Sunday, 8 December 2013

Frack from Fiction - The Pros and Cons of Fracking

It seems that everybody is talking about fracking recently. It has been the cause of many polarised debates and is a hot topic amongst environmentalists and energy companies alike. Yet it is nothing new; breaking rocks to extract gas was first experimented with in the late 1940s and the method used today has been a serious source of gas since the late 1990s.

With the cost of fracking declining and the demand for cheap natural gas increasing, it looks as if the argument is here to stay. The number of new fracking sites have now outstripped the building of new conventional rigs and in excess of 200,000km3 of recoverable shale gas is reportedly trapped under our feet. 

It's probably time, therefore, to take an impartial look at the facts of fracking.

How it works

A simple diagram of how fracking works. Source
Fracking, or ‘hydraulic fracturing’ to be precise, is the process of drawing out gas that is trapped within rocks. A long shaft is drilled through the Earth until the gas-bearing layer, usually shale, is reached. This is usually a long way down – in the UK for example, even the shallowest well is a mile deep. When the shaft reaches the correct layer of rock, the drill takes a 90° turn and bores horizontally into the gas reserves. 

Simply drilling into the rock won't yield any meaningful amount of gas, with the majority still trapped within tiny pores and cracks. To get this out, millions of gallons of chemically treated water is pumped into the well at super high pressure, causing the rock to crack apart and allowing the gas to escape. The chemicals are designed to reduce friction and dissolve unwanted minerals. It also contains sand in order to prevent the new cracks from closing up again. With the gas released from the rock, the watery mixture is pumped back out and the gas travels up the borehole to be recovered. Once it has all been collected, which could take multiple fracks, the chemically polluted water is pumped back in for storage deep underground and the well is sealed up. 

As simple as the process sounds, fracking shale-gas is incredibly complicated and took over 25 years to become technologically and economically successful. After all that time and effort, there are still many unknowns and of course a lot of controversy.

The Pros

The Economy

The big winner in all of this is the economy, especially in the gas-rich USA. The fracking boom really took off in 2005, when the USA exempted it from compliance with the Clean Water Act, the Safe Drinking Water Act and the Clean Air Act. By 2012, it added nearly $75 billion to federal revenue, added $238 billion to the US GDP and made the average citizen better off from cheaper energy prices.

Across the pond the picture is a little different. Fracking in Europe is more restricted and reserves are 26% smaller than in the USA. On top of that, the differing geology and deeper deposits makes the gas harder and more expensive to extract. Despite this, the economic benefits aren't exactly frugal; the recoverable reserves across Europe could add between £1.7 to 3.8 trillion to the EU's economy between 2020 and 2050 and create over a million new jobs. 

Shale-gas reserves and restrictive laws in Europe. Source

Elsewhere around the world the picture is much the same. Similarly huge reserves, in excess of 400 trillion cubic feet, can be found in China, Mexico, Argentina, Australia and South Africa. The potential returns to governments and investors around the world are, to put it lightly, significant.

Energy Security

Perhaps the greatest benefit of such vast areas of untapped gas is the added energy security. US reserves could power the nation for 35 years based on 2010 consumption levels and reserves from northern England alone could keep Britain going for 40 years. This is a key part of national security. Oil and gas is one of the most essential imports for a lot of countries and newly discovered reserves could serve as a vital buffer if diplomatic tensions were to increase.

World reserves of shale gas. Basins with resource estimate (red) and without
resource estimate (yellow).  Source
The Cons

The Environment

Natural gas is a fossil fuel. It's non-renewable and it's a source of greenhouse gas. This is an inescapable fact and a serious one when put in context with the increasingly apparent risks of neglecting our climate system. A silver lining, perhaps, is that gas is a 'cleaner' energy source compared to coal. The pound-for-pound environmental impact is therefore less.

There is, however, a caveat. Unburnt gas releases methane, an extremely potent greenhouse gas that is much more powerful at trapping our suns energy than CO2, even if it does last in the atmosphere for less time. Compared to oil or coal accidents, gas cannot be recovered. Leakages put unburnt gas straight into the atmosphere and is unrecoverable. Research has suggested that fracking will only yield a benefit to climate (compared to burning coal) if leakage is kept below 2.5%, with some models suggesting it should be kept to a minimum of 2%. An investigation into a fracking site in Colorado determined that about 4% of gas was escaping to the atmosphere, turning natural gas back into a 'dirty' energy source that has no benefit to the climate over coal.

Water Supply

Fracking needs a lot of water. Each frack uses an average of 8 million litres of water, but could use anything up to 20 million litres. In the USA alone, the Environment Protection Agency estimates that 35,000 wells are fracked each year. Scale that up and fracking suddenly becomes a significant source of water, particularly in drought-prone areas.

There are also many reports that fracking contaminates drinking water, the idea being that the chemically-laced fracking fluid or escaping gas eventually finds its way into drinking water aquifers. Some research does link methane contamination in drinking water to fracking, although it is likely that the contamination is caused by improperly sealed wells and not a direct result of the actual fracking process. This is because shale gas is typically much deeper than drinking water aquifers and by definition a layer of impermeable rock must separate the two. If there wasn't, the gas would have escaped naturally a long time before it could be fracked.

Methane contamination in drinking water. Source
Therefore, images like the one to the right are difficult to directly attribute to fracking and are probably the result of poorly maintained wells or naturally occurring methane. More stringent licensing laws, such as those in Europe, should eliminate contamination in these areas.

Probably the greater risk to drinking water is above-ground contamination. Remember that such vast quantities of water and chemicals must be transported and there will inevitably be accidents and spillages. Reports include suspicions of one energy company dumping 20,000 gallons of contaminated water into a river and nearly 84,000 gallons of fracking waste spilled at a broken well in Denver.


A dramatic increase in earthquakes in and around fracking areas are too much of a coincidence to ignore. Research in Texas suggests there was more than 50 earthquakes in Cleburne, Texas in 2009 and 2010. Before 2008, there had never been a single recorded earthquake. In Oklahoma, earthquake numbers rose from 50 a year to over 1,000 in 2010, soon after fracking began. Even the relatively small fracking industry in the UK has been attributed to causing earthquakes. Although the majority of them are tiny and pose no risk to society, the sharp rise must surely raise concern that the possibility of larger earthquakes cannot be ignored.

The Bigger Picture

Compared to coal, natural gas is a relatively 'clean' source of energy when burnt. This, however, does not mean it isn't damaging. As stated on ClimateReach before, humanity is on course to hit the fabled 2°C of warming by 2040 unless significant action on reducing pollution is taken. Perhaps the fracking debate is looking in the wrong direction. The arguments over whether it causes earthquakes, whether it poisons our water supply or whether it's cleaner than coal may all be superficial compared to the ultimate point - we've got to start leaving fossil fuels in the ground.

If the world is going to full-heartedly attempt to limit its ecological impact it has to seriously rethink how to approach fracking. We should look to fracking as a short term compromise to provide cleaner energy until renewable sources can take over. We shouldn't look at it as a quick fix to cheaper bills and a way to shift the energy and climate crisis to the next generation.

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