Shale gas fracking is a controversial method of extracting natural gas from underground shale rock formations. It involves injecting water, sand, and chemicals into the ground at high pressure to fracture the rock and release gas. In this article, we will examine the effect of shale gas fracking on the environment in Australia.

A Brief Introduction to Shale Gas Fracking in Australia

Shale gas fracking has been used in Australia for over a decade, primarily in the Cooper Basin in South Australia. The industry has increased, with several companies investing billions of dollars in exploration and production. Australia’s abundance of shale gas reserves has increased interest in the industry, with some estimates suggesting that the country could become one of the world’s largest shale gas producers.

Environmental Concerns with Shale Gas Fracking

Public health is at risk from the shale gas industry. Shale gas wells release toxic chemicals into the air and water, severely affecting human health. In Australia, there needs to be more regulation and oversight of the shale gas industry, which raises safety concerns.

Climate change and emissions are also significant risks associated with shale gas fracking. Natural gas production contributes to greenhouse gas emissions, negatively impacting the environment. The processes involved in shale gas fracking also release toxic chemicals into the air and water can severely affect wildlife and habitats.

Despite its potential economic benefits, shale gas fracking has been intensely scrutinised due to its potential environmental impact. Some of the most commonly cited concerns include:

• Water contamination: The process of shale gas fracking requires large amounts of water, which can lead to groundwater contamination if chemicals used in the process leak into the water supply.
• Air pollution: The release of greenhouse gases and toxic air pollutants during fracking can contribute to air pollution and global warming.
• Land degradation: The construction of fracking wells and related infrastructure can lead to land degradation and loss of habitat for wildlife.
• Earthquakes: The injection of fluids into the ground during fracking has been linked to increased seismic activity, including tremors.

The Current State of Shale Gas Fracking in Australia

Despite these concerns, Australia’s shale gas fracking industry continues to grow, with several new projects planned in the coming years. The industry has been subject to increasing regulation, with the Australian government implementing several measures to minimise the potential impact of fracking on the environment.

In recent years, the industry has also faced opposition from environmental groups, who have raised concerns about the potential impact of shale gas fracking on the environment. In response, the industry has attempted to address these concerns by implementing best practices and developing cutting-edge technologies to minimise the environmental impact of fracking.

Understanding the process of extracting gas from impermeable shale through fracking (hydraulic fracturing)

Fracking is a process used to extract natural gas from deep underground shale formations by injecting water, sand, and chemicals into the rock. The pressure of the mixture creates fractures in the rock, allowing the trapped gas to escape and be collected at the surface. Despite its widespread use, many people still need to become more familiar with the fracking process and the environmental consequences it can have. This chapter provides an overview of fracking, including the methods, chemicals, and potential ecological impacts. We also examine the history of shale gas fracking in Australia, exploring how it has evolved and why it has become a controversial issue.

To make informed decisions, a comprehensive understanding of the fracking process before discussing the environmental impacts of shale gas fracking in Australia is essential. Whether you are a concerned citizen, an environmental advocate, or a policymaker, this chapter will give you the knowledge you need to make informed decisions about the future of energy in Australia.

Shale gas fracking has the potential to provide significant economic benefits for Australia but raises significant environmental concerns. While the industry has taken steps to minimise its environmental impact, these efforts must continue. It will be necessary for the government to ensure regulations are in place to protect the environment.

Answers to Common Questions About Shale Gas Fracking in Australia

Does shale fracking need thousands of close-drilled wells, restricting land use?

Due to their greater depth, shale wells are costly to drill, so operators have a cost incentive to minimise the number of wells required. With horizontal drilling, multiple wells can be drilled from the same drilling pad, which minimises costs and land disturbance. 

Once a field enters production, a well pad could be required every one to four kilometres. Each well pad would cover less than the size of a suburban house block. The location of wells and pipeline routes is agreed upon in consultation with landholders.

Is fracking (hydraulic fracturing) a new technology?

