It has long been known that shales contain oil and gas but it is only within the last decade that the development of two technologies has made the extraction of gas from shale an economic proposition:
- The first of these is the ability to drill horizontally from an initial deep vertical bore.
- The second is the development of a process called ‘hydraulic fracturing’ .
Hydraulic fracturing is the use of a fluid made up of around 90% water carrying a load of sands, chemicals and sometimes diesel oil and forcing it into shales under high pressure, causing them to fracture and release the gas they contain.
This is the process from whose name the brute industrial tag of ‘fracking’ has been hacked.
To extract shale gas, you drill one or two miles down into the shale band, and then turn the drill head to bore horizontally for up to the same distance. This obviously increases the exposure of available shale to the well. A series of explosive charges in a perforated pipe are then detonated in the stretch designated for fracking, starting the fissuring of the rock for the hydrofracturing that then follows – directed into the new cracks, forcing them more widely apart and extending them.
Shale is hard and pretty impermeable so breaking it up in this way is the only means of releasing the gas it contains.
The gas then flows along the bore and escapes upwards to the well head.
The chemicals that are part of the water borne material injected into the rock include benzene – a known carcinogen that destroys bacteria that might otherwise clog up the fissures created in the rock.
Areas of gas carrying shales are known in the industry as ‘shale plays’ – as opposed to ‘shale explorations’. The difference between the two is that the risk of ‘shale plays’ not containing extractable gas is lower.
Shale gas production and reserves
The USA is the only country where shale gas has yet been commercially exploited – and has been in production there for a decade. In 2009, shale gas accounted for 14% of the overall natural gas usage in the United States. Increasing production is expected to deliver 45% by 2035.
The first major shale play in production there was the Barnett Shale in Texas. Other major plays are the east coast’s Marcellus and Utica Shales, the Fayetteville Shale in Arkansas and the Haynesville Shale in Louisiana.
The USA’s Energy Information Administration’s Annual Energy Outlook 2011 estimates that the United States has 2,552 trillion cubic feet (Tcf) of potential natural gas resources – including shale gas.
The small UK energy consortium, Cuadrilla, that has drilled two exploratory wells, with another currently being drilled and has found shale gas in Lancashire, is now saying that its test wells indicate a 200 trillion cubic feet reserve there, in the Bowland Shale.
This estimate is, however, already being questioned by academics, one of whom – oil and gas expert at Imperial College London, Professor Al Fraser, says that there is a lot of variability in these wells – meaning that the Cuadrilla test wells may not be reliably indicative. He is quoted as saying that the Cuadrilla figures may be optimistic by as much as a factor of 10.
On 1st November 2009 the Murdoch press’s Sunday Times announced that America has been able to cut – very significantly – its imports of liquefied natural gas (LNG) because of its discovery of massive resources of shale gas which it is energetically producing. As noted above, in 2009 America was getting 14% of its natural gas usage from shale gas sources.
In a blowout of its own, the Sunday Times said, breathlessly, that the shale gas ‘breakthrough has opened a new frontier for the energy industry and turned long-held assumptions about the world’s dwindling supplies on their head.’ This forgets that these supplies too are finite. The Marcellus Shale under Pennsylvania is the second largest gas field in the world – and, according to Bloomberg Businessweek in March 2011, ‘enough to heat U.S. homes and power electric plants for two decades’. That’s only twenty years – and 1990 doesn’t seem that long ago. However, its total resources of shale gas are said to be capable, at today’s usage rates, of fuelling the United States for 100 years.
The 23rd September 2011 edition of The Telegraph claims in a headline that: ‘Shale gas could solve the world’s energy problems’ – but fails to say for how long – except. airily, ‘hundreds of years’. This is irresponsible journalism – and it comes from Christopher Booker. He goes on to say: ‘So miraculous is the potential of shale gas to change the world that several countries, led by the US and China, are already piling in to exploit it on a huge scale.’
The positives of shale gas are simply that it buys us time – but the cost of that purchase is complex and its total unknown. Some of that cost is detailed below and some in the closing paragraphs of this article.
Impact on global warming
Shale gas may accelerate rather than reduce global warming. It emits much greater volumes of methane than does conventional gas. Methane is a very potent greenhouse gas, estimated in late 2010 by the USA’s Environmental Protection Agency (EPA) to have a global warming potential of 105 times, mass for mass, that of carbon dioxide over 20 years and 33 times more over 100 years. In May 2010, concerned about the potential impact of shale gas on global warming, the Council of Scientific Society Presidents – who represent a total of 1.4 million scientists, wrote to President Obama pressing the urgent need for a stronger scientific foundation before going ahead with a national policy for developing shale gas production.
Scale of need for water
Drilling and fracking both require huge volumes of water – drilling for keeping the drill bit cool and for washing the rock debris out of the borehole; fracking for the water which is 90% of the process, needing up to 3 million gallons per treatment. The centrality of such volumes of water to the process may be an issue where extraction is planned for an area with limited supplies. Such a scenario could leave households and industrial users with short supplies. An area also with limited water supplies and prone to drought would leave production under constant threat of being unable to continue in such conditions.
