Hydraulic Fracturing

  • Depending on the subsurface formation, a technique called hydraulic fracturing is required to release the gas trapped deep underground.
  • Hydraulic fracturing involves pumping a fluid down the well at high pressure to open tiny cracks in the target rock reservoir.
  • Hydraulic fracturing can be traced back over 60 years in Australia.

The hydraulic fracturing process – also referred to as ‘fraccing’ or ‘fracking’ – is used to increase the flow of oil and gas to a well, increasing production and reducing the total number of wells needed to develop a resource. It allows commercialisation of low permeability reservoirs in which oil and gas do not easily flow. It can also be used with other natural resources, such as to access geothermal energy, and to increase water production.

The Process

Hydraulic fracturing involves pumping a fluid down the well at high pressure to open tiny cracks in the target rock reservoir. This fluid contains ‘proppants’, primarily sand, which is used to hold the fissures open and improve the flow of gas or oil. Most fluid contains less than one per cent of chemical additives to make the technique more efficient.

While the proppants remain behind in the rock formation, most of the injected fluid either breaks down into harmless materials (such as starch or water) or is removed and carefully collected at the surface.

All recovered fluids are isolated in sealed storage areas designed to prevent leakage, including specially designed and constructed dams or above-ground holding tanks. Depending on regulatory conditions, these fluids are then reused in subsequent well stimulation activities, treated for other uses or disposed of through an approved facility.

Hydraulic fracturing isn’t used automatically in the exploration and production process. The process occurs after the actual drilling of a well and is considered a separate process in the development of an oil and gas field.

Shale and tight gas wells will undergo a series of fractures of the same well which are carried out in multiple stages. Multistage hydraulic fracturing, when combined with horizontal drilling, is a prime example of the importance of innovation in the oil and gas industry.

The combination of these techniques has resulted in fewer wells needing to be drilled to access large resources of oil and gas, resulting in less environmental impact at a surface level.

History in Australia

In Australia, hydraulic fracturing can be traced back over 60 years where it was used in the production of energy resources, including oil and natural gas.

For example, natural gas wells in South Australia’s Cooper Basin have been fracture stimulated since the 1970s, while in Western Australia, the Department of Minerals and Petroleum reports that almost eight hundred fracture stimulations have been carried out in that State since 1958 – with no observed or reportable adverse consequences.

A majority of the hydraulic fracturing undertaken in Western Australia has occurred on Barrow Island since 1965.

Located off the coast of Western Australia, Barrow Island has been identified as an ‘A’ Class nature reserve – the highest level of environmental protection afforded in the State.

Scientific Consensus on Hydraulic Fracturing

The technical literature on horizontal wells and hydraulic fracturing adapted to shale is extensive, covering 30 years of development, with over 550 papers on shale hydraulic fracturing and 3000 papers on aspects of horizontal wells.

The possibility of hydraulic fracturing causing earthquakes of sufficient magnitude to cause structural damage (2 or greater on the Richter scale) has been examined. Based on an extensive review of the evidence, the Panel has concluded that this is unlikely to occur as a result of hydraulic fracturing for onshore shale gas in the NT.

Regulated petroleum activities have been occurring in Western Australia for the past 60 years without compromising health, safety or the environment. During that period, nearly 780 hydraulic fracture stimulation activities have been conducted without major incident.

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