Hydraulic fracturing has been around for a long time, with the first use of hydraulic fracturing taking place in 1949. The process has been used safely in oil and gas for over 65 years in more than 2 million wells worldwide.

Are oil and gas operations harmful to human health?

Properly regulated oil and gas operations are safe, and the Australian oil and gas industry has a strong compliance record. The people with the highest exposure to oil and gas are workers in the industry, and an independent epidemiology program linked with Monash University clearly shows that petroleum industry employees have better health than the general Australian community and are less likely to die of the diseases commonly causing death – including cancer, heart and respiratory conditions.

Is fracking (hydraulic fracturing) a new technology?

Hydraulic fracturing has been around for a long time, with the first use of hydraulic fracturing taking place in 1949. The process has been used safely in oil and gas for over 65 years in more than 2 million wells worldwide.

Does anyone understand hydraulic fracturing (fracking) or know what chemicals are used?

All chemicals used in hydraulic fracturing are disclosed to the relevant regulator for assessment and approval. In several states, lists of these chemicals are published in their entirety so that anyone can view what is being used in operation.

Water and sand comprise about 99% of the volume of fracking fluid. Companies must identify the chemicals used in any fracking operation and detail any likely interactions with the fracking area’s water and rock formations.

What chemicals are used in fracking, and why are they necessary?

Fracking fluid is generally 90% water, 9.5% sand and 0.5% chemical additives. Most of the chemicals used in fracking are found in familiar household products and food additives. Commonly abused substances include guar gum (a thickener found in food products), acetic acid (in vinegar), sodium chloride (salt), ethanol, sodium bicarbonate (baking soda) and sodium hypochlorite and hydrochloric acid (both used in swimming pools), cellulose (used to make paper), acetic acid (the active part of vinegar) and small amounts of disinfectants. These chemicals are all used in low concentrations, and in almost all cases, they are biodegradable, meaning they break down.

Chemicals are used because the tiny cracks in the rock created by fracking will quickly close unless held open in some way. This is done by injecting proppant made from sand into the cracks. However, sand does not dissolve in water, so a thickener (guar gum) is needed to carry it. Other chemicals help reduce friction, remove bacteria and prevent scale from building up in the well.

All chemical additives are assessed, fully disclosed and managed according to strict government regulations. In some states and the Northern Territory, the complete list of chemicals is published on government websites.

Does fracking involve carcinogenic chemicals such as BTEX?

BTEX (benzene, toluene, ethylbenzene and xylene) chemicals cannot be used in fracking fluids in Australia. They can also be detected in industrial and irrigation waters.

Fluids play a crucial role in hydraulic fracturing, opening fractures and maintaining them with proppant materials. The specific composition of these fluids varies based on site conditions, usually consisting of 97-99% water and sand with a mix of additives such as pH buffers, biocides, gelling agents, and others, excluding the use of BTEX (benzene, toluene, ethyl-benzene, and xylenes) which are prohibited in Queensland and New South Wales. It is considered best practice to recover a more significant amount of flow-back water from a well after hydraulic fracturing is finished, compared to the volume of fluid injected.

How can we be sure fracking fluids will not contaminate the environment?

Once fracking has been completed, 20% and 70% of the fracking fluid is recovered. The fracking fluid is then stored in lined pits or steel tanks so it can be reused in another fracking stage or well.

The fluids and residue are placed in lined evaporation ponds when no longer needed. The bulk is sand that returns from the bore, plus the remaining fluid with additives. Most additives will break down quickly under light, and the sand settles with the remaining salt. Once these have dried out, the remaining residue is taken to a licensed facility.

Do drilling and fracking cause gas to migrate into water bores and aquifers?

Natural gas wells are constructed to ensure gas cannot migrate to neighbouring bores and aquifers. It is not in the gas companies’ interests to allow gas leakage into aquifers, and such leaks would make extracting the gas difficult and reduce the amount of gas available for sale.

The shale rocks fractured are 2-5km underground, whereas the aquifers containing potable water used for drinking and industry are generally within 300 metres of the surface. So more than 1.5km of barrier rock separates fracture zones from useable water aquifers.

