Gas Mining in Outback Queensland

Those vast flat plains of Western Queensland hide a number of secrets. For so long they were seen as boring stretches of nothingness, home only to great towns such as Longreach, Winton, Hughenden, and Cloncurry. Yet in recent years we’ve learned that this region’s story runs a little deeper...

Huge bones of strange creatures have come to the surface as armies of enthusiastic researchers have decoded the history of the rocks beneath their feet. Remains of dinosaurs, huge marine reptiles and soaring flying creatures seemingly out of a Gothic nightmare have become the currency of a tourist boom. Turns out this place is well-suited to those who love detective work or simply the notion of walking in the footprints of ancient creatures.

MORE THAN MEETS THE ICHTHYOSAUR

However, there’s more than just bones in those rocks. Along a broad area just west of the Queensland coast, from northern NSW north to Townsville, and in the south-west corner, the rocks hold valuable resources – shale and coal seam gas (CSG) – that have helped turn Australia into notionally the largest producer and exporter of natural gas in the world.

Mining companies want to tap into this gold mine of money, governments want the revenues which flow to their treasuries, workers in this field want the employment, while impacted towns and communities hate it and live in fear of the threats that they see in its rapid spread.

CSG has filled a short to medium term demand for a cleaner and readily available source of energy for a world battling with difficulties over climate change and pollution. CSG burns more cleanly, with fewer pollutants and unwanted byproducts than the current energy staple, coal (about 30 per cent less).

The gas is trapped in coal seams deep underground as well as in layers of shale, a sedimentary rock often rich in organic matter which breaks down into the gas over time. This gas escapes from the coal or shale very slowly where it’s exposed at the surface, and quite rapidly when the coal is being mined. It’s been the source of many explosions in underground coal mines, where it can gather in a confined environment and has been ignited by a spark or naked flame.

The release of the gas can be enhanced by drilling into these subterranean layers of rock and injecting fluids under immense pressure, which cracks or fractures the rock. The gas (and sometimes oil) is then collected at a well-head. The fluids injected into the rock are largely water, with some added chemicals and some “proppants”, such as sand or small ceramic beads, to hold the fractures open.

PASTORAL OPPOSITION

It sounds like a fairly benign process, but it has created significant opposition from pastoral communities.

The vertical drilling can pierce holes in layers of rock known as aquicludes, which normally prevent the downward migration of the water that flows underground. Pastoralists with properties dependent on these underground water reserves report falls in the water table below their properties after such drilling, and the concern is that eventually there will be insufficient water left to provide for the needs of the cattle and agricultural properties and towns above.

The chemicals in the mix of fluids represent less than one per cent of the total volume. These include a gum to increase the viscosity of the liquid, a solvent to enable a free flow of the liquid when it is time to remove it, and additives to kill off any bacteria or other natural agents which might act to block up the fractures or piping. In NSW and Queensland the use of toxic chemicals such as benzene, toluene, ethylbenzene and xylene for this purpose has been banned.

The whole process is quite water intensive, especially when drilling in shale, a serious issue in a desiccated climate where there is rarely enough water. Plus water discovered in drilling is often extracted and used for the fracking process, using up a valuable pastoral asset. In the United States water usage in shale drilling can be anywhere from 10 to 25 million litres per well.

Anywhere from 30 to 80 per cent of the water that is pumped in is typically recovered, and it is usually recycled for other wells in the area. Drilling in coal can, however, often result in the recovery of more water than was pumped in.

THE LAY OF THE LAND

The boom in CGS extraction by fracking has resulted in an explosion of gas supplies, which ironically has resulted in a quadrupling of gas prices, which has contributed materially to the rise in electricity prices.

Critics of fracking argue that the long term impacts of degradation of drinking water supplies and consequent health impacts far outweighs any employment or commercial benefits. In the US, both scientific and health organisations, citing up to 1200 peer-reviewed studies, have stated that there was no way for fracking to proceed without impacting human health. They cited health impacts such as respiratory disease, cancer risk, low birth weight and preterm birth. These risks came from toxic air pollution and degraded drinking water. Earthquakes have even been triggered.

The petroleum industry has stated that these risks do not apply in Australia.

CSG extraction has been banned in a number of other countries around the world, including New Zealand, France, Germany, Scotland and Spain.

The regulation of CSG recovery in Australia lies principally with State Governments. There is a ban on fracking in Victoria, as well as moratoriums on the practice in Tasmania and most of Western Australia, most of New South Wales, half of the NT, and a small portion of South Australia, while there is no CSG in the ACT (though some might argue there’s enough gas above ground to offset this shortcoming).

Queensland is, however, the most lenient jurisdiction in the nation when it comes to fracking. The Bowen and Surat Basins are the two largest areas of production, with there are three major production facilities converting CSG to liquefied natural gas (LNG) for export.

Whatever your take on it all, CSG and fracking promise to remain a part of Australia’s energy mix for some time to come, with the assurance that this will remain a controversial and volatile source of friction between industry and community groups.