Goodbye to Bass Strait gas
Date published:
15 Apr 2020

Author:
Tim Forcey

It's time to reduce gas demand. Expanding gas production in Australia mostly now means unconventional gas, from fracking or horizontal drilling. This photo shows coal seam gas wells in Queensland, where producers talk about eventually drilling 40,000 such wells, with detrimental effects on water and emissions. Image: Lock the Gate Alliance
After 55 years, Bass Strait gas output is running down. Are you ready, asks Tim Forcey?
Are you thinking of buying a new gas heater? Or, are you future-proofing your home by moving off gas? If it’s the latter, that’s a good move, because signing up to fossil gas is signing up to an uncertain future.

Here’s something you might not have heard. In eastern Australia in 2025—just five years from now—we have no idea where up to half of our wintertime gas will come from. If you haven’t heard about this, it’s because few people are talking about it.

Is this yet another energy and climate crisis on our near horizon? Is this another case of Australia being unprepared for the inevitable? This somewhat hidden news comes from the Australian Energy Market Operator (AEMO), a regulatory body responsible for planning aspects of our gas and electricity systems. And it’s certainly big news! But who’s talking about it?

AEMO hasn’t had good information
In years past, AEMO has been criticised for failing to collect good information from gas suppliers. The eastern Australia gas industry (or gas ’cartel’ as it’s often called) treats gas reserve and production information as a tightly held corporate secret. They are allowed to do this, even though minerals beneath the ground are owned by the Crown and should be used for the benefit of the Australian people. Despite AEMO having the legal power to obtain this critical data, they’ve been reluctant to do so.

Finally in 2019, Exxon Mobil and BHP, the controllers of Bass Strait oil and gas production, had to let the cat out of the bag. Their ability to produce gas at the high volume we’ve been accustomed to for over 50 years is coming to an end. AEMO broke the news in their 2019 Gas Statement of Opportunities (GSOO) by publishing two charts: one representing 2018 and the ‘good old days’ of high rates of gas production and a second showing 2025, the date that a number of formerly prolific Bass Strait gas fields become ‘used up’.

2018: the way we were
Figure 1 shows how Australia’s network of gas supplies comfortably met demand in the southern states (Victoria, New South Wales, South Australia, Tasmania and the Australian Capital Territory) in 2018.

The top dark jagged line shows the daily ups and downs of eastern Australian domestic gas demand. Throughout the year there is a nearly constant base gas demand for electricity generation, industry and cooking and water heating in homes. On top of that base, gas demand also has a broad peak across the colder months of May through October, as people switch on their gas-fired space heaters.

The dominant red area in Figure 1 represents how gas has traditionally been supplied from the Bass Strait, the Moomba gas field in central Australia and other smaller conventional oil and gas fields. The yellow area shows some Queensland coal seam gas (CSG) being supplied to the southern states via interstate gas pipelines. (You can see this supply network represented in Figure 3.)

The orange area shows some gas that is topping up wintertime supply by being withdrawn from seasonal storage, such as from the underground gas storage facility near Port Campbell, Victoria.

Because Queensland usage is not included in Figure 1, the massive liquefied natural gas (LNG) exports from the port of Gladstone in that state are not shown. (You can see this dramatically illustrated in Figure 4: with those exports starting in 2015, the amount of gas exported is now around three times larger than the amount of gas used domestically in eastern Australia.)

In 2025, where did all the gas go?
Let’s now compare how gas was supplied to the southern states in 2018, to AEMO’s assessment of what will happen in 2025, based on data received from the gas producers. AEMO does not assume much change in the historical level of gas demand, but, in the 2025 data represented in Figure 2, we suddenly see the traditional gas supplies dramatically shrinking, to just one-third of what they were a few years before.

To partly cover for this loss of traditional gas supplies, AEMO models maximum flow of Queensland coal seam gas down the interstate pipelines (the yellow area in Figure 2). Gas drawn from storage (the orange area) hardly makes any impact.

After those ways of supplying gas are ‘maxed out’, what remains is a big gap of uncertain supply, nearly half of winter gas demand in 2025. This is gas that people in the colder regions of eastern Australia traditionally relied on to heat their water and living spaces and to cook their food. ...