The design of the well and the cementing and casing practices also protect the aquifers from water entering the borehole or the gas and oil from the hole entering the aquifer. The standards for oil and gas wells are far higher than those for water bores.

Wells have multiple layers of steel casing and specially engineered concrete, separating the well’s contents from water aquifers. Each segment of steel casing is cemented in place, then pressure tested and scanned to ensure there are no cracks or leaks before the next layer of the casing is inserted and cemented in place. The standards for oil and gas wells drilled through water aquifers are very high and much higher than those for water bores.

The use of multiple layers of protection around wells to ensure no connectivity with water aquifers has been used in producing conventional oil and gas for many decades. Instances of well failure are still being determined.

Could the fractures extend vertically into drinking water aquifers?

No. Each fracture stage is engineered and controlled to limit fractures to the oil and gas-bearing rocks. It is also physically impossible for fractures to extend more than 150 metres on either side of a well (less vertically) because of the high pressure in rocks at those depths. Research on hundreds of wells in the US has demonstrated that fractures are confined to the rocks close to the target zone.

Is fracking riskier when combined with horizontal drilling?

No. The same technology, engineering and risk management processes are used for fracking a vertical well as to frack a horizontal section of a well. Horizontal wells into shale rocks are deeper than vertical wells into conventional oil and gas fields, so there is an even greater separation between fracture zones and drinking water aquifers.

How do companies ensure that evaporation ponds do not overflow into local water courses during or after heavy rain?

All by-products of drilling and hydraulic fracturing are disposed of in line with regulatory requirements and are managed with consideration for environment and weather conditions. For example, companies must show the relevant regulator that their storage facilities can accommodate additional water in areas with high rainfall. In some cases, companies will plan activities for drier times of the year.

Does fracking require much water?

Fracking does require water but far less than industries such as agriculture or mining. Each hydraulic fracturing stage can use about 2.5 million litres of water – equivalent to an Olympic swimming pool.

 A well subjected to multiple fracking stages could require between 4- 22 ML of water. Where multiple fracks are done, much water can be reused, reducing the overall water requirement. Once a well is fracked, it does not need to be repeated yearly, so this is a one-off water requirement, unlike mining and agriculture.

It is important to note that the gas industry can use salty or non-potable water for fracking. The industry aims to use water from aquifers deep below the surface that it can access when drilling rather than tapping the freshwater aquifers used by people and agriculture.

How do operators ensure they are not depleting or contaminating groundwater sources?

Companies use extensive monitoring to detect any possible environmental changes due to operations. Before, during and after activities begin, monitoring is put in place to measure the potential impact on the environment. 

Before drilling a well, companies undertake extensive surveys to understand the environment entirely. This includes baseline surveys of water levels and chemical analysis of water in local bore fields before, during and after drilling, fracking and production operations. The government closely regulates monitoring programs.

The government closely regulates all exploration and drilling activities. Before obtaining approval to drill or frac, operators must develop environmental management plans describing the risks and how they will be managed. Every step of the drilling and fracking process must be reported to the regulator, which will closely monitor these operations.

Will sinkholes be created as oil and gas are drained below the ground?

Sinkholes are yet to occur with conventional oil and gas production. The sandstone and shales remain in place, so underground caverns cannot be created.

How can we be sure that wells will not deteriorate over time and cause environmental problems 50 or 100 years from now?

The risk of a well casing failure in Australia is low because the industry is committed to ensuring that wells are constructed and maintained to the highest standards using the latest technology. Specially engineered steels and cement used in well casings are designed to withstand pressures far above those found underground. 

In the absence of air and water, steel does not corrode, and well casings have been recovered after 40 years with very little deterioration. A 2011 study by the US Groundwater Protection Council showed that less than 0.1% of wells drilled since the early 1980s had issues with well integrity (12 out of 34,000 wells in Ohio and 2 out of 187,000 wells in Texas). Most of these were drilled in the 1980s and 1990s before improved cement formulas and regulations were in place.