Menu Close

Switching to coal seam gas could drastically reduce emissions - so what’s the fraccing problem?

Australia could meet its Kyoto targets by replacing coal with natural gas. AAP

In a coal-abundant nation trying to go green, coal seam gas drilling offers us a cleaner source of energy.

But there is a draw back.

Many coal seam wells will require fraccing and the community is concerned about water supply contamination with unknown and potentially toxic frac chemicals, environmental disturbance and adequate regulation.

So how can we get the most out of our natural gas supplies and protect the environment?

Natural gas: why we should make the switch

The natural gas produced from coal seam gas wells is a cleaner alternative to brown coal: it generates about half the amount of CO2.

Eastern Australia generates most of its electricity from coal – and most of that is emissions-intensive brown coal.

The potential of natural gas as an energy source is huge.

It has been estimated that Australia could meet its Kyoto CO2 reduction targets just by replacing the large amount of coal we burn for electricity generation with natural gas.

So eastern Australia could switch from coal to natural gas and lessen its impact on the climate and environment. But coal is cheaper than natural gas so, for now, we burn coal.

An average coal seam gas well can be drilled in less than a week, produce gas and water for 20-30 years and costs about $2-4 million.

The average well will produce the energy equivalent of 30-50 million litres of petrol, produce a few hundred giga-litres of water and generate hundreds of thousands of dollars in tax revenue. The planned Queensland LNG plants will require between ten and twenty thousand gas wells.

Most of the gas to be extracted from the new proposed coal seam gas wells will be exported to Asia and will not be available to displace coal as an energy source in Australia.

It seems our Asian neighbours value cleaner-burning fuels more than we do.

Tapping the coal seam

To understand the issues surrounding coal seam gas drilling in Australia, it’s important understand how gas is stored in coal and how we get it out. It’s this process that goes to the heart of community concern about fraccing.

The important facets of coal are the coal bed, the fractures in the coal bed, the ‘small’ amount of water stored in the coal and the large amount of gas stored in the coal.

In order to get the gas to flow out of the coal, the water must be pumped out first. The water is stored in the coal like water is stored in a sponge.

The volume of water in a coal is approximately 1% of the volume of coal. This may sound like a small amount of water, but one needs to remember that the amount of coal underground is huge.

A single coal seam may be 10 metres thick and extend for tens of kilometers in all directions. One percent of that coal volume corresponds to a huge amount of water.

So the coal seam gas wells are designed to pump this water and gas to the surface. But coal is impermeable - water and gas will not flow through it.

The water and gas can flow through the fractures – if they are open. But for perhaps half of the wells, the fractures are not open.

This is where fraccing comes in. Fraccing will force the closed fractures open using high pressure water – and some chemicals.

Once the fractures are opened, a much greater quantity of water from the coal bed can flow back to the well bore where it is pumped to the surface. As time goes on, the water level and water pressure in the coal drops and the flow rate of gas increases.

Coal seam gas well regulations are supposed to ensure that frac chemicals do not harm the community, gas does not leak from the well and that no water flows in the well into or out of acquifers found between the surface and the coal bed.

Similarly, environmental regulations are supposed to ensure that produced water does not harm the soils, waterways or bore water.

The ghosts of Gasland

Community concerns about frac chemicals are a direct result of American regulators giving frac companies permission to keep the mix of chemicals secret.

Those companies did this not because they wanted to hide the fact that these chemical were toxic – but because they felt that their particular mix of chemicals was a competitive advantage that they did not wish to reveal to the public or to competitors.

This strategy backfired and became a public relations nightmare when the American documentary Gasland showed a farmer igniting the water coming from his kitchen tap. The implication in Gasland is that the farmer’s well water had been contaminated with frac chemicals.

The kitchen tap water in Gasland ignited because the farmer’s well water came from a well drilled into coal. The farmer’s well – or other coal seam gas wells - had lowered the water level in his coals and the coals were starting to produce gas.

This is exactly the behaviour expected and observed from thousands of coal seam gas wells in Queensland.

With regard to the toxicity of these chemicals: the frac fluids are 95% water, and the frac companies have always insisted that the remaining 5% chemicals in the frac fluid are safe.

Of course, nobody believes that these ‘secret’ chemicals are safe – especially after Gasland. The frac companies now are struggling to repair their reputation and are happy to reveal what the frac chemicals are.

In fact, some frac companies are considering only using 100% water as a frac fluid – and ensuring that the water meets drinking water quality standards.

As with most energy production, those who live in rural areas are most impacted by coal seam gas activity. Frequently, these people stay in the bush because they prefer a quiet and clean environment.

Coal seam gas production involves frequent trucks, drilling, pipelines, and processing plants, making their bush environment more industrial.

Are there proper regulations in place to protect the rural nature these citizens treasure? Is it reasonable to suppress coal seam gas development, as well as tax dollars and jobs, in an effort to protect the bush lifestyle?

These are very tough, highly political questions the government and regulators need to consider.

It’s worth noting, however, that an open pit coal mine, our current energy sourcing default, is more damaging to the landscape than coal seam gas wells and much worse for the environment.

Once the water is pumped from the coal, it can be fresh or it can be very saline (salty). Where it’s too salty for irrigation, the water is stored in evaporation ponds.

The worst-case scenario is that important ground wells are contaminated with this saline water. There is a very low chance of this happening but if an accident occured it would be very difficult to detect until after the contamination has happened.

The importance of regulation

If coal seam gas drilling is to be well-regulated, and it’s crucial that it is, the question must be asked: do the different state agencies regulating the industry have sufficient manpower?

There has been a huge upswing in activity to assemble plans and obtain permits for wells, pipelines, evaporation ponds and LNG plants, but companies are finding it difficult to find trained personnel to assemble acceptable plans.

Furthermore, the companies usually pay more than state regulatory agencies, and like to hire state regulators and inspectors because they know the regulations.

There’s a genuine concern that the state regulators and inspectors are stretched too thin to adequately review plans and inspect wells associated with this boom of coal seam gas activity.

If we’re going to take advantage of cleaner energy options, we have to ensure we have the resources and regulations in place to do it safely.

Want to write?

Write an article and join a growing community of more than 175,100 academics and researchers from 4,818 institutions.

Register now