Coal seam gas

Coal seam gas (CSG) is a natural gas, consisting primarily of methane, which is found in coal deposits.

Coal seam gas collects in the coal seams by bonding to the surface of coal particles. The coal seams are generally filled with water, and it is the pressure of the water that keeps the gas as a thin film on the surface of the coal.

CSG is extracted through wells drilled into coal seams. The initial phase of CSG production usually involves the extraction of water from the coal seams in order to reduce the pressure and release gas from the coal.

If the pressure within the seam is high, the gas may flow to the surface unaided. Conversely, the gas may have to be pumped to the surface if the pressure is lower.

When CSG comes to the surface, water in the gas is separated.

The water is then treated to ensure it meets water quality standards, before it is injected into underground water systems, called aquifers, used for other purposes such as irrigating crops, watering livestock or for commercial use, for water supplies or added to watercourses.

CSG in use

CSG is used safely to power Queensland homes.

It is used in the same ways as natural gas including fuelling natural gas appliances, such as heaters and stoves, and generating electricity.

Electricity generated from CSG is a cleaner energy source as it produces around half the emissions of electricity generated by coal.

LNG industry

LNG is simply CSG that has been cooled to minus 161°C so it becomes a liquid, reducing it to 1/600 of its original size so it is able to be transported safely and economically to Queensland’s export markets.

Queensland’s CSG reserves will provide the basis for the developing LNG industry which will become one of the state’s major exports.

Read more about the gas industry.

Legislative requirements

Petroleum activities are regulated under the Environmental Protection Act 1994 and an environmental authority is required before any petroleum activity can commence. The environmental authority imposes conditions to reduce or avoid potential environmental impacts associated with the petroleum industry. For more information on the legislative requirements associated with petroleum activities see the following pages:

• Environmental legislation
• Project requirements
• Environmental authorities
• Compliance and enforcement

Other legislation may offer specific protection to areas with the potential to be impacted by conventional and unconventional gas or oil exploration, such as the Regional Planning Interests Regulation 2014 offers protection to the Lake Eyre Basin rivers and floodplains. For more information see the webpage Protection of Lake Eyre Basin rivers and floodplains.

Environmental considerations

Environmental considerations include:

• groundwater impacts and aquifer interconnectivity from hydraulic fracturing
• impacts to land from production activities and accidental spills
• environmental nuisance from noise, dust, light and odour.