Other water problems related to fracking arise from the volume of contaminated wastewater it produces. It is alleged that this can invade water tables and contaminate drinking water. While there have been no documented cases of this underground contamination, there have been above ground spillages. Most companies pump as much as they can of the millions of gallons of fracking wastewater back to the surface. There have been occasions where some of this – carrying the powerful carcinogen, benzene – has spilled from holding tanks. Such spillages can swamp treatment plants not equipped to handle high levels of contaminants. A New York Times article in February 2011, referring to documents from the Environmental Protection Agency and from state regulators, described how radioactive wastewater is being discharged into river basins. This of course opens up a direct route for such contaminants to enter the water supply, surface waters and wetland habitats. The Marcellus Shale – under Philadelphia and the second largest gas source in the world, runs beneath the watershed supplying an unfiltered 1 billion gallons of water a day to New York City.
Blowouts are a risk in any oil or gas drilling operation. In shale gas production, a blowout in June 2010 in Clearwater County in the USA threw a 75ft high combustible rocket of gas and toxic wastewater into the air. It took the gas company concerned a full 16 hours to bring this under control and the authorities had to evacuate the area. Water wells and springs supplying local forest cabins were contaminated.
Cuadrilla’s drilling in to the Bowland Shale in Lancashire, near Blackpool, has had to be put in limbo while research is done into the causes of two earthquakes that occurred during drilling and appear to be related to the drilling sites. On 1st April 2011 the North West of England shook to a 2.3 magnitude quake whose epicentre was under two miles from one of Cuadrilla’s shale gas test wells near Blackpool. Only two months later, on 27th May 2011, there was another, more minor, quake registered at 1.5 and with its epicentre under 500 yards from the well. The British Geological Survey has said that it is probable that the tremors and the fracking process are linked. While the tremors are alarming, their magnitude was such that they were barely noticeable. But they were caused by a modest volume of fracking. In full production, with the country overwhelmed by a rush for energy and profit, there would have to be certainty that multiple simultaneous frackings would not trigger more muscular quakes. It is inconceivable that the fracturing and fissuring of rock a mile or two down can be without consequence of some serious kind.
Concerns on regulation
A major issue with fracking – given the level of known risk in the process, never mind the risk level associated with issues not yet understood or quantified – is the regulatory framework within which it is to be conducted, scrutinised and held to account.
In America, as Bloomberg Businessweek reported in March this year: ‘The Delaware River Basin Commission, which manages the watershed that supplies drinking water to 15 million people in New York, Pennsylvania, New Jersey, and Delaware, has put gas development on hold while it drafts rules.’ This is the watershed lying above the massive Marcellus Shale.
Other states are also making their own rules and the White House is signalling that federal regulation will be either light or unnecessary: ‘It’s not necessarily federal regulation that will be needed’.
Worryingly, even if America’s Environmental Protection Agency were to intervene, its hands and ankles are already tied – by that well known company to whom ‘corporate social responsibility is a funny language for wimps. Enter Halliburton, whose head was George W Bush’s Vice President, Dick Cheney, a man about whom history will have much to say.
Halliburton was one of the pioneers of fracking and, coincidentally, also sells fracking fluids.
A clause, popularly known as ‘The Halliburton loophole’, in the USA’s 2005 energy law – which is said not to have reflected the Environmental Protection Agency’s concerns about water pollution - actually exempts fracking from parts of the Safe Drinking Water Act. Dick Cheney is alleged by a Congressman, Maurice Hinchey, to have pushed for this exemption during his Vice Presidency.
This clause, unbelievably, allows companies to treat the composition of fracking fluids as trade secrets – so there is little public information available on what they contain or what risks these contents involve.
Closer to home and therefore even more worrying, Prime Minister David Cameron has been indicating light regulation for shale gas production. Energy Minister, Charles Hendry, seems equally underinformed or equally willfully irresponsible, saying in an article in the Guardian on 22nd September 2011, that ‘given the amount of attention shale gas drilling has attracted recently, one could be forgiven for thinking there was a large, unregulated industry in operation in the UK. The is far from the reality. Shale gas exploration is just beginning here and is governed by one of the most robust and stringent regulatory frameworks in the world. ‘ He says.
The following day, 23rd September 2011, The Guardian published an article on government documents it has seen, showing that the regulation of fracking in the UK will be minimal.
We are still living with the consequences of our last sashay with ‘regulation with a light touch’. As Santayana said, ‘Those who cannot remember the past are condemned to repeat it.’
Green MP, Caroline Lucas, arguing that we must stall fracking until we know more, points out that the process has already been banned in France, New York, New Jersey, Quebec and the Swiss canton of Fribourg; and that, in July 2011, the government of New South Wales in Australia extended its moratorium on fracking for extracting coal seam gas – doing so in response to the concerns expressed by local communities.
There are clearly significant environmental and public health issues which require meticulous and honest investigation before any decision on whether or not to licence fracking in the UK is taken.
But beyond that is a different kind of issue – a psychological one and one bred in our cultural lack of a guiding philosophy.
The chief advantage of shale gas production is that it buys us time – time before we run out of adequate present sources of energy, time to develop and mature the new renewable energy technologies, time to upgrade our own national grid, time to negotiate and build international interconnectors to share power.
But where, in our cultural history, can we point to a moment when we have used the time available to prepare for a very different future?
If we go ahead with shale gas production it’s a safe bet that we’ll take the foot off the accelerator of developing renewable energies and carry on as thirstily as now.
Do we have the sheer character to make the hard choice, leaving this stuff in the ground, leaving the bedrock strong and pressing on as fast as we can with developing a future based on renewables? Improbable. Short termism rules.
The image at the top, of a shale gas rig drilling in the Appallachian Basin, is by copyright holder Meredithw and reproduced here under the Creative Commons licence.