Fraccing is the process of creating cracks in underground reservoir rock formations to increase the flow and recovery of gas out of a well. This is done by pumping fluid under pressure into the reservoir to prop open small cracks and openings that allow more gas to be released. It is a well-established technique. Fraccing is one of many different ‘stimulation’ techniques used to increase the productivity of a well.

In Queensland, fraccing fluids are made up almost entirely of water and sand (typically 99 percent) but they also include additives used for various purposes, such as the prevention of bacterial growth and corrosion of infrastructure.

Many of the fraccing additives are used in everyday life such as in swimming pools, soaps and vinegar, and are generally designed to either oxidise or biodegrade during the fraccing activity or soon thereafter. Use of the more toxic BTEX chemicals in fraccing fluid is banned.

Due to the varying geology of reservoirs, fraccing is not carried out at every well. Of the approximate 5,000 conventional and domestic petroleum and gas wells currently in Queensland, just over eight per cent have been fracced (around 400 wells). It is estimated that as the industry expands, between 10 and 40 per cent of wells may be fracced.