out of ExxonMobil's Barry Beach Marine Terminal near Port Welshpool.

The ships operate 24 hours a day and move between platforms loading and unloading cargo. They have a crew of 11 and are equipped with specialised navigational equipment and propulsion systems which allow them to operate close to the offshore platforms.

Around 50% of the cargo delivered to the platforms is bulk products essential for drilling and oil and gas production - diesel, water, glycol, barites and cement. These are carried in below deck tanks. The balance of cargo is food and machinery which is transported on deck packed in specially designed containers.