Shale Gas: What are the Environmental Risks and Regulatory Issues?

Go back less than two years to December 2010.  The BBC Newsnight programme included an item entitled, “Is the controversial extraction of shale gas by fracking safe?”  The Science Editor Susan Watts wrote an accompanying blog, which started by saying, “Never heard of ‘fracking’? If not, chances are you will soon.”[1]  This is the first UK-based news article containing the word “fracking” listed by a popular internet search engine.  Two years on, it is clear that Susan Watts was spot on.  Most people – or at least, most people likely to read the Newsnight Science Editor’s blog – have now heard of fracking. 

Over that two year period, there has been a lot of talk about the use of hydraulic fracturing for extraction of shale gas in the UK and throughout Europe.  However, this has not been accompanied by a high level of shale gas exploration activity in Europe – let alone commercial extraction.  AEA’s research for the European Commission indicates that the new technique of hydraulic fracturing using horizontally drilled wells and high volumes of fluids (more than 1,000 m³ per stage) has only been used at one exploratory site in the UK and up to five sites in Poland.[2]

Does this low level of activity mean that concerns about the environmental risks of hydraulic fracturing are just a storm in a teacup?  Not at all.  A combination of public concern, a precautionary approach adopted by some authorities, economic challenges, and technical difficulties has slowed the development of shale gas resources in Europe.  However, sooner or later, the development of Europe’s extensive shale gas reserves will become economically and technically viable.  When that happens, developers and regulators need to be ready to meet the environmental challenges.  Meanwhile, there are hearts and minds to be won, with a vigorous debate taking place in the blogosphere, the Twittersphere, and more traditional forums such as daily newspapers and Select Committees at the House of Commons.

We are currently in a window of opportunity, in which public concerns can be aired and considered, and appropriate regulations can be designed and put in place to protect the environment while enabling the development of a potentially valuable energy resource for Europe.  In doing this, we can take the opportunity to learn from the experience of shale gas extraction in the US.  In many parts of the US, the regulatory authorities have been playing catch-up with intensive development of shale gas resources.  This has led the authorities in New York State, where shale gas development is yet to take place, to develop a detailed analysis of environmental and health risks to inform their regulatory decisions. [3]  Intensive research is taking place into health and environmental issues in the US, and we in Europe can draw on this growing knowledge base.

Regulators need to be aware of the risks posed by individual developments, and also the potential for cumulative impacts associated with development of shale gas resources across wide areas, which could extend to thousands of square kilometres with potentially dozens or even hundreds of well pads.  AEA’s risk assessment work for the European Commission² indicates that the key areas of concern for individual well pad development, and cumulative development of multiple pads, are as follows:

AEA’s risk assessments highlight the importance of managing the potential cumulative land-take of wide-scale development of shale gas.  It is estimated that approximately 1.4% of the land above a productive shale gas well may need to be used to exploit the reservoir fully.  This impact could be significant, even where the most up-to-date multi-well pad technology is used to enable 10 or more wells to be drilled at a single site. 

The need for proper well design and construction is well established in the oil and gas industry, but the risks may be more acute where high volume hydraulic fracturing is carried out.  And a visit to an area of intensive shale gas development confirms the significance of road vehicle movements associated with drilling and hydraulic fracturing.  Interestingly, the risk of earth tremors resulting from hydraulic fracturing was not identified as a higher priority risk, even though it is one of the topics of greatest concern to the public.

The questions of whether the development of shale gas will result in a net increase or decrease in greenhouse gases, and how a beneficial outcome can be delivered, are hugely important, but lie beyond the focus of this article.  Our recent study for the European Commission entitled, “Climate Impact of Potential Shale Gas Production in the EU” shows that, provided the climate impacts of shale gas extraction are well managed, they may be less than those resulting from the use of imported gas from outside the EU.

There are environmental risks with any oil and gas extraction activity – witness the recent leak at the North Sea Elgin platform, for example.  Operators always have to act responsibly and minimise the risks of accidents and emissions to the environment.  The use of hydraulic fracturing introduces a set of new issues to deal with – for example, sourcing, transporting and handling water; mixing chemicals; recycling and disposing of waste waters.  The opportunity is now there for regulators to put the measures in place to ensure that any future development of our shale gas resources is carried out safely and responsibly.

Dr Mark Broomfield, Specialist Consultant, AEA Technology
mark.broomfield@aeat.co.uk

Mark Broomfield is a speaker at the Shale Gas Environmental Summit, 29^th to 30^th October 2012, London, United Kingdom (see http://www.smi-online.co.uk/energy/uk/shale-gas-environmental-